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Sample records for age-period-cohort model application

  1. Mixed models, linear dependency, and identification in age-period-cohort models.

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    O'Brien, Robert M

    2017-07-20

    This paper examines the identification problem in age-period-cohort models that use either linear or categorically coded ages, periods, and cohorts or combinations of these parameterizations. These models are not identified using the traditional fixed effect regression model approach because of a linear dependency between the ages, periods, and cohorts. However, these models can be identified if the researcher introduces a single just identifying constraint on the model coefficients. The problem with such constraints is that the results can differ substantially depending on the constraint chosen. Somewhat surprisingly, age-period-cohort models that specify one or more of ages and/or periods and/or cohorts as random effects are identified. This is the case without introducing an additional constraint. I label this identification as statistical model identification and show how statistical model identification comes about in mixed models and why which effects are treated as fixed and which are treated as random can substantially change the estimates of the age, period, and cohort effects. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Bayesian Age-Period-Cohort Model of Lung Cancer Mortality

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    Bhikhari P. Tharu

    2015-09-01

    Full Text Available Background The objective of this study was to analyze the time trend for lung cancer mortality in the population of the USA by 5 years based on most recent available data namely to 2010. The knowledge of the mortality rates in the temporal trends is necessary to understand cancer burden.Methods Bayesian Age-Period-Cohort model was fitted using Poisson regression with histogram smoothing prior to decompose mortality rates based on age at death, period at death, and birth-cohort.Results Mortality rates from lung cancer increased more rapidly from age 52 years. It ended up to 325 deaths annually for 82 years on average. The mortality of younger cohorts was lower than older cohorts. The risk of lung cancer was lowered from period 1993 to recent periods.Conclusions The fitted Bayesian Age-Period-Cohort model with histogram smoothing prior is capable of explaining mortality rate of lung cancer. The reduction in carcinogens in cigarettes and increase in smoking cessation from around 1960 might led to decreasing trend of lung cancer mortality after calendar period 1993.

  3. Bayesian Age-Period-Cohort Modeling and Prediction - BAMP

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    Volker J. Schmid

    2007-10-01

    Full Text Available The software package BAMP provides a method of analyzing incidence or mortality data on the Lexis diagram, using a Bayesian version of an age-period-cohort model. A hierarchical model is assumed with a binomial model in the first-stage. As smoothing priors for the age, period and cohort parameters random walks of first and second order, with and without an additional unstructured component are available. Unstructured heterogeneity can also be included in the model. In order to evaluate the model fit, posterior deviance, DIC and predictive deviances are computed. By projecting the random walk prior into the future, future death rates can be predicted.

  4. Age-period-cohort analysis of suicides among Japanese 1950-2003: a Bayesian cohort model analysis.

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    Ooe, Yosuke; Ohno, Yuko; Nakamura, Takashi

    2009-07-01

    The suicide rate in Japan is one of the highest in the world and presents us with a considerable challenge. Demographic statistics show that the number of suicides is on the rise, and at roughly 30,000 people per year have committed suicide since 1998. Suicide trends are not only related to economic boom and bust but also to certain generations and age groups. During the 1950s, there was a remarkably high suicide rate among people in their 20s, and this cohort was identical to that of the middle-age generation in the 1980s. It is important to separately understand both the trend of suicide rates and the numbers analyzed to determine the different factors that influence suicide. These include age, time period, cohort, interaction between age and time period, and changes in population composition. We performed an age-period-cohort analysis of annual trends of suicide rates by age group in Japan using a Bayesian cohort model. With the help of the Nakamura method, we have been able to break down the effects of age, time period, cohort, and the age-by-period interaction. The cohort comprised of people born in the 1930s demonstrated a relatively high suicide rate. Men currently in their 50s also belong to a high suicide rate cohort. Regarding the period effect, business cycles and by-period interaction effect, it became apparent that the high suicide rate among young adults in their early 20s around 1960 was slowing, especially among men. Instead, there was an obvious recent trend for men in their late 50s to have the highest suicide rate. This study confirmed that age-period-cohort analysis can describe these trends of suicide mortality of the Japanese.

  5. A Novel Approach for Analysis of the Log-Linear Age-Period-Cohort Model: Application to Lung Cancer Incidence

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    Tengiz Mdzinarishvili

    2009-12-01

    Full Text Available A simple, computationally efficient procedure for analyses of the time period and birth cohort effects on the distribution of the age-specific incidence rates of cancers is proposed. Assuming that cohort effects for neighboring cohorts are almost equal and using the Log-Linear Age-Period-Cohort Model, this procedure allows one to evaluate temporal trends and birth cohort variations of any type of cancer without prior knowledge of the hazard function. This procedure was used to estimate the influence of time period and birth cohort effects on the distribution of the age-specific incidence rates of first primary, microscopically confirmed lung cancer (LC cases from the SEER9 database. It was shown that since 1975, the time period effect coefficients for men increase up to 1980 and then decrease until 2004. For women, these coefficients increase from 1975 up to 1990 and then remain nearly constant. The LC birth cohort effect coefficients for men and women increase from the cohort of 1890–94 until the cohort of 1925–29, then decrease until the cohort of 1950–54 and then remain almost unchanged. Overall, LC incidence rates, adjusted by period and cohort effects, increase up to the age of about 72–75, turn over, and then fall after the age of 75–78. The peak of the adjusted rates in men is around the age of 77–78, while in women, it is around the age of 72–73. Therefore, these results suggest that the age distribution of the incidence rates in men and women fall at old ages.

  6. Patterns of lung cancer mortality in 23 countries: Application of the Age-Period-Cohort model

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    Huang Yi-Chia

    2005-03-01

    Full Text Available Abstract Background Smoking habits do not seem to be the main explanation of the epidemiological characteristics of female lung cancer mortality in Asian countries. However, Asian countries are often excluded from studies of geographical differences in trends for lung cancer mortality. We thus examined lung cancer trends from 1971 to 1995 among men and women for 23 countries, including four in Asia. Methods International and national data were used to analyze lung cancer mortality from 1971 to 1995 in both sexes. Age-standardized mortality rates (ASMR were analyzed in five consecutive five-year periods and for each five-year age group in the age range 30 to 79. The age-period-cohort (APC model was used to estimate the period effect (adjusted for age and cohort effects for mortality from lung cancer. Results The sex ratio of the ASMR for lung cancer was lower in Asian countries, while the sex ratio of smoking prevalence was higher in Asian countries. The mean values of the sex ratio of the ASMR from lung cancer in Taiwan, Hong Kong, Singapore, and Japan for the five 5-year period were 2.10, 2.39, 3.07, and 3.55, respectively. These values not only remained quite constant over each five-year period, but were also lower than seen in the western countries. The period effect, for lung cancer mortality as derived for the 23 countries from the APC model, could be classified into seven patterns. Conclusion Period effects for both men and women in 23 countries, as derived using the APC model, could be classified into seven patterns. Four Asian countries have a relatively low sex ratio in lung cancer mortality and a relatively high sex ratio in smoking prevalence. Factors other than smoking might be important, especially for women in Asian countries.

  7. Description of cervical cancer mortality in Belgium using Bayesian age-period-cohort models

    Science.gov (United States)

    2009-01-01

    Objective To correct cervical cancer mortality rates for death cause certification problems in Belgium and to describe the corrected trends (1954-1997) using Bayesian models. Method Cervical cancer (cervix uteri (CVX), corpus uteri (CRP), not otherwise specified (NOS) uterus cancer and other very rare uterus cancer (OTH) mortality data were extracted from the WHO mortality database together with population data for Belgium and the Netherlands. Different ICD (International Classification of Diseases) were used over time for death cause certification. In the Netherlands, the proportion of not-otherwise specified uterine cancer deaths was small over large periods and therefore internal reallocation could be used to estimate the corrected rates cervical cancer mortality. In Belgium, the proportion of improperly defined uterus deaths was high. Therefore, the age-specific proportions of uterus cancer deaths that are probably of cervical origin for the Netherlands was applied to Belgian uterus cancer deaths to estimate the corrected number of cervix cancer deaths (corCVX). A Bayesian loglinear Poisson-regression model was performed to disentangle the separate effects of age, period and cohort. Results The corrected age standardized mortality rate (ASMR) decreased regularly from 9.2/100 000 in the mid 1950s to 2.5/100,000 in the late 1990s. Inclusion of age, period and cohort into the models were required to obtain an adequate fit. Cervical cancer mortality increases with age, declines over calendar period and varied irregularly by cohort. Conclusion Mortality increased with ageing and declined over time in most age-groups, but varied irregularly by birth cohort. In global, with some discrete exceptions, mortality decreased for successive generations up to the cohorts born in the 1930s. This decline stopped for cohorts born in the 1940s and thereafter. For the youngest cohorts, even a tendency of increasing risk of dying from cervical cancer could be observed, reflecting

  8. Understanding trends in Australian alcohol consumption-an age-period-cohort model.

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    Livingston, Michael; Raninen, Jonas; Slade, Tim; Swift, Wendy; Lloyd, Belinda; Dietze, Paul

    2016-09-01

    To decompose Australian trends in alcohol consumption into their age, period (survey year) and cohort (birth year/generation) components. In particular, we aimed to test whether recent declines in overall consumption have been influenced by reductions in drinking among recently born cohorts. Seven cross-sectional waves of the Australian National Drug Strategy Household Survey (1995-2013). Age, period and cohort effects were estimated using a linear and logistic cross-classified random-effects models (CCREMs). Australia A total of 124 440 Australians (69 193 females and 55 257 males), aged 14-79 years. Whether or not respondents consumed alcohol in the 12 months prior to the survey and, for those who did, the estimated volume of pure alcohol consumed, derived using standard quantity-frequency survey questions. Controlling for age and period effects, there was significant variation in drinking participation and drinking volume by birth cohort. In particular, male cohorts born between the 1965 and 1974 and female cohorts born between 1955 and 1974 reported higher rates of drinking participation (P women (P < 0.01). Recent birth cohorts (born between 1995 and 1999) in Australia report significantly lower rates of both drinking participation and drinking volume than previous cohorts, controlling for their age distribution and overall changes in population drinking. These findings suggest that the recent decline in alcohol consumption in Australia has been driven by declines in drinking among these recently born cohorts. These trends are consistent with international shifts in youth drinking. © 2016 Society for the Study of Addiction.

  9. An R package for fitting age, period and cohort models

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    Adriano Decarli

    2014-11-01

    Full Text Available In this paper we present the R implementation of a GLIM macro which fits age-period-cohort model following Osmond and Gardner. In addition to the estimates of the corresponding model, owing to the programming capability of R as an object oriented language, methods for printing, plotting and summarizing the results are provided. Furthermore, the researcher has fully access to the output of the main function (apc which returns all the models fitted within the function. It is so possible to critically evaluate the goodness of fit of the resulting model.

  10. Age-period-cohort modelling of breast cancer incidence in the Nordic countries

    DEFF Research Database (Denmark)

    Rostgaard, K; Vaeth, M; Holst, H

    2001-01-01

    into account. Assuming the age dependency of the incidence pattern in old age to be common for the Nordic countries, an internal comparison could be made among the four countries of the cohort effects and the period effects. The study indicated that the period effects have been of importance for the increase...... in breast cancer incidence seen in the Nordic countries. The widespread practice of neglecting the period effects in age-period-cohort analysis of time trends in breast cancer incidence therefore probably needs reconsideration. A key finding was that Danish women born in the 20th century seem to have been...... exposed to an increasing load of cohort borne breast cancer risk factors not experienced to the same extent by Norwegian women, whereas they were seemingly subjected to the same period effects....

  11. Age, period and cohort effects on first-child fertility in Danish men

    DEFF Research Database (Denmark)

    Kamper-Jørgensen, Mads; Keiding, Niels; Knudsen, Lisbeth B.

    Demographic studies of fertility are most often based solely on information about women, leaving out characteristics of men. Thereby valuable information may be lost. The present note intends to explore the potential of the classical age-period-cohort model for describing male first-child fertility...... patterns. The model was fitted to fertility data on Danish men aged 15 to 49 years in the calendar period from 1960 to 1994. We found the classical age-period-cohodt model to be an appropriate model for describing male first-child fertility patterns in Denmark. Fluctuations in age-specific male first-child...... fertility rates over period were found,  with a nadir in the mid-1980s. Furthermore, age-specific first-child fertility rates were found to be lower in men from younger cirth cohorts than in men from older birth cohorts....

  12. Comment: Distinguishing Cohort Effects from Age*Period Effects on Non-Marital Fertility

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    Martin, Steve

    2009-01-01

    In the article "Cohort Effects on Non-marital Fertility," in this issue of "Social Forces," Jean Stockard employs a novel strategy for disentangling cohort, period, and age effects on the non-marital fertility ratio. In a model with fixed-effect controls for age and for time period, the author documents evidence for three cohort-specific factors…

  13. Age, Period, and Cohort Differences in Work Centrality and Work Values

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    Gábor Hajdu

    2018-02-01

    Full Text Available In this paper, we analyze whether work values differ between three dimensions of time (age, birth cohort, period. Using data of five waves of the World Values Survey and the European Values Study from more than forty countries and hierarchical age-period-cohort regression models, we did not find relevant gaps between birth cohorts with respect to the relative importance of work or with respect to work values. Thus, we claim that, in European and Euro-Atlantic countries, birth cohorts, on average, do not differ significantly with regard to their work values. Our results suggest, however, that the relative importance of work is significantly higher in the middle-age groups than among the younger or older groups. Regarding work values, we found that the importance of having an interesting job, good pay, and good hours decreases with age, and that job security is equally important at every age, whereas the importance of having a useful job increases with age.

  14. Age, time period, and birth cohort differences in self-esteem: Reexamining a cohort-sequential longitudinal study.

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    Twenge, Jean M; Carter, Nathan T; Campbell, W Keith

    2017-05-01

    Orth, Trzesniewski, and Robins (2010) concluded that the nationally representative Americans' Changing Lives (ACL) cohort-sequential study demonstrated moderate to large age differences in self-esteem, and no birth cohort (generational) differences in the age trajectory. In a reanalysis of these data using 2 different statistical techniques, we find significant increases in self-esteem that could be attributed to birth cohort or time period. First, hierarchical linear modeling analyses with birth cohort as a continuous variable (vs. the multiple group formulation used by Orth et al.) find that birth cohort has a measurable influence on self-esteem through its interaction with age. Participants born in later years (e.g., 1960) were higher in self-esteem and were more likely to increase in self-esteem as they aged than participants born in earlier years (e.g., 1920). However, the estimated age trajectory up to age 60 is similar in Orth et al.'s results and in the results from our analyses including cohort. Second, comparing ACL respondents of the same age in 1986 versus 2002 (a time-lag design) yields significant birth cohort differences in self-esteem, with 2002 participants of the same age higher in self-esteem than those in 1986. Combined with some previous studies finding significant increases in self-esteem and positive self-views over time, these results suggest that cultural change in the form of cohort and time period cannot be ignored as influences in cross-sectional and longitudinal studies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Life-course and cohort trajectories of mental health in the UK, 1991-2008--a multilevel age-period-cohort analysis.

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    Bell, Andrew

    2014-11-01

    There is ongoing debate regarding the shape of life-course trajectories in mental health. Many argue the relationship is U-shaped, with mental health declining with age to mid-life, then improving. However, I argue that these models are beset by the age-period-cohort (APC) identification problem, whereby age, cohort and year of measurement are exactly collinear and their effects cannot be meaningfully separated. This means an apparent life-course effect could be explained by cohorts. This paper critiques two sets of literature: the substantive literature regarding life-course trajectories in mental health, and the methodological literature that claims erroneously to have 'solved' the APC identification problem statistically (e.g. using Yang and Land's Hierarchical APC-HAPC-model). I then use a variant of the HAPC model, making strong but justified assumptions that allow the modelling of life-course trajectories in mental health (measured by the General Health Questionnaire) net of any cohort effects, using data from the British Household Panel Survey, 1991-2008. The model additionally employs a complex multilevel structure that allows the relative importance of spatial (households, local authority districts) and temporal (periods, cohorts) levels to be assessed. Mental health is found to increase throughout the life-course; this slows at mid-life before worsening again into old age, but there is no evidence of a U-shape--I argue that such findings result from confounding with cohort processes (whereby more recent cohorts have generally worse mental health). Other covariates were also evaluated; income, smoking, education, social class, urbanity, ethnicity, gender and marriage were all related to mental health, with the latter two in particular affecting life-course and cohort trajectories. The paper shows the importance of understanding APC in life-course research generally, and mental health research in particular. Copyright © 2014 Elsevier Ltd. All rights

  16. Modelling regional variation of first-time births in Denmark 1980-1994 by an age-period-cohort model

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    Lisbeth B. Knudsen

    2005-12-01

    Full Text Available Despite the small size of Denmark, there have traditionally been rather consistent regional differences in fertility rates. We apply the statistical age-period-cohort model to include the effect of these three time-related factors thereby concisely illuminating the regional differences of first-time births in Denmark. From the Fertility of Women and Couples Dataset we obtain data on number of births by nulliparous women by year (1980-1994, age (15-45 and county of residence. We show that the APC-model describes the fertility rates of nulliparous women satisfactorily. To catch the regional variation an interaction parameter between age and county is necessary, which provides a surprisingly good description suggesting that the county-specific age-distributions of first-time fertility rates differ. Our results are in general agreement with the 'moral geography' concepts of Tonboe (2001.

  17. Modelling regional variation of first-time births in Denmark 1980-1994 by an age-period-cohort model

    DEFF Research Database (Denmark)

    Thygesen, Lau Caspar; Knudsen, Lisbeth B.; Keiding, Niels

    2005-01-01

    Despite the small size of Denmark, there have traditionally been rather consistent regional differences in fertility rates. We apply the statistical age-period-cohort model to include the effect of these three time-related factors thereby concisely illuminating the regional differences of first......-time births in Denmark. From the Fertility of Women and Couples Dataset we obtain data on number of births by nulliparous women by year (1980-1994), age (15-45) and county of residence. We show that the APC-model describes the fertility rates of nulliparous women satisfactorily. To catch the regional...... variation an interaction parameter between age and county is necessary, which provides a surprisingly good description suggesting that the county-specific age-distributions of first-time fertility rates differ. Our results are in general agreement with the 'moral geography' concepts of Tonboe (2001)....

  18. Mortality of breast cancer in Taiwan, 1971-2010: temporal changes and an age-period-cohort analysis.

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    Ho, M-L; Hsiao, Y-H; Su, S-Y; Chou, M-C; Liaw, Y-P

    2015-01-01

    The current paper describes the age, period and cohort effects on breast cancer mortality in Taiwan. Female breast cancer mortality data were collected from the Taiwan death registries for 1971-2010. The annual percentage changes, age- standardised mortality rates (ASMR) and age-period-cohort model were calculated. The mortality rates increased with advancing age groups when fixing the period. The percentage change in the breast cancer mortality rate increased from 54.79% at aged 20-44 years, to 149.78% in those aged 45-64 years (between 1971-75 and 2006-10). The mortality rates in the 45-64 age group increased steadily from 1971 to 1975 and 2006-10. The 1951 birth cohorts (actual birth cohort; 1947-55) showed peak mortalities in both the 50-54 and 45-49 age groups. We found that the 1951 birth cohorts had the greatest mortality risk from breast cancer. This might be attributed to the DDT that was used in large amounts to prevent deaths from malaria in Taiwan. However, future researches require DDT data to evaluate the association between breast cancer and DDT use.

  19. Support for Marijuana (Cannabis Legalization: Untangling Age, Period, and Cohort Effects

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    William Campbell

    2017-02-01

    Full Text Available In three large, nationally representative surveys of U.S. 12th graders, college students, and adults ('N' = 9 million conducted 1968–2015, Americans became significantly more supportive of legal marijuana (cannabis starting in the mid-1980’s. Hierarchical models using age-period-cohort analysis on the adult (General Social Survey sample showed that the increased support for legalization is primarily a time period effect rather than generational or age effect; thus, Americans of all ages became more supportive of legal marijuana. Among 12th graders, support for marijuana legalization was closely linked to perceptions of marijuana safety.

  20. Age-period-cohort analysis of infectious disease mortality in urban-rural China, 1990-2010.

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    Li, Zhi; Wang, Peigang; Gao, Ge; Xu, Chunling; Chen, Xinguang

    2016-03-31

    Although a number of studies on infectious disease trends in China exist, these studies have not distinguished the age, period, and cohort effects simultaneously. Here, we analyze infectious disease mortality trends among urban and rural residents in China and distinguish the age, period, and cohort effects simultaneously. Infectious disease mortality rates (1990-2010) of urban and rural residents (5-84 years old) were obtained from the China Health Statistical Yearbook and analyzed with an age-period-cohort (APC) model based on Intrinsic Estimator (IE). Infectious disease mortality is relatively high at age group 5-9, reaches a minimum in adolescence (age group 10-19), then rises with age, with the growth rate gradually slowing down from approximately age 75. From 1990 to 2010, except for a slight rise among urban residents from 2000 to 2005, the mortality of Chinese residents experienced a substantial decline, though at a slower pace from 2005 to 2010. In contrast to the urban residents, rural residents experienced a rapid decline in mortality during 2000 to 2005. The mortality gap between urban and rural residents substantially narrowed during this period. Overall, later birth cohorts experienced lower infectious disease mortality risk. From the 1906-1910 to the 1941-1945 birth cohorts, the decrease of mortality among urban residents was significantly faster than that of subsequent birth cohorts and rural counterparts. With the rapid aging of the Chinese population, the prevention and control of infectious disease in elderly people will present greater challenges. From 1990 to 2010, the infectious disease mortality of Chinese residents and the urban-rural disparity have experienced substantial declines. However, the re-emergence of previously prevalent diseases and the emergence of new infectious diseases created new challenges. It is necessary to further strengthen screening, immunization, and treatment for the elderly and for older cohorts at high risk.

  1. An Empirical Study on Stochastic Mortality Modelling under the Age-Period-Cohort Framework: The Case of Greece with Applications to Insurance Pricing

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    Apostolos Bozikas

    2018-04-01

    Full Text Available During the last decades, life expectancy has risen significantly in the most developed countries all over the world. Greece is a case in point; consequently, higher governmental financial responsibilities occur as well as serious concerns are raised owing to population ageing. To address this issue, an efficient forecasting method is required. Therefore, the most important stochastic models were comparatively applied to Greek data for the first time. An analysis of their fitting behaviour by gender was conducted and the corresponding forecasting results were evaluated. In particular, we incorporated the Greek population data into seven stochastic mortality models under a common age-period-cohort framework. The fitting performance of each model was thoroughly evaluated based on information criteria values as well as the likelihood ratio test and their robustness to period changes was investigated. In addition, parameter risk in forecasts was assessed by employing bootstrapping techniques. For completeness, projection results for both genders were also illustrated in pricing insurance-related products.

  2. Materialism across the life span: An age-period-cohort analysis.

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    Jaspers, Esther D T; Pieters, Rik G M

    2016-09-01

    This research examined the development of materialism across the life span. Two initial studies revealed that (a) lay beliefs were that materialism declines with age and (b) previous research findings also implied a modest, negative relationship between age and materialism. Yet, previous research has considered age only as a linear control variable, thereby precluding the possibility of more intricate relationships between age and materialism. Moreover, prior studies have relied on cross-sectional data and thus confound age and cohort effects. To improve on this, the main study used longitudinal data from 8 waves spanning 9 years of over 4,200 individuals (16 to 90 years) to examine age effects on materialism while controlling for cohort and period effects. Using a multivariate multilevel latent growth model, it found that materialism followed a curvilinear trajectory across the life span, with the lowest levels at middle age and higher levels before and after that. Thus, in contrast to lay beliefs, materialism increased in older age. Moreover, age effects on materialism differed markedly between 3 core themes of materialism: acquisition centrality, possession-defined success, and acquisition as the pursuit of happiness. In particular, acquisition centrality and possession-defined success were higher at younger and older age. Independent of these age effects, older birth cohorts were oriented more toward possession-defined success, whereas younger birth cohorts were oriented more toward acquisition centrality. The economic downturn since 2008 led to a decrease in acquisition as the pursuit of happiness and in desires for personal growth, but to an increase in desires for achievement. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  3. Age, period, or birth cohort: What determines demographic differences in seafood consumption?

    DEFF Research Database (Denmark)

    Scholderer, Joachim; Lund, Eiliv; Trondsen, Torbjørn

    Effects of age, period and birth cohort on consumption of fat fish, lean fish and processed fish were estimated based on panel data from the Norwegian Women and Seafood Consumption Study (NOWAC). Cohorts selected for the present analysis were women born between 1951 and 1966. Survey questionnaires...... fish increased between 1996 and 2001, while consumption of lean fish decreased. All three period effects were stable across birth cohorts. Estimation of polynomial contrasts indicated that birth cohort itself had linear effects on consumption, with older generations consuming significantly more fat...... and lean fish, but less processed fish than younger generations. Finally, the effects of cohort and period on consumption of lean and processed fish remained stable when biological age was controlled for, whilst the effect of period on fat fish consumption vanished. Regarding total consumption of fat fish...

  4. Trends in ischemic heart disease mortality in Korea, 1985-2009: an age-period-cohort analysis.

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    Lee, Hye Ah; Park, Hyesook

    2012-09-01

    Economic growth and development of medical technology help to improve the average life expectancy, but the western diet and rapid conversions to poor lifestyles lead an increasing risk of major chronic diseases. Coronary heart disease mortality in Korea has been on the increase, while showing a steady decline in the other industrialized countries. An age-period-cohort analysis can help understand the trends in mortality and predict the near future. We analyzed the time trends of ischemic heart disease mortality, which is on the increase, from 1985 to 2009 using an age-period-cohort model to characterize the effects of ischemic heart disease on changes in the mortality rate over time. All three effects on total ischemic heart disease mortality were statistically significant. Regarding the period effect, the mortality rate was decreased slightly in 2000 to 2004, after it had continuously increased since the late 1980s that trend was similar in both sexes. The expected age effect was noticeable, starting from the mid-60's. In addition, the age effect in women was more remarkable than that in men. Women born from the early 1900s to 1925 observed an increase in ischemic heart mortality. That cohort effect showed significance only in women. The future cohort effect might have a lasting impact on the risk of ischemic heart disease in women with the increasing elderly population, and a national prevention policy is need to establish management of high risk by considering the age-period-cohort effect.

  5. The marriage boom and marriage bust in the United States: An age-period-cohort analysis.

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    Schellekens, Jona

    2017-03-01

    In the 1950s and 1960s there was an unprecedented marriage boom in the United States. This was followed in the 1970s by a marriage bust. Some argue that both phenomena are cohort effects, while others argue that they are period effects. The study reported here tested the major period and cohort theories of the marriage boom and bust, by estimating an age-period-cohort model of first marriage for the years 1925-79 using census microdata. The results of the analysis indicate that the marriage boom was mostly a period effect, although there were also cohort influences. More specifically, the hypothesis that the marriage boom was mostly a response to rising wages is shown to be consistent with the data. However, much of the marriage bust can be accounted for by unidentified cohort influences, at least until 1980.

  6. Effects of age, time period, and birth cohort on the prevalence of diabetes and obesity in Korean men.

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    Kwon, Jin-Won; Song, Yun-mi; Park, Hye soon; Sung, Joohon; Kim, Ho; Cho, Sung-il

    2008-02-01

    We examined changes in the prevalence of diabetes, obesity, and overweight in 412,881 Korean men in birth cohorts from 1933 to 1972 over 8 years from 1992 to 2000 and separately analyzed the effects of age, time period, and birth cohort. The study included male employees of Korean government organizations and schools who were between 20 and 59 years of age in 1992. Diabetes was diagnosed on the basis of self-reports in 1992 or fasting blood glucose levels (>or=126 mg/ml, 7.0 mmol/l). The age-period-cohort model was used to estimate the effects of age, time period, and birth cohort. In Korean male birth cohorts from 1933 to 1972, the age-specific prevalence of diabetes, obesity, and overweight in men aged 28-59 years increased annually by 0.41% (3.03 to 6.29%), 0.18% (0.70 to 2.16%), and 1.49% (23.48 to 35.41%), respectively, from 1992 to 2000. The relative change in diabetes was largest among the younger cohorts (>400% increase over 8 years) and corresponded to the change in obesity. Apart from the contribution of age, clear cohort and period effects were evident for diabetes, although the magnitude of the effect was slightly less than that for obesity. Prevention of diabetes through the control of obesity, particularly in young men, clearly needs to be emphasized.

  7. Life satisfaction and age : Dealing with underidentification in age-period-cohort models

    NARCIS (Netherlands)

    de Ree, Joppe; Alessie, Rob

    Recent literature typically finds a U shaped relationship between life satisfaction and age. Age profiles, however, are not identified without forcing arbitrary restrictions on the cohort and/or time profiles. In this paper we report what can be identified about the relationship between life

  8. Age-period-cohort analysis of tuberculosis notifications in Hong Kong from 1961 to 2005.

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    Wu, P; Cowling, B J; Schooling, C M; Wong, I O L; Johnston, J M; Leung, C-C; Tam, C-M; Leung, G M

    2008-04-01

    Despite its wealth, excellent vital indices and robust health care infrastructure, Hong Kong has a relatively high incidence of tuberculosis (TB) (85.4 per 100 000). Hong Kong residents have also experienced a very rapid and recent epidemiological transition; the population largely originated from migration by southern Chinese in the mid 20th century. Given the potentially long latency period of TB infection, an investigation was undertaken to determine the extent to which TB incidence rates reflect the population history and the impact of public health interventions. An age-period-cohort model was used to break down the Hong Kong TB notification rates from 1961 to 2005 into the effects of age, calendar period and birth cohort. Analysis by age showed a consistent pattern across all the cohorts by year of birth, with a peak in the relative risk of TB at 20-24 years of age. Analysis by year of birth showed an increase in the relative risk of TB from 1880 to 1900, stable risk until 1910, then a linear rate of decline from 1910 with an inflection point at 1990 for a steeper rate of decline. Period effects yielded only one inflection during the calendar years 1971-5. Economic development, social change and the World Health Organisation's short-course directly observed therapy (DOTS) strategy have contributed to TB control in Hong Kong. The linear cohort effect until 1990 suggests that a relatively high, but slowly falling, incidence of TB in Hong Kong will continue into the next few decades.

  9. Maternal mortality in Mexico, beyond millennial development objectives: An age-period-cohort model.

    Science.gov (United States)

    Rodríguez-Aguilar, Román

    2018-01-01

    The maternal mortality situation is analyzed in México as an indicator that reflects the social development level of the country and was one of the millennial development objectives. The effect of a maternal death in the related social group has multiplier effects, since it involves family dislocation, economic impact and disruption of the orphans' normal social development. Two perspectives that causes of maternal mortality were analyzed, on one hand, their relationship with social determinants and on the other, factors directly related to the health system. Evidence shows that comparing populations based on group of selected variables according to social conditions and health care access, statistically significant differences prevail according to education and marginalization levels, and access to medical care. In addition, the Age-Period-Cohort model raised, shows significant progress in terms of a downward trend in maternal mortality in a generational level. Those women born before 1980 had a greater probability of maternal death in relation to recent generations, which is a reflection of the improvement in social determinants and in the Health System. The age effect shows a problem in maternal mortality in women under 15 years old, so teen pregnancy is a priority in health and must be addressed in short term. There is no clear evidence of a period effect.

  10. Time trend and age-period-cohort effect on kidney cancer mortality in Europe, 1981–2000

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    López-Abente Gonzalo

    2006-05-01

    Full Text Available Abstract Background The incorporation of diagnostic and therapeutic improvements, as well as the different smoking patterns, may have had an influence on the observed variability in renal cancer mortality across Europe. This study examined time trends in kidney cancer mortality in fourteen European countries during the last two decades of the 20th century. Methods Kidney cancer deaths and population estimates for each country during the period 1981–2000 were drawn from the World Health Organization Mortality Database. Age- and period-adjusted mortality rates, as well as annual percentage changes in age-adjusted mortality rates, were calculated for each country and geographical region. Log-linear Poisson models were also fitted to study the effect of age, death period, and birth cohort on kidney cancer mortality rates within each country. Results For men, the overall standardized kidney cancer mortality rates in the eastern, western, and northern European countries were 20, 25, and 53% higher than those for the southern European countries, respectively. However, age-adjusted mortality rates showed a significant annual decrease of -0.7% in the north of Europe, a moderate rise of 0.7% in the west, and substantial increases of 1.4% in the south and 2.0% in the east. This trend was similar among women, but with lower mortality rates. Age-period-cohort models showed three different birth-cohort patterns for both men and women: a decrease in mortality trend for those generations born after 1920 in the Nordic countries, a similar but lagged decline for cohorts born after 1930 in western and southern European countries, and a continuous increase throughout all birth cohorts in eastern Europe. Similar but more heterogeneous regional patterns were observed for period effects. Conclusion Kidney cancer mortality trends in Europe showed a clear north-south pattern, with high rates on a downward trend in the north, intermediate rates on a more marked rising

  11. Separating the effects of age, period and birth cohort on seafood consumption in Norway

    DEFF Research Database (Denmark)

    Scholderer, Joachim; Trondsen, Torbjørn; Lund, Eiliv

    Effects of age, period and birth cohort on consumption of fat fish, lean fish and processed fish were estimated based on panel data from the Norwegian Women and Seafood Consumption Study (NOWAC). Cohorts selected for the present analysis were women born between 1951 and 1966. Survey questionnaires...... fish increased between 1996 and 2001, while consumption of lean fish decreased. All three period effects were stable across birth cohorts. Estimation of polynomial contrasts indicated that birth cohort itself had linear effects on consumption, with older generations consuming significantly more fat...... and lean fish, but less processed fish than younger generations. Finally, the effects of cohort and period on consumption of lean and processed fish remained stable when biological age was controlled for, whilst the effect of period on fat fish consumption vanished. Regarding total consumption of fat fish...

  12. A new approach to age-period-cohort analysis using partial least squares regression: the trend in blood pressure in the Glasgow Alumni cohort.

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    Yu-Kang Tu

    2011-04-01

    Full Text Available Due to a problem of identification, how to estimate the distinct effects of age, time period and cohort has been a controversial issue in the analysis of trends in health outcomes in epidemiology. In this study, we propose a novel approach, partial least squares (PLS analysis, to separate the effects of age, period, and cohort. Our example for illustration is taken from the Glasgow Alumni cohort. A total of 15,322 students (11,755 men and 3,567 women received medical screening at the Glasgow University between 1948 and 1968. The aim is to investigate the secular trends in blood pressure over 1925 and 1950 while taking into account the year of examination and age at examination. We excluded students born before 1925 or aged over 25 years at examination and those with missing values in confounders from the analyses, resulting in 12,546 and 12,516 students for analysis of systolic and diastolic blood pressure, respectively. PLS analysis shows that both systolic and diastolic blood pressure increased with students' age, and students born later had on average lower blood pressure (SBP: -0.17 mmHg/per year [95% confidence intervals: -0.19 to -0.15] for men and -0.25 [-0.28 to -0.22] for women; DBP: -0.14 [-0.15 to -0.13] for men; -0.09 [-0.11 to -0.07] for women. PLS also shows a decreasing trend in blood pressure over the examination period. As identification is not a problem for PLS, it provides a flexible modelling strategy for age-period-cohort analysis. More emphasis is then required to clarify the substantive and conceptual issues surrounding the definitions and interpretations of age, period and cohort effects.

  13. An international contrast of rates of placental abruption: an age-period-cohort analysis.

    Science.gov (United States)

    Ananth, Cande V; Keyes, Katherine M; Hamilton, Ava; Gissler, Mika; Wu, Chunsen; Liu, Shiliang; Luque-Fernandez, Miguel Angel; Skjærven, Rolv; Williams, Michelle A; Tikkanen, Minna; Cnattingius, Sven

    2015-01-01

    Although rare, placental abruption is implicated in disproportionately high rates of perinatal morbidity and mortality. Understanding geographic and temporal variations may provide insights into possible amenable factors of abruption. We examined abruption frequencies by maternal age, delivery year, and maternal birth cohorts over three decades across seven countries. Women that delivered in the US (n = 863,879; 1979-10), Canada (4 provinces, n = 5,407,463; 1982-11), Sweden (n = 3,266,742; 1978-10), Denmark (n = 1,773,895; 1978-08), Norway (n = 1,780,271, 1978-09), Finland (n = 1,411,867; 1987-10), and Spain (n = 6,151,508; 1999-12) were analyzed. Abruption diagnosis was based on ICD coding. Rates were modeled using Poisson regression within the framework of an age-period-cohort analysis, and multi-level models to examine the contribution of smoking in four countries. Abruption rates varied across the seven countries (3-10 per 1000), Maternal age showed a consistent J-shaped pattern with increased rates at the extremes of the age distribution. In comparison to births in 2000, births after 2000 in European countries had lower abruption rates; in the US there was an increase in rate up to 2000 and a plateau thereafter. No birth cohort effects were evident. Changes in smoking prevalence partially explained the period effect in the US (P = 0.01) and Sweden (Prate has plateaued since 2000 in the US, all other countries show declining rates. These findings suggest considerable variation in abruption frequencies across countries; differences in the distribution of risk factors, especially smoking, may help guide policy to reduce abruption rates.

  14. Decomposing the effects of time on the social acceptability of biotechnology using age-period-cohort-country models.

    Science.gov (United States)

    Rousselière, Damien; Rousselière, Samira

    2017-08-01

    The study of European attitudes toward biotechnologies underlines a situation that is relatively contrasting in Europe. However, as different effects of time can influence the social attitudes (a life-cycle effect, a generational effect, and an exogenous temporal effect potentially affecting the entire population), an appropriate methodology should be used. To this end, age-period-cohort-country models have thus been estimated based on Eurobarometer data from 1991 onward. Applied to different data subsets, these models give similar results underlining the importance of the life-cycle effects as well as the heterogeneity of the link between political affiliation and biotechnologies attitudes across the European countries.

  15. Trends in mouth cancer incidence in Mumbai, India (1995-2009): An age-period-cohort analysis.

    Science.gov (United States)

    Shridhar, Krithiga; Rajaraman, Preetha; Koyande, Shravani; Parikh, Purvish M; Chaturvedi, Pankaj; Dhillon, Preet K; Dikshit, Rajesh P

    2016-06-01

    Despite tobacco control and health promotion efforts, the incidence rates of mouth cancer are increasing across most regions in India. Analysing the influence of age, time period and birth cohort on these secular trends can point towards underlying factors and help identify high-risk populations for improved cancer control programmes. We evaluated secular changes in mouth cancer incidence among men and women aged 25-74 years in Mumbai between 1995 and 2009 by calculating age-specific and age-standardized incidence rates (ASR). We estimated the age-adjusted linear trend for annual percent change (EAPC) using the drift parameter, and conducted an age-period-cohort (APC) analysis to quantify recent time trends and to evaluate the significance of birth cohort and calendar period effects. Over the 15-year period, age-standardized incidence rates of mouth cancer in men in Mumbai increased by 2.7% annually (95% CI:1.9 to 3.4), pMumbai cancer registry indicate a significant linear increase of mouth cancer incidence from 1995 to 2009 in men, which was driven by younger men aged 25-49 years, and a non-significant upward trend in similarly aged younger women. Health promotion efforts should more effectively target younger cohorts. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Age, period and cohort influences on beer, wine and spirits consumption trends in the US National Alcohol Surveys.

    Science.gov (United States)

    Kerr, William C; Greenfield, Thomas K; Bond, Jason; Ye, Yu; Rehm, Jürgen

    2004-09-01

    To estimate the separate influences of age, period and cohort on the consumption of beer wine and spirits in the United States. Linear age-period-cohort models controlling for demographic change with extensive specification testing. Setting US general population 1979-2000. Monthly average of past-year consumption of beer, wine and spirits in five National Alcohol Surveys. Findings The strongest cohort effects are found for spirits; cohorts born before 1940 are found to have significantly higher consumption than those born after 1946, with especially high spirits consumption for men in the pre-1930s cohorts. Significant cohort effects are also found for beer with elevated consumption in the 1946-65 cohorts for men but in the pre-1940 cohorts for women. Significant negative effects of age are found for beer and spirits consumption, although not for wine. Significant period effects are found for men's beer and wine consumption and for women's spirits consumption. Increased educational attainment in the population over time is associated with reduced beer consumption and increased wine consumption. Changing cohort demographics are found to have significant effects on beverage-specific consumption, indicating the importance of controlling for these effects in the evaluation of alcohol policy effectiveness and the potential for substantial improvement in the forecasting of future beverage-specific consumption trends, alcohol dependence treatment demand and morbidity and mortality outcomes.

  17. An international contrast of rates of placental abruption: an age-period-cohort analysis.

    Directory of Open Access Journals (Sweden)

    Cande V Ananth

    Full Text Available Although rare, placental abruption is implicated in disproportionately high rates of perinatal morbidity and mortality. Understanding geographic and temporal variations may provide insights into possible amenable factors of abruption. We examined abruption frequencies by maternal age, delivery year, and maternal birth cohorts over three decades across seven countries.Women that delivered in the US (n = 863,879; 1979-10, Canada (4 provinces, n = 5,407,463; 1982-11, Sweden (n = 3,266,742; 1978-10, Denmark (n = 1,773,895; 1978-08, Norway (n = 1,780,271, 1978-09, Finland (n = 1,411,867; 1987-10, and Spain (n = 6,151,508; 1999-12 were analyzed. Abruption diagnosis was based on ICD coding. Rates were modeled using Poisson regression within the framework of an age-period-cohort analysis, and multi-level models to examine the contribution of smoking in four countries.Abruption rates varied across the seven countries (3-10 per 1000, Maternal age showed a consistent J-shaped pattern with increased rates at the extremes of the age distribution. In comparison to births in 2000, births after 2000 in European countries had lower abruption rates; in the US there was an increase in rate up to 2000 and a plateau thereafter. No birth cohort effects were evident. Changes in smoking prevalence partially explained the period effect in the US (P = 0.01 and Sweden (P<0.01.There is a strong maternal age effect on abruption. While the abruption rate has plateaued since 2000 in the US, all other countries show declining rates. These findings suggest considerable variation in abruption frequencies across countries; differences in the distribution of risk factors, especially smoking, may help guide policy to reduce abruption rates.

  18. Thyroid Cancer Incidences From Selected South America Population-Based Cancer Registries: An Age-Period-Cohort Study

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    Anne Karin da Mota Borges

    2017-08-01

    Full Text Available Purpose: The incidence of thyroid cancer (TC has increased substantially worldwide. However, there is a lack of knowledge about age-period-cohort (APC effects on incidence rates in South American countries. This study describes the TC incidence trends and analyzes APC effects in Cali, Colombia; Costa Rica; Goiânia, Brazil; and Quito, Ecuador. Materials and Methods: Data were obtained from the Cancer Incidence in Five Continents series, and the crude and age-standardized incidence rates were calculated. Trends were assessed using the estimated annual percentage change, and APC models were estimated using Poisson regression for individuals between age 20 and 79 years. Results: An increasing trend in age-standardized incidence rates was observed among women from Goiânia (9.2%, Costa Rica (5.7%, Quito (4.0%, and Cali (3.4%, and in men from Goiânia (10.0% and Costa Rica (3.4%. The APC modeling showed that there was a period effect in all regions and for both sexes. Increasing rate ratios were observed among women over the periods. The best fit model was the APC model in women from all regions and in men from Quito, whereas the age-cohort model showed a better fit in men from Cali and Costa Rica, and the age-drift model showed a better fit among men from Goiânia. Conclusion: These findings suggest that overdiagnosis is a possible explanation for the observed increasing pattern of TC incidence. However, some environmental exposures may also have contributed to the observed increase.

  19. Spatiotemporal Scan and Age-Period-Cohort Analysis of Hepatitis C Virus in Henan, China: 2005-2012.

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    Fangfang Chen

    Full Text Available Studies have shown that hepatitis C virus (HCV infection increased during the past decades in China. However, little evidence is available on when, where, and who were infected with HCV. There are gaps in knowledge on the epidemiological burden and evolution of the HCV epidemic in China.Data on HCV cases were collected by the disease surveillance system from 2005 to 2012 to explore the epidemic in Henan province. Spatiotemporal scan statistics and age-period-cohort (APC model were used to examine the effects of age, period, birth cohort, and spatiotemporal clustering.177,171 HCV cases were reported in Henan province between 2005 and 2012. APC modelling showed that the HCV reported rates significantly increased in people aged > 50 years. A moderate increase in HCV reported rates was observed for females aged about 25 years. HCV reported rates increased over the study period. Infection rates were greatest among people born between 1960 and 1980. People born around 1970 had the highest relative risk of HCV infection. Women born between 1960 and 1980 had a five-fold increase in HCV infection rates compared to men, for the same birth cohort. Spatiotemporal mapping showed major clustering of cases in northern Henan, which probably evolved much earlier than other areas in the province.Spatiotemporal mapping and APC methods are useful to help delineate the evolution of the HCV epidemic. Birth cohort should be part of the criteria screening programmes for HCV in order to identify those at highest risk of infection and unaware of their status. As Henan is unique in the transmission route for HCV, these methods should be used in other high burden provinces to help identify subpopulations at risk.

  20. Trends in oral cavity, pharyngeal, oesophageal and gastric cancer mortality rates in Spain, 1952-2006: an age-period-cohort analysis.

    Science.gov (United States)

    Seoane-Mato, Daniel; Aragonés, Nuria; Ferreras, Eva; García-Pérez, Javier; Cervantes-Amat, Marta; Fernández-Navarro, Pablo; Pastor-Barriuso, Roberto; López-Abente, Gonzalo

    2014-04-11

    Although oral cavity, pharyngeal, oesophageal and gastric cancers share some risk factors, no comparative analysis of mortality rate trends in these illnesses has been undertaken in Spain. This study aimed to evaluate the independent effects of age, death period and birth cohort on the mortality rates of these tumours. Specific and age-adjusted mortality rates by tumour and sex were analysed. Age-period-cohort log-linear models were fitted separately for each tumour and sex, and segmented regression models were used to detect changes in period- and cohort-effect curvatures. Among men, the period-effect curvatures for oral cavity/pharyngeal and oesophageal cancers displayed a mortality trend that rose until 1995 and then declined. Among women, oral cavity/pharyngeal cancer mortality increased throughout the study period whereas oesophageal cancer mortality decreased after 1970. Stomach cancer mortality decreased in both sexes from 1965 onwards. Lastly, the cohort-effect curvature showed a certain degree of similarity for all three tumours in both sexes, which was greater among oral cavity, pharyngeal and oesophageal cancers, with a change point in evidence, after which risk of death increased in cohorts born from the 1910-1920s onwards and decreased among the 1950-1960 cohorts and successive generations. This latter feature was likewise observed for stomach cancer. While the similarities of the cohort effects in oral cavity/pharyngeal, oesophageal and gastric tumours support the implication of shared risk factors, the more marked changes in cohort-effect curvature for oral cavity/pharyngeal and oesophageal cancer could be due to the greater influence of some risk factors in their aetiology, such as smoking and alcohol consumption. The increase in oral cavity/pharyngeal cancer mortality in women deserves further study.

  1. Análisis edad-periodo-cohorte de la mortalidad por accidentes de tráfico en España Age-period-cohort analysis of traffic accident mortality in Spain

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    Carmen Saiz-Sánchez

    1999-05-01

    Full Text Available OBJETIVO. Estudiar la evolución de la mortalidad por accidentes de tráfico en España y su posible aplicación a un modelo edad-periodo-cohorte, así como el efecto que pueden tener algunas medidas de seguridad vial seleccionadas. MATERIAL Y MÉTODOS. Se obtuvieron las tasas de mortalidad por accidentes de tráfico y las tasas en intervalos quinquenales de edad para cada sexo, lo que permite su estudio como tasas específicas de edad por cohortes de nacimiento. Para determinar la asociación entre las medidas de seguridad vial seleccionadas y la mortalidad se han construido modelos de regresión de Poisson. RESULTADOS. Se observaron dos ondas evolutivas en la mortalidad por accidentes de tráfico. Respecto a la edad, no podemos hablar de un efecto claro; tampoco se encontró un efecto cohorte ni para varones ni para mujeres. En relación con las medidas de seguridad vial, se discutió la consistencia que guardaban los modelos seleccionados con los resultados gráficos, y se obtuvo que el uso obligatorio del casco y de las luces de cruce en motocicletas se ha asociado significativamente a la reducción de la mortalidad (RR 0.73, pOBJECTIVE. To study the evolution of traffic accidents mortality in Spain and its possible application to an age-period-cohort analysis, as well as the effect of selected road safety measures. MATERIAL AND METHODS. Road accidents rates of mortality were obtained, and five-year interval age rates for each sex, which allows the study of specific rates of age by birth cohorts. To determine the association between the selected road safety measures and mortality, Poisson regression models were adjusted. RESULTS. Two waves emerge in the evolution of traffic accidents. There was no clear effect with respect to age, nor was there a cohort effect for men or women. As to the road safety measures, we discuss the consistency between the selected models and graphic results. The compulsory use of helmet and of crossing lights is

  2. Changing Attitudes Toward Euthanasia and Suicide for Terminally Ill Persons, 1977 to 2016: An Age-Period-Cohort Analysis.

    Science.gov (United States)

    Attell, Brandon K

    2017-01-01

    Several longitudinal studies show that over time the American public has become more approving of euthanasia and suicide for terminally ill persons. Yet, these previous findings are limited because they derive from biased estimates of disaggregated hierarchical data. Using insights from life course sociological theory and cross-classified logistic regression models, I better account for this liberalization process by disentangling the age, period, and cohort effects that contribute to longitudinal changes in these attitudes. The results of the analysis point toward a continued liberalization of both attitudes over time, although the magnitude of change was greater for suicide compared with euthanasia. More fluctuation in the probability of supporting both measures was exhibited for the age and period effects over the cohort effects. In addition, age-based differences in supporting both measures were found between men and women and various religious affiliations.

  3. Mortality in Danish women: age, period and cohort analysis

    DEFF Research Database (Denmark)

    Lindahl-Jacobsen, Rune

    smokers throughout their adult life, suggesting that these smoking habits may be an important factor for their increased mortality. Study aim 3 The analysis of causes of death suggested an increased risk for deaths associated with the respiratory system and from causes traditionally associated....... Conclusion This study has shown that examination of total mortality trends in relation to age, period and cohort is a powerful exploratory tool for understanding changes in mortality and thus life expectancy. The analysis of differences in mortality trends among women in Denmark, Norway and Sweden...

  4. An Age-Period-Cohort Analysis

    OpenAIRE

    Ananth, Cande V.; Keyes, Katherine M.; Hamilton, Ava; Gissler, Mika; Wu, Chunsen; Liu, Shiliang; Luque-Fernandez, Miguel Angel; Skjaerven, Rolv; Williams, Michelle A.; Tikkanen, Minna; Cnattingius, Sven

    2015-01-01

    Background. Although rare, placental abruption is implicated in disproportionately high rates of perinatal morbidity and mortality. Understanding geographic and temporal variations may provide insights into possible amenable factors of abruption. We examined abruption frequencies by maternal age, delivery year, and maternal birth cohorts over three decades across seven countries. Methods. Women that delivered in the US (n = 863,879; 1979–10), Canada (4 provinces, n = 5,407,463; 1982–11), ...

  5. Educational expansion and the education gradient in health: A hierarchical age-period-cohort analysis.

    Science.gov (United States)

    Delaruelle, Katrijn; Buffel, Veerle; Bracke, Piet

    2015-11-01

    Researchers have recently been investigating the temporal variation in the educational gradient in health. While there is abundant literature concerning age trajectories, theoretical knowledge about cohort differences is relatively limited. Therefore, in analogy with the life course perspective, we introduce two contrasting cohort-specific hypotheses. The diminishing health returns hypothesis predicts a decrease in educational disparities in health across cohorts. By contrast, the cohort accretion hypothesis suggests that the education-health gap will be more pronounced among younger cohorts. To shed light on this, we perform a hierarchical age-period-cohort analysis (HAPC), using data from a subsample of individuals between 25 and 85 years of age (N = 232,573) from 32 countries in the European Social Survey (six waves: 2002-2012). The analysis leads to three important conclusions. First, we observe a widening health gap between different educational levels over the life course. Second, we find that these educational differences in the age trajectories of health seem to strengthen with each successive birth cohort. However, the two age-related effects disappear when we control for employment status, household income, and family characteristics. Last, when adjusting for these mediators, we reveal evidence to support the diminishing health returns hypothesis, implying that it is primarily the direct association between education and health that decreases across cohorts. This finding raises concerns about potential barriers to education being a vehicle for empowerment and the promotion of health. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Mortality of colorectal cancer in Taiwan, 1971-2010: temporal changes and age-period-cohort analysis.

    Science.gov (United States)

    Su, Shih-Yung; Huang, Jing-Yang; Jian, Zhi-Hong; Ho, Chien-Chang; Lung, Chia-Chi; Liaw, Yung-Po

    2012-12-01

    Colorectal cancer (CRC) is the second most common cause of cancer death in developed countries among men (after lung cancer) and the third most common among women. This study thus examines the long-term trends of CRC mortality in Taiwan. CRC cases were collective between patients aged 30 years or older and younger than 85 years from the Taiwan death registries during 1971-2010. Standard descriptive techniques such as age-standardized mortality rates (ASMR), aural percent change, and age-period-cohort analyses were used. The increase of percentage change by each age group in men was higher than in women. The ASMR of CRC increased 2-fold for men and almost 1.5-fold for women during the periods 1971-1975 and 2006-2010. For age-period-cohort analysis, the estimated mortality rate increased steadily with age in both sexes, and plateaued at 175.29 per 100,000 people for men and 128.14 per 100,000 for women in the 80- to 84-year-old group. Period effects were weak in both sexes. Cohort effects were strong. Between 30 and 59 years of age, the sex ratio showed that the female CRC mortality rate was higher than that of their male counterparts. Conversely, the mortality risk of CRC in men was higher than that in women when they were between 60 and 84 years old. The current findings showed a consistent increase in mortality from CRC over the years. Changes in the patient sex ratio indicated an important etiological role of sex hormones, especially in women aged 60 years or younger.

  7. Time trends for prostate cancer mortality in Brazil and its geographic regions: An age-period-cohort analysis.

    Science.gov (United States)

    Braga, Sonia Faria Mendes; de Souza, Mirian Carvalho; Cherchiglia, Mariangela Leal

    2017-10-01

    In the 1980s, an increase in mortality rates for prostate cancer was observed in North America and developed European countries. In the 1990s, however, mortality rates decreased for these countries, an outcome related to early detection of the disease. Conversely, an upward trend in mortality rates was observed in Brazil. This study describe the trends in mortality for prostate cancer in Brazil and geographic regions (North, Northeast, South, Southeast, and Central-West) between 1980 until 2014 and analyze the influence of age, period, and cohort effects on mortality rates. This time-series study used data from the Mortality Information System (SIM) and population data from Brazilian Institute for Geography and Statistics (IBGE). The effects on mortality rates were examined using age-period-cohort (APC) models. Crude and standardized mortality rates showed an upward trend for Brazil and its regions more than 2-fold the last 30 years. Age effects showed an increased risk of death in all regions. Period effects showed a higher risk of death in the finals periods for the North and Northeast. Cohort effects showed risk of death was higher for younger than older generations in Brazil and regions, mainly Northeast (RR Adjusted =3.12, 95% CI 1.29-1.41; RR Adjusted =0.28, 95% CI 0.26-0.30, respectively). The increase in prostate cancer mortality rates in Brazil and its regions was mainly due to population aging. The differences in mortality rates and APC effects between regions are related to demographic differences and access of health services across the country. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Less overdiagnosis of kidney cancer? an age-period-cohort analysis of incidence trends in 16 populations worldwide.

    Science.gov (United States)

    Znaor, Ariana; Laversanne, Mathieu; Bray, Freddie

    2017-09-01

    The increasing rates of kidney cancer incidence, reported in many populations globally, have been attributed both to increasing exposures to environmental risk factors, as well as increasing levels of incidental diagnosis due to widespread use of imaging. To better understand these trends, we examine long-term cancer registry data worldwide, focusing on the roles of birth cohort and calendar period, proxies for changes in risk factor prevalence and detection practice respectively. We used an augmented version of the Cancer Incidence in Five Continents series to analyze kidney cancer incidence rates 1978-2007 in 16 geographically representative populations worldwide by sex for ages 30-74, using age-period-cohort (APC) analysis. The full APC model provided the best fit to the data in most studied populations. While kidney cancer incidence rates have been increasing in successive generations born from the early twentieth century in most countries, equivalent period-specific rises were observed from the late-1970s, although these have subsequently stabilized in certain European countries (the Czech Republic, Lithuania, Finland, Spain) as well as Japan from the mid-1990s, and from the mid-2000s, in Colombia, Costa Rica and Australia. Our results indicate that the effects of both birth cohort and calendar period contribute to the international kidney cancer incidence trends. While cohort-specific increases may partly reflect the rising trends in obesity prevalence and the need for more effective primary prevention policies, the attenuations in period-specific increases (observed in 8 of the 16 populations) highlight a possible change in imaging practices that could lead to mitigation of overdiagnosis and overtreatment. © 2017 UICC.

  9. Time trends in exposure of cattle to bovine spongiform encephalopathy and cohort effect in France and Italy: value of the classical Age-Period-Cohort approach.

    Science.gov (United States)

    Sala, Carole; Ru, Giuseppe

    2009-09-18

    The Age-Period-Cohort (APC) analysis is routinely used for time trend analysis of cancer incidence or mortality rates, but in veterinary epidemiology, there are still only a few examples of this application. APC models were recently used to model the French epidemic assuming that the time trend for BSE was mainly due to a cohort effect in relation to the control measures that may have modified the BSE exposure of cohorts over time. We used a categorical APC analysis which did not require any functional form for the effect of the variables, and examined second differences to estimate the variation of the BSE trend. We also reanalysed the French epidemic and performed a simultaneous analysis of Italian data using more appropriate birth cohort categories for comparison. We used data from the exhaustive surveillance carried out in France and Italy between 2001 and 2007, and comparatively described the trend of the epidemic in both countries. At the end, the shape and irregularities of the trends were discussed in light of the main control measures adopted to control the disease. In Italy a decrease in the epidemic became apparent from 1996, following the application of rendering standards for the processing of specific risk material (SRM). For the French epidemic, the pattern of second differences in the birth cohorts confirmed the beginning of the decrease from 1995, just after the implementation of the meat and bone meal (MBM) ban for all ruminants (1994). The APC analysis proved to be highly suitable for the study of the trend in BSE epidemics and was helpful in understanding the effects of management and control of the disease. Additionally, such an approach may help in the implementation of changes in BSE regulations.

  10. Trend analysis and modelling of gender-specific age, period and birth cohort effects on alcohol abstention and consumption level for drinkers in Great Britain using the General Lifestyle Survey 1984-2009.

    Science.gov (United States)

    Meng, Yang; Holmes, John; Hill-McManus, Daniel; Brennan, Alan; Meier, Petra Sylvia

    2014-02-01

    British alcohol consumption and abstinence rates have increased substantially in the last 3 decades. This study aims to disentangle age, period and birth cohort effects to improve our understanding of these trends and suggest groups for targeted interventions to reduce resultant harms. Age, period, cohort analysis of repeated cross-sectional surveys using separate logistic and negative binomial models for each gender. Great Britain 1984-2009. Annual nationally representative samples of approximately 20 000 adults (16+) within 13 000 households. Age (eight groups: 16-17 to 75+ years), period (six groups: 1980-84 to 2005-09) and birth cohorts (19 groups: 1900-04 to 1990-94). Outcome measures were abstinence and average weekly alcohol consumption. Controls were income, education, ethnicity and country. After accounting for period and cohort trends, 18-24-year-olds have the highest consumption levels (incident rate ratio = 1.18-1.15) and lower abstention rates (odds ratio = 0.67-0.87). Consumption generally decreases and abstention rates increase in later life. Until recently, successive birth cohorts' consumption levels were also increasing. However, for those born post-1985, abstention rates are increasing and male consumption is falling relative to preceding cohorts. In contrast, female drinking behaviours have polarized over the study period, with increasing abstention rates accompanying increases in drinkers' consumption levels. Rising female consumption of alcohol and progression of higher-consuming birth cohorts through the life course are key drivers of increased per capita alcohol consumption in the United Kingdom. Recent declines in alcohol consumption appear to be attributable to reduced consumption and increased abstinence rates among the most recent birth cohorts, especially males, and general increased rates of abstention across the study period. © 2013 Society for the Study of Addiction.

  11. Age, Period, and Cohort Effects in Psychological Distress in the United States and Canada

    Science.gov (United States)

    Keyes, Katherine M.; Nicholson, Ryan; Kinley, Jolene; Raposo, Sarah; Stein, Murray B.; Goldner, Elliot M.; Sareen, Jitender

    2014-01-01

    Although treatment utilization for depression and anxiety symptoms has increased substantially in the United States and elsewhere, it remains unclear whether the underlying population distribution of psychological distress is changing over time. We estimated age, period, and cohort effects using data from 2 countries over more than 20 years, including National Health Interview Surveys from 1997 to 2010 (n = 447,058) and Canadian Community Health Surveys from 2000 to 2007 (n = 125,306). Psychological distress was measured with the Kessler Psychological Distress Scale. By period, both countries showed the highest levels of psychological distress in 2001 and the lowest levels in 2007. By age, psychological distress was highest in adolescence and during the late 40s and early 50s. By cohort, Canadian Community Health Survey results indicated a decreasing cohort effect among those born in 1922–1925 through 1935–1939 (β = −0.36, 95% confidence interval: −0.45, −0.27) and then a continuously increasing cohort effect during the remainder of the 20th century through 1989–1992 (β = 0.49, 95% confidence interval: 0.38, 0.61). The National Health Interview Survey data captured earlier-born cohorts and indicated an increased cohort effect for the earliest born (for 1912–1914, β = 0.44, 95% confidence interval: 0.26, 0.61). In sum, individuals in the oldest and more recently born birth cohorts have higher mean psychological distress symptoms compared with those born in midcentury, underscoring the importance of a broad, population-level lens for conceptualizing mental health. PMID:24692432

  12. Global patterns and trends in stomach cancer incidence: Age, period and birth cohort analysis.

    Science.gov (United States)

    Luo, Ganfeng; Zhang, Yanting; Guo, Pi; Wang, Li; Huang, Yuanwei; Li, Ke

    2017-10-01

    The cases of stomach cancer (SC) incidence are increasing per year and the SC burden has remained very high in some countries. We aimed to evaluate the global geographical variation in SC incidence and temporal trends from 1978 to 2007, with an emphasis on the effect of birth cohort. Joinpoint regression and age-period-cohort model were applied. From 2003 to 2007, male rate were 1.5- to 3-fold higher than female in all countries. Rates were highest in Eastern Asian and South American countries. Except for Uganda, all countries showed favorable trends. Pronounced cohort-specific increases in risk for recent birth cohorts were seen in Brazil, Colombia, Iceland, New Zealand, Norway, Uganda and US white people for males and in Australia, Brazil, Colombia, Costa Rica, Czech Republic, Ecuador, Iceland, India, Malta, New Zealand, Norway, Switzerland, United Kingdom, Uganda, US black and white people for females. The cohort-specific ratio for male significantly decreased in Japan, Malta and Spain for cohorts born since 1950 and in Austria, China, Croatia, Ecuador, Russia, Switzerland and Thailand for cohorts born since 1960 and for female in Japan for cohorts born since 1950 and in Canada, China, Croatia, Latvia, Russia and Thailand for cohorts born since 1960. Disparities in incidence and carcinogenic risk persist worldwide. The favorable trends may be due to changes in environmental exposure and lifestyle, including decreased Helicobacter pylori prevalence, increased intake of fresh fruits and vegetables, the availability of refrigeration and decreased intake of salted and preserved food and smoking prevalence. © 2017 UICC.

  13. Trends in esophageal cancer mortality in China during 1987-2009: age, period and birth cohort analyzes.

    Science.gov (United States)

    Guo, Pi; Li, Ke

    2012-04-01

    Esophageal cancer is one of the most commonly diagnosed malignant tumors in China. The aim of this study was to provide the representative and comprehensive informations about the long-term mortality trends of this disease in China between 1987 and 2009, using joinpoint regression and generalized additive models (GAMs). Age-standardized mortality rates (ASMR), overall and truncated (35-64 years), were calculated using the direct calculation method, and joinpoint regression was performed to obtain the estimated annual percentage changes (EAPC). GAMs were fitted to study the effects of age, period and birth cohort on mortality trends. ASMR exhibited an overall remarked decline for rural females (EAPC=-2.3 95%CI: -3.3, -1.2), urban males (EAPC=-1.8 95%CI: -2.6, -1.0) and urban females (EAPC=-3.7 95%CI: -4.9, -2.4), but a small drop observed was not statistically significant for rural males (EAPC=-0.9 95%CI: -2.0, 0.3). The declines in ASMR were more noticeable for urban residents in recent years. Among all the residents, age effect showed an progressively increasing trend, whereas cohort effect declined steadily after the year corresponding to the maximum risk value. Period effect seemed to remain substantially unchanged throughout the years. Although variations in mortality rates were observed according to sex and area, the overall decreasing trends in esophageal cancer mortality were found in most Chinese people, aside from rural males. The findings could correspond to the changes in age- and cohort-related factors in the population. Further study is required to understand these potential factors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Age-specific mortality trends in France and Italy since 1900: period and cohort effects.

    Science.gov (United States)

    Caselli, G; Vallin, J; Vaupel, J W; Yashin, A

    1987-11-01

    The age/sex-specific mortality trends of France and Italy were studied over the 1899-1979 period in as much detail as possible in an effort to distinguish between cohort effects and those related to period changes. Complete series of mortality data by individual years of age and calendar years were available from 1869 to 1979 for Italy and from 1899 to 1982 for France. For both countries, these data include the military and civil deaths not registered in vital statistics during the war periods. They cover each national territory as defined by its present boundaries. The graphical representation method of mortality surfaces, elaborated by Vaupel, Gambill, and Yashin (1985), was adopted. The age/sex-specific mortality patterns of France and Italy have not followed the same trends, and the differences observed today are not those of 100 years ago. The mean death probabilities for the 1975-79 period were used to illustrate the age-specific patterns of mortality. Although infant mortality was higher in Italy than in France, the death probabilities at ages 1-15 for both sexes were roughly the same for both countries. At ages 15-23, they were much higher in France than in Italy, and they remained considerably higher in France up to age 55. From then on, the sexes differ: for males, the 2 countries showed similar patterns, whereas for females the probabilities were noticeably higher for France. The situation was very different for both countries at the beginning of the century. For both sexes, higher mortality was observed in Italy not only during infancy but throughout childhood and the adolescent years up to age 15. The 2 countries showed similar patterns from 15-25. Above age 25, the 2 countries had similar patterns for females, whereas male mortality was higher in France right up to the old age groups. Such differences in the age-specific mortality trends depend in part on a different development of health and social conditions but also may be due to factors concerning

  15. Changing BMI scores among Canadian Indigenous and non-Indigenous children, youth, and young adults: Untangling age, period, and cohort effects

    Directory of Open Access Journals (Sweden)

    Piotr Wilk

    2017-04-01

    Full Text Available The objective of this study was to examine age, period and cohort effects on BMI among Indigenous and non-Indigenous populations, using repeated cross-sectional survey data from the CCHS (2001 to 2014. Cross-classified random-effect two-level models were used to estimate fixed effects for age and its quadratic term (Level 1, and also to estimate random effects for time periods and birth cohorts (Level 2, while controlling for the effects of Level 1 control variables: sex, model of interview and response by proxy. Overall, the results support the hypothesis that age and period effects are primarily responsible for the current obesity epidemic. L’objectif de cette étude était d’examiner les effets de l’âge, de la période et de la cohorte sur l’IMC chez les populations autochtones et non autochtones, en utilisant des données d’enquêtes transversales répétées de l’ESCC (2001 à 2014. On a utilisé des modèles à deux niveaux à effets aléatoires croisés pour estimer les effets fixes pour l’âge et son terme quadratique (niveau 1, et également estimer les effets aléatoires pour les périodes et les cohortes de naissance (niveau 2, tout en contrôlant les effets du niveau 1 Variables de contrôle: sexe, modèle d’interview et réponse par procuration. Dans l’ensemble, les résultats confirment l’hypothèse selon laquelle les effets de l’âge et de la période sont les principaux responsables de l’épidémie actuelle d’obésité.

  16. Period Effects, Cohort Effects, and the Narrowing Gender Wage Gap

    OpenAIRE

    Campbell, Colin; Pearlman, Jessica

    2013-01-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use Age-Period-Cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effe...

  17. Sexual Inactivity During Young Adulthood Is More Common Among U.S. Millennials and iGen: Age, Period, and Cohort Effects on Having No Sexual Partners After Age 18.

    Science.gov (United States)

    Twenge, Jean M; Sherman, Ryne A; Wells, Brooke E

    2017-02-01

    Examining age, time period, and cohort/generational changes in sexual experience is key to better understanding sociocultural influences on sexuality and relationships. Americans born in the 1980s and 1990s (commonly known as Millennials and iGen) were more likely to report having no sexual partners as adults compared to GenX'ers born in the 1960s and 1970s in the General Social Survey, a nationally representative sample of American adults (N = 26,707). Among those aged 20-24, more than twice as many Millennials born in the 1990s (15 %) had no sexual partners since age 18 compared to GenX'ers born in the 1960s (6 %). Higher rates of sexual inactivity among Millennials and iGen also appeared in analyses using a generalized hierarchical linear modeling technique known as age-period-cohort analysis to control for age and time period effects among adults of all ages. Americans born early in the 20th century also showed elevated rates of adult sexual inactivity. The shift toward higher rates of sexual inactivity among Millennials and iGen'ers was more pronounced among women and absent among Black Americans and those with a college education. Contrary to popular media conceptions of a "hookup generation" more likely to engage in frequent casual sex, a higher percentage of Americans in recent cohorts, particularly Millennials and iGen'ers born in the 1990s, had no sexual partners after age 18.

  18. Time trends of esophageal and gastric cancer mortality in China, 1991?2009: an age-period-cohort analysis

    OpenAIRE

    Li, Mengmeng; Wan, Xia; Wang, Yanhong; Sun, Yuanyuan; Yang, Gonghuan; Wang, Li

    2017-01-01

    Esophageal and gastric cancers share some risk factors. This study aimed to compare the long-term trends in mortality rates of esophageal and gastric cancers in China to provide evidence for cancer prevention and control. Mortality data were derived from 103 continuous points of the Disease Surveillance Points system during 1991?2009, stratified by gender and urban-rural locations. Age-period-cohort models were used to disentangle the time trends of esophageal and gastric cancer mortality. Th...

  19. Period Effects, Cohort Effects, and the Narrowing Gender Wage Gap

    Science.gov (United States)

    Campbell, Colin; Pearlman, Jessica

    2015-01-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use Age-Period-Cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages. PMID:24090861

  20. On the relationship between period and cohort mortality

    Directory of Open Access Journals (Sweden)

    John R. Wilmoth

    2005-11-01

    Full Text Available In this paper I explore the formal relationship between period and cohort mortality, focusing on a comparison of measures of mean lifespan. I consider not only the usual measures (life expectancy at birth for time periods and birth cohorts but also some alternative measures that have been proposed recently. I examine (and reject the claim made by Bongaarts and Feeney that the level of period is distorted, or biased, due to changes in the timing of mortality. I show that their proposed alternative measure, called "tempo-adjusted" life expectancy, is exactly equivalent in its generalized form to a measure proposed by both Brouard and Guillot, the cross-sectional average length of life (or CAL, which substitutes cohort survival probabilities for their period counterparts in the calculation of mean lifespan. I conclude that this measure does not in any sense correct for a distortion in period life expectancy at birth, but rather offers an alternative measure of mean lifespan that is approximately equal to two analytically interesting quantities: 1 the mean age at death in a given year for a hypothetical population subject to observed historical mortality conditions but with a constant annual number of births; and 2 the mean age at death, , for a cohort born years ago. However, I also observe that the trend in period does indeed offer a biased depiction of the pace of change in mean lifespan from cohort to cohort. Holding other factors constant, an historical increase in life expectancy at birth is somewhat faster when viewed from the perspective of cohorts (i.e., year of birth than from the perspective of periods (i.e., year of death.

  1. Period effects, cohort effects, and the narrowing gender wage gap.

    Science.gov (United States)

    Campbell, Colin; Pearlman, Jessica

    2013-11-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use age-period-cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Colorectal cancer mortality trends in Serbia during 1991-2010: an age-period-cohort analysis and a joinpoint regression analysis.

    Science.gov (United States)

    Ilic, Milena; Ilic, Irena

    2016-06-22

    For both men and women worldwide, colorectal cancer is among the leading causes of cancer-related death. This study aimed to assess the mortality trends of colorectal cancer in Serbia between 1991 and 2010, prior to the introduction of population-based screening. Joinpoint regression analysis was used to estimate average annual percent change (AAPC) with the corresponding 95% confidence interval (CI). Furthermore, age-period-cohort analysis was performed to examine the effects of birth cohort and calendar period on the observed temporal trends. We observed a significantly increased trend in colorectal cancer mortality in Serbia during the study period (AAPC = 1.6%, 95% CI 1.3%-1.8%). Colorectal cancer showed an increased mortality trend in both men (AAPC = 2.0%, 95% CI 1.7%-2.2%) and women (AAPC = 1.0%, 95% CI 0.6%-1.4%). The temporal trend of colorectal cancer mortality was significantly affected by birth cohort (P < 0.05), whereas the study period did not significantly affect the trend (P = 0.072). Colorectal cancer mortality increased for the first several birth cohorts in Serbia (from 1916 to 1955), followed by downward flexion for people born after the 1960s. According to comparability test, overall mortality trends for colon cancer and rectal and anal cancer were not parallel (the final selected model rejected parallelism, P < 0.05). We found that colorectal cancer mortality in Serbia increased considerably over the past two decades. Mortality increased particularly in men, but the trends were different according to age group and subsite. In Serbia, interventions to reduce colorectal cancer burden, especially the implementation of a national screening program, as well as treatment improvements and measures to encourage the adoption of a healthy lifestyle, are needed.

  3. Age, period and cohort effects on adult physical activity levels from 1991 to 2011 in China.

    Science.gov (United States)

    Zang, Jiajie; Ng, Shu Wen

    2016-04-20

    To date no work has differentiated the effects of age, period, and cohort on physical activity (PA) among Chinese adults, while also considering biological, behavioral, economic, and environmental factors over time. We used data from the China Health and Nutrition Survey (CHNS) between 1991 and 2011 (20 years). The outcomes of interest are metabolic equivalent of task (MET) hours per week from work and domestic activities. Age, individual characteristics, household size, asset ownership, urbanization were included as covariates. Analyses for adult (≥20y) males (n = 29,343) and females (n = 31,094) was conducted to explicitly assess differences in PA due to age vs period effects, and implicitly assess differences by cohorts due to the period-specific experiences across individuals of varying ages. The mean age of the sample rose from 41.31 to 50.8 years and PA decreased from 427.75 ± 264.35 MET hours per week (MET-hr/wk) in 1991 to 245.99 ± 206.65 MET-hr/wk in 2011, with much steeper declines for women compared to men. For both genders, we found non-linear decreases in PA with age over time. Controlling for age effects, negative period effects on PA were observed in each survey year, and were substantial from 1993 to 2000 for males and from 1993 to 2011 for females. The interaction between survey year and age (P < 0.05) were observed from 2004 to 2011. Higher community urbanicity, vehicle ownership, TV and computer ownership, overweight and obese, higher education served as negative predictors. Bicycle ownership, bigger household size, non-professional jobs, being married and having more children (for women) were positive predictors of PA (P < 0.05). Furthermore, at any given age, individuals who were younger at baseline had higher mean PA compared with individuals older at baseline. This study followed a large cohort of adults over a significant portion of their lives. Strong age and secular trends were observed, resulting in an

  4. Age-period-cohort projections of ischaemic heart disease mortality by socio-economic position in a rapidly transitioning Chinese population.

    Directory of Open Access Journals (Sweden)

    Irene O L Wong

    Full Text Available BACKGROUND: With economic development and population aging, ischaemic heart disease (IHD is becoming a leading cause of mortality with widening inequalities in China. To forewarn the trends in China we projected IHD trends in the most economically developed part of China, i.e., Hong Kong. METHODS: Based on sex-specific IHD mortality rates from 1976 to 2005, we projected mortality rates by neighborhood-level socio-economic position (i.e., low- or high-income groups to 2020 in Hong Kong using Poisson age-period-cohort models with autoregressive priors. RESULTS: In the low-income group, age-standardized IHD mortality rates among women declined from 33.3 deaths in 1976-1980 to 19.7 per 100,000 in 2016-2020 (from 55.5 deaths to 34.2 per 100,000 among men. The rates in the high-income group were initially higher in both sexes, particularly among men, but this had reversed by the end of the study periods. The rates declined faster for the high-income group than for the low-income group in both sexes. The rates were projected to decline faster in the high-income group, such that by the end of the projection period the high-income group would have lower IHD mortality rates, particularly for women. Birth cohort effects varied with sex, with a marked upturn in IHD mortality around 1945, i.e., for the first generation of men to grow up in a more economically developed environment. There was no such upturn in women. Birth cohort effects were the main drivers of change in IHD mortality rates. CONCLUSION: IHD mortality rates are declining in Hong Kong and are projected to continue to do so, even taking into account greater vulnerability for the first generation of men born into a more developed environment. At the same time social disparities in IHD have reversed and are widening, partly as a result of a cohort effect, with corresponding implications for prevention.

  5. Recent hip fracture trends in Sweden and Denmark with age-period-cohort effects

    DEFF Research Database (Denmark)

    Rosengren, B E; Björk, J; Cooper, C

    2017-01-01

    This study used nationwide hip fracture data from Denmark and Sweden during 1987-2010 to examine effects of (birth) cohort and period. We found that time trends, cohort, and period effects were different in the two countries. Results also indicated that hip fracture rates may increase in the not ...

  6. Breast cancer mortality in mexico: an age-period-cohort analysis Mortalidad por cáncer de mama en méxico: un análisis de edad-periodo-cohorte

    Directory of Open Access Journals (Sweden)

    Francisco Franco-Marina

    2009-01-01

    Full Text Available OBJECTIVE: To assess the age, period and cohort effects on breast cancer (BC mortality in Mexico. MATERIAL AND METHODS: Age, period and cohort curvature trends for BC mortality were estimated through the Poisson Regression model proposed by Holford. RESULTS: Nationally, BC death rates have leveled off since 1995 in most age groups. BC mortality trends are mainly determined by birth cohort and age effects in Mexico. Women born between 1940 and 1955 show the highest rate of increase in BC mortality. Women born afterwards still show an increasing trend but at a much lower rate. Mammography and adjuvant therapy have had a limited impact on mortality. Potential reasons for observed patterns are discussed. An increase in BC mortality in Mexico is expected in the following decades. CONCLUSIONS: Mammography screening programs and timely access to effective treatment should be a national priority to reverse the expected increasing BC mortality trend.OBJETIVO: Evaluar efectos de edad-periodo-cohorte en la mortalidad por cáncer de mama (CaMa en México. MATERIAL Y MÉTODOS: Las tendencias de los efectos de edad-periodo-cohorte fueron estimados mediante un modelo de regresión de Poisson propuesto por Holford. RESULTADOS: Las tasas de mortalidad por CaMa se han estabilizado en la mayoría de los grupos de edad desde 1995 y están determinadas principalmente por efectos de cohorte y edad. Las mujeres nacidas entre 1940 y 1955 muestran los mayores aumentos en la mortalidad en comparación con las nacidas después de este período. La mamografía y la terapia adyuvante han tenido un impacto limitado sobre la mortalidad. Se discuten posibles explicaciones de las tendencias observadas. En las siguientes décadas se espera continúe aumentando la mortalidad por CaMa. CONCLUSIONES: El acceso a mamografía y a tratamiento oportuno y efectivo debieran ser una prioridad para revertir la tendencia creciente esperada de la mortalidad por CM.

  7. Working Life and Retirement Expectancies at Age 50 by Social Class: Period and Cohort Trends and Projections for Finland.

    Science.gov (United States)

    Leinonen, Taina; Martikainen, Pekka; Myrskylä, Mikko

    2018-01-11

    The balance between the amount of time spent in work and in retirement underlies the long-term sustainability of the social security system. We examined socioeconomic differences in how increasing longevity is distributed between labor market statuses in Finland. We used register data and the Sullivan method to analyze life expectancy at age 50 spent in different labor market statuses over the period 1989-2012 and across cohorts born in 1938-1953. We projected the future mortality and labor market participation rates of partially observed cohorts. Both working life expectancy at age 50 and the share of remaining life spent in work have increased across periods following the recession of the early 1990s, and across successive cohorts. The trends were similar across the social classes, but there were large differences in the numbers of years spent in various states: for the most recent period and the youngest cohort, we find that compared with upper non-manual employees, male and female manual workers were expected to spend 3.6-3.7 fewer years in work, 1.7-4.7 fewer years in statutory retirement, and 3.2-3.9 more years in other forms of nonemployment. Our finding that the share of remaining life at age 50 spent in work is increasing implies that pressure on the welfare system is not as severe as is commonly thought. © The Author(s) 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Dissemination of periodic mammography and patterns of use, by birth cohort, in Catalonia (Spain)

    Science.gov (United States)

    Rue, Montserrat; Carles, Misericordia; Vilaprinyo, Ester; Martinez-Alonso, Montserrat; Espinas, Josep-Alfons; Pla, Roger; Brugulat, Pilar

    2008-01-01

    Background In Catalonia (Spain) breast cancer mortality has declined since the beginning of the 1990s. The dissemination of early detection by mammography and the introduction of adjuvant treatments are among the possible causes of this decrease, and both were almost coincident in time. Thus, understanding how these procedures were incorporated into use in the general population and in women diagnosed with breast cancer is very important for assessing their contribution to the reduction in breast cancer mortality. In this work we have modeled the dissemination of periodic mammography and described repeat mammography behavior in Catalonia from 1975 to 2006. Methods Cross-sectional data from three Catalan Health Surveys for the calendar years 1994, 2002 and 2006 was used. The dissemination of mammography by birth cohort was modeled using a mixed effects model and repeat mammography behavior was described by age and survey year. Results For women born from 1938 to 1952, mammography clearly had a period effect, meaning that they started to have periodic mammograms at the same calendar years but at different ages. The age at which approximately 50% of the women were receiving periodic mammograms went from 57.8 years of age for women born in 1938–1942 to 37.3 years of age for women born in 1963–1967. Women in all age groups experienced an increase in periodic mammography use over time, although women in the 50–69 age group have experienced the highest increase. Currently, the target population of the Catalan Breast Cancer Screening Program, 50–69 years of age, is the group that self-reports the highest utilization of periodic mammograms, followed by the 40–49 age group. A higher proportion of women of all age groups have annual mammograms rather than biennial or irregular ones. Conclusion Mammography in Catalonia became more widely implemented during the 1990s. We estimated when cohorts initiated periodic mammograms and how frequently women are receiving them

  9. Age, period, and cohort analysis of regular dental care behavior and edentulism: A marginal approach

    Science.gov (United States)

    2011-01-01

    Background To analyze the regular dental care behavior and prevalence of edentulism in adult Danes, reported in sequential cross-sectional oral health surveys by the application of a marginal approach to consider the possible clustering effect of birth cohorts. Methods Data from four sequential cross-sectional surveys of non-institutionalized Danes conducted from 1975-2005 comprising 4330 respondents aged 15+ years in 9 birth cohorts were analyzed. The key study variables were seeking dental care on an annual basis (ADC) and edentulism. For the analysis of ADC, survey year, age, gender, socio-economic status (SES) group, denture-wearing, and school dental care (SDC) during childhood were considered. For the analysis of edentulism, only respondents aged 35+ years were included. Survey year, age, gender, SES group, ADC, and SDC during childhood were considered as the independent factors. To take into account the clustering effect of birth cohorts, marginal logistic regressions with an independent correlation structure in generalized estimating equations (GEE) were carried out, with PROC GENMOD in SAS software. Results The overall proportion of people seeking ADC increased from 58.8% in 1975 to 86.7% in 2005, while for respondents aged 35 years or older, the overall prevalence of edentulism (35+ years) decreased from 36.4% in 1975 to 5.0% in 2005. Females, respondents in the higher SES group, in more recent survey years, with no denture, and receiving SDC in all grades during childhood were associated with higher probability of seeking ADC regularly (P dental health policy was demonstrated by a continued increase of regular dental visiting habits and tooth retention in adults because school dental care was provided to Danes in their childhood. PMID:21410991

  10. Age, cohort and period effects in the prevalence of sleep disturbances among older people: the impact of economic downturn.

    Science.gov (United States)

    Dregan, Alex; Armstrong, David

    2009-11-01

    Using two longitudinal and nationally representative datasets, this study employs a cross-cohort analysis to examine age, cohort and period effects in the prevalence of sleep loss through worry for people over the age of 50 in the UK. The likelihood of reporting sleep loss through worry is calculated at two time-points for 7785 respondents from the Health and Activity Survey (HALs) and 21,834 respondents from the English Longitudinal Study of Ageing (ELSA), with baseline information on sleep loss through worry. Descriptive statistical methods were applied to determine the prevalence rates in sleep loss through worry at each survey within both datasets. The results of analysis reveal that sleep loss through worry declined with age, but this pattern was tempered by a temporary increase in the early 1990s. The contemporary economic downturn is suggested as a possible explanation for the significant increase in the prevalence of sleep loss through worry in 1991.

  11. Who theorizes age? The "socio-demographic variables" device and age-period-cohort analysis in the rhetoric of survey research.

    Science.gov (United States)

    Rughiniș, Cosima; Humă, Bogdana

    2015-12-01

    In this paper we argue that quantitative survey-based social research essentializes age, through specific rhetorical tools. We outline the device of 'socio-demographic variables' and we discuss its argumentative functions, looking at scientific survey-based analyses of adult scientific literacy, in the Public Understanding of Science research field. 'Socio-demographics' are virtually omnipresent in survey literature: they are, as a rule, used and discussed as bundles of independent variables, requiring little, if any, theoretical and measurement attention. 'Socio-demographics' are rhetorically effective through their common-sense richness of meaning and inferential power. We identify their main argumentation functions as 'structure building', 'pacification', and 'purification'. Socio-demographics are used to uphold causal vocabularies, supporting the transmutation of the descriptive statistical jargon of 'effects' and 'explained variance' into 'explanatory factors'. Age can also be studied statistically as a main variable of interest, through the age-period-cohort (APC) disambiguation technique. While this approach has generated interesting findings, it did not mitigate the reductionism that appears when treating age as a socio-demographic variable. By working with age as a 'socio-demographic variable', quantitative researchers convert it (inadvertently) into a quasi-biological feature, symmetrical, as regards analytical treatment, with pathogens in epidemiological research. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Practical applications of age-dependent reliability models and analysis of operational data

    Energy Technology Data Exchange (ETDEWEB)

    Lannoy, A.; Nitoi, M.; Backstrom, O.; Burgazzi, L.; Couallier, V.; Nikulin, M.; Derode, A.; Rodionov, A.; Atwood, C.; Fradet, F.; Antonov, A.; Berezhnoy, A.; Choi, S.Y.; Starr, F.; Dawson, J.; Palmen, H.; Clerjaud, L

    2005-07-01

    The purpose of the workshop was to present the experience of practical application of time-dependent reliability models. The program of the workshop comprises the following sessions: -) aging management and aging PSA (Probabilistic Safety Assessment), -) modeling, -) operation experience, and -) accelerating aging tests. In order to introduce time aging effect of particular component to the PSA model, it has been proposed to use the constant unavailability values on the short period of time (one year for example) calculated on the basis of age-dependent reliability models. As for modeling, it appears that the problem of too detailed statistical models for application is the lack of data for required parameters. As for operating experience, several methods of operating experience analysis have been presented (algorithms for reliability data elaboration and statistical identification of aging trend). As for accelerated aging tests, it is demonstrated that a combination of operating experience analysis with the results of accelerated aging tests of naturally aged equipment could provide a good basis for continuous operation of instrumentation and control systems.

  13. Practical applications of age-dependent reliability models and analysis of operational data

    International Nuclear Information System (INIS)

    Lannoy, A.; Nitoi, M.; Backstrom, O.; Burgazzi, L.; Couallier, V.; Nikulin, M.; Derode, A.; Rodionov, A.; Atwood, C.; Fradet, F.; Antonov, A.; Berezhnoy, A.; Choi, S.Y.; Starr, F.; Dawson, J.; Palmen, H.; Clerjaud, L.

    2005-01-01

    The purpose of the workshop was to present the experience of practical application of time-dependent reliability models. The program of the workshop comprises the following sessions: -) aging management and aging PSA (Probabilistic Safety Assessment), -) modeling, -) operation experience, and -) accelerating aging tests. In order to introduce time aging effect of particular component to the PSA model, it has been proposed to use the constant unavailability values on the short period of time (one year for example) calculated on the basis of age-dependent reliability models. As for modeling, it appears that the problem of too detailed statistical models for application is the lack of data for required parameters. As for operating experience, several methods of operating experience analysis have been presented (algorithms for reliability data elaboration and statistical identification of aging trend). As for accelerated aging tests, it is demonstrated that a combination of operating experience analysis with the results of accelerated aging tests of naturally aged equipment could provide a good basis for continuous operation of instrumentation and control systems

  14. Trends of stomach cancer mortality in Eastern Asia in 1950-2004: comparative study of Japan, Hong Kong and Singapore using age, period and cohort analysis.

    Science.gov (United States)

    Tanaka, Masahiro; Ma, Enbo; Tanaka, Hideo; Ioka, Akiko; Nakahara, Toshitaka; Takahashi, Hideto

    2012-02-15

    To characterize the temporal trends of stomach cancer mortality in Eastern Asia and to better interpret the causes of the trends, we performed age, period and cohort analysis (APC analysis) on the mortality rates in Japan, Hong Kong and Singapore during 1950-2004, as well as the rates in the US as a control population. For the APC analysis, Holford's approach was used to avoid the identification problem. Age-standardized mortality rates (ASMR) decreased consistently in all four areas during the observation period in both males and females. Japan had the highest ASMR in both sexes, followed by Singapore, Hong Kong and the US, but the differences in ASMR among the four areas diminished with time. The results of APC analysis suggested that the decreasing mortality rates in Eastern Asia were caused by the combination of decreasing cohort effect since the end of the 1800s and decreasing period effect from the 1950s. The US showed similar results, but its decreases in the period and cohort effect preceded those of Eastern Asia. Possible causes for the decrease in the cohort effect include improvement in the socioeconomic conditions during childhood and a decrease in the prevalence of H. pylori infection, while possible causes for the decrease in the period effect include a decrease in dietary salt intake and improvements in cancer detection and treatment. These findings may help us to predict future changes in the mortality rates of stomach cancer. Copyright © 2011 UICC.

  15. Cognitive Ageing in Great Britain in the New Century: Cohort Differences in Episodic Memory.

    Directory of Open Access Journals (Sweden)

    Gindo Tampubolon

    Full Text Available Dementias in high income countries are set to be the third major burden of disease even as older people are increasingly required to think for themselves how to provide for their lives in retirement. Meanwhile the period of older age continues to extend with increase in life expectancy. This challenge demands an understanding of how cognition changes over an extended period in later life. But studying cognitive ageing in the population faces a difficulty from the fact that older respondents are liable to leave (attrite before study completion. This study tested three hypotheses: trajectories of cognitive ageing in Britain show an improvement beyond the age of 50; and they are lifted by secular improvement in cognition across cohorts; lastly they are susceptible to distortion due to attrition.Using the English Longitudinal Study of Ageing, this paper studied trajectories of episodic memory of Britons aged 50-89 from 2002 to 2013 (N = 5931. Using joint models the analysis found that levels of episodic memory follow a curvilinear shape, not a steady decline, in later life. The findings also revealed secular improvement in cognitive ageing such that as a cohort is being replaced episodic memory levels in the population improve. The analysis lastly demonstrated that failure to simultaneously model attrition can produce distorted pictures of cognitive ageing.Old age in this century is not necessarily a period dominated by cognitive decline. In identifying behavioural factors associated with better cognitive ageing, such as social connections of traditional and online kinds, the paper raises possibilities of mustering an adequate response to the cognition challenge.

  16. Homicides among women in the different Brazilian regions in the last 35 years: an analysis of age-period-birth cohort effects.

    Science.gov (United States)

    Souza, Edinilsa Ramos de; Meira, Karina Cardoso; Ribeiro, Adalgisa Peixoto; Santos, Juliano Dos; Guimarães, Raphael Mendonça; Borges, Laiane Felix; Oliveira, Lannuzya Veríssimo E; Simões, Taynãna César

    2017-09-01

    The aim of this study is to estimate the effects of age-period-birth cohort (APC) on female homicides. This is an ecological study which analyzed the violence-related death records of women aged 10 years and older, in the Brazilian geographic regions, between 1980 and 2014. Data on mortality were extracted from the Mortality Information System. The trend analysis was conducted using negative binomial regression and APC effects were analyzed using estimable functions. The average mortality rate for the period was 5.13 deaths per 100,000 women, with the highest rates observed in the Central-West (7.98 deaths), followed by the Southeast (4.78 deaths), North (4.77 deaths), Northeast (4.05 deaths) and South (3.82 deaths) regions. All regions presented a decrease in the risk of death in the period from 2010 to 2014, except for the Northeast region (RR = 1.06, 95% CI 1.02 to 1.10). There was a progressive increase in the homicide risk for women born from 1955 to 1959 in all Brazilian regions. Younger women are at higher risk of dying from homicides in all Brazilian geographic regions. The upward trend of homicide mortality rates according to birth cohort was significant and the highest risk was observed in women born between 2000 and 2004.

  17. Cohort Differences in Cognitive Aging in the Longitudinal Aging Study Amsterdam.

    Science.gov (United States)

    Brailean, Anamaria; Huisman, Martijn; Prince, Martin; Prina, A Matthew; Deeg, Dorly J H; Comijs, Hannie

    2016-09-30

    This study aims to examine cohort differences in cognitive performance and rates of change in episodic memory, processing speed, inductive reasoning, and general cognitive performance and to investigate whether these cohort effects may be accounted for by education attainment. The first cohort (N = 705) was born between 1920 and 1930, whereas the second cohort (N = 646) was born between 1931 and 1941. Both birth cohorts were aged 65 to 75 years at baseline and were followed up 3 and 6 years later. Data were analyzed using linear mixed models. The later born cohort had better general cognitive performance, inductive reasoning, and processing speed at baseline, but cohort differences in inductive reasoning and general cognitive performance disappeared after adjusting for education. The later born cohort showed steeper decline in processing speed. Memory decline was steeper in the earlier born cohort but only from Time 1 to Time 3 when the same memory test was administered. Education did not account for cohort differences in cognitive decline. The later born cohort showed better initial performance in certain cognitive abilities, but no better preservation of cognitive abilities overtime compared with the earlier born cohort. These findings carry implications for healthy cognitive aging. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

  18. Age, period, and cohort effects in motor vehicle mortality in the United States, 1980-2010: the role of sex, alcohol involvement, and position in vehicle.

    Science.gov (United States)

    Macinko, James; Silver, Diana; Bae, Jin Yung

    2015-02-01

    Although substantive declines in motor vehicle fatalities in 1980-2010 have been observed, declines by position in the vehicle and alcohol involvement have not been well elucidated. Analyses of FARS data use the Intrinsic Estimator (IE) to produce estimates of all age, period, and cohort effects simultaneously by position in the car and by alcohol involvement. Declines in MVC deaths by position in the car vary for men and women by age and cohort over time. Cohorts born before 1970 had higher risks than those born later. Analyses using proxy indicators of alcohol involvement found the highest risks for those aged 16-24. By period, these risks declined more rapidly than non- alcohol related traffic fatalities. Changes in risk patterns are consistent with evidence regarding the contributions of new technologies and public policy efforts to reduce fatalities, but gains have not been shared evenly by sex or position in the car. Greater attention is needed in reducing deaths among older drivers and pedestrians. Gender differences should be addressed in prevention efforts aimed at reducing MVCs due to alcohol involvement. Copyright © 2014 Elsevier Ltd and National Safety Council. All rights reserved.

  19. Periodicity in Age-Resolved Populations

    Science.gov (United States)

    Esipov, Sergei

    We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.

  20. Economic Stressors and Psychological Distress: Exploring Age Cohort Variation in the Wake of the Great Recession.

    Science.gov (United States)

    Brown, Robyn Lewis; Richman, Judith A; Rospenda, Kathleen M

    2017-08-01

    This study examined processes linking age cohort, economic stressors, coping strategies and two indicators of psychological distress (i.e. depressive symptoms and anxiety symptoms). Structural equation models were conducted utilizing data from a national survey that was undertaken in order to understand life change consequences of the period of economic downturn from 2007 to 2009 known as the Great Recession. Findings revealed that the associations between economic stressors and symptoms of both depression and anxiety were significantly greater for members of the millennial cohort compared with baby boomers. These effects are partly explained by the greater tendency of members of the baby boomer cohort to use active coping strategies. These findings clarify the circumstances in which age matters most for the associations among economy-related stressors, coping strategies and psychological well-being. They highlight how difficult economic circumstances influence the availability of coping strategies and, in turn, psychological well-being-and differently for younger and older age cohorts. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Linear spline multilevel models for summarising childhood growth trajectories: A guide to their application using examples from five birth cohorts.

    Science.gov (United States)

    Howe, Laura D; Tilling, Kate; Matijasevich, Alicia; Petherick, Emily S; Santos, Ana Cristina; Fairley, Lesley; Wright, John; Santos, Iná S; Barros, Aluísio Jd; Martin, Richard M; Kramer, Michael S; Bogdanovich, Natalia; Matush, Lidia; Barros, Henrique; Lawlor, Debbie A

    2016-10-01

    Childhood growth is of interest in medical research concerned with determinants and consequences of variation from healthy growth and development. Linear spline multilevel modelling is a useful approach for deriving individual summary measures of growth, which overcomes several data issues (co-linearity of repeat measures, the requirement for all individuals to be measured at the same ages and bias due to missing data). Here, we outline the application of this methodology to model individual trajectories of length/height and weight, drawing on examples from five cohorts from different generations and different geographical regions with varying levels of economic development. We describe the unique features of the data within each cohort that have implications for the application of linear spline multilevel models, for example, differences in the density and inter-individual variation in measurement occasions, and multiple sources of measurement with varying measurement error. After providing example Stata syntax and a suggested workflow for the implementation of linear spline multilevel models, we conclude with a discussion of the advantages and disadvantages of the linear spline approach compared with other growth modelling methods such as fractional polynomials, more complex spline functions and other non-linear models. © The Author(s) 2013.

  2. The bystander effect model of Brenner and Sachs fitted to lung cancer data in 11 cohorts of underground miners, and equivalence of fit of a linear relative risk model with adjustment for attained age and age at exposure

    International Nuclear Information System (INIS)

    Little, M P

    2004-01-01

    Bystander effects following exposure to α-particles have been observed in many experimental systems, and imply that linearly extrapolating low dose risks from high dose data might materially underestimate risk. Brenner and Sachs (2002 Int. J. Radiat. Biol. 78 593-604; 2003 Health Phys. 85 103-8) have recently proposed a model of the bystander effect which they use to explain the inverse dose rate effect observed for lung cancer in underground miners exposed to radon daughters. In this paper we fit the model of the bystander effect proposed by Brenner and Sachs to 11 cohorts of underground miners, taking account of the covariance structure of the data and the period of latency between the development of the first pre-malignant cell and clinically overt cancer. We also fitted a simple linear relative risk model, with adjustment for age at exposure and attained age. The methods that we use for fitting both models are different from those used by Brenner and Sachs, in particular taking account of the covariance structure, which they did not, and omitting certain unjustifiable adjustments to the miner data. The fit of the original model of Brenner and Sachs (with 0 y period of latency) is generally poor, although it is much improved by assuming a 5 or 6 y period of latency from the first appearance of a pre-malignant cell to cancer. The fit of this latter model is equivalent to that of a linear relative risk model with adjustment for age at exposure and attained age. In particular, both models are capable of describing the observed inverse dose rate effect in this data set

  3. Trends in breast, ovarian and cervical cancer incidence in Mumbai, India over a 30-year period, 1976–2005: an age–period–cohort analysis

    Science.gov (United States)

    Dhillon, P K; Yeole, B B; Dikshit, R; Kurkure, A P; Bray, F

    2011-01-01

    Background: Demographic, socioeconomic and cultural changes in India have increased longevity, delayed childbearing, decreased parity and resulted in a more westernised lifestyle, contributing to the increasing burden of cancer, especially among women. Methods: We evaluated secular changes in the incidence of breast, cervical and ovarian cancer in Mumbai women aged 30–64 between 1976 and 2005. Age-standardised incidence rates were calculated and presented by site and calendar period. An age–period–cohort (APC) analysis quantified recent time trends and the significance of birth cohort and calendar period effects. The estimated annual percent change (EAPC) was obtained from the drift parameter, expressing the linear time trend common to both calendar period and birth cohort. Results: Over the 30-year study period, the age-standardised rates significantly increased for breast cancer (EAPC: 1.1% (95% confidence interval (CI): 1.0, 1.3)), significantly decreased for cervical cancer (EAPC: −1.8% (95% CI: −2.0, −1.6)) and there was no statistically significant change for ovarian cancer (EAPC: 0.3% (95% CI: −0.1, 0.6)). For breast and cervical cancer, the best-fitting model was the APC model. Conclusions: The rates of breast, cervical and ovarian cancer remain low in comparison with western countries, and the divergent trends of breast (increasing) and cervical cancer (decreasing) in Mumbai were similar to those observed in several other Asian countries. The changing risk profile in successive generations – improved education, higher socioeconomic status, later age at marriage and at first child, and lower parity – may in combination partially explain the diverging generational changes in breast and cervical cancer in Mumbai in the last decades. PMID:21829198

  4. Influence of birth cohort on age of onset cluster analysis in bipolar I disorder

    DEFF Research Database (Denmark)

    Bauer, M; Glenn, T; Alda, M

    2015-01-01

    Purpose: Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset...... cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared. Results: There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After...... on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more...

  5. COHORT EFFECTS OF SUICIDE MORTALITY ARE SEX SPECIFIC IN THE RAPIDLY DEVELOPED HONG KONG CHINESE POPULATION, 1976-2010.

    Science.gov (United States)

    Chung, Roger Y; Yip, Benjamin H K; Chan, Sandra S M; Wong, Samuel Y S

    2016-06-01

    To examine temporal variations of age, period, and cohort on suicide mortality rate in Hong Kong (HK) from 1976 to 2010, and speculate the macroenvironmental mechanisms of the observed trends. Poisson age-period-cohort modeling was used to delineate the effects of age, period, and cohort on suicide mortality. Analysis by sex was also conducted to examine if gender difference exists for suicidal behaviours. Age-cohort model provides the best fit to the mortality data, implying that the cohort effect is likely to explain more of the contributions to HK's suicide mortality pattern than the period effect. Risk of suicide mortality increases nonlinearly with age and accelerates after age 65-69 for both sexes. Moreover, the cohort effects differ between the sexes-risk of mortality increases continually for men born after 1961, but no change is observed for women since the 1941 cohort. With increased risk of suicide mortality in younger cohorts and the age effect of suicide mortality, we may see future increase in suicide mortality as these younger cohorts age. Further studies are needed to clarify plausible associations between broader sociohistorical changes in the population impacting psychological risk factors and suicidal behaviour to better inform suicide prevention strategies. © 2015 Wiley Periodicals, Inc.

  6. Uneven transitions: Period- and cohort-related changes in gender attitudes in China, 1995-2007.

    Science.gov (United States)

    Shu, Xiaoling; Zhu, Yifei

    2012-09-01

    This paper analyzes temporal variations in two gender attitudes in China: beliefs about gender equality and perspectives on women's combined work and family roles. It uses the most currently available population series from the 1995, 2001 and 2007 World Value Surveys of 4500 respondents and a series of multilevel cross-classified models to properly estimate period and cohort effects. Attitudes toward women's dual roles manifest neither period nor cohort effects; the population displays a universal high level of acceptance of women's paid employment. Orientations toward gender equality manifest both cohort and period effects: members of the youngest cohort of both sexes hold the most liberal attitudes; the positive effect of college education has increased over time. Attitude toward gender equality in China displays neither a shift toward conservatism nor an over-time trend toward egalitarianism in 1995-2007, a time of rapid economic growth. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Cohort profile: the lidA Cohort Study-a German Cohort Study on Work, Age, Health and Work Participation.

    Science.gov (United States)

    Hasselhorn, Hans Martin; Peter, Richard; Rauch, Angela; Schröder, Helmut; Swart, Enno; Bender, Stefan; du Prel, Jean-Baptist; Ebener, Melanie; March, Stefanie; Trappmann, Mark; Steinwede, Jacob; Müller, Bernd Hans

    2014-12-01

    The lidA Cohort Study (German Cohort Study on Work, Age, Health and Work Participation) was set up to investigate and follow the effects of work and work context on the physical and psychological health of the ageing workforce in Germany and subsequently on work participation. Cohort participants are initially employed people subject to social security contributions and born in either 1959 (n = 2909) or 1965 (n = 3676). They were personally interviewed in their homes in 2011 and will be visited every 3 years. Data collection comprises socio-demographic data, work and private exposures, work ability, work and work participation attitudes, health, health-related behaviour, personality and attitudinal indicators. Employment biographies are assessed using register data. Subjective health reports and physical strength measures are complemented by health insurance claims data, where permission was given. A conceptual framework has been developed for the lidA Cohort Study within which three confirmatory sub-models assess the interdependencies of work and health considering age, gender and socioeconomic status. The first set of the data will be available to the scientific community by 2015. Access will be given by the Research Data Centre of the German Federal Employment Agency at the Institute for Employment Research (http://fdz.iab.de/en.aspx). © The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.

  8. Cohort difference in age-related trajectories in network size in old age: are networks expanding?

    NARCIS (Netherlands)

    Suanet, B.; Huxhold, O.

    2018-01-01

    Objectives. Contemporary societal views on old age as well as a rise in retirement age raise the question whether patterns of stability and/or decline in network size as found in earlier studies similarly apply to later birth cohorts of older adults. Methods. Change score models are estimated to

  9. Multistate cohort models with proportional transfer rates

    DEFF Research Database (Denmark)

    Schoen, Robert; Canudas-Romo, Vladimir

    2006-01-01

    of transfer rates. The two living state case and hierarchical multistate models with any number of living states are analyzed in detail. Applying our approach to 1997 U.S. fertility data, we find that observed rates of parity progression are roughly proportional over age. Our proportional transfer rate...... approach provides trajectories by parity state and facilitates analyses of the implications of changes in parity rate levels and patterns. More women complete childbearing at parity 2 than at any other parity, and parity 2 would be the modal parity in models with total fertility rates (TFRs) of 1.40 to 2......We present a new, broadly applicable approach to summarizing the behavior of a cohort as it moves through a variety of statuses (or states). The approach is based on the assumption that all rates of transfer maintain a constant ratio to one another over age. We present closed-form expressions...

  10. The Lothian Birth Cohort 1936: a study to examine influences on cognitive ageing from age 11 to age 70 and beyond

    Directory of Open Access Journals (Sweden)

    Whalley Lawrence J

    2007-12-01

    Full Text Available Abstract Background Cognitive ageing is a major burden for society and a major influence in lowering people's independence and quality of life. It is the most feared aspect of ageing. There are large individual differences in age-related cognitive changes. Seeking the determinants of cognitive ageing is a research priority. A limitation of many studies is the lack of a sufficiently long period between cognitive assessments to examine determinants. Here, the aim is to examine influences on cognitive ageing between childhood and old age. Methods/Design The study is designed as a follow-up cohort study. The participants comprise surviving members of the Scottish Mental Survey of 1947 (SMS1947; N = 70,805 who reside in the Edinburgh area (Lothian of Scotland. The SMS1947 applied a valid test of general intelligence to all children born in 1936 and attending Scottish schools in June 1947. A total of 1091 participants make up the Lothian Birth Cohort 1936. They undertook: a medical interview and examination; physical fitness testing; extensive cognitive testing (reasoning, memory, speed of information processing, and executive function; personality, quality of life and other psycho-social questionnaires; and a food frequency questionnaire. They have taken the same mental ability test (the Moray House Test No. 12 at age 11 and age 70. They provided blood samples for DNA extraction and testing and other biomarker analyses. Here we describe the background and aims of the study, the recruitment procedures and details of numbers tested, and the details of all examinations. Discussion The principal strength of this cohort is the rarely captured phenotype of lifetime cognitive change. There is additional rich information to examine the determinants of individual differences in this lifetime cognitive change. This protocol report is important in alerting other researchers to the data available in the cohort.

  11. Degradation modeling with application to aging and maintenance effectiveness evaluations

    International Nuclear Information System (INIS)

    Samanta, P.K.; Hsu, F.; Subduhi, M.; Vesely, W.E.

    1990-01-01

    This paper describes a modeling approach to analyze component degradation and failure data to understand the aging process of components. As used here, degradation modeling is the analysis of information on component degradation in order to develop models of the process and its implications. This particular modeling focuses on the analysis of the times of component degradations, to model how the rate of degradation changes with the age of the component. The methodology presented also discusses the effectiveness of maintenance as applicable to aging evaluations. The specific applications which are performed show quantitative models of component degradation rates and component failure rates from plant-specific data. The statistical techniques which are developed and applied allow aging trends to be effectively identified in the degradation data, and in the failure data. Initial estimates of the effectiveness of maintenance in limiting degradations from becoming failures also are developed. These results are important first steps in degradation modeling, and show that degradation can be modeled to identify aging trends. 2 refs., 8 figs

  12. Degradation modeling with application to aging and maintenance effectiveness evaluations

    International Nuclear Information System (INIS)

    Samanta, P.K.; Vesely, W.E.; Hsu, F.; Subudhi, M.

    1991-01-01

    This paper describes a modeling approach to analyze light water reactor component degradation and failure data to understand the aging process of components. As used here, degradation modeling is the analysis of information on component degradation in order to develop models of the process and its implications. This particular modeling focuses on the analysis of the times of component degradations, to model how the rate of degradation changes with the age of the component. The methodology presented also discusses the effectiveness of maintenance as applicable to aging evaluations. The specific applications which are performed show quantitative models of component degradation rates and component failure rates from plant-specific data. The statistical techniques which are developed and applied allow aging trends to be effectively identified in the degradation data, and in the failure data. Initial estimates of the effectiveness of maintenance in limiting degradations from becoming failures also are developed. These results are important first steps in degradation modeling, and show that degradation can be modeled to identify aging trends

  13. The role of under-employment and unemployment in recent birth cohort effects in Australian suicide.

    Science.gov (United States)

    Page, Andrew; Milner, Allison; Morrell, Stephen; Taylor, Richard

    2013-09-01

    High suicide rates evident in Australian young adults during an epidemic period in the 1990s appear to have been sustained in older age-groups in the subsequent decade. This period also coincides with changes in employment patterns in Australia. This study investigates age, period, and birth cohort effects in Australian suicide over the 20th century, with particular reference to the period subsequent to the 1990s youth suicide epidemic in young males. Period- and cohort-specific trends in suicide were examined for 1907-2010 based on descriptive analysis of age-specific suicide rates and a series of age-period-cohort (APC) models using Poisson regression. Under-employment rates (those employed part-time seeking additional hours of work) and unemployment rates (those currently seeking employment) for the latter part of this time series (1978-2010) were also examined and compared with period- and cohort-specific trends in suicide. A significant increasing birth cohort effect in male suicide rates was evident in birth cohorts born after 1970-74, after adjusting for the effects age and period. An increasing birth cohort effect was also evident in female suicide rates, but was of a lesser magnitude. Increases in male cohort-specific suicide rates were significantly correlated with increases in cohort-specific under-employment and unemployment rates. Birth cohorts that experienced the peak of the suicide epidemic during the 1990s have continued to have higher suicide rates than cohorts born in earlier epochs. This increase coincides with changes to a labour force characterised by greater 'flexibility' and 'casualised' employment, especially in younger aged cohorts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Changes in the use practitioner-based complementary and alternative medicine over time in Canada: Cohort and period effects.

    Directory of Open Access Journals (Sweden)

    Mayilee Canizares

    Full Text Available The use of complementary and alternative medicine (CAM is growing. However the factors contributing to changes over time and to birth cohort differences in CAM use are not well understood.We used data from 10186 participants, who were aged 20-69 years at the first cycle of data collection in the longitudinal component of the Canadian National Population Health Survey (1994/95-2010/11. We examined chiropractic and other practitioner-based CAM use with a focus on five birth cohorts: pre-World War II (born 1925-1934; World War II (born 1935-1944; older baby boomers (born 1945-1954; younger baby boomers (born 1955-1964; and Gen Xers (born 1965-1974. The survey collected data every two years on predisposing (e.g., sex, education, enabling (e.g., income, behavior-related factors (e.g., obesity, need (e.g., chronic conditions, and use of conventional care (primary care and specialists.The findings suggest that, at corresponding ages, more recent cohorts reported greater CAM (OR = 25.9, 95% CI: 20.0; 33.6 for Gen Xers vs. pre-World War and chiropractic use than their predecessors (OR = 2.2, 95% CI: 1.7; 2.8 for Gen Xers vs. pre-World War. There was also a secular trend of increasing CAM use, but not chiropractic use, over time (period effect across all ages. Factors associated with cohort differences were different for CAM and chiropractic use. Cohort differences in CAM use were partially related to a period effect of increasing CAM use over time across all ages while cohort differences in chiropractic use were related to the higher prevalence of chronic conditions among recent cohorts. The use of conventional care was positively related to greater CAM use (OR = 1.8, 95% CI: 1.6; 2.0 and chiropractic use (OR = 1.2, 95% CI: 1.1; 1.4 but did not contribute to changes over time or to cohort differences in CAM and chiropractic use.The higher CAM use over time and in recent cohorts could reflect how recent generations are approaching their healthcare needs

  15. Significant calendar period deviations in testicular germ cell tumors indicate that postnatal exposures are etiologically relevant.

    Science.gov (United States)

    Speaks, Crystal; McGlynn, Katherine A; Cook, Michael B

    2012-10-01

    The current working model of type II testicular germ cell tumor (TGCT) pathogenesis states that carcinoma in situ arises during embryogenesis, is a necessary precursor, and always progresses to cancer. An implicit condition of this model is that only in utero exposures affect the development of TGCT in later life. In an age-period-cohort analysis, this working model contends an absence of calendar period deviations. We tested this contention using data from the SEER registries of the United States. We assessed age-period-cohort models of TGCTs, seminomas, and nonseminomas for the period 1973-2008. Analyses were restricted to whites diagnosed at ages 15-74 years. We tested whether calendar period deviations were significant in TGCT incidence trends adjusted for age deviations and cohort effects. This analysis included 32,250 TGCTs (18,475 seminomas and 13,775 nonseminomas). Seminoma incidence trends have increased with an average annual percentage change in log-linear rates (net drift) of 1.25 %, relative to just 0.14 % for nonseminoma. In more recent time periods, TGCT incidence trends have plateaued and then undergone a slight decrease. Calendar period deviations were highly statistically significant in models of TGCT (p = 1.24(-9)) and seminoma (p = 3.99(-14)), after adjustment for age deviations and cohort effects; results for nonseminoma (p = 0.02) indicated that the effects of calendar period were much more muted. Calendar period deviations play a significant role in incidence trends of TGCT, which indicates that postnatal exposures are etiologically relevant.

  16. Age, Cohort and Co-Authorship

    OpenAIRE

    Hamermesh, Daniel S.

    2015-01-01

    The previously documented trend toward more co- and multi-authored research in economics is partly (perhaps 20 percent) due to different research styles of scholars in different birth cohorts (of different ages). Most of the trend reflects profession-wide changes in research style. Older scholars show greater variation in their research styles than younger ones, who use similar numbers of co-authors in each published paper; but there are no differences across cohorts in scholars’ willingness ...

  17. Seventy Years of Asthma in Italy: Age, Period and Cohort Effects on Incidence and Remission of Self-Reported Asthma from 1940 to 2010.

    Directory of Open Access Journals (Sweden)

    Giancarlo Pesce

    Full Text Available It is well known that asthma prevalence has been increasing all over the world in the last decades. However, few data are available on temporal trends of incidence and remission of asthma.To evaluate the rates of asthma incidence and remission in Italy from 1940 to 2010.The subjects were randomly sampled from the general Italian population between 1991 and 2010 in the three population-based multicentre studies: ECRHS, ISAYA, and GEIRD. Individual information on the history of asthma (age at onset, age at the last attack, use of drugs for asthma control, co-presence of hay-fever was collected on 35,495 subjects aged 20-84 and born between 1925-1989. Temporal changes in rates of asthma incidence and remission in relation to age, birth cohort and calendar period (APC were modelled using Poisson regression and APC models.The average yearly rate of asthma incidence was 2.6/1000 (3,297 new cases among 1,263,885 person-years. The incidence rates have been linearly increasing, with a percentage increase of +3.9% (95%CI: 3.1-4.5, from 1940 up to the year 1995, when the rates begun to level off. The stabilization of asthma incidence was mainly due to a decrease in the rates of atopic asthma after 1995, while non-atopic asthma has continued to increase. The overall rate of remission was 43.2/1000person-years, and it did not vary significantly across generations, but was associated with atopy, age at asthma onset and duration of the disease.After 50 years of a continuous upward trend, the rates of asthma incidence underwent a substantial stabilization in the late 90s. Despite remarkable improvements in the treatment of asthma, the rate of remission did not change significantly in the last seventy years. Some caveats are required in interpreting our results, given that our estimates are based on self-reported events that could be affected by the recall bias.

  18. A Practical Model for Forecasting New Freshman Enrollment during the Application Period.

    Science.gov (United States)

    Paulsen, Michael B.

    1989-01-01

    A simple and effective model for forecasting freshman enrollment during the application period is presented step by step. The model requires minimal and readily available information, uses a simple linear regression analysis on a personal computer, and provides updated monthly forecasts. (MSE)

  19. Persistent Organic Pollutants in Norwegian Men from 1979 to 2007: Intraindividual Changes, Age–Period–Cohort Effects, and Model Predictions

    Science.gov (United States)

    Breivik, Knut; Fuskevåg, Ole-Martin; Nieboer, Evert; Odland, Jon Øyvind; Sandanger, Torkjel Manning

    2013-01-01

    Background: Longitudinal monitoring studies of persistent organic pollutants (POPs) in human populations are important to better understand changes with time and age, and for future predictions. Objectives: We sought to describe serum POP time trends on an individual level, investigate age–period–cohort effects, and compare predicted polychlorinated biphenyl (PCB) concentrations to measured values. Methods: Serum was sampled in 1979, 1986, 1994, 2001, and 2007 from a cohort of 53 men in Northern Norway and analyzed for 41 POPs. Time period, age, and birth cohort effects were assessed by graphical analyses and mixed-effect models. We derived the predicted concentrations of four PCBs for each sampling year using the CoZMoMAN model. Results: The median decreases in summed serum POP concentrations (lipid-adjusted) in 1986, 1994, 2001, and 2007 relative to 1979 were –22%, –52%, –54%, and –68%, respectively. We observed substantial declines in all POP groups with the exception of chlordanes. Time period (reflected by sampling year) was the strongest descriptor of changes in PCB-153 concentrations. Predicted PCB-153 concentrations were consistent with measured concentrations in the study population. Conclusions: Our results suggest substantial intraindividual declines in serum concentrations of legacy POPs from 1979 to 2007 in men from Northern Norway. These changes are consistent with reduced environmental exposure during these 30 years and highlight the relation between historic emissions and POP concentrations measured in humans. Observed data and interpretations are supported by estimates from the CoZMoMAN emission-based model. A longitudinal decrease in concentrations with age was evident for all birth cohorts. Overall, our findings support the relevance of age–period–cohort effects to human biomonitoring of environmental contaminants. Citation: Nøst TH, Breivik K, Fuskevåg OM, Nieboer E, Odland JØ, Sandanger TM. 2013. Persistent organic pollutants

  20. Trends in colorectal cancer incidence: a period and birth-cohort analysis in a well-defined French population.

    Science.gov (United States)

    Chauvenet, Marion; Cottet, Vanessa; Lepage, Côme; Jooste, Valérie; Faivre, Jean; Bouvier, Anne-Marie

    2011-06-30

    France stands among high-risk areas for colorectal cancer. Different trends in CRC incidence are reported around the world. The aim of this study was to provide temporal trends in CRC incidence over a 30-year period in a French well-defined population. Between 1976 and 2005, 17,028 new cases were registered by the Burgundy digestive cancer registry. The mean variations in age-standardized incidence rates were estimated using a Poisson regression adjusted for age for each gender and location. The cumulative risk by birth cohort of developing a cancer over the age range 0-74 years was estimated using an age-cohort model. Incidence rates for right and left colon cancers increased more rapidly in males (respectively +11.7% and +10.3% on average by 5-year period) than in females (respectively +5.9% and +6.1%). It remained stable for sigmoid cancers in males (-0.1%) and decreased in females (-5.2%). It also decreased for rectal cancers both in males (-2.7%) and in females (-2.0%). The cumulative risk increased from 3.9% for males born around 1900 to 4.9% for those born around 1930 and then slightly decreased (4.5% among those born around 1950). It remained at the same level for females born around 1900 (2.7%) as for those born around 1930 (2.7%) and then slightly increased (2.9%) for those born around 1950. For right colon cancers, the cumulative risk increased strikingly in successive birth cohorts from 0.53% to 1.2% in males and 0.55% to 0.77% in females. The corresponding cumulative risks for the left colon were 0.24% and 0.42% in males and 0.14% and 0.29% in females. For sigmoid cancer, they decreased from 1.59% to 1.08% in males, and 0.88% to 0.80% in females. Temporal variations in incidence rates of colorectal cancers differed according to subsite, suggesting different aetiological factors and implications for diagnosis and screening strategies. Total colonoscopy must be the preferred strategy in high-risk groups or after a positive faecal occult blood test.

  1. Trends in colorectal cancer incidence: a period and birth-cohort analysis in a well-defined French population

    Directory of Open Access Journals (Sweden)

    Faivre Jean

    2011-06-01

    Full Text Available Abstract Background France stands among high-risk areas for colorectal cancer. Different trends in CRC incidence are reported around the world. The aim of this study was to provide temporal trends in CRC incidence over a 30-year period in a French well-defined population. Methods Between 1976 and 2005, 17,028 new cases were registered by the Burgundy digestive cancer registry. The mean variations in age-standardized incidence rates were estimated using a Poisson regression adjusted for age for each gender and location. The cumulative risk by birth cohort of developing a cancer over the age range 0-74 years was estimated using an age-cohort model. Results Incidence rates for right and left colon cancers increased more rapidly in males (respectively +11.7% and +10.3% on average by 5-year period than in females (respectively +5.9% and +6.1%. It remained stable for sigmoid cancers in males (-0.1% and decreased in females (-5.2%. It also decreased for rectal cancers both in males (-2.7% and in females (-2.0%. The cumulative risk increased from 3.9% for males born around 1900 to 4.9% for those born around 1930 and then slightly decreased (4.5% among those born around 1950. It remained at the same level for females born around 1900 (2.7% as for those born around 1930 (2.7% and then slightly increased (2.9% for those born around 1950. For right colon cancers, the cumulative risk increased strikingly in successive birth cohorts from 0.53% to 1.2% in males and 0.55% to 0.77% in females. The corresponding cumulative risks for the left colon were 0.24% and 0.42% in males and 0.14% and 0.29% in females. For sigmoid cancer, they decreased from 1.59% to 1.08% in males, and 0.88% to 0.80% in females. Conclusion Temporal variations in incidence rates of colorectal cancers differed according to subsite, suggesting different aetiological factors and implications for diagnosis and screening strategies. Total colonoscopy must be the preferred strategy in high

  2. Age Effects and Temporal Trends in HPV-Related and HPV-Unrelated Oral Cancer in the United States: A Multistage Carcinogenesis Modeling Analysis.

    Directory of Open Access Journals (Sweden)

    Andrew F Brouwer

    Full Text Available Differences in prognosis in HPV-positive and HPV-negative oral (oropharyngeal and oral cavity squamous cell carcinomas (OSCCs and increasing incidence of HPV-related cancers have spurred interest in demographic and temporal trends in OSCC incidence. We leverage multistage clonal expansion (MSCE models coupled with age-period-cohort (APC epidemiological models to analyze OSCC data in the SEER cancer registry (1973-2012. MSCE models are based on the initiation-promotion-malignant conversion paradigm in carcinogenesis and allow for interpretation of trends in terms of biological mechanisms. APC models seek to differentiate between the temporal effects of age, period, and birth cohort on cancer risk. Previous studies have looked at the effect of period and cohort on tumor initiation, and we extend this to compare model fits of period and cohort effects on each of tumor initiation, promotion, and malignant conversion rates. HPV-related, HPV-unrelated except oral tongue, and HPV-unrelated oral tongue sites are best described by placing period and cohort effects on the initiation rate. HPV-related and non-oral-tongue HPV-unrelated cancers have similar promotion rates, suggesting similar tumorigenesis dynamics once initiated. Estimates of promotion rates at oral tongue sites are lower, corresponding to a longer sojourn time; this finding is consistent with the hypothesis of an etiology distinct from HPV or alcohol and tobacco use. Finally, for the three subsite groups, men have higher initiation rates than women of the same race, and black people have higher promotion than white people of the same sex. These differences explain part of the racial and sex differences in OSCC incidence.

  3. Analyzing age-specific genetic effects on human extreme age survival in cohort-based longitudinal studies

    DEFF Research Database (Denmark)

    Tan, Qihua; Jacobsen, Rune; Sørensen, Mette

    2013-01-01

    The analysis of age-specific genetic effects on human survival over extreme ages is confronted with a deceleration pattern in mortality that deviates from traditional survival models and sparse genetic data available. As human late life is a distinct phase of life history, exploring the genetic...... effects on extreme age survival can be of special interest to evolutionary biology and health science. We introduce a non-parametric survival analysis approach that combines population survival information with individual genotype data in assessing the genetic effects in cohort-based longitudinal studies...

  4. An application of the 'Bayesian cohort model' to nuclear power plant cost analyses

    International Nuclear Information System (INIS)

    Ono, Kenji; Nakamura, Takashi

    2002-01-01

    We have developed a new method for identifying the effects of calendar year, plant age and commercial operation starting year on the costs and performances of nuclear power plants and also developed an analysis system running on personal computers. The method extends the Bayesian cohort model for time series social survey data proposed by one of the authors. The proposed method was shown to be able to separate the above three effects more properly than traditional methods such as taking simple means by time domain. The analyses of US nuclear plant cost and performance data by using the proposed method suggest that many of the US plants spent relatively long time and much capital cost for modification at their age of about 10 to 20 years, but that, after those ages, they performed fairly well with lower and stabilized O and M and additional capital costs. (author)

  5. Geography of breast cancer incidence according to age & birth cohorts.

    Science.gov (United States)

    Gregorio, David I; Ford, Chandler; Samociuk, Holly

    2017-06-01

    Geographic variation in breast cancer incidence across Connecticut was examined according to age and birth cohort -specific groups. We assigned each of 60,937 incident breast cancer cases diagnosed in Connecticut, 1986-2009, to one of 828 census tracts around the state. Global and local spatial statistics estimated rate variation across the state according to age and birth cohorts. We found the global distribution of incidence rates across places to be more heterogeneous for younger women and later birth cohorts. Concurrently, the spatial scan identified more locations with significantly high rates that pertained to larger proportions of at-risk women within these groups. Geographic variation by age groups was more pronounced than by birth cohorts. Geographic patterns of cancer incidence exhibit differences within and across age and birth cohorts. With the continued insights from descriptive epidemiology, our capacity to effectively limit spatial disparities in cancer will improve. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. How does socioeconomic development affect COPD mortality? An age-period-cohort analysis from a recently transitioned population in China.

    Directory of Open Access Journals (Sweden)

    Jing Chen

    Full Text Available BACKGROUND: Chronic obstructive pulmonary disease (COPD is a leading cause of death, particularly in developing countries. Little is known about the effects of economic development on COPD mortality, although economic development may potentially have positive and negative influences over the life course on COPD. We took advantage of a unique population whose rapid and recent economic development is marked by changes at clearly delineated and identifiable time points, and where few women smoke, to examine the effect of macro-level events on COPD mortality. METHODS: We used Poisson regression to decompose sex-specific COPD mortality rates in Hong Kong from 1981 to 2005 into the effects of age, period and cohort. RESULTS: COPD mortality declined strongly over generations for people born from the early to mid 20th century, which was particularly evident for the first generation to grow up in a more economically developed environment for both sexes. Population wide COPD mortality decreased when air quality improved and increased with increasing air pollution. COPD mortality increased with age, particularly after menopause among women. CONCLUSIONS: Economic development may reduce vulnerability to COPD by reducing long-lasting insults to the respiratory system, such as infections, poor nutrition and indoor air pollution. However, some of these gains may be offset if economic development results in increasing air pollution or increasing smoking.

  7. Trends in Dementia Incidence in a Birth Cohort Analysis of the Einstein Aging Study.

    Science.gov (United States)

    Derby, Carol A; Katz, Mindy J; Lipton, Richard B; Hall, Charles B

    2017-11-01

    Trends in dementia incidence rates have important implications for planning and prevention. To better understand incidence trends over time requires separation of age and cohort effects, and few prior studies have used this approach. To examine trends in dementia incidence and concomitant trends in cardiovascular comorbidities among individuals aged 70 years or older who were enrolled in the Einstein Aging Study between 1993 and 2015. In this birth cohort analysis of all-cause dementia incidence in persons enrolled in the Einstein Aging Study from October 20, 1993, through November 17, 2015, a systematically recruited, population-based sample of 1348 participants from Bronx County, New York, who were 70 years or older without dementia at enrollment and at least one annual follow-up was studied. Poisson regression was used to model dementia incidence as a function of age, sex, educational level, race, and birth cohort, with profile likelihood used to identify the timing of significant increases or decreases in incidence. Birth year and age. Incident dementia defined by consensus case conference based on annual, standardized neuropsychological and neurologic examination findings, using criteria from the DSM-IV. Among 1348 individuals (mean [SD] baseline age, 78.5 [5.4] years; 830 [61.6%] female; 915 [67.9%] non-Hispanic white), 150 incident dementia cases developed during 5932 person-years (mean [SD] follow-up, 4.4 [3.4] years). Dementia incidence decreased in successive birth cohorts. Incidence per 100 person-years was 5.09 in birth cohorts before 1920, 3.11 in the 1920 through 1924 birth cohorts, 1.73 in the 1925 through 1929 birth cohorts, and 0.23 in cohorts born after 1929. Change point analyses identified a significant decrease in dementia incidence among those born after July 1929 (95% CI, June 1929 to January 1930). The relative rate for birth cohorts before July 1929 vs after was 0.13 (95% CI, 0.04-0.41). Prevalence of stroke and myocardial infarction

  8. Are baby boomer women unique? The moderating effect of birth cohort on age in substance use patterns during midlife.

    Science.gov (United States)

    Sarabia, Stephanie Elias; Martin, James I

    2016-01-01

    This study examined the relationships of age to use of alcohol, marijuana, and illicit drugs, and misuse of prescription drugs, among midlife women and whether these relationships are modified by birth cohort. Structural Equation Modeling was used to analyze National Survey on Drug Use and Health data, which included 2,035 baby boomer and silent generation cohort women, ages 30 to 55. Midlife women across cohorts reduced alcohol and marijuana use, but not illicit and prescription drug misuse, as they aged. A modifying effect of birth cohort was not supported, but findings did support differential aging effects across substances. Implications are discussed.

  9. The Relationship between Health and Community across Aging Cohorts

    Directory of Open Access Journals (Sweden)

    Julie Norstrand

    2014-01-01

    Full Text Available Research is needed to examine the connection between older adults and their community as they age. This is important as increasing numbers of older adults wish to age in place. Regression models were examined across 3 cohorts testing relationships among social capital indicators (neighborhood trust, neighborhood support, neighborhood cohesion, neighborhood participation, and telephone interaction with health outcomes (self-rated health, activities of daily living (ADL, and instrumental activities of daily living (IADL. Results showed that most social capital indicators remained significant for all health outcomes into very old age. Development of tools for individual and community interventions to ensure optimal fit between the aging individual and their environment is discussed, along with recommendations for enhancing social work theory and practice.

  10. Confirming the cognition of rising scores: Fox and Mitchum (2013) predicts violations of measurement invariance in series completion between age-matched cohorts.

    Science.gov (United States)

    Fox, Mark C; Mitchum, Ainsley L

    2014-01-01

    The trend of rising scores on intelligence tests raises important questions about the comparability of variation within and between time periods. Descriptions of the processes that mediate selection of item responses provide meaningful psychological criteria upon which to base such comparisons. In a recent paper, Fox and Mitchum presented and tested a cognitive theory of rising scores on analogical and inductive reasoning tests that is specific enough to make novel predictions about cohort differences in patterns of item responses for tests such as the Raven's Matrices. In this paper we extend the same proposal in two important ways by (1) testing it against a dataset that enables the effects of cohort to be isolated from those of age, and (2) applying it to two other inductive reasoning tests that exhibit large Flynn effects: Letter Series and Word Series. Following specification and testing of a confirmatory item response model, predicted violations of measurement invariance are observed between two age-matched cohorts that are separated by only 20 years, as members of the later cohort are found to map objects at higher levels of abstraction than members of the earlier cohort who possess the same overall level of ability. Results have implications for the Flynn effect and cognitive aging while underscoring the value of establishing psychological criteria for equating members of distinct groups who achieve the same scores.

  11. Confirming the cognition of rising scores: Fox and Mitchum (2013 predicts violations of measurement invariance in series completion between age-matched cohorts.

    Directory of Open Access Journals (Sweden)

    Mark C Fox

    Full Text Available The trend of rising scores on intelligence tests raises important questions about the comparability of variation within and between time periods. Descriptions of the processes that mediate selection of item responses provide meaningful psychological criteria upon which to base such comparisons. In a recent paper, Fox and Mitchum presented and tested a cognitive theory of rising scores on analogical and inductive reasoning tests that is specific enough to make novel predictions about cohort differences in patterns of item responses for tests such as the Raven's Matrices. In this paper we extend the same proposal in two important ways by (1 testing it against a dataset that enables the effects of cohort to be isolated from those of age, and (2 applying it to two other inductive reasoning tests that exhibit large Flynn effects: Letter Series and Word Series. Following specification and testing of a confirmatory item response model, predicted violations of measurement invariance are observed between two age-matched cohorts that are separated by only 20 years, as members of the later cohort are found to map objects at higher levels of abstraction than members of the earlier cohort who possess the same overall level of ability. Results have implications for the Flynn effect and cognitive aging while underscoring the value of establishing psychological criteria for equating members of distinct groups who achieve the same scores.

  12. Cohort-based income gradients in obesity among U.S. adults.

    Science.gov (United States)

    Heo, Jongho; Beck, Audrey N; Lin, Shih-Fan; Marcelli, Enrico; Lindsay, Suzanne; Karl Finch, Brian

    2018-03-01

    No studies have focused on socioeconomic disparities in obesity within and between cohorts. Our objectives were to examine income gradients in obesity between birth-cohorts (inter-cohort variations) and within each birth-cohort (intra-cohort variations) by gender and race/ethnicity. Our sample includes 56,820 white and black adults from pooled, cross-sectional National Health and Nutrition Examination Surveys (1971-2012). We fit a series of logistic hierarchical Age-Period-Cohort models to control for the effects of age and period, simultaneously. Predicted probabilities of obesity by poverty-to-income ratio were estimated and graphed for 5-year cohort groups from 1901-1990. We also stratified this relationship for four gender and racial/ethnic subgroups. Obesity disparities due to income were weaker for post-World War I and II generations, specifically the mid-1920s and the mid-1940s to 1950s cohorts, than for other cohorts. In contrast, we found greater income gradients in obesity among cohorts from the 1930s to mid-1940s and mid-1960s to 1970s. Moreover, obesity disparities due to income across cohorts vary markedly by gender and race/ethnicity. White women with higher income consistently exhibited a lower likelihood of obesity than those with lower income since early 1900s cohorts; whereas, black men with higher income exhibited higher risks of obesity than those with lower income in most cohorts. Our findings suggest that strategies that address race and/or gender inequalities in obesity should be cognizant of significant historical factors that may be unique to cohorts. Period-based approaches that ignore life-course experiences captured in significant cohort-based experiences may limit the utility of policies and interventions. © 2017 Wiley Periodicals, Inc.

  13. Materialism across the lifespan : An age-period-cohort analysis

    NARCIS (Netherlands)

    Jaspers, Esther; Pieters, Rik

    This research examined the development of materialism across the lifespan. Two initial studies revealed that: 1) lay beliefs were that materialism declines with age; and 2) previous research findings also implied a modest, negative relationship between age and materialism. Yet, previous research has

  14. Age-related changes in cortical bone mass: data from a German female cohort

    International Nuclear Information System (INIS)

    Toledo, V.A. Molina; Jergas, M.

    2006-01-01

    To describe data from digital radiogrammetry (DXR) in an unselected German female cohort over a wide age range. Using a retrospective study design we analyzed radiographs of the hand from 540 German women (aged 5-96 years) using an automated assessment of cortical thickness, metacarpal index (MCI), and estimated cortical bone mineral density (DXR-BMD) on digitized radiographs. Both hands were radiographed in 97 women. In this group DXR-BMD and cortical thickness were significantly higher in the right metacarpals while there was no significant difference in MCI. To study the association with age we differentiated young ( 45 years). In young women all parameters increased significantly with age in a linear fashion (r=0.8 for DXR-BMD, r=0.7 for MCI). In those aged 25-45 years DXR-BMD and MCI were highest (peak bone mass). In women aged 45 or older all parameters decreased with age in an almost linear fashion with an annual change ranging from 0.7% to 0.9%. Our results for an unselected German female cohort indicate that DXR is a reliable, widely available osteodensitometric technique based on the refinement of conventional radiogrammetry. These findings are comparable to those from other studies and represent a valid resource for clinical application and for comparisons with other ethnic groups. (orig.)

  15. The period-age relation for cepheids

    International Nuclear Information System (INIS)

    Efremov, Yu.N.

    1978-01-01

    The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

  16. Mothers, places and small for gestational age births: a cohort study.

    Science.gov (United States)

    Sundquist, Jan; Sundquist, Kristina; Johansson, Sven-Erik; Li, Xinjun; Winkleby, Marilyn

    2011-04-01

    This study examines whether neighbourhood deprivation increases the risk of giving birth to a small for gestational age (SGA) infant, after accounting for individual-level maternal socioeconomic characteristics. An open cohort of women, aged 20-44 years, was followed from 1 January 1992 through 31 December 2004 for first singleton births. The women's residential addresses during the two consecutive years preceding the birth of their infants were geocoded and classified into three levels of neighbourhood deprivation. Gestational age was confirmed by ultrasound examinations. Multilevel logistic regression models were used in the statistical analysis. Sweden. During the study period, women gave birth to 720 357 infants, of whom 20 487 (2.8%) were SGA. Age-adjusted incidence rates of SGA births increased with increasing level of neighbourhood deprivation. In the total population, 2.5% of births in the least deprived neighbourhoods and 3.5% of births in the most deprived neighbourhoods were SGA. A similar pattern of higher incidence with increasing level of neighbourhood-level deprivation was observed across all individual-level sociodemographic categories, including maternal age, marital status, family income, educational attainment, employment, mobility and urban/rural status. High neighbourhood-level deprivation remained significantly associated with SGA risk after adjusting for maternal sociodemographic characteristics (OR 1.28, 95% CI 1.22 to 1.34). This study is the largest to date of the influence of neighbourhood on SGA birth, with SGA confirmed by ultrasound examination. Results suggest that the characteristics of a mother's neighbourhood affect the risk of delivering an SGA infant independently of maternal sociodemographic characteristics.

  17. Advanced maternal age and adverse pregnancy outcome: evidence from a large contemporary cohort.

    Directory of Open Access Journals (Sweden)

    Louise C Kenny

    Full Text Available BACKGROUND: Recent decades have witnessed an increase in mean maternal age at childbirth in most high-resourced countries. Advanced maternal age has been associated with several adverse maternal and perinatal outcomes. Although there are many studies on this topic, data from large contemporary population-based cohorts that controls for demographic variables known to influence perinatal outcomes is limited. METHODS: We performed a population-based cohort study using data on all singleton births in 2004-2008 from the North Western Perinatal Survey based at The University of Manchester, UK. We compared pregnancy outcomes in women aged 30-34, 35-39 and ≥40 years with women aged 20-29 years using log-linear binomial regression. Models were adjusted for parity, ethnicity, social deprivation score and body mass index. RESULTS: The final study cohort consisted of 215,344 births; 122,307 mothers (54.19% were aged 20-29 years, 62,371(27.63% were aged 30-34 years, 33,966(15.05% were aged 35-39 years and 7,066(3.13% were aged ≥40 years. Women aged 40+ at delivery were at increased risk of stillbirth (RR = 1.83, [95% CI 1.37-2.43], pre-term (RR = 1.25, [95% CI: 1.14-1.36] and very pre-term birth (RR = 1.29, [95% CI:1.08-1.55], Macrosomia (RR = 1.31, [95% CI: 1.12-1.54], extremely large for gestational age (RR = 1.40, [95% CI: 1.25-1.58] and Caesarean delivery (RR = 1.83, [95% CI: 1.77-1.90]. CONCLUSIONS: Advanced maternal age is associated with a range of adverse pregnancy outcomes. These risks are independent of parity and remain after adjusting for the ameliorating effects of higher socioeconomic status. The data from this large contemporary cohort will be of interest to healthcare providers and women and will facilitate evidence based counselling of older expectant mothers.

  18. Perceived age as clinically useful biomarker of ageing: cohort study

    DEFF Research Database (Denmark)

    Christensen, Kaare; Thinggaard, Mikael; McGue, Matt

    2009-01-01

    OBJECTIVE: To determine whether perceived age correlates with survival and important age related phenotypes. DESIGN: Follow-up study, with survival of twins determined up to January 2008, by which time 675 (37%) had died. SETTING: Population based twin cohort in Denmark. PARTICIPANTS: 20 nurses, 10...... young men, and 11 older women (assessors); 1826 twins aged >or=70. MAIN OUTCOME MEASURES: Assessors: perceived age of twins from photographs. Twins: physical and cognitive tests and molecular biomarker of ageing (leucocyte telomere length). RESULTS: For all three groups of assessors, perceived age...... increased with increasing discordance in perceived age within the twin pair-that is, the bigger the difference in perceived age within the pair, the more likely that the older looking twin died first. Twin analyses suggested that common genetic factors influence both perceived age and survival. Perceived...

  19. Economic independence in survivors of cancer diagnosed at a young age: A Norwegian national cohort study.

    Science.gov (United States)

    Gunnes, Maria W; Lie, Rolv Terje; Bjørge, Tone; Syse, Astri; Ruud, Ellen; Wesenberg, Finn; Moster, Dag

    2016-12-15

    The impact of cancer on socioeconomic outcomes is attracting attention as the number of survivors of cancer in young age continues to rise. This study examines economic independence in a national cohort of survivors of cancer at a young age in Norway. Through the linkage of several national registries, the study cohort comprised 1,212,013 individuals born in Norway during 1965 through 1985, of which 5440 had received a cancer diagnosis before age 25 years. Follow-up was through 2007, and the main outcomes were receipt of governmental financial assistance, employment, income, and occupation. Analytic methods included Cox proportional hazard regression, log-binomial regression, and quantile regression models. Individuals in the cancer survivor group had an increased probability of receiving governmental financial assistance (men: hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.3-1.5; women: HR, 1.5; 95% CI, 1.3-1.6) and of not being employed (men: HR, 1.4; 95% CI, 1.2-1.7; women: HR, 1.4; 95% CI, 1.2-1.6) compared with those in the noncancer group. Income discrepancies were particularly pronounced for survivors of central nervous system tumors. There was no difference in representation in higher skilled occupations. Survivors of cancer at a young age in Norway had an increased risk of being economically dependent and unemployed. This was evident in several tumor groups and was most pronounced in female survivors. There were only small differences in income or representation in higher skilled occupations for most employed survivors compared with the noncancer group. The current results are important for understanding the impact of a cancer diagnosis at a young age on subsequent job market outcomes. Cancer 2016;122:3873-3882. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

  20. External validation of prognostic models to predict risk of gestational diabetes mellitus in one Dutch cohort: prospective multicentre cohort study.

    Science.gov (United States)

    Lamain-de Ruiter, Marije; Kwee, Anneke; Naaktgeboren, Christiana A; de Groot, Inge; Evers, Inge M; Groenendaal, Floris; Hering, Yolanda R; Huisjes, Anjoke J M; Kirpestein, Cornel; Monincx, Wilma M; Siljee, Jacqueline E; Van 't Zelfde, Annewil; van Oirschot, Charlotte M; Vankan-Buitelaar, Simone A; Vonk, Mariska A A W; Wiegers, Therese A; Zwart, Joost J; Franx, Arie; Moons, Karel G M; Koster, Maria P H

    2016-08-30

     To perform an external validation and direct comparison of published prognostic models for early prediction of the risk of gestational diabetes mellitus, including predictors applicable in the first trimester of pregnancy.  External validation of all published prognostic models in large scale, prospective, multicentre cohort study.  31 independent midwifery practices and six hospitals in the Netherlands.  Women recruited in their first trimester (diabetes mellitus of any type were excluded.  Discrimination of the prognostic models was assessed by the C statistic, and calibration assessed by calibration plots.  3723 women were included for analysis, of whom 181 (4.9%) developed gestational diabetes mellitus in pregnancy. 12 prognostic models for the disorder could be validated in the cohort. C statistics ranged from 0.67 to 0.78. Calibration plots showed that eight of the 12 models were well calibrated. The four models with the highest C statistics included almost all of the following predictors: maternal age, maternal body mass index, history of gestational diabetes mellitus, ethnicity, and family history of diabetes. Prognostic models had a similar performance in a subgroup of nulliparous women only. Decision curve analysis showed that the use of these four models always had a positive net benefit.  In this external validation study, most of the published prognostic models for gestational diabetes mellitus show acceptable discrimination and calibration. The four models with the highest discriminative abilities in this study cohort, which also perform well in a subgroup of nulliparous women, are easy models to apply in clinical practice and therefore deserve further evaluation regarding their clinical impact. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Lifecourse Activity Participation From Early, Mid, and Later Adulthood as Determinants of Cognitive Aging: The Lothian Birth Cohort 1921.

    Science.gov (United States)

    Gow, Alan J; Pattie, Alison; Deary, Ian J

    2017-01-01

    To examine potential sensitive periods for activity participation across adulthood to reduce cognitive decline and to determine whether associations persist after accounting for the lifetime stability of cognitive ability. The Lothian Birth Cohort 1921 is a longitudinal study of cognitive aging. Participants were born in 1921 and most completed a mental ability test at the age of 11 years. Cognitive assessments were completed at mean ages 79 (N = 550), 83 (N = 321), 87 (N = 235), and 90 years (N = 129). Participants provided retrospective details of their activity participation for young (20-35 years), mid (40-55 years), and later adulthood (60-75 years), and contemporaneously at age 79. Associations between activity and the level of, and change in, cognitive ability in old age were examined with latent growth curve models. Accounting for demographics and childhood cognitive ability, engagement in leisure activities in midlife was positively associated with cognitive ability level (path coefficient = .32), whereas higher physical activity in later adulthood was associated with less cognitive decline (.27). The findings support a lifecourse approach in identifying determinants of cognitive aging; leisure and physical activity during different periods of adulthood may enhance cognitive abilities or reduce decline. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

  2. Birth cohort effects on mortality in Danish women

    DEFF Research Database (Denmark)

    Jacobsen, Rune; Keiding, Niels; Lynge, Elsebeth

    the mothers of the babyboomers, and the women most heavily hit by the epidemic of sexually transmitted diseases in the mid 1940s. These generations of women furthermore entered the Danish labour market in massive numbers in the 1960s. In the present study we examine the mortality of Danish women and compare...... it to mortality of Danish men, Norwegian women and Swedish women. Specifically we aim to answer the questions: 1) Are there comparable birth cohort effects on mortality in Norway and Sweden and what is the impact of the respective Danish birth cohorts on the life expectancy measure 2) Are there specific causes...... groups. The data was analysed using descriptive techniques, Age-period-cohort modelling and age-decomposing of life expectancies. Results: The results showed no similar birth cohort effect for Norway and Sweden when compared to Denmark and a relatively high impact of the birth cohort effect on life...

  3. Application of the Periodic Average System Model in Dam Deformation Analysis

    Directory of Open Access Journals (Sweden)

    Yueqian Shen

    2015-01-01

    Full Text Available Dams are among the most important hydraulic engineering facilities used for water supply, flood control, and hydroelectric power. Monitoring of dams is crucial since deformation might have occurred. How to obtain the deformation information and then judge the safe conditions is the key and difficult problem in dam deformation monitoring field. This paper proposes the periodic average system model and creates the concept of “settlement activity” based on the dam deformation issue. Long-term deformation monitoring data is carried out in a pumped-storage power station, this model combined with settlement activity is used to make the single point deformation analysis, and then the whole settlement activity profile is drawn by clustering analysis. Considering the cumulative settlement value of every point, the dam deformation trend is analyzed in an intuitive effect way. The analysis mode of combined single point with multipoints is realized. The results show that the key deformation information of the dam can be easily grasped by the application of the periodic average system model combined with the distribution diagram of settlement activity. And, above all, the ideas of this research provide an effective method for dam deformation analysis.

  4. Mortality of breast cancer in Taiwan, 1971–2010: Temporal changes and an age–period–cohort analysis

    Science.gov (United States)

    Ho, M.-L.; Hsiao, Y.-H.; Su, S.-Y.

    2015-01-01

    The current paper describes the age, period and cohort effects on breast cancer mortality in Taiwan. Female breast cancer mortality data were collected from the Taiwan death registries for 1971–2010. The annual percentage changes, age- standardised mortality rates (ASMR) and age–period–cohort model were calculated. The mortality rates increased with advancing age groups when fixing the period. The percentage change in the breast cancer mortality rate increased from 54.79% at aged 20–44 years, to 149.78% in those aged 45–64 years (between 1971–75 and 2006–10). The mortality rates in the 45–64 age group increased steadily from 1971 to 1975 and 2006–10. The 1951 birth cohorts (actual birth cohort; 1947–55) showed peak mortalities in both the 50–54 and 45–49 age groups. We found that the 1951 birth cohorts had the greatest mortality risk from breast cancer. This might be attributed to the DDT that was used in large amounts to prevent deaths from malaria in Taiwan. However, future researches require DDT data to evaluate the association between breast cancer and DDT use. PMID:25020211

  5. Accelerated optical polymer aging studies for LED luminaire applications

    Science.gov (United States)

    Estupiñán, Edgar; Wendling, Peter; Kostrun, Marijan; Garner, Richard

    2013-09-01

    There is a need in the lighting industry to design and implement accelerated aging methods that accurately simulate the aging process of LED luminaire components. In response to this need, we have built a flexible and reliable system to study the aging characteristics of optical polymer materials, and we have employed it to study a commercially available LED luminaire diffuser made of PMMA. The experimental system consists of a "Blue LED Emitter" and a working surface. Both the temperatures of the samples and the optical powers of the LEDs are appropriately characterized in the system. Several accelerated aging experiments are carried out at different temperatures and optical powers over a 90 hour period and the measured transmission values are used as inputs to a degradation model derived using plausibility arguments. This model seems capable of predicting the behavior of the material as a function of time, temperature and optical power. The model satisfactorily predicts the measured transmission values of diffusers aged in luminaires at two different times and thus can be used to make application recommendations for this material. Specifically, at 35000 hours (the manufacturer's stated life of the luminaire) and at the typical operational temperature of the diffuser, the model predicts a transmission loss of only a few percent over the original transmission of the material at 450 nm, which renders this material suitable for this application.

  6. Probabilistic risk analysis of aging components which fail on demand. A Bayesian model. Application to maintenance optimization of Diesel engine linings

    International Nuclear Information System (INIS)

    Procaccia, H.; Lannoy, A.; Clarotti, C.A.

    1997-01-01

    The optimization of preventive maintenance of aging materials can be well modelled through the application of the two-parameters Weibull law. Unfortunately there is no theoretical model describing the aging of components implied in emergency interventions which may fail in very moment of demand. These components are relevant to the safety of Nuclear Power Plants and the main problem with them is the optimization of the maintenance and the test schedule. Indeed the effect of any test is twofold, namely: the test reveals failures which otherwise would occur when the Power Plant would need urgent intervention but at the same time it causes the aging process to step up. The aging process is suspected to affect certain safeguard equipment, but it does not exist a theoretical model of component aging in function of demands. Sections 2.1 and 2.2 of the paper are devoted to the description of a Bayesian model of discrete aging, deriving the likelihood function of the model (data modelling) and to selecting 'the best prior' (Analyst knowledge) that can be associated to the likelihood, respectively. The aspects of numerical integration relative to assessing the predictive reliability of the aging components are discussed in Section 2.3. Section 3 reports a Reliability Centered Maintenance application of the model to cylinders of emergency electrical generators of the NPP nuclear sectors. These components are subjected to an annual endoscopic checking and to a systematical replacement at every 5 years. The statistical Bayesian decision theory was applied to determine an optimal period of cylinder replacement based on the aging model presented in this paper. It is shown that the optimal value is between 10 to 12 years. (author)

  7. Trends in Female Breast Cancer by Age Group in the Chiang

    Science.gov (United States)

    Sripan, Patumrat; Sriplung, Hutcha; Pongnikorn, Donsuk; Virani, Shama; Bilheem, Surichai; Chaisaengkhaum, Udomlak; Maneesai, Puttachart; Waisri, Narate; Hanpragopsuk, Chirapong; Tansiri, Panrada; Khamsan, Varunee; Poungsombat, Malisa; Mawoot, Aumnart; Chitapanarux, Imjai

    2017-05-01

    Objectives: This study was conducted to determine incidence trends of female breast cancer according to age groups and to predict future change in Chiang Mai women through 2028. Method: Data were collected from all hospitals in Chiang Mai in northern Thailand, from 1989 through 2013, and used to investigate effects of age, year of diagnosis (period) and year of birth (cohort) on female breast cancer incidences using an age-period-cohort model. This model features geometric cut trends to predict change by young (<40 years), middle-aged (40-59) and elderly (≥60) age groups. Result: Of 5, 417 female breast cancer patients with a median age of 50 years (interquartile range: 43 to 59 years), 15%, 61% and 24% were young, middle-aged and elderly, respectively. Seventy nine percent of cancer cases in this study were detected at advanced stage. The trend in stage classification showed an increase in percentage of early stage and a decrease in metastatic cancers. Linear trends for cohort and period were not found in young females but were observed in middle-aged and elderly groups. Age-standardized rates (ASR) can be expected to remain stable around 6.8 per 100,000 women-years in young females. In the other age groups, the ASR trends were calculated to increase and reach peaks in 2024 of 120.2 and 138.2 per 100,000 women-years, respectively. Conclusion: Cohort effects or generation-specific effects, such as life style factors and the year of diagnosis (period) might have impacted on increased incidence in women aged over 40 years but not those under 40 years. A budget should be provided for treatment facilities and strategies to detect early stage cancers. The cost effectiveness of screening measures i.e. mammographic screening may need to be reconsidered for women age over 40 years. Creative Commons Attribution License

  8. Age- and cohort-related variance of type-A behavior over 24 years: the Young Finns Study.

    Science.gov (United States)

    Hintsa, Taina; Jokela, Markus; Pulkki-Råback, Laura; Keltikangas-Järvinen, Liisa

    2014-12-01

    Over the recent decades, the incidence of cardiovascular and heart diseases has decreased while levels of type-A behavior, i.e., a potential risk factor, appear to have increased. However, the long-term developmental patterns of type-A behavior is poorly understood. Both age- and cohort-related changes may be involved in these developments. The purpose of this study was to examine an age- and cohort-related changes of Hunter-Wolf type-A behavior from adolescence to adulthood. Type-A behavior and its components (aggressiveness, leadership, hard driving, and eagerness energy) were assessed using the Hunter-Wolf A-B rating scale at five time points (1983, 1986, 1989, 2001, and 2007) in a population-based sample consisting of six birth cohorts born between 1962 and 1977 (n = 3,341, a total of 10,506 person observations). Development of type-A behavior and its components was examined with cohort-sequential multilevel modeling. Aggressiveness decreased with age, eagerness energy, hard driving, and global type-A behavior increased, and leadership exhibited no mean level changes. Younger cohorts had higher aggressiveness, lower hard driving, and global type-A behavior. The findings suggest that in order to understand the health consequences of type-A behavior, both life span and societal changes should be considered.

  9. Modelling survival and mortality risk to 15 years of age for a national cohort of children with serious congenital heart defects diagnosed in infancy.

    Directory of Open Access Journals (Sweden)

    Rachel L Knowles

    Full Text Available Congenital heart defects (CHDs are a significant cause of death in infancy. Although contemporary management ensures that 80% of affected children reach adulthood, post-infant mortality and factors associated with death during childhood are not well-characterised. Using data from a UK-wide multicentre birth cohort of children with serious CHDs, we observed survival and investigated independent predictors of mortality up to age 15 years.Data were extracted retrospectively from hospital records and death certificates of 3,897 children (57% boys in a prospectively identified cohort, born 1992-1995 with CHDs requiring intervention or resulting in death before age one year. A discrete-time survival model accounted for time-varying predictors; hazards ratios were estimated for mortality. Incomplete data were addressed through multilevel multiple imputation.By age 15 years, 932 children had died; 144 died without any procedure. Survival to one year was 79.8% (95% confidence intervals [CI] 78.5, 81.1% and to 15 years was 71.7% (63.9, 73.4%, with variation by cardiac diagnosis. Importantly, 20% of cohort deaths occurred after age one year. Models using imputed data (including all children from birth demonstrated higher mortality risk as independently associated with cardiac diagnosis, female sex, preterm birth, having additional cardiac defects or non-cardiac malformations. In models excluding children who had no procedure, additional predictors of higher mortality were younger age at first procedure, lower weight or height, longer cardiopulmonary bypass or circulatory arrest duration, and peri-procedural complications; non-cardiac malformations were no longer significant.We confirm the high mortality risk associated with CHDs in the first year of life and demonstrate an important persisting risk of death throughout childhood. Late mortality may be underestimated by procedure-based audit focusing on shorter-term surgical outcomes. National monitoring

  10. Modelling survival and mortality risk to 15 years of age for a national cohort of children with serious congenital heart defects diagnosed in infancy.

    Science.gov (United States)

    Knowles, Rachel L; Bull, Catherine; Wren, Christopher; Wade, Angela; Goldstein, Harvey; Dezateux, Carol

    2014-01-01

    Congenital heart defects (CHDs) are a significant cause of death in infancy. Although contemporary management ensures that 80% of affected children reach adulthood, post-infant mortality and factors associated with death during childhood are not well-characterised. Using data from a UK-wide multicentre birth cohort of children with serious CHDs, we observed survival and investigated independent predictors of mortality up to age 15 years. Data were extracted retrospectively from hospital records and death certificates of 3,897 children (57% boys) in a prospectively identified cohort, born 1992-1995 with CHDs requiring intervention or resulting in death before age one year. A discrete-time survival model accounted for time-varying predictors; hazards ratios were estimated for mortality. Incomplete data were addressed through multilevel multiple imputation. By age 15 years, 932 children had died; 144 died without any procedure. Survival to one year was 79.8% (95% confidence intervals [CI] 78.5, 81.1%) and to 15 years was 71.7% (63.9, 73.4%), with variation by cardiac diagnosis. Importantly, 20% of cohort deaths occurred after age one year. Models using imputed data (including all children from birth) demonstrated higher mortality risk as independently associated with cardiac diagnosis, female sex, preterm birth, having additional cardiac defects or non-cardiac malformations. In models excluding children who had no procedure, additional predictors of higher mortality were younger age at first procedure, lower weight or height, longer cardiopulmonary bypass or circulatory arrest duration, and peri-procedural complications; non-cardiac malformations were no longer significant. We confirm the high mortality risk associated with CHDs in the first year of life and demonstrate an important persisting risk of death throughout childhood. Late mortality may be underestimated by procedure-based audit focusing on shorter-term surgical outcomes. National monitoring systems should

  11. Delirium symptoms are associated with decline in cognitive function between ages 53 and 69 years: Findings from a British birth cohort study.

    Science.gov (United States)

    Tsui, Alex; Kuh, Diana; Richards, Marcus; Davis, Daniel

    2017-11-21

    Few population studies have investigated whether longitudinal decline after delirium in mid-to-late life might affect specific cognitive domains. Participants from a birth cohort completing assessments of search speed, verbal memory, and the Addenbrooke's Cognitive Examination at age 69 were asked about delirium symptoms between ages 60 and 69 years. Linear regression models estimated associations between delirium symptoms and cognitive outcomes. Period prevalence of delirium between 60 and 69 years was 4% (95% confidence interval 3.2%-4.9%). Self-reported symptoms of delirium over the seventh decade were associated with worse scores in the Addenbrooke's Cognitive Examination (-1.7 points; 95% confidence interval -3.2, -0.1; P = .04). In association with delirium symptoms, verbal memory scores were initially lower, with subsequent decline in search speed by the age of 69 years. These effects were independent of other Alzheimer's risk factors. Delirium symptoms may be common even at relatively younger ages, and their presence may herald cognitive decline, particularly in search speed, over this time period. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Cohorts based on decade of death: no evidence for secular trends favoring later cohorts in cognitive aging and terminal decline in the AHEAD study.

    Science.gov (United States)

    Hülür, Gizem; Infurna, Frank J; Ram, Nilam; Gerstorf, Denis

    2013-03-01

    Studies of birth-year cohorts examined over the same age range often report secular trends favoring later-born cohorts, who are cognitively fitter and show less steep cognitive declines than earlier-born cohorts. However, there is initial evidence that those advantages of later-born cohorts do not carry into the last years of life, suggesting that pervasive mortality-related processes minimize differences that were apparent earlier in life. Elaborating this work from an alternative perspective on cohort differences, we compared rates of cognitive aging and terminal decline in episodic memory between cohorts based on the year participants had died, earlier (between 1993 and 1999) or later in historical time (between 2000 and 2010). Specifically, we compared trajectories of cognitive decline in 2 death-year cohorts of participants in the Asset and Health Dynamics Among the Oldest Old study that were matched on age at death and education and controlled for a variety of additional covariates. Results revealed little evidence of secular trends favoring later cohorts. To the contrary, the cohort that died in the 2000s showed a less favorable trajectory of age-related memory decline than the cohort that died in the 1990s. In examinations of change in relation to time to death, the cohort dying in the 2000s experienced even steeper terminal declines than the cohort dying in the 1990s. We suggest that secular increases in "manufacturing" survival may exacerbate age- and mortality-related cognitive declines among the oldest old.

  13. The importance of age dependent mortality and the extrinsic incubation period in models of mosquito-borne disease transmission and control.

    Directory of Open Access Journals (Sweden)

    Steve E Bellan

    2010-04-01

    Full Text Available Nearly all mathematical models of vector-borne diseases have assumed that vectors die at constant rates. However, recent empirical research suggests that mosquito mortality rates are frequently age dependent. This work develops a simple mathematical model to assess how relaxing the classical assumption of constant mortality affects the predicted effectiveness of anti-vectorial interventions. The effectiveness of mosquito control when mosquitoes die at age dependent rates was also compared across different extrinsic incubation periods. Compared to a more realistic age dependent model, constant mortality models overestimated the sensitivity of disease transmission to interventions that reduce mosquito survival. Interventions that reduce mosquito survival were also found to be slightly less effective when implemented in systems with shorter EIPs. Future transmission models that examine anti-vectorial interventions should incorporate realistic age dependent mortality rates.

  14. Readmissions after Hospitalization for Heart Failure, Acute Myocardial Infarction, or Pneumonia among Young and Middle-Aged Adults: A Retrospective Observational Cohort Study

    Science.gov (United States)

    Ranasinghe, Isuru; Wang, Yongfei; Dharmarajan, Kumar; Hsieh, Angela F.; Bernheim, Susannah M.; Krumholz, Harlan M.

    2014-01-01

    Background Patients aged ≥65 years are vulnerable to readmissions due to a transient period of generalized risk after hospitalization. However, whether young and middle-aged adults share a similar risk pattern is uncertain. We compared the rate, timing, and readmission diagnoses following hospitalization for heart failure (HF), acute myocardial infarction (AMI), and pneumonia among patients aged 18–64 years with patients aged ≥65 years. Methods and Findings We used an all-payer administrative dataset from California consisting of all hospitalizations for HF (n = 206,141), AMI (n = 107,256), and pneumonia (n = 199,620) from 2007–2009. The primary outcomes were unplanned 30-day readmission rate, timing of readmission, and readmission diagnoses. Our findings show that the readmission rate among patients aged 18–64 years exceeded the readmission rate in patients aged ≥65 years in the HF cohort (23.4% vs. 22.0%, preadmission risk in patients aged 18–64 years was similar to patients ≥65 years in the HF (HR 0.99; 95%CI 0.97–1.02) and pneumonia (HR 0.97; 95%CI 0.94–1.01) cohorts and was marginally lower in the AMI cohort (HR 0.92; 95%CI 0.87–0.96). For all cohorts, the timing of readmission was similar; readmission risks were highest between days 2 and 5 and declined thereafter across all age groups. Diagnoses other than the index admission diagnosis accounted for a substantial proportion of readmissions among age groups readmissions in the HF cohort and 37–45% of readmissions in the AMI cohort, while a non-pulmonary diagnosis represented 61–64% of patients in the pneumonia cohort. Conclusion When adjusted for differences in patient characteristics, young and middle-aged adults have 30-day readmission rates that are similar to elderly patients for HF, AMI, and pneumonia. A generalized risk after hospitalization is present regardless of age. Please see later in the article for the Editors' Summary PMID:25268126

  15. Age and fecundability in a North American preconception cohort study.

    Science.gov (United States)

    Wesselink, Amelia K; Rothman, Kenneth J; Hatch, Elizabeth E; Mikkelsen, Ellen M; Sørensen, Henrik T; Wise, Lauren A

    2017-12-01

    There is a well-documented decline in fertility treatment success with increasing female age; however, there are few preconception cohort studies that have examined female age and natural fertility. In addition, data on male age and fertility are inconsistent. Given the increasing number of couples who are attempting conception at older ages, a more detailed characterization of age-related fecundability in the general population is of great clinical utility. The purpose of this study was to examine the association between female and male age with fecundability. We conducted a web-based preconception cohort study of pregnancy planners from the United States and Canada. Participants were enrolled between June 2013 and July 2017. Eligible participants were 21-45 years old (female) or ≥21 years old (male) and had not been using fertility treatments. Couples were followed until pregnancy or for up to 12 menstrual cycles. We analyzed data from 2962 couples who had been trying to conceive for ≤3 cycles at study entry and reported no history of infertility. We used life-table methods to estimate the unadjusted cumulative pregnancy proportion at 6 and 12 cycles by female and male age. We used proportional probabilities regression models to estimate fecundability ratios, the per-cycle probability of conception for each age category relative to the referent (21-24 years old), and 95% confidence intervals. Among female patients, the unadjusted cumulative pregnancy proportion at 6 cycles of attempt time ranged from 62.0% (age 28-30 years) to 27.6% (age 40-45 years); the cumulative pregnancy proportion at 12 cycles of attempt time ranged from 79.3% (age 25-27 years old) to 55.5% (age 40-45 years old). Similar patterns were observed among male patients, although differences between age groups were smaller. After adjusting for potential confounders, we observed a nearly monotonic decline in fecundability with increasing female age, with the exception of 28-33 years, at which

  16. Does the Spectrum model accurately predict trends in adult mortality? Evaluation of model estimates using empirical data from a rural HIV community cohort study in north-western Tanzania

    Directory of Open Access Journals (Sweden)

    Denna Michael

    2014-01-01

    Full Text Available Introduction: Spectrum epidemiological models are used by UNAIDS to provide global, regional and national HIV estimates and projections, which are then used for evidence-based health planning for HIV services. However, there are no validations of the Spectrum model against empirical serological and mortality data from populations in sub-Saharan Africa. Methods: Serologic, demographic and verbal autopsy data have been regularly collected among over 30,000 residents in north-western Tanzania since 1994. Five-year age-specific mortality rates (ASMRs per 1,000 person years and the probability of dying between 15 and 60 years of age (45Q15, were calculated and compared with the Spectrum model outputs. Mortality trends by HIV status are shown for periods before the introduction of antiretroviral therapy (1994–1999, 2000–2005 and the first 5 years afterwards (2005–2009. Results: Among 30–34 year olds of both sexes, observed ASMRs per 1,000 person years were 13.33 (95% CI: 10.75–16.52 in the period 1994–1999, 11.03 (95% CI: 8.84–13.77 in 2000–2004, and 6.22 (95% CI; 4.75–8.15 in 2005–2009. Among the same age group, the ASMRs estimated by the Spectrum model were 10.55, 11.13 and 8.15 for the periods 1994–1999, 2000–2004 and 2005–2009, respectively. The cohort data, for both sexes combined, showed that the 45Q15 declined from 39% (95% CI: 27–55% in 1994 to 22% (95% CI: 17–29% in 2009, whereas the Spectrum model predicted a decline from 43% in 1994 to 37% in 2009. Conclusion: From 1994 to 2009, the observed decrease in ASMRs was steeper in younger age groups than that predicted by the Spectrum model, perhaps because the Spectrum model under-estimated the ASMRs in 30–34 year olds in 1994–99. However, the Spectrum model predicted a greater decrease in 45Q15 mortality than observed in the cohort, although the reasons for this over-estimate are unclear.

  17. Trends in Female Breast Cancer by Age Group in the Chiang Mai Population

    Science.gov (United States)

    Sripan, Patumrat; Sriplung, Hutcha; Pongnikorn, Donsuk; Virani, Shama; Bilheem, Surichai; Chaisaengkhaum, Udomlak; Maneesai, Puttachart; Waisri, Narate; Hanpragopsuk, Chirapong; Tansiri, Panrada; Khamsan, Varunee; Poungsombat, Malisa; Mawoot, Aumnart; Chitapanarux, Imjai

    2017-01-01

    Objectives: This study was conducted to determine incidence trends of female breast cancer according to age groups and to predict future change in Chiang Mai women through 2028. Method: Data were collected from all hospitals in Chiang Mai in northern Thailand, from 1989 through 2013, and used to investigate effects of age, year of diagnosis (period) and year of birth (cohort) on female breast cancer incidences using an age-period-cohort model. This model features geometric cut trends to predict change by young (<40 years), middle-aged (40-59) and elderly (≥60) age groups. Result: Of 5, 417 female breast cancer patients with a median age of 50 years (interquartile range: 43 to 59 years), 15%, 61% and 24% were young, middle-aged and elderly, respectively. Seventy nine percent of cancer cases in this study were detected at advanced stage. The trend in stage classification showed an increase in percentage of early stage and a decrease in metastatic cancers. Linear trends for cohort and period were not found in young females but were observed in middle-aged and elderly groups. Age-standardized rates (ASR) can be expected to remain stable around 6.8 per 100,000 women-years in young females. In the other age groups, the ASR trends were calculated to increase and reach peaks in 2024 of 120.2 and 138.2 per 100,000 women-years, respectively. Conclusion: Cohort effects or generation-specific effects, such as life style factors and the year of diagnosis (period) might have impacted on increased incidence in women aged over 40 years but not those under 40 years. A budget should be provided for treatment facilities and strategies to detect early stage cancers. The cost effectiveness of screening measures i.e. mammographic screening may need to be reconsidered for women age over 40 years. PMID:28612595

  18. Teasing apart the relations between age, birth cohort, and vocational interests.

    Science.gov (United States)

    Leuty, Melanie E; Hansen, Jo-Ida C

    2014-04-01

    Empirical evidence supports that aging is related to differences in work attitudes and motivation (Inceoglu, Segers, & Bartram, 2012; Kooij, de Lange, Jansen, Kanfer, & Kikkers, 2011; Ng & Feldman, 2008, 2010), but little research has explored the relations between age and vocational interests. Furthermore, recent studies of age and work attitudes suggest that generational experiences (i.e., birth year) may account for age differences in the workplace (Inceoglu et al., 2012; Ng & Feldman, 2008, 2010), which in turn suggests that researchers need to incorporate both age and birth cohort effects in their designs. Thus, this study was designed to explore the relations of age at the time of testing and birth year to vocational interests using a sample of adults (N = 1,792) collected over a period of 3 decades. As expected, age was not a significant predictor of most interests, but birth year also was not found to predict most interests, with the significant prediction of Realistic interests by both age and birth year being the exception. Gender, however, significantly predicted most areas of interests. Neither age nor gender moderated any relationships between birth year and interests. Results suggest that birth year and age were minimally related to interests as all effect sizes were small. Discussion of the results illustrates the need for further research on this issue and also offers considerations for attracting and retaining different generations of workers in light of the findings. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  19. Age-dependent branching processes for surveillance of vaccine-preventable diseases with incubation period

    Directory of Open Access Journals (Sweden)

    Marusia N Bojkova

    2010-10-01

    Full Text Available The purpose of this paper is to review the recent results of the authors in the area of infectious disease modelling by means of branching stochastic processes. This is a new approach involving age-dependent branching models, which turned out to be more appropriate and flexible for describing the spread of an infection in a given population, than discrete time ones. Concretely, Bellman-Harris and Sevast’yanov’s branching processes are investigated. It is justified that the proposed models are proper candidates as models of infectious diseases with incubation period like measles, mumps, avian flu, etc. It is worth to notice that in general the developed methodology is applicable to the diseases that follow the so-called SIR (susceptible- infected-removed scheme in terms of epidemiological models. Two policies of extra-vaccination level are proposed and compared on the ground of simulation examples.

  20. Self-esteem development from young adulthood to old age: a cohort-sequential longitudinal study.

    Science.gov (United States)

    Orth, Ulrich; Trzesniewski, Kali H; Robins, Richard W

    2010-04-01

    The authors examined the development of self-esteem from young adulthood to old age. Data came from the Americans' Changing Lives study, which includes 4 assessments across a 16-year period of a nationally representative sample of 3,617 individuals aged 25 years to 104 years. Latent growth curve analyses indicated that self-esteem follows a quadratic trajectory across the adult life span, increasing during young and middle adulthood, reaching a peak at about age 60 years, and then declining in old age. No cohort differences in the self-esteem trajectory were found. Women had lower self-esteem than did men in young adulthood, but their trajectories converged in old age. Whites and Blacks had similar trajectories in young and middle adulthood, but the self-esteem of Blacks declined more sharply in old age than did the self-esteem of Whites. More educated individuals had higher self-esteem than did less educated individuals, but their trajectories were similar. Moreover, the results suggested that changes in socioeconomic status and physical health account for the decline in self-esteem that occurs in old age.

  1. Centenarians - a useful model for healthy aging?

    DEFF Research Database (Denmark)

    Engberg, Henriette; Oksuzyan, Anna; Jeune, Bernard

    2009-01-01

    Centenarians surpass the current human life expectancy with about 20-25 years. However, whether centenarians represent healthy aging still remains an open question. Previous studies have been hampered by a number of methodological shortcomings such as a cross-sectional design and lack...... of an appropriate control group. In a longitudinal population-based cohort, it was examined whether the centenarian phenotype may be a useful model for healthy aging. The study was based on a completefollow up of 39 945 individuals alive in the Danish 1905 birth cohort on January 1, 1977 identified through...... with 68.4% among individuals who died in their early 80s. This trend was evident in both sexes. As a result of their lower hospitalization rates and length of stay in hospital compared with their contemporaries, who died at younger ages, Danish centenarians represent healthy agers. Centenarians constitute...

  2. Testicular cancer: marked birth cohort effects on incidence and a decline in mortality in southern Netherlands since 1970.

    Science.gov (United States)

    Verhoeven, Rob; Houterman, Saskia; Kiemeney, Bart; Koldewijn, Evert; Coebergh, Jan Willem

    2008-02-01

    The aim of our study was to interpret the changing incidence, and to describe the mortality of patients with testicular cancer in the south of the Netherlands between 1970 and 2004. On the basis of data from the Eindhoven Cancer Registry and Statistics Netherlands, 5-year moving average standardised incidence and mortality rates were calculated. An age-period-cohort (APC) Poisson regression analysis was performed to disentangle time and birth cohort effects on incidence. The incidence rate remained stable for all ages at about 3 per 100,000 person-years until 1989 but increased annually thereafter by 4% to 6 in 2004. This increase can almost completely be attributed to an increase in localised tumours. The largest increase was found for seminoma testicular cancer (TC) patients aged 35-39 and non-seminoma TC patients aged 20-24 years. Relatively more localised and tumours with lymph node metastases were detected in the later periods. APC analysis showed the best fit with an age-cohort model. An increase in incidence of TC was found for birth cohorts since 1950. The mortality rate dropped from 1.0 per 100,000 person-years in 1970 to 0.3 in 2005, with a steep annual decline of 12% in the period 1979-1986. In conclusion, the increase in incidence of TC was strongly correlated with birth cohorts since 1945. The increase in incidence is possibly caused by in utero or early life exposure to a yet unknown risk factor. There was a steep decline in mortality in the period 1979-1986. (c) 2007 Wiley-Liss, Inc.

  3. Missed epidemics and missing links: international birth cohort trends in multiple sclerosis.

    Science.gov (United States)

    Ajdacic-Gross, V; Tschopp, A; Schmid, M; Bopp, M; Gutzwiller, F

    2013-03-01

    Many hypotheses on the etiopathogenesis of multiple sclerosis (MS) focus on risk factors occurring early in life. This study examined the variability of birth cohort trends in international MS data by means of age-period-cohort (APC) analysis. The data from 25 countries were taken from the WHO mortality database. Data were encoded according to the International Classification of Diseases and covered slightly varying periods between 1951 and 2009. The APC analyses were based on logit models applied to cohort tables with 5-year age- and period intervals. In most countries, the birth cohort estimates peaked in those born in the first half of the 20th century. In countries from Central and Western Europe, the peak concerned those born before and around 1920. A second group of countries (Denmark, Sweden, Italy, Ireland, Scotland) shared a later peak amongst cohorts born in the 1920s and 1930s. Group 3 included Commonwealth countries, the USA and Norway, with a double or extended peak starting in the 1910s or 1920s, and ending by the 1950s. The fourth group, consisting of Mediterranean countries and Finland, was characterized by a steady increase in the birth cohort estimates until the 1950s. The fifth group with countries from Eastern Europe and Japan showed no particular pattern. Birth cohort trends have influenced the change in MS risk across the 20th century in many Western countries. This silent epidemic points to a most important but unknown latent risk factor in MS. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  4. Early nasal continuous positive airway pressure in a cohort of the smallest infants in Denmark

    DEFF Research Database (Denmark)

    Hansen, Bo M; Esbjørn, Barbara Hoff; Greisen, G

    2004-01-01

    To evaluate neurodevelopmental outcome at age 5 y of age in a cohort of preterm children treated mainly with nasal continuous positive airway pressure (CPAP) in the neonatal period.......To evaluate neurodevelopmental outcome at age 5 y of age in a cohort of preterm children treated mainly with nasal continuous positive airway pressure (CPAP) in the neonatal period....

  5. Mortality in the cohort of nuclear workers of the French electricity company: 1968-2003 period

    International Nuclear Information System (INIS)

    Rogel, A.; Joly, K.; Metz-Flamant, C.; Laurier, D.; Tirmarche, M.; Hubert, D.; Garcier, Y.

    2008-01-01

    Full text: Background: We conducted a mortality study on a cohort of French nuclear workers employed at Electricite de France (EDF). A first mortality analysis relied on the period 1968-1994. Present results consider an updated mortality analysis including 9 additional years of follow-up and rely on the period 1968-2003. Methods: The cohort includes 22,393 workers, 96% of them are males. Employment data were updated using Personnel EDF file. Vital status was ascertained using the French National Registry of individual identification, and further completed using EDF personnel and pension files. Causes of death were obtained through the National file of causes of death. The observed mortality was compared with national rates by indirect standardisation and expressed by Standardised Mortality Ratios (SMR). All causes, all cancers and external causes SMRs were detailed according to sex, age and calendar year. Variations according to date of entry into cohort, duration of employment and socio-economic status (SES) were studied. Comparison with the earlier follow-up is presented. Results: At the present study end point (31/12/2003), 74% of workers are still in active service. Only 0.3% of workers are lost to follow up. The total number of person-years is nearly 450,000. Causes were ascertained for 96 % of deaths. The total number of deaths is 874: 307 are cancer deaths, including 16 leukaemia. SMRs for all causes of death and all cancers show a significant deficit compared to the French national mortality. Significant variations of all causes and all cancers SMRs according to SES were observed. No significant excess compared to French national mortality was observed for any of the 30 different cancer sites studied. Borderline significant excess were observed however for pancreatic, pleural, kidney and brain cancer. SMR for leukaemia is equal to unity. Conclusion: There is a clear evidence for an effect of selection of healthy individuals into the workforce. Although 9

  6. VTE Risk assessment - a prognostic Model: BATER Cohort Study of young women.

    Science.gov (United States)

    Heinemann, Lothar Aj; Dominh, Thai; Assmann, Anita; Schramm, Wolfgang; Schürmann, Rolf; Hilpert, Jan; Spannagl, Michael

    2005-04-18

    BACKGROUND: Community-based cohort studies are not available that evaluated the predictive power of both clinical and genetic risk factors for venous thromboembolism (VTE). There is, however, clinical need to forecast the likelihood of future occurrence of VTE, at least qualitatively, to support decisions about intensity of diagnostic or preventive measures. MATERIALS AND METHODS: A 10-year observation period of the Bavarian Thromboembolic Risk (BATER) study, a cohort study of 4337 women (18-55 years), was used to develop a predictive model of VTE based on clinical and genetic variables at baseline (1993). The objective was to prepare a probabilistic scheme that discriminates women with virtually no VTE risk from those at higher levels of absolute VTE risk in the foreseeable future. A multivariate analysis determined which variables at baseline were the best predictors of a future VTE event, provided a ranking according to the predictive power, and permitted to design a simple graphic scheme to assess the individual VTE risk using five predictor variables. RESULTS: Thirty-four new confirmed VTEs occurred during the observation period of over 32,000 women-years (WYs). A model was developed mainly based on clinical information (personal history of previous VTE and family history of VTE, age, BMI) and one composite genetic risk markers (combining Factor V Leiden and Prothrombin G20210A Mutation). Four levels of increasing VTE risk were arbitrarily defined to map the prevalence in the study population: No/low risk of VTE (61.3%), moderate risk (21.1%), high risk (6.0%), very high risk of future VTE (0.9%). In 10.6% of the population the risk assessment was not possible due to lacking VTE cases. The average incidence rates for VTE in these four levels were: 4.1, 12.3, 47.2, and 170.5 per 104 WYs for no, moderate, high, and very high risk, respectively. CONCLUSION: Our prognostic tool - containing clinical information (and if available also genetic data) - seems to be

  7. Normative personality trait development in adulthood: A 6-year cohort-sequential growth model.

    Science.gov (United States)

    Milojev, Petar; Sibley, Chris G

    2017-03-01

    The present study investigated patterns of normative change in personality traits across the adult life span (19 through 74 years of age). We examined change in extraversion, agreeableness, conscientiousness, neuroticism, openness to experience and honesty-humility using data from the first 6 annual waves of the New Zealand Attitudes and Values Study (N = 10,416; 61.1% female, average age = 49.46). We present a cohort-sequential latent growth model assessing patterns of mean-level change due to both aging and cohort effects. Extraversion decreased as people aged, with the most pronounced declines occurring in young adulthood, and then again in old age. Agreeableness, indexed with a measure focusing on empathy, decreased in young adulthood and remained relatively unchanged thereafter. Conscientiousness increased among young adults then leveled off and remained fairly consistent for the rest of the adult life span. Neuroticism and openness to experience decreased as people aged. However, the models suggest that these latter effects may also be partially due to cohort differences, as older people showed lower levels of neuroticism and openness to experience more generally. Honesty-humility showed a pronounced and consistent increase across the adult life span. These analyses of large-scale longitudinal national probability panel data indicate that different dimensions of personality follow distinct developmental processes throughout adulthood. Our findings also highlight the importance of young adulthood (up to about the age of 30) in personality trait development, as well as continuing change throughout the adult life span. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Practical problems of groundwater model ages for groundwater protection studies

    International Nuclear Information System (INIS)

    Matthess, G.; Muennich, K.O.; Sonntag, C.

    1976-01-01

    Water authorities in the Federal Republic of Germany have established a system of protection zones for the protection of groundwater supplies from pollution. One zone (Zone II) is defined by an outer boundary from which the groundwater needs 50 days to flow to the well. 50 days is the period accepted for the elimination of pathogenic germs. However, within Zone II carbon-14 measurements of water may give model ages of several thousand years, which may lead to some confusion in the legal and practical aspects of this scheme. These model ages may result from uncertainties in the chemical model, or from mixing of waters of different ages, either within the aquifer or during extraction at the well. The paper discusses scientific aspects of the establishment of protection zones. Two processes affecting the model age determinations are examined in detail. First, the mechanism of diffusion transport downwards through porous, but impermeable, aquicludes is examined for stable trace substances and radioactive isotopes. Secondly, examples are given of model ages resulting from mixtures of new and old waters. It is recommended that such model ages should not be reported as 'ages' since they may be misinterpreted in groundwater protection applications. (author)

  9. [Willingness to accept an Internet-based mobility platform in different age cohorts. Empiric results of the project S-Mobil 100].

    Science.gov (United States)

    Beil, J; Cihlar, V; Kruse, A

    2015-02-01

    The aim of the project S-Mobil 100 is to develop and implement a prototype of an internet-based, generation-appropriate mobility platform in the model region Siegen-Wittgenstein. In the context of an empirical preliminary study, use of technology, experience with technology, general attitudes towards technology, general technology commitment, and the willingness to accept the mobility platform were investigated in different age cohorts. The investigation was carried out using a written survey based on a standardized questionnaire. The sample of 358 persons aged 40-90 years was divided in four age cohorts (40-54, 55-64, 65-74, and 75 + years). Our results show a high willingness to accept the mobility platform in the overall sample. Age, residence, income, and general technology commitment were significant predictors for the judgment of the platform. Although there were group differences in accepting the mobility platform, the older cohorts are also open-minded towards this new technology.

  10. A class of non-linear exposure-response models suitable for health impact assessment applicable to large cohort studies of ambient air pollution.

    Science.gov (United States)

    Nasari, Masoud M; Szyszkowicz, Mieczysław; Chen, Hong; Crouse, Daniel; Turner, Michelle C; Jerrett, Michael; Pope, C Arden; Hubbell, Bryan; Fann, Neal; Cohen, Aaron; Gapstur, Susan M; Diver, W Ryan; Stieb, David; Forouzanfar, Mohammad H; Kim, Sun-Young; Olives, Casey; Krewski, Daniel; Burnett, Richard T

    2016-01-01

    The effectiveness of regulatory actions designed to improve air quality is often assessed by predicting changes in public health resulting from their implementation. Risk of premature mortality from long-term exposure to ambient air pollution is the single most important contributor to such assessments and is estimated from observational studies generally assuming a log-linear, no-threshold association between ambient concentrations and death. There has been only limited assessment of this assumption in part because of a lack of methods to estimate the shape of the exposure-response function in very large study populations. In this paper, we propose a new class of variable coefficient risk functions capable of capturing a variety of potentially non-linear associations which are suitable for health impact assessment. We construct the class by defining transformations of concentration as the product of either a linear or log-linear function of concentration multiplied by a logistic weighting function. These risk functions can be estimated using hazard regression survival models with currently available computer software and can accommodate large population-based cohorts which are increasingly being used for this purpose. We illustrate our modeling approach with two large cohort studies of long-term concentrations of ambient air pollution and mortality: the American Cancer Society Cancer Prevention Study II (CPS II) cohort and the Canadian Census Health and Environment Cohort (CanCHEC). We then estimate the number of deaths attributable to changes in fine particulate matter concentrations over the 2000 to 2010 time period in both Canada and the USA using both linear and non-linear hazard function models.

  11. Reproductive period, endogenous estrogen exposure and dementia incidence among women in Latin America and China; A 10/66 population-based cohort study

    Science.gov (United States)

    Acosta, Daisy; Guerra, Mariella; Jimenez-Velazquez, Ivonne Z.; Salas, Aquiles; Sosa, Ana Luisa; Valhuerdi, Adolfo

    2018-01-01

    Background Exposure to endogenous estrogen may protect against dementia, but evidence remains equivocal. Such effects may be assessed more precisely in settings where exogenous estrogen administration is rare. We aimed to determine whether reproductive period (menarche to menopause), and other indicators of endogenous estrogen exposure are inversely associated with dementia incidence. Methods Population-based cohort studies of women aged 65 years and over in urban sites in Cuba, Dominican Republic, Puerto Rico and Venezuela, and rural and urban sites in Peru, Mexico and China. Sociodemographic and risk factor questionnaires were administered to all participants, including ages at menarche, birth of first child, and menopause, and parity, with ascertainment of incident 10/66 dementia, and mortality, three to five years later. Results 9,428 women participated at baseline, with 72–98% responding by site. The ‘at risk’ cohort comprised 8,466 dementia-free women. Mean age varied from 72.0 to 75.4 years, lower in rural than urban sites and in China than in Latin America. Mean parity was 4.1 (2.4–7.2 by site), generally higher in rural than urban sites. 6,854 women with baseline reproductive period data were followed up for 26,463 person years. There were 692 cases of incident dementia, and 895 dementia free deaths. Pooled meta-analysed fixed effects, per year, for reproductive period (Adjusted Sub-Hazard Ratio [ASHR] 1.001, 95% CI 0.988–1.015) did not support any association with dementia incidence, with no evidence for effect modification by APOE genotype. No association was observed between incident dementia and; ages at menarche, birth of first child, and menopause: nulliparity; or index of cumulative endogenous estrogen exposure. Greater parity was positively associated with incident dementia (ASHR 1.030, 95% CI 1.002–1.059, I2 = 0.0%). Conclusions We found no evidence to support the theory that natural variation in cumulative exposure to endogenous

  12. Reproductive period, endogenous estrogen exposure and dementia incidence among women in Latin America and China; A 10/66 population-based cohort study.

    Science.gov (United States)

    Prince, Martin J; Acosta, Daisy; Guerra, Mariella; Huang, Yueqin; Jimenez-Velazquez, Ivonne Z; Llibre Rodriguez, Juan J; Salas, Aquiles; Sosa, Ana Luisa; Chua, Kia-Chong; Dewey, Michael E; Liu, Zhaorui; Mayston, Rosie; Valhuerdi, Adolfo

    2018-01-01

    Exposure to endogenous estrogen may protect against dementia, but evidence remains equivocal. Such effects may be assessed more precisely in settings where exogenous estrogen administration is rare. We aimed to determine whether reproductive period (menarche to menopause), and other indicators of endogenous estrogen exposure are inversely associated with dementia incidence. Population-based cohort studies of women aged 65 years and over in urban sites in Cuba, Dominican Republic, Puerto Rico and Venezuela, and rural and urban sites in Peru, Mexico and China. Sociodemographic and risk factor questionnaires were administered to all participants, including ages at menarche, birth of first child, and menopause, and parity, with ascertainment of incident 10/66 dementia, and mortality, three to five years later. 9,428 women participated at baseline, with 72-98% responding by site. The 'at risk' cohort comprised 8,466 dementia-free women. Mean age varied from 72.0 to 75.4 years, lower in rural than urban sites and in China than in Latin America. Mean parity was 4.1 (2.4-7.2 by site), generally higher in rural than urban sites. 6,854 women with baseline reproductive period data were followed up for 26,463 person years. There were 692 cases of incident dementia, and 895 dementia free deaths. Pooled meta-analysed fixed effects, per year, for reproductive period (Adjusted Sub-Hazard Ratio [ASHR] 1.001, 95% CI 0.988-1.015) did not support any association with dementia incidence, with no evidence for effect modification by APOE genotype. No association was observed between incident dementia and; ages at menarche, birth of first child, and menopause: nulliparity; or index of cumulative endogenous estrogen exposure. Greater parity was positively associated with incident dementia (ASHR 1.030, 95% CI 1.002-1.059, I2 = 0.0%). We found no evidence to support the theory that natural variation in cumulative exposure to endogenous oestrogens across the reproductive period influences

  13. Reproductive period, endogenous estrogen exposure and dementia incidence among women in Latin America and China; A 10/66 population-based cohort study.

    Directory of Open Access Journals (Sweden)

    Martin J Prince

    Full Text Available Exposure to endogenous estrogen may protect against dementia, but evidence remains equivocal. Such effects may be assessed more precisely in settings where exogenous estrogen administration is rare. We aimed to determine whether reproductive period (menarche to menopause, and other indicators of endogenous estrogen exposure are inversely associated with dementia incidence.Population-based cohort studies of women aged 65 years and over in urban sites in Cuba, Dominican Republic, Puerto Rico and Venezuela, and rural and urban sites in Peru, Mexico and China. Sociodemographic and risk factor questionnaires were administered to all participants, including ages at menarche, birth of first child, and menopause, and parity, with ascertainment of incident 10/66 dementia, and mortality, three to five years later.9,428 women participated at baseline, with 72-98% responding by site. The 'at risk' cohort comprised 8,466 dementia-free women. Mean age varied from 72.0 to 75.4 years, lower in rural than urban sites and in China than in Latin America. Mean parity was 4.1 (2.4-7.2 by site, generally higher in rural than urban sites. 6,854 women with baseline reproductive period data were followed up for 26,463 person years. There were 692 cases of incident dementia, and 895 dementia free deaths. Pooled meta-analysed fixed effects, per year, for reproductive period (Adjusted Sub-Hazard Ratio [ASHR] 1.001, 95% CI 0.988-1.015 did not support any association with dementia incidence, with no evidence for effect modification by APOE genotype. No association was observed between incident dementia and; ages at menarche, birth of first child, and menopause: nulliparity; or index of cumulative endogenous estrogen exposure. Greater parity was positively associated with incident dementia (ASHR 1.030, 95% CI 1.002-1.059, I2 = 0.0%.We found no evidence to support the theory that natural variation in cumulative exposure to endogenous oestrogens across the reproductive period

  14. Recipient Age and Mortality Risk after Liver Transplantation: A Population-Based Cohort Study.

    Science.gov (United States)

    Chen, Hsiu-Pin; Tsai, Yung-Fong; Lin, Jr-Rung; Liu, Fu-Chao; Yu, Huang-Ping

    2016-01-01

    The aim of the present large population-based cohort study is to explore the risk factors of age-related mortality in liver transplant recipients in Taiwan. Basic information and data on medical comorbidities for 2938 patients who received liver transplants between July 1, 1998, and December 31, 2012, were extracted from the National Health Insurance Research Database on the basis of ICD-9-codes. Mortality risks were analyzed after adjusting for preoperative comorbidities and compared among age cohorts. All patients were followed up until the study endpoint or death. This study finally included 2588 adults and 350 children [2068 (70.4%) male and 870 (29.6%) female patients]. The median age at transplantation was 52 (interquartile range, 43-58) years. Recipients were categorized into the following age cohorts: recipients (≥60 years), especially dialysis patients, have a higher mortality rate, possibly because they have more medical comorbidities. Our findings should make clinicians aware of the need for better risk stratification among elderly liver transplantation candidates.

  15. Whole-Genome Sequencing of a Healthy Aging Cohort.

    Science.gov (United States)

    Erikson, Galina A; Bodian, Dale L; Rueda, Manuel; Molparia, Bhuvan; Scott, Erick R; Scott-Van Zeeland, Ashley A; Topol, Sarah E; Wineinger, Nathan E; Niederhuber, John E; Topol, Eric J; Torkamani, Ali

    2016-05-05

    Studies of long-lived individuals have revealed few genetic mechanisms for protection against age-associated disease. Therefore, we pursued genome sequencing of a related phenotype-healthy aging-to understand the genetics of disease-free aging without medical intervention. In contrast with studies of exceptional longevity, usually focused on centenarians, healthy aging is not associated with known longevity variants, but is associated with reduced genetic susceptibility to Alzheimer and coronary artery disease. Additionally, healthy aging is not associated with a decreased rate of rare pathogenic variants, potentially indicating the presence of disease-resistance factors. In keeping with this possibility, we identify suggestive common and rare variant genetic associations implying that protection against cognitive decline is a genetic component of healthy aging. These findings, based on a relatively small cohort, require independent replication. Overall, our results suggest healthy aging is an overlapping but distinct phenotype from exceptional longevity that may be enriched with disease-protective genetic factors. VIDEO ABSTRACT. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Variations over time in the effects of age and sex on hospitalization rates before and after admission to a nursing home: A German cohort study.

    Science.gov (United States)

    Hoffmann, Falk; Allers, Katharina

    2017-08-01

    We examined hospitalization rates for nursing home residents before and after their entry to the home, stratified by sex and age. A cohort study was conducted using data from a large health insurance fund on 127,227 residents aged 65 years and over newly admitted to a nursing home between January 1, 2010, and December 31, 2014. We assessed hospitalization rates and proportions being hospitalized in 6-month intervals one year before nursing home placement and up to 5 years thereafter. Multiple Poisson regression models were fitted to calculate relative risks (RR). Mean age was 84.0 years and 74.6% of the cohort were females. Hospitalization rates were 194.4 per 100 person-years (PY) in the 12 months before entry to the nursing home and 120.0 per 100 PY thereafter. Rates were highest immediately before entry in both sexes. The influence of age was most pronounced in the 12-7 months before entry (RR: 2.37 for 65-74 vs. 95+ years) and declined thereafter (1.29-1.38 up to month 24 after entry). In contrast, the influence of sex was greater after entry (RR: 1.13 for males vs. females in the 12-7 months before and 1.23-1.31 up to month 24 after entry). Hospitalization rates of nursing home residents are much higher in Germany than in other Western countries. We have provided some insight into the influence of age and sex on hospitalization rates, which varied over the period (time before and after entry to the nursing home) analyzed. We urgently recommend that future studies on the hospitalization of residents stratify their analyses by sex, age and period. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. VTE Risk assessment – a prognostic Model: BATER Cohort Study of young women

    Directory of Open Access Journals (Sweden)

    Schürmann Rolf

    2005-04-01

    Full Text Available Abstract Background Community-based cohort studies are not available that evaluated the predictive power of both clinical and genetic risk factors for venous thromboembolism (VTE. There is, however, clinical need to forecast the likelihood of future occurrence of VTE, at least qualitatively, to support decisions about intensity of diagnostic or preventive measures. Materials and methods A 10-year observation period of the Bavarian Thromboembolic Risk (BATER study, a cohort study of 4337 women (18–55 years, was used to develop a predictive model of VTE based on clinical and genetic variables at baseline (1993. The objective was to prepare a probabilistic scheme that discriminates women with virtually no VTE risk from those at higher levels of absolute VTE risk in the foreseeable future. A multivariate analysis determined which variables at baseline were the best predictors of a future VTE event, provided a ranking according to the predictive power, and permitted to design a simple graphic scheme to assess the individual VTE risk using five predictor variables. Results Thirty-four new confirmed VTEs occurred during the observation period of over 32,000 women-years (WYs. A model was developed mainly based on clinical information (personal history of previous VTE and family history of VTE, age, BMI and one composite genetic risk markers (combining Factor V Leiden and Prothrombin G20210A Mutation. Four levels of increasing VTE risk were arbitrarily defined to map the prevalence in the study population: No/low risk of VTE (61.3%, moderate risk (21.1%, high risk (6.0%, very high risk of future VTE (0.9%. In 10.6% of the population the risk assessment was not possible due to lacking VTE cases. The average incidence rates for VTE in these four levels were: 4.1, 12.3, 47.2, and 170.5 per 104 WYs for no, moderate, high, and very high risk, respectively. Conclusion Our prognostic tool – containing clinical information (and if available also genetic data

  18. Happiness and social determinants across age cohorts in Taiwan.

    Science.gov (United States)

    Hsu, Hui-Chuan; Chang, Wen-Chiung; Chong, Young-Sook; An, Jeong Shin

    2016-09-01

    The purpose of this study was to examine happiness and social determinants across age cohorts in Taiwan. The data were obtained from the 2011 Taiwan Social Change Survey (aged 18 +, n = 2,199). The social determinants of happiness included socioeconomic status and social connection. Happiness was not different across the age groups. Receiving less family support, less formal support, more social trust and more control over life were significant for the younger group. Being married and having more social participation were significant for the middle-aged. Receiving less family support and having a higher economic status were significant for the older group. © The Author(s) 2015.

  19. Cohort Differences in Received Social Support in Later Life: The Role of Network Type.

    Science.gov (United States)

    Suanet, Bianca; Antonucci, Toni C

    2017-07-01

    The objective is to assess cohort differences in received emotional and instrumental support in relation to network types. The main guiding hypothesis is that due to increased salience of non-kin with recent social change, those in friend-focused and diverse network types receive more support in later birth cohorts than earlier birth cohorts. Data from the Longitudinal Aging Study Amsterdam are employed. We investigate cohort differences in total received emotional and instrumental support in a series of linear regression models comparing birth cohorts aged 55-64, 65-74, 75-84, and 85-94 across three time periods (1992, 2002, and 2012). Four network types (friend, family, restricted, and diverse) are identified. Friend-focused networks are more common in later birth cohorts, restrictive networks less common. Those in friend-focused networks in later cohorts report receiving more emotional and instrumental support. No differences in received support are evident upon diverse networks. The increased salience of non-kin is reflected in an increase in received emotional and instrumental support in friend-focused networks in later birth cohorts. The preponderance of non-kin in networks should not be perceived as a deficit model for social relationships as restrictive networks are declining across birth cohorts. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. A new model of wheezing severity in young children using the validated ISAAC wheezing module: A latent variable approach with validation in independent cohorts.

    Science.gov (United States)

    Brunwasser, Steven M; Gebretsadik, Tebeb; Gold, Diane R; Turi, Kedir N; Stone, Cosby A; Datta, Soma; Gern, James E; Hartert, Tina V

    2018-01-01

    The International Study of Asthma and Allergies in Children (ISAAC) Wheezing Module is commonly used to characterize pediatric asthma in epidemiological studies, including nearly all airway cohorts participating in the Environmental Influences on Child Health Outcomes (ECHO) consortium. However, there is no consensus model for operationalizing wheezing severity with this instrument in explanatory research studies. Severity is typically measured using coarsely-defined categorical variables, reducing power and potentially underestimating etiological associations. More precise measurement approaches could improve testing of etiological theories of wheezing illness. We evaluated a continuous latent variable model of pediatric wheezing severity based on four ISAAC Wheezing Module items. Analyses included subgroups of children from three independent cohorts whose parents reported past wheezing: infants ages 0-2 in the INSPIRE birth cohort study (Cohort 1; n = 657), 6-7-year-old North American children from Phase One of the ISAAC study (Cohort 2; n = 2,765), and 5-6-year-old children in the EHAAS birth cohort study (Cohort 3; n = 102). Models were estimated using structural equation modeling. In all cohorts, covariance patterns implied by the latent variable model were consistent with the observed data, as indicated by non-significant χ2 goodness of fit tests (no evidence of model misspecification). Cohort 1 analyses showed that the latent factor structure was stable across time points and child sexes. In both cohorts 1 and 3, the latent wheezing severity variable was prospectively associated with wheeze-related clinical outcomes, including physician asthma diagnosis, acute corticosteroid use, and wheeze-related outpatient medical visits when adjusting for confounders. We developed an easily applicable continuous latent variable model of pediatric wheezing severity based on items from the well-validated ISAAC Wheezing Module. This model prospectively associates with

  1. Birth cohort differences in cardiovascular risk factors in a Brazilian population of older elderly: the Bambuí cohort study of aging (1997 and 2008

    Directory of Open Access Journals (Sweden)

    Marco Polo Dias Freitas

    2011-01-01

    Full Text Available The aim of this study was to investigate whether cohort differences exist in the prevalence of cardiovascular risk factors among older elderly from the Bambuí Cohort Study of Aging. Participants were those aged 71-81 years at two points in time a decade apart: 457 in 1997 (earlier cohort and 553 in 2008 (recent cohort. The prevalence of hypertension (PR = 1.27; 95%CI: 1.19-1.36 and of diabetes mellitus (PR = 1.39; 95%CI: 1.06-1.83 was higher in the recent cohort compared to the earlier one, regardless of sex. The recent cohort had a lower prevalence of smoking (PR = 0.58; 95%CI: 0.42-0.80, and lower total cholesterol/HDL cholesterol ratio level (PR = 0.85; 95%CI: 0.80-0.89. There was a 136% increase in the pharmacologic treatment of diabetes and a 56% increase in pharmacologic management of hypertension in 2008 in comparison with 1997. Overall, the number of cardiovascular risk factors in the recent cohort remained similar to that of the early cohort.

  2. Prospective validation of a prognostic model for respiratory syncytial virus bronchiolitis in late preterm infants: a multicenter birth cohort study.

    Directory of Open Access Journals (Sweden)

    Maarten O Blanken

    Full Text Available This study aimed to update and validate a prediction rule for respiratory syncytial virus (RSV hospitalization in preterm infants 33-35 weeks gestational age (WGA.The RISK study consisted of 2 multicenter prospective birth cohorts in 41 hospitals. Risk factors were assessed at birth among healthy preterm infants 33-35 WGA. All hospitalizations for respiratory tract infection were screened for proven RSV infection by immunofluorescence or polymerase chain reaction. Multivariate logistic regression analysis was used to update an existing prediction model in the derivation cohort (n = 1,227. In the validation cohort (n = 1,194, predicted versus actual RSV hospitalization rates were compared to determine validity of the model.RSV hospitalization risk in both cohorts was comparable (5.7% versus 4.9%. In the derivation cohort, a prediction rule to determine probability of RSV hospitalization was developed using 4 predictors: family atopy (OR 1.9; 95%CI, 1.1-3.2, birth period (OR 2.6; 1.6-4.2, breastfeeding (OR 1.7; 1.0-2.7 and siblings or daycare attendance (OR 4.7; 1.7-13.1. The model showed good discrimination (c-statistic 0.703; 0.64-0.76, 0.702 after bootstrapping. External validation showed good discrimination and calibration (c-statistic 0.678; 0.61-0.74.Our prospectively validated prediction rule identifies infants at increased RSV hospitalization risk, who may benefit from targeted preventive interventions. This prediction rule can facilitate country-specific, cost-effective use of RSV prophylaxis in late preterm infants.

  3. Age, growth and population structure of invasive lionfish (Pterois volitans/miles in northeast Florida using a length-based, age-structured population model

    Directory of Open Access Journals (Sweden)

    Eric G. Johnson

    2016-12-01

    Full Text Available The effective management of invasive species requires detailed understanding of the invader’s life history. This information is essential for modeling population growth and predicting rates of expansion, quantifying ecological impacts and assessing the efficacy of removal and control strategies. Indo-Pacific lionfish (Pterois volitans/miles have rapidly invaded the western Atlantic, Gulf of Mexico and Caribbean Sea with documented negative impacts on native ecosystems. To better understand the life history of this species, we developed and validated a length-based, age-structured model to investigate age, growth and population structure in northeast Florida. The main findings of this study were: (1 lionfish exhibited rapid growth with seasonal variation in growth rates; (2 distinct cohorts were clearly identifiable in the length-frequency data, suggesting that lionfish are recruiting during a relatively short period in summer; and (3 the majority of lionfish were less than two years old with no lionfish older than three years of age, which may be the result of culling efforts as well as ontogenetic habitat shifts to deeper water.

  4. Age, growth and population structure of invasive lionfish (Pterois volitans/miles) in northeast Florida using a length-based, age-structured population model.

    Science.gov (United States)

    Johnson, Eric G; Swenarton, Mary Katherine

    2016-01-01

    The effective management of invasive species requires detailed understanding of the invader's life history. This information is essential for modeling population growth and predicting rates of expansion, quantifying ecological impacts and assessing the efficacy of removal and control strategies. Indo-Pacific lionfish ( Pterois volitans/miles ) have rapidly invaded the western Atlantic, Gulf of Mexico and Caribbean Sea with documented negative impacts on native ecosystems. To better understand the life history of this species, we developed and validated a length-based, age-structured model to investigate age, growth and population structure in northeast Florida. The main findings of this study were: (1) lionfish exhibited rapid growth with seasonal variation in growth rates; (2) distinct cohorts were clearly identifiable in the length-frequency data, suggesting that lionfish are recruiting during a relatively short period in summer; and (3) the majority of lionfish were less than two years old with no lionfish older than three years of age, which may be the result of culling efforts as well as ontogenetic habitat shifts to deeper water.

  5. Risk evaluations of aging phenomena: the linear aging reliability model and its extensions

    International Nuclear Information System (INIS)

    Vesely, W.E.

    1987-01-01

    A model for component failure rates due to aging mechanisms has been developed from basic phenomenological considerations. In the treatment, the occurrences of deterioration are modeled as following a Poisson process. The severity of damage is allowed to have any distribution, however the damage is assumed to accumulate independently. Finally, the failure rate is modeled as being proportional to the accumulated damage. Using this treatment, the linear aging failure rate model is obtained. The applicability of the linear aging model to various mechanisms is discussed. The model can be extended to cover nonlinear and dependent aging phenomena. The implementability of the linear aging model is demonstrated by applying it to the aging data collected in NRC's Nuclear Plant Aging Research (NPAR) Program. The applications show that aging as observed in collected data have significant effects on the component failure probability and component reliability when aging is not effectively detected and controlled by testing and maintenance

  6. Risk evaluations of aging phenomena: The linear aging reliability model and its extensions

    International Nuclear Information System (INIS)

    Vesely, W.E.

    1986-01-01

    A model for component failure rates due to aging mechanisms has been developed from basic phenomenological considerations. In the treatment, the occurrences of deterioration are modeled as following a Poisson process. The severity of damage is allowed to have any distribution, however the damage is assumed to accumulate independently. Finally, the failure rate is modeled as being proportional to the accumulated damage. Using this treatment, the linear aging failure rate model is obtained. The applicability of the linear aging model to various mechanisms is discussed. The model can be extended to cover nonlinear and dependent aging phenomena. The implementability of the linear aging model is demonstrated by applying it of the aging data collected in NRC's Nuclear Plant Aging Research (NPAR) Program. The applications show that aging as observed in collected data have significant effects on the component failure probability and component reliability when aging is not effectively detected and controlled by testing and maintenance

  7. Data from three prospective longitudinal human cohorts of prenatal marijuana exposure and offspring outcomes from the fetal period through young adulthood

    Directory of Open Access Journals (Sweden)

    Gabrielle L. McLemore

    2016-12-01

    Full Text Available This article includes data from three prospective longitudinal human cohorts of prenatal marijuana exposure (PME and offspring outcomes from the fetal period through young adulthood. The table herein contains an overview of the major adverse effects associated with PME from the following human cohorts: (1 The Ottawa Prenatal Prospective Study (OPPS; (2 The Maternal Health Practices and Child Development Study (MHPCD; and (3 The Generation R Study (Gen R. In the OPPS, fetal gestational age was measured and age-appropriate standardized neuropsychological instruments were used to assess neonatal responses, and infant–child and adolescent–young adult cognitive and behavioral skills. In the MHPCD, birth length and weight, neonatal body length, and infant–child sleep, cognition, and behavioral parameters were measured. In the Gen R, birth weight and growth were measured, as were infant–child attention and aggression. The data in this article are in support of our report entitled “Prenatal Cannabis Exposure - The "First Hit" to the Endocannabinoid System” (K.A. Richardson, A.K. Hester, G.L. McLemore, 2016 [13].

  8. Exposure-lag-response in Longitudinal Studies: Application of Distributed Lag Non-linear Models in an Occupational Cohort.

    Science.gov (United States)

    Neophytou, Andreas M; Picciotto, Sally; Brown, Daniel M; Gallagher, Lisa E; Checkoway, Harvey; Eisen, Ellen A; Costello, Sadie

    2018-02-13

    Prolonged exposures can have complex relationships with health outcomes, as timing, duration, and intensity of exposure are all potentially relevant. Summary measures such as cumulative exposure or average intensity of exposure may not fully capture these relationships. We applied penalized and unpenalized distributed lag non-linear models (DLNMs) with flexible exposure-response and lag-response functions in order to examine the association between crystalline silica exposure and mortality from lung cancer and non-malignant respiratory disease in a cohort study of 2,342 California diatomaceous earth workers, followed 1942-2011. We also assessed associations using simple measures of cumulative exposure assuming linear exposure-response and constant lag-response. Measures of association from DLNMs were generally higher than from simpler models. Rate ratios from penalized DLNMs corresponding to average daily exposures of 0.4 mg/m3 during lag years 31-50 prior to the age of observed cases were 1.47 (95% confidence interval (CI) 0.92, 2.35) for lung cancer and 1.80 (95% CI: 1.14, 2.85) for non-malignant respiratory disease. Rate ratios from the simpler models for the same exposure scenario were 1.15 (95% CI: 0.89-1.48) and 1.23 (95% CI: 1.03-1.46) respectively. Longitudinal cohort studies of prolonged exposures and chronic health outcomes should explore methods allowing for flexibility and non-linearities in the exposure-lag-response. © The Author(s) 2018. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

  9. Mortality rates for chronic lower respiratory diseases in Italy from 1979 to 2010: an age–period–cohort analysis

    Directory of Open Access Journals (Sweden)

    Giancarlo Pesce

    2016-03-01

    Full Text Available Chronic lower respiratory diseases (CLRDs are a major cause of morbidity and mortality worldwide. The objectives of this study were to estimate the trends in CLRD mortality in Italy, and the specific contributions of age, time period and birth cohort in driving these trends. Population and cause-of-death data in Italy between 1979 and 2010 were collected from the World Health Organization website. Age-specific mortality rates for CLRDs, and effects for age, time period and birth cohort on mortality trends were estimated using age–period–cohort models. Chronic obstructive pulmonary disease (COPD and chronic bronchitis represent nearly 98% of the deaths from CLRDs. Despite the overall number of deaths have been stable (in men or increasing (in women, the age-standardised rates have been steadily decreasing from 1979 to 2010, passing from 104.3 to 55.4 per 100 000 person-years in men and from 32.2 to 19.6 per 100 000 person-years in women. The average relative annual decrease was −3.6% in men and −2.7% in women. Since the end of the 1990s, the decreasing trend of CLRD mortality has started to level off, in particular in women. The decrease in CLRD mortality rates has been more accentuated in more recent cohorts and in younger age groups. Both birth cohort and time period significantly affected the CLRD mortality rates, suggesting that changes in the spread of risk factors (smoking habits, early-life and occupational exposures across different birth cohorts, as well as in advanced in healthcare and medical practice, may have played a major role in secular changes in COPD mortality rates in Italy.

  10. Mode of Delivery and Asthma at School Age in 9 European Birth Cohorts

    DEFF Research Database (Denmark)

    Rusconi, Franca; Zugna, Daniela; Annesi-Maesano, Isabella

    2017-01-01

    Evidence on the association between mode of delivery and asthma at school age is inconclusive. We assessed the associations between specific modes of delivery and asthma in children from 9 European birth cohorts that enrolled participants between 1996 and 2006. Cohort-specific crude and adjusted ...

  11. Prospective comparative effectiveness cohort study comparing two models of advance care planning provision for Australian community aged care clients.

    Science.gov (United States)

    Detering, Karen Margaret; Carter, Rachel Zoe; Sellars, Marcus William; Lewis, Virginia; Sutton, Elizabeth Anne

    2017-12-01

    Conduct a prospective comparative effectiveness cohort study comparing two models of advance care planning (ACP) provision in community aged care: ACP conducted by the client's case manager (CM) ('Facilitator') and ACP conducted by an external ACP service ('Referral') over a 6-month period. This Australian study involved CMs and their clients. Eligible CM were English speaking, ≥18 years, had expected availability for the trial and worked ≥3 days per week. CMs were recruited via their organisations, sequentially allocated to a group and received education based on the group allocation. They were expected to initiate ACP with all clients and to facilitate ACP or refer for ACP. Outcomes were quantity of new ACP conversations and quantity and quality of new advance care directives (ACDs). 30 CMs (16 Facilitator, 14 Referral) completed the study; all 784 client's files (427 Facilitator, 357 Referral) were audited. ACP was initiated with 508 (65%) clients (293 Facilitator, 215 Referral; p<0.05); 89 (18%) of these (53 Facilitator, 36 Referral) and 41 (46%) (13 Facilitator, 28 Referral; p<0.005) completed ACDs. Most ACDs (71%) were of poor quality/not valid. A further 167 clients (facilitator 124; referral 43; p<0.005) reported ACP was in progress at study completion. While there were some differences, overall, models achieved similar outcomes. ACP was initiated with 65% of clients. However, fewer clients completed ACP, there was low numbers of ACDs and document quality was generally poor. The findings raise questions for future implementation and research into community ACP provision. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Neurodevelopmental outcome at 5 years of age of a national cohort of extremely low birth weight infants who were born in 1996-1997.

    Science.gov (United States)

    Mikkola, Kaija; Ritari, Niina; Tommiska, Viena; Salokorpi, Teija; Lehtonen, Liisa; Tammela, Outi; Pääkkönen, Leena; Olsen, Päivi; Korkman, Marit; Fellman, Vineta

    2005-12-01

    Increasing survival of extremely low birth weight (ELBW; birth weight infants raises a concern regarding the risks of adverse long-term outcome such as cognitive dysfunction. Few studies have reported long-term follow-up of representative regional cohorts. The objective of this study was to assess the 5-year outcome of a prospectively followed national ELBW infant cohort. Of all live-born ELBW infants (n = 351) who were delivered in the 2-year period 1996-1997 in Finland, 206 (59%) survived until the age of 5 years. Of these, 103 were born at infants who were born at memory values of NEPSY assessment were significantly poorer compared with normal population means. Four percent needed a hearing aid, and 30% had ophthalmic findings. Of 21 children who had been treated with laser/cryo for retinopathy of prematurity, 17 (81%) had abnormal ophthalmic findings. Of the whole cohort, 41 (20%) exhibited major disabilities, 38 (19%) exhibited minor disabilities, and 124 (61%) showed development with no functional abnormalities but subtle departures from the norm. Only 53 (26%) of the total ELBW infant cohort were classified to have normal outcome excluding any abnormal ophthalmic, auditory, neurologic, or developmental findings. Being small for gestational age at birth was associated with suboptimal growth at least until age 5. Only one fourth of the ELBW infants were classified as normally developed at age 5. The high rate of cognitive dysfunction suggests an increased risk for learning difficulties that needs to be evaluated at a later age. Extended follow-up should be the rule in outcome studies of ELBW infant cohorts to elucidate the impact of immaturity on school achievement and social behavior later in life.

  13. Activities and sources of income after a period of long-term sick leave - a population-based prospective cohort study

    Directory of Open Access Journals (Sweden)

    Wikman Anders

    2012-09-01

    Full Text Available Abstract Background There is limited knowledge about what happens to people after long-term sick leave. The aim of this report was to conduct a prospective study of individuals who were on prolonged sick leave during a particular year, considering their activities and sources of income during subsequent years. To enable comparison of different time periods, we used three cohorts of individuals with different starting years. Methods Using data from national registers, three separate cohorts were constructed that included all people living in Sweden who were 20-64 years of age (>5 million in the years 1995, 2000 and 2005, respectively. The individual members of the cohorts were classified into the following groups based on their main source of income and activity in 1995-2008: on long-term sick leave, employed, old-age pensioner, long-term unemployed, disability pensioner, on parental leave, social assistance recipient, student allowance recipient, deceased, or emigrated. Results Most individuals on long-term (> 6 months sick leave in 1995 were not employed 13 years later. Only 11% of the women and 13% of the men were primarily in employment after 13 years. Instead, a wide range of alternatives existed, for example, many had been granted disability pension, and about 10% of the women and 17% of the men had died during the follow-up period. A larger proportion of those with long-term sick leave were back in employment when 2005 was the starting year for the follow-up. Conclusions The low future employment rates for people on long-term sick leave may seem surprising. There are several possible explanations for the finding: The disorders these people may have, might have entailed longstanding difficulties on the labor market. Besides, long-term absence from work, no matter what its causes were, might have worsen the chances of further employment. The economic cycles may also have been of importance. The improving labor market during later years seems

  14. Activities and sources of income after a period of long-term sick leave--a population-based prospective cohort study.

    Science.gov (United States)

    Wikman, Anders; Wiberg, Michael; Marklund, Staffan; Alexanderson, Kristina

    2012-09-06

    There is limited knowledge about what happens to people after long-term sick leave. The aim of this report was to conduct a prospective study of individuals who were on prolonged sick leave during a particular year, considering their activities and sources of income during subsequent years. To enable comparison of different time periods, we used three cohorts of individuals with different starting years. Using data from national registers, three separate cohorts were constructed that included all people living in Sweden who were 20-64 years of age (>5 million) in the years 1995, 2000 and 2005, respectively. The individual members of the cohorts were classified into the following groups based on their main source of income and activity in 1995-2008: on long-term sick leave, employed, old-age pensioner, long-term unemployed, disability pensioner, on parental leave, social assistance recipient, student allowance recipient, deceased, or emigrated. Most individuals on long-term (> 6 months) sick leave in 1995 were not employed 13 years later. Only 11% of the women and 13% of the men were primarily in employment after 13 years. Instead, a wide range of alternatives existed, for example, many had been granted disability pension, and about 10% of the women and 17% of the men had died during the follow-up period. A larger proportion of those with long-term sick leave were back in employment when 2005 was the starting year for the follow-up. The low future employment rates for people on long-term sick leave may seem surprising. There are several possible explanations for the finding: The disorders these people may have, might have entailed longstanding difficulties on the labor market. Besides, long-term absence from work, no matter what its causes were, might have worsen the chances of further employment. The economic cycles may also have been of importance. The improving labor market during later years seems to have improved the chances for employment among those earlier

  15. The individual determinants of care-seeking among middle-aged women reporting urinary incontinence: analysis of a 2273-woman cohort.

    Science.gov (United States)

    Fritel, Xavier; Panjo, Henri; Varnoux, Noëlle; Ringa, Virginie

    2014-09-01

    Our main objective was to analyze individual determinants that lead middle-aged women to seek medical care for urinary incontinence (UI). Observational longitudinal study among GAZEL cohort participants: 2,640 women aged 50-62 completed a self-administered questionnaire at baseline. Eight years later (2008) 2,273 (86%) responded to a follow-up questionnaire. Seeking care for UI was defined as any consultation for UI during the 8-year follow-up period. Individual determinants considered in the regression analysis were social and demographic characteristics, social relations, UI type and severity, and other health factors. Among 1,192 women reporting incontinence at baseline, 24.4% had visited a physician at least once for UI during the follow-up period (56.0% of those reporting severe UI). The care-seeking rate increased with age at baseline. Multivariate analysis showed that women who reported severe UI (OR = 4.1; 95% CI 2.6-6.5), mixed UI (2.0; 1.3-3.0), or neurologic disease (1.6; 1.1-2.6), had weak social support (1.4; 1.0-2.0), or talked about their UI with close friends or family (1.5; 1.0-2.1) were more likely to seek care for UI. A model including these factors had a 78% probability of correctly differentiating women with incontinence who chose to seek care from those who did not. Our analysis could not take factors related to the organization of health services into account. Women do not always seek care for UI, even when it is severe. Besides UI severity and type, consultation is associated with aging, weak social support, conversation about it with close friends and family, and neurologic disorders. © 2013 Wiley Periodicals, Inc.

  16. Extensions and applications of degradation modeling

    International Nuclear Information System (INIS)

    Hsu, F.; Subudhi, M.; Samanta, P.K.; Vesely, W.E.

    1991-01-01

    Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, the authors discuss some of the extensions and applications of degradation modeling. The extensions and applications of the degradation modeling approaches discussed are: (a) theoretical developments to study reliability effects of different maintenance strategies and policies, (b) relating aging-failure rate to degradation rate, and (c) application to a continuously operating component

  17. Green space and cognitive ageing: A retrospective life course analysis in the Lothian Birth Cohort 1936.

    Science.gov (United States)

    Cherrie, Mark P C; Shortt, Niamh K; Mitchell, Richard J; Taylor, Adele M; Redmond, Paul; Thompson, Catharine Ward; Starr, John M; Deary, Ian J; Pearce, Jamie R

    2018-01-01

    International evidence suggests that green space has beneficial effects on general and mental health but little is known about how lifetime exposure to green space influences cognitive ageing. Employing a novel longitudinal life course approach, we examined the association between lifetime availability of public parks and cognitive ageing. Lifetime residential information was gathered from the participants of the Lothian Birth Cohort 1936 using a "life-grid" questionnaire at age 78 years. Parks information from 1949, 1969 and 2009 was used to determine a percentage of parks within a 1500 m buffer zone surrounding residence for childhood, adulthood, and later adulthood periods. Linear regressions were undertaken to test for association with age-standardised, residualised change in cognitive function (Moray House Test score) from age 11 to 70 years, and from age 70 to 76 (n = 281). The most appropriate model was selected using the results of a partial F-test, and then stratified by demographic, genetic and socioeconomic factors. The local provision of park space in childhood and adulthood were both important in explaining the change in cognitive function in later life. The association between childhood and adulthood park availability and change in the Moray House Test Score from age 70 to 76 was strongest for women, those without an APOE e4 allele (a genetic risk factor), and those in the lowest socioeconomic groups. Greater neighbourhood provision of public parks from childhood through to adulthood may help to slow down the rate of cognitive decline in later life, recognising that such environmental associations are always sensitive to individual characteristics. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Changing attitudes toward aging policy in the United States during the 1980s and 1990s: a cohort analysis.

    Science.gov (United States)

    Silverstein, M; Angelelli, J J; Parrott, T M

    2001-01-01

    This research assessed how the attitudes of Americans toward government programs that serve older people changed between the mid-1980s and late 1990s and how much of the shift was dueto intracohort change and how much was due to cohort replacement. Data come from three nationally representative cross-sectional samples, surveyed by telephone in 1986 (N = 1.209), 1990 (N = 1,500), and 1997 (N = 1,559). Attitudes of Americans have become less supportive of expanding entitlement programs for older people and more supportive of cutting their costs and benefits. Between 1986 and 1997, most cohorts, particularly older adults, grew more in favor of maintaining Social Security benefit levels but less in favor of expanding them. Young adults tended to be driving the societal shift in attitudes toward decreasing benefits. Intercohort change was more important than cohort replacement in this process. Analyses of change in 2 attitude domains between 1990 and 1997 revealed that the general population felt less strongly that older people are entitled to benefits and expressed greater opposition to the associated costs. However, young adults moderated their concerns about costs as they got older, although the young adults in the cohort replacing them had become more critical of the principle of entitlement. These findings enhance the understanding of the roles that historical conditions and aging play in shaping the attitudes of adult cohorts toward public programs for older citizens. Discrepant findings based on the intercohort change in younger age groups are reconciled by differentiating maturation effects from period effects on impressionable youth.

  19. Attachment to place in advanced age: A study of the LiLACS NZ cohort.

    Science.gov (United States)

    Wiles, Janine L; Rolleston, Anna; Pillai, Avinesh; Broad, Joanna; Teh, Ruth; Gott, Merryn; Kerse, Ngaire

    2017-07-01

    An extensive body of research theorises that attachment to place is positively associated with health, particularly for older people. Building on this, we measure how indicators of attachment to place are associated with health for in people of advanced age in New Zealand. We use data from a cohort study (LiLACS NZ), which includes an indigenous Māori cohort aged 80-90 years and a non-Māori cohort aged 85 years from a mixed urban/rural region in New Zealand. Each cohort undertook a comprehensive interview and health assessment (n = 267 Māori and n = 404 non-Māori). Using multivariate regression analyses, we explore participants' feelings for and connectedness with their home, community and neighbourhood; nature and the outdoors; expectations about and enthusiasm for residential mobility; and how all these are associated with measures of health (e.g., SF-12 physical and mental health related quality of life) and functional status (e.g., NEADL). We demonstrate that people in advanced age hold strong feelings of attachment to place. We also establish some positive associations between attachment to place and health in advanced age, and show how these differ for the indigenous and non-indigenous cohorts. For older Māori there were strong associations between various health measures and the importance of nature and the outdoors, and connectedness to neighbourhood and community. For older non-Māori, there were strong associations between health and liking home and neighbourhood, and feeling connected to their community and neighbourhood. Place attachment, and particularly its relationship to health, operates in different ways for different groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Mutation risk associated with paternal and maternal age in a cohort of retinoblastoma survivors.

    Science.gov (United States)

    Mills, Melissa B; Hudgins, Louanne; Balise, Raymond R; Abramson, David H; Kleinerman, Ruth A

    2012-07-01

    Autosomal dominant conditions are known to be associated with advanced paternal age, and it has been suggested that retinoblastoma (Rb) also exhibits a paternal age effect due to the paternal origin of most new germline RB1 mutations. To further our understanding of the association of parental age and risk of de novo germline RB1 mutations, we evaluated the effect of parental age in a cohort of Rb survivors in the United States. A cohort of 262 Rb patients was retrospectively identified at one institution, and telephone interviews were conducted with parents of 160 survivors (65.3%). We classified Rb survivors into three groups: those with unilateral Rb were classified as sporadic if they had no or unknown family history of Rb, those with bilateral Rb were classified as having a de novo germline mutation if they had no or unknown family history of Rb, and those with unilateral or bilateral Rb, who had a family history of Rb, were classified as familial. We built two sets of nested logistic regression models to detect an increased odds of the de novo germline mutation classification related to older parental age compared to sporadic and familial Rb classifications. The modeling strategy evaluated effects of continuous increasing maternal and paternal age and 5-year age increases adjusted for the age of the other parent. Mean maternal ages for survivors classified as having de novo germline mutations and sporadic Rb were similar (28.3 and 28.5, respectively) as were mean paternal ages (31.9 and 31.2, respectively), and all were significantly higher than the weighted general US population means. In contrast, maternal and paternal ages for familial Rb did not differ significantly from the weighted US general population means. Although we noted no significant differences between mean maternal and paternal ages between each of the three Rb classification groups, we found increased odds of a survivor being in the de novo germline mutation group for each 5-year increase in

  1. National cohort study of absolute risk and age-specific incidence of multiple adverse outcomes between adolescence and early middle age.

    Science.gov (United States)

    Mok, Pearl L H; Antonsen, Sussie; Pedersen, Carsten Bøcker; Appleby, Louis; Shaw, Jenny; Webb, Roger T

    2015-09-19

    Psychiatric illness, substance misuse, suicidality, criminality and premature death represent major public health challenges that afflict a sizeable proportion of young people. However, studies of multiple adverse outcomes in the same cohort at risk are rare. In a national Danish cohort we estimated sex- and age-specific incidence rates and absolute risks of these outcomes between adolescence and early middle age. Using interlinked registers, persons born in Denmark 1966-1996 were followed from their 15(th) until 40(th) birthday or December 2011 (N = 2,070,904). We estimated sex- and age-specific incidence rates of nine adverse outcomes, in three main categories: Premature mortality (all-causes, suicide, accident); Psychiatric morbidity (any mental illness diagnosis, suicide attempt, alcohol or drug misuse disorder); Criminality (violent offending, receiving custodial sentence, driving under influence of alcohol or drugs). Cumulative incidences were also calculated using competing risk survival analyses. For cohort members alive on their 15(th) birthday, the absolute risks of dying by age 40 were 1.99 % for males [95 % confidence interval (CI) 1.95-2.03 %] and 0.85 % for females (95 % CI 0.83-0.88 %). The risks of substance misuse and criminality were also much higher for males, especially younger males, than for females. Specifically, the risk of a first conviction for a violent offence was highest amongst males aged below 20. Females, however, were more likely than males to have a hospital-treated psychiatric disorder. By age 40, 13.25 % of females (95 % CI 13.16-13.33 %) and 9.98 % of males (95 % CI 9.91-10.06 %) had been treated. Women aged below 25 were also more likely than men to first attempt suicide, but this pattern was reversed beyond this age. The greatest gender differentials in incidence rates were in criminality outcomes. This is the first comprehensive assessment of the incidence rates and absolute risks of these multiple adverse outcomes

  2. Protective versus risk factors for self-objectification in different age and gender cohorts

    Directory of Open Access Journals (Sweden)

    Rollero Chiara

    2018-01-01

    Full Text Available The harmful effects of objectification and self-objectification have been widely investigated, but few studies have examined factors that may predict self-objectification. This research intends to assess the protective versus risk role of sociodemographic and physical characteristics (age, BMI, psychosocial variables (self-esteem; self-oriented perfectionism and socially prescribed perfectionism, and social factors (influence of family and friends; internalization of media standards on self-objectification in men and women. The selfobjectification was assessed with two subscales of the Objectified Body Consciousness Scale: Body Shame and Body Surveillance. Participants were 812 Italian adults of different age cohorts (age range 21–60 years; 50.7% females recruited via a quota sampling method. Two regression models separately for males and females were performed. Results showed that mass media influence was the strongest predictor for body surveillance and body shame in both men and women, whereas gender-related patterns emerged for physical, psychological, and relational variables with age as moderator.

  3. Age at death of major cardiovascular diseases in 13 cohorts. The seven countries study of cardiovascular diseases 45-year follow-up.

    Science.gov (United States)

    Menotti, Alessandro; Puddu, Paolo Emilio; Tolonen, Hanna; Adachi, Hisashi; Kafatos, Anthony; Kromhout, Daan

    2018-03-23

    To explore age at death (AD) for major cardiovascular diseases (CVD) and their risk factors in originally middle-aged men followed nearly to extinction in the Seven Countries Study. Thirteen cohorts of men aged 40-59 years (N = 10,628) in seven countries (USA, Finland, the Netherlands, Italy, Serbia, Greece, Japan) were enrolled in late 1950s and early 1960s and were followed 45 years for mortality. AD was computed for coronary heart disease (CHD), stroke (STR), heart disease of uncertain aetiology (HDUE) and for all-causes. AD was compared across CHD-HDUE-STR. Cox models were computed for each end-point using baseline age, cigarettes smoking, systolic blood pressure and serum cholesterol. After 45 years 92.9% of men had died. The most common CVD death was CHD in most cohorts except some Mediterranean and Japanese cohorts where STR or HDUE were most prevalent. In 13 cohorts mean AD was 74.5, 73.5, 75.7 and 79.1 years, respectively, for all-cause, CHD, STR and HDUE mortality (all possible differences were significant). The difference, across cohorts, between the highest and the lowest mean AD was 12.9, 9.0 and 4.7 years for CHD, HDUE and STR mortality, respectively. Risk factors explored were significant predictors of all three CVD end-points, except serum cholesterol, specific to CHD mortality. AD is a useful indicator of previous health and aging populations. STR and HDUE are diseases appearing later in life, thus being associated with a higher AD compared with CHD mortality.

  4. Benefits Gained, Benefits Lost: Comparing Baby Boomers to Other Generations in a Longitudinal Cohort Study of Self-Rated Health

    Science.gov (United States)

    BADLEY, ELIZABETH M; CANIZARES, MAYILEE; PERRUCCIO, ANTHONY V; HOGG-JOHNSON, SHEILAH; GIGNAC, MONIQUE AM

    2015-01-01

    Policy Points Despite beliefs that baby boomers are healthier than previous generations, we found no evidence that the health of baby boomers is substantially different from that of the previous or succeeding cohorts. The effects of increased education, higher income, and lower smoking rates on improving self-rated health were nearly counterbalanced by the adverse effect of increasing body mass index (BMI). Assumptions that baby boomers will require less health care as they age because of better education, more prosperity, and less propensity to smoke may not be realized because of increases in obesity. Context Baby boomers are commonly believed to be healthier than the previous generation. Using self-rated health (SRH) as an indicator of health status, this study examines the effects of age, period, and birth cohort on the trajectory of health across 4 generations: World War II (born between 1935 and 1944), older baby boomers (born between 1945 and 1954), younger baby boomers (born between 1955 and 1964), and Generation X (born between 1965 and 1974). Methods We analyzed Canada’s longitudinal National Population Health Survey 1994-2010 (n = 8,570 at baseline), using multilevel growth models to estimate the age trajectory of SRH by cohort, accounting for period and incorporating the influence of changes in education, household income, smoking status, and body mass index (BMI) on SRH over time. Findings SRH worsened with increasing age in all cohorts. Cohort differences in SRH were modest (p = 0.034), but there was a significant period effect (p = 0.002). We found marked cohort effects for increasing education, income, and BMI, and decreasing smoking from the youngest to the oldest cohorts, which were much reduced (education and smoking) or removed (income and BMI) once period was taken into account. At the population level, multivariable analysis showed the benefits of increasing education and income and declines in smoking on the trajectory of improving SRH were

  5. Case-Cohort Studies: Design and Applicability to Hand Surgery.

    Science.gov (United States)

    Vojvodic, Miliana; Shafarenko, Mark; McCabe, Steven J

    2018-04-24

    Observational studies are common research strategies in hand surgery. The case-cohort design offers an efficient and resource-friendly method for risk assessment and outcomes analysis. Case-cohorts remain underrepresented in upper extremity research despite several practical and economic advantages over case-control studies. This report outlines the purpose, utility, and structure of the case-cohort design and offers a sample research question to demonstrate its value to risk estimation for adverse surgical outcomes. The application of well-designed case-cohort studies is advocated in an effort to improve the quality and quantity of observational research evidence in hand and upper extremity surgery. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  6. Air Pollution and Cognitive Development at Age 7 in a Prospective Italian Birth Cohort.

    Science.gov (United States)

    Porta, Daniela; Narduzzi, Silvia; Badaloni, Chiara; Bucci, Simone; Cesaroni, Giulia; Colelli, Valentina; Davoli, Marina; Sunyer, Jordi; Zirro, Eleonora; Schwartz, Joel; Forastiere, Francesco

    2016-03-01

    Early life exposure to air pollution has been linked with cognitive impairment in children, but the results have not been conclusive. We analyzed the association between traffic-related air pollution and cognitive function in a prospective birth cohort in Rome. A cohort of 719 newborns was enrolled in 2003-2004 as part of the GASPII project. At age 7 years, 474 children took the Wechsler Intelligence Scale for Children-III to assess their cognitive development in terms of IQ composite scores. Exposure to air pollutants (NO2, PMcoarse, PM2.5, PM2.5 absorbance) at birth was assessed using land use regression models. We also considered variables indicating traffic intensity. The effect of environmental pollution on IQ was evaluated performing a linear regression model for each outcome, adjusting for gender, child age at cognitive test, maternal age at delivery, parental educational level, siblings, socio-economic status, maternal smoking during pregnancy, and tester. To account for selection bias at enrollment and during follow-up, the regression models were weighted for the inverse probabilities of participation and follow-up. A 10 μg/m³ higher NO2 exposure during pregnancy was associated with 1.4 fewer points (95% confidence interval = -2.6, -0.20) of verbal IQ, and 1.4 fewer points (95% confidence interval = -2.7, -0.20) of verbal comprehension IQ. Similar associations were found for traffic intensity in a 100 m buffer around home. Other pollutants showed negative associations with larger confidence intervals. Consistent with previous evidence, this study suggests an association of exposure to NO2 and traffic intensity with the verbal area of cognitive development.See Video Abstract at http://links.lww.com/EDE/B12.

  7. Development and validation of a predictive model for excessive postpartum blood loss: A retrospective, cohort study.

    Science.gov (United States)

    Rubio-Álvarez, Ana; Molina-Alarcón, Milagros; Arias-Arias, Ángel; Hernández-Martínez, Antonio

    2018-03-01

    postpartum haemorrhage is one of the leading causes of maternal morbidity and mortality worldwide. Despite the use of uterotonics agents as preventive measure, it remains a challenge to identify those women who are at increased risk of postpartum bleeding. to develop and to validate a predictive model to assess the risk of excessive bleeding in women with vaginal birth. retrospective cohorts study. "Mancha-Centro Hospital" (Spain). the elaboration of the predictive model was based on a derivation cohort consisting of 2336 women between 2009 and 2011. For validation purposes, a prospective cohort of 953 women between 2013 and 2014 were employed. Women with antenatal fetal demise, multiple pregnancies and gestations under 35 weeks were excluded METHODS: we used a multivariate analysis with binary logistic regression, Ridge Regression and areas under the Receiver Operating Characteristic curves to determine the predictive ability of the proposed model. there was 197 (8.43%) women with excessive bleeding in the derivation cohort and 63 (6.61%) women in the validation cohort. Predictive factors in the final model were: maternal age, primiparity, duration of the first and second stages of labour, neonatal birth weight and antepartum haemoglobin levels. Accordingly, the predictive ability of this model in the derivation cohort was 0.90 (95% CI: 0.85-0.93), while it remained 0.83 (95% CI: 0.74-0.92) in the validation cohort. this predictive model is proved to have an excellent predictive ability in the derivation cohort, and its validation in a latter population equally shows a good ability for prediction. This model can be employed to identify women with a higher risk of postpartum haemorrhage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Is hypertension in adult age related to unemployment at a young age? Results from the Northern Swedish Cohort.

    Science.gov (United States)

    Nygren, Karina; Gong, Weidan; Hammarström, Anne

    2015-02-01

    The aim of this study was to analyse the relationship between early unemployment (ages 16-21 years) and adult hypertension after controlling for earlier hypertension, unemployment in adult life, risk factors for hypertension and confounders. A cohort of 927 (86.6% of the original cohort) 9th grade school-leavers was followed from 1981 until 2008. Data were collected through questionnaires, health examinations, and national registers. Univariate and multivariate logistic regression were used as primary statistical methods. At ages 21 and 43, hypertension was significantly more prevalent among men than women (p Unemployment between the ages of 16 and 21 was related to hypertension at age 43 among women but not men. The odds ratio (OR) was persistently high (OR 3.16 [95% confidence interval 1.45-6.89]) after controlling for late unemployment, hypertension at age 16, risk factors for hypertension and confounders. There was no significant relationship between exposure to early unemployment and hypertension at age 21 for women or men. From a public health perspective, youth unemployment is a societal problem in need of more attention and intervention in order to prevent long-term adverse health outcomes. © 2014 the Nordic Societies of Public Health.

  9. Multi-Cohort Stand Structural Classification: Ground- and LiDAR-based Approaches for Boreal Mixedwood and Black Spruce Forest Types of Northeastern Ontario

    Science.gov (United States)

    Kuttner, Benjamin George

    Natural fire return intervals are relatively long in eastern Canadian boreal forests and often allow for the development of stands with multiple, successive cohorts of trees. Multi-cohort forest management (MCM) provides a strategy to maintain such multi-cohort stands that focuses on three broad phases of increasingly complex, post-fire stand development, termed "cohorts", and recommends different silvicultural approaches be applied to emulate different cohort types. Previous research on structural cohort typing has relied upon primarily subjective classification methods; in this thesis, I develop more comprehensive and objective methods for three common boreal mixedwood and black spruce forest types in northeastern Ontario. Additionally, I examine relationships between cohort types and stand age, productivity, and disturbance history and the utility of airborne LiDAR to retrieve ground-based classifications and to extend structural cohort typing from plot- to stand-levels. In both mixedwood and black spruce forest types, stand age and age-related deadwood features varied systematically with cohort classes in support of an age-based interpretation of increasing cohort complexity. However, correlations of stand age with cohort classes were surprisingly weak. Differences in site productivity had a significant effect on the accrual of increasingly complex multi-cohort stand structure in both forest types, especially in black spruce stands. The effects of past harvesting in predictive models of class membership were only significant when considered in isolation of age. As an age-emulation strategy, the three cohort model appeared to be poorly suited to black spruce forests where the accrual of structural complexity appeared to be more a function of site productivity than age. Airborne LiDAR data appear to be particularly useful in recovering plot-based cohort types and extending them to the stand-level. The main gradients of structural variability detected using Li

  10. Age in antiretroviral therapy programmes in South Africa: a multi-centre observational cohort study

    Science.gov (United States)

    Cornell, Morna; Johnson, Leigh F; Schomaker, Michael; Tanser, Frank; Maskew, Mhairi; Wood, Robin; Prozesky, Hans; Giddy, Janet; Stinson, Kathryn; Egger, Matthias; Boulle, Andrew; Myer, Landon

    2015-01-01

    Background As access to antiretroviral therapy (ART) expands, increasing numbers of older patients will start treatment and require specialised long-term care. However the impact of age in ART programs in resource-constrained settings is poorly understood. South Africa has the second largest population of older (≥50 years) people in sub-Saharan Africa. The HIV epidemic is also ageing rapidly and the country has one of the highest HIV population prevalences worldwide. This study explored the effect of age on mortality on ART in South Africa and whether this effect was mediated by baseline immunologic status. Methods IeDEA-SA is a regional collaboration which combines routine observational data from large ART programmes across Southern Africa. This study was a retrospective cohort analysis of adults starting ART from 2004-2013 in six large South African cohorts: two primary care clinics, three hospitals and a large rural cohort. The primary outcome was mortality; secondary outcomes were loss to follow-up (LTF), immunologic and virologic responses. Patients' vital status was ascertained through linkage to the National Population Register. Inverse probability weighting was used to correct mortality for LTF. Mortality was estimated using Cox's proportional hazards and competing risks regression. The interaction between baseline CD4+ cell count and age was tested. Immunologic responses were graphed by age and duration on ART. Findings 83 566 patients were followed for 174 640 patient-years. Patients were predominantly female, especially in the younger age groups: 81% (18 819/23 258) of patients 16-29 years and 66% (12 812/19 372) of those aged 30-34. Mortality increased with age in a dose response, mediated by baseline immunologic status. Patients with CD4 counts <50 cells/μL were a particularly high risk group, comprising 14% of all older patients starting ART. The percentage of older patients enrolling increased with successive calendar years from 6% (290/4 999) in

  11. Vision and Intelligence at Age 83 in the Lothian Birth Cohort 1921

    Science.gov (United States)

    Henderson, Ross D.; Allerhand, Michael; Patton, Niall; Pattie, Alison; Gow, Alan J.; Dhillon, Baljean; Starr, John M.; Deary, Ian J.

    2011-01-01

    The extent to which visual function, measured as near and distant visual acuity and contrast sensitivity, is correlated with concurrently measured cognitive function and prior intellectual ability was investigated in a narrow age range group known as the Lothian Birth Cohort of 1921 (LBC1921). Participants were aged approximately 83 years at the…

  12. Cognitive development in children up to age 11 years born after ART-a longitudinal cohort study.

    Science.gov (United States)

    Barbuscia, Anna; Mills, Melinda C

    2017-07-01

    between ART and NC groups. Growth curve models (random-coefficient, latent trajectory models) were used to study the effect of ART, confounding parental characteristics and health outcomes at birth, both at a baseline level of cognitive ability at age 3 years and on its growth rate. At age 3 and 5 years, children conceived with the aid of ART have higher verbal cognitive abilities than NC children (P children's cognitive development. The sample size of the ART cohort of children is small across each time period (N = 150-180) in comparison with NC children (N = 10 496-11 955). Owing to a limited sample size, we are also unable to compare IVF versus ICSI treatment. With the increasing use of IVF and ICSI, these results indicate that there are no detrimental effects on children's early cognitive outcomes up to age 11 years, and highlight the importance of parental characteristics. Funding for this project was provided by the European Union's Seventh Framework Program (FP7 2007-2013) (No. 320116 Families and Societies), ESRC/NCRM SOCGEN Grant (ES/N0011856/1) and the SOCIOGENOME ERC Consolidator Grant (ERC-2013-CoG-615603) (to M.C.M.). The authors have no competing interests to declare. N/A. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

  13. Modeling Interdependent and Periodic Real-World Action Sequences

    Science.gov (United States)

    Kurashima, Takeshi; Althoff, Tim; Leskovec, Jure

    2018-01-01

    Mobile health applications, including those that track activities such as exercise, sleep, and diet, are becoming widely used. Accurately predicting human actions in the real world is essential for targeted recommendations that could improve our health and for personalization of these applications. However, making such predictions is extremely difficult due to the complexities of human behavior, which consists of a large number of potential actions that vary over time, depend on each other, and are periodic. Previous work has not jointly modeled these dynamics and has largely focused on item consumption patterns instead of broader types of behaviors such as eating, commuting or exercising. In this work, we develop a novel statistical model, called TIPAS, for Time-varying, Interdependent, and Periodic Action Sequences. Our approach is based on personalized, multivariate temporal point processes that model time-varying action propensities through a mixture of Gaussian intensities. Our model captures short-term and long-term periodic interdependencies between actions through Hawkes process-based self-excitations. We evaluate our approach on two activity logging datasets comprising 12 million real-world actions (e.g., eating, sleep, and exercise) taken by 20 thousand users over 17 months. We demonstrate that our approach allows us to make successful predictions of future user actions and their timing. Specifically, TIPAS improves predictions of actions, and their timing, over existing methods across multiple datasets by up to 156%, and up to 37%, respectively. Performance improvements are particularly large for relatively rare and periodic actions such as walking and biking, improving over baselines by up to 256%. This demonstrates that explicit modeling of dependencies and periodicities in real-world behavior enables successful predictions of future actions, with implications for modeling human behavior, app personalization, and targeting of health interventions. PMID

  14. Infant eczema, infant sleeping problems, and mental health at 10 years of age: the prospective birth cohort study LISAplus.

    Science.gov (United States)

    Schmitt, J; Chen, C-M; Apfelbacher, C; Romanos, M; Lehmann, I; Herbarth, O; Schaaf, B; Kraemer, U; von Berg, A; Wichmann, H-E; Heinrich, J

    2011-03-01

    Cross-sectional studies suggest an association between eczema and mental health problems, possibly modified by sleeping problems, but prospective evidence is missing. We aimed to prospectively investigate the relationship between infant eczema (within first 2 years of age), infant sleeping problems (within first 2 years of age), and the risk of mental health problems at 10 years of age. Between 1997 and 1999, a population-based birth cohort was recruited in Munich, Leipzig, Wesel, and Bad Honnef, Germany, and followed until 10 years of age. Physician-diagnosed eczema, parent-reported sleeping problems, and known environmental risk factors for atopy were regularly assessed until 10 years of age. Mental health was measured using the Strengths and Difficulties Questionnaire (parent version) at 10 years of age. We applied logistic regression modeling adjusting for environmental and lifestyle factors, allergic comorbidity, and family history of eczema. From the original cohort of 3097 neonates, 1658 (54%) were followed until age 10, while 1578 (51%) were eligible for analysis. In the fully adjusted model, children with infant eczema were at increased risk of hyperactivity/inattention at 10 years of age [odds ratio (OR) 1.78; 95% confidence interval (95% CI) 1.02-3.09]. Infant eczema with concurrent sleeping problems predicted emotional problems [OR 2.63; 95% confidence interval (95% CI) 1.20-5.76] and conduct problems (OR 3.03; 95% CI 1.01-9.12) at 10 years of age. Infant eczema with concurrent sleeping problems appears to be a risk factor for the development of mental health problems. © 2010 John Wiley & Sons A/S.

  15. Applications and extensions of degradation modeling

    International Nuclear Information System (INIS)

    Hsu, F.; Subudhi, M.; Samanta, P.K.; Vesely, W.E.

    1991-01-01

    Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs

  16. Applications and extensions of degradation modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, F.; Subudhi, M.; Samanta, P.K. [Brookhaven National Lab., Upton, NY (United States); Vesely, W.E. [Science Applications International Corp., Columbus, OH (United States)

    1991-12-31

    Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs.

  17. Applications and extensions of degradation modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, F.; Subudhi, M.; Samanta, P.K. (Brookhaven National Lab., Upton, NY (United States)); Vesely, W.E. (Science Applications International Corp., Columbus, OH (United States))

    1991-01-01

    Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs.

  18. Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region: an individual-based pooled analysis of 40 twin cohorts.

    Science.gov (United States)

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo; Yokoyama, Yoshie; Hur, Yoon-Mi; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; Honda, Chika; Inui, Fujio; Iwatani, Yoshinori; Watanabe, Mikio; Tomizawa, Rie; Pietiläinen, Kirsi H; Rissanen, Aila; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Rijsdijk, Fruhling; Tan, Qihua; Zhang, Dongfeng; Pang, Zengchang; Piirtola, Maarit; Aaltonen, Sari; Öncel, Sevgi Y; Aliev, Fazil; Rebato, Esther; Hjelmborg, Jacob B; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Silberg, Judy L; Eaves, Lindon J; Cutler, Tessa L; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Franz, Carol E; Kremen, William S; Lyons, Michael J; Busjahn, Andreas; Nelson, Tracy L; Whitfield, Keith E; Kandler, Christian; Jang, Kerry L; Gatz, Margaret; Butler, David A; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Duncan, Glen E; Buchwald, Dedra; Martin, Nicholas G; Medland, Sarah E; Montgomery, Grant W; Jeong, Hoe-Uk; Swan, Gary E; Krasnow, Ruth; Magnusson, Patrik Ke; Pedersen, Nancy L; Dahl Aslan, Anna K; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Tynelius, Per; Baker, Laura A; Tuvblad, Catherine; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Spector, Timothy D; Mangino, Massimo; Lachance, Genevieve; Burt, S Alexandra; Klump, Kelly L; Harris, Jennifer R; Brandt, Ingunn; Nilsen, Thomas S; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Corley, Robin P; Huibregtse, Brooke M; Bartels, Meike; van Beijsterveldt, Catharina Em; Willemsen, Gonneke; Goldberg, Jack H; Rasmussen, Finn; Tarnoki, Adam D; Tarnoki, David L; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth Jf; Hopper, John L; Sung, Joohon; Maes, Hermine H; Turkheimer, Eric; Boomsma, Dorret I; Sørensen, Thorkild Ia; Kaprio, Jaakko

    2017-08-01

    Background: Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m 2 )], but factors modifying these variance components are poorly understood. Objective: We analyzed genetic and environmental variation in BMI between men and women from young adulthood to old age from the 1940s to the 2000s and between cultural-geographic regions representing high (North America and Australia), moderate (Europe), and low (East Asia) prevalence of obesity. Design: We used genetic structural equation modeling to analyze BMI in twins ≥20 y of age from 40 cohorts representing 20 countries (140,379 complete twin pairs). Results: The heritability of BMI decreased from 0.77 (95% CI: 0.77, 0.78) and 0.75 (95% CI: 0.74, 0.75) in men and women 20-29 y of age to 0.57 (95% CI: 0.54, 0.60) and 0.59 (95% CI: 0.53, 0.65) in men 70-79 y of age and women 80 y of age, respectively. The relative influence of unique environmental factors correspondingly increased. Differences in the sets of genes affecting BMI in men and women increased from 20-29 to 60-69 y of age. Mean BMI and variances in BMI increased from the 1940s to the 2000s and were greatest in North America and Australia, followed by Europe and East Asia. However, heritability estimates were largely similar over measurement years and between regions. There was no evidence of environmental factors shared by co-twins affecting BMI. Conclusions: The heritability of BMI decreased and differences in the sets of genes affecting BMI in men and women increased from young adulthood to old age. The heritability of BMI was largely similar between cultural-geographic regions and measurement years, despite large differences in mean BMI and variances in BMI. Our results show a strong influence of genetic factors on BMI, especially in early adulthood, regardless of the obesity level in the population. © 2017 American Society for Nutrition.

  19. A changing epidemiology of suicide? The influence of birth cohorts on suicide rates in the United States.

    Science.gov (United States)

    Phillips, Julie A

    2014-08-01

    The increases in suicide among middle-aged baby boomers (born between 1946 and 1964) in the United States since 1999 suggest a changing epidemiology of suicide. Using data from 1935 to 2010, this paper conducts age-period-cohort analyses to determine the impact of cohorts in shaping temporal patterns of suicide in the United States. The analysis demonstrates that age, period and cohort effects are all important in determining suicide trends. Net of age and period effects, the cohort pattern of suicide rates is U-shaped, with cohorts born between 1915 and 1945 possessing among the very lowest suicide rates. Suicide rates begin to rise with boomers and subsequent cohorts exhibit increasingly higher rates of suicide. The general pattern exists for both men and women but is especially pronounced among males. The average suicide rate over the entire period for males is about 28 per 100,000, 95% CI [27.4, 28.7]. For males born in 1930-34, the suicide rate is estimated to be 17.4 per 100,000, 95% CI [15.9, 18.8]; for males born between 1955 and 1959, the rate is essentially the same as the average for the period while for males born between 1985 and 1989, the suicide rate is estimated to be 37.8 per 100,000, 95% CI [33.1, 43.4]. The results dispute popular claims that boomers exhibit an elevated suicide rate relative to other generations, but boomers do appear to have ushered in new cohort patterns of suicide rates over the life course. These patterns are interpreted within a Durkheimian framework that suggests weakened forms of social integration and regulation among postwar cohorts may be producing increased suicide rates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Age and Environmental Concern: Some Specification of Effects.

    Science.gov (United States)

    Honnold, Julie A.

    1984-01-01

    Distinguishes possible aging, cohort, and period effects, explaining time series differences by age groups in the General Social Survey data. Results indicate that the decline in environmental concern among most age groups can be accounted for by period effects, but an aging effect is important among young adults. (Author/JN)

  1. Seasonal Forecasting of Agriculture Gross Domestic Production in Iran: Application of Periodic Autoregressive Model

    Directory of Open Access Journals (Sweden)

    Mohammad Ghahremanzadeh

    2014-06-01

    Full Text Available Agriculture as one of the major economic sectors of Iran, has an important role in Gross Domestic Production by providing about 14% of GDP. This study attempts to forecast the value of the agriculture GDP using Periodic Autoregressive model (PAR, as the new seasonal time series techniques. To address this aim, the quarterly data were collected from March 1988 to July 1989. The collected data was firstly analyzed using periodic unit root test Franses & Paap (2004. The analysis found non-periodic unit root in the seasonal data. Second, periodic seasonal behavior (Boswijk & Franses, 1996 was examined. The results showed that periodic autoregressive model fits agriculture GDP well. This makes an accurate forecast of agriculture GDP possible. Using the estimated model, the future value of quarter agricultural GDP from March 2011 to July 2012was forecasted. With consideration to the fair fit of this model with agricultural GDP, It is recommended to use periodic autoregressive model for the future studies.

  2. The risk of AIDS-defining events is decreasing over time in the German HIV-1 Seroconverter Cohort

    Directory of Open Access Journals (Sweden)

    Altmann Mathias

    2012-04-01

    Full Text Available Abstract Background With ageing of the HIV-infected population, long-term exposure to treatment, varying adherence, emerging resistance and complications to therapies, effectiveness of Highly Active Antiretroviral Therapy (HAART needs to be monitored continuously at the population level. The German HIV-1 Seroconverter Cohort is a multi-centre, open, long-term observational cohort including patients with a known or reliably estimated date of HIV-infection i.e. last negative and first positive HIV antibody test within a maximum three-year interval or laboratory evidence of seroconversion. Our study aims to investigate survival improvements and changes in AIDS risk over calendar periods in the German HIV-1 Seroconverter Cohort. Methods Retrospective (for the pre-1997 period and prospective (since 1997 data from the German HIV-1 Seroconverter Cohort were used. Time from seroconversion to first AIDS-defining event over calendar periods was analysed by using Cox models adjusting for age at seroconversion, sex, transmission groups and short HIV test interval. Kaplan-Meier methods were used to determine expected survival (remaining AIDS-free by calendar period. Results 2162 seroconverters with 8976 person-years of observation were included in our analysis (up to 31.12.2010. A total of 196 first AIDSdefining events were reported. Two periods i.e. 19972000 and 2007-2010 were statistically associated with a reduction in the risk of AIDS, accounting for an overall reduction of 80%. Compared to1997-2000, hazard ratios were 2.6 (95%CI, 1.6-4.8; p=0.000 in pre-1997 and 0.5 (95%CI, 0.3-0.8; p=0.007 in 20072010. Independent risk factor for AIDS progression was age at seroconversion (HR, 1.3 per 10year-increase; p=0.001. Conclusion HAART effectiveness has improved in the German HIV-1-Seroconverter Cohort. The risk to develop AIDS decreased significantly in 19972000 and in 20072010. However, elderly may require particular monitoring in view of their faster

  3. Gender as a Moderator of the Relation Between Age Cohort and Three-Dimensional Wisdom in Iranian Culture.

    Science.gov (United States)

    Cheraghi, Fereshte; Kadivar, Parvin; Ardelt, Monika; Asgari, Ali; Farzad, Valiollah

    2015-07-01

    This study examined whether gender moderated the association between age cohort and the cognitive, reflective, and compassionate dimensions of wisdom, using an Iranian sample of 439 adults from three age cohorts: young (18-34), middle-aged (35-54), and older (55 and above). Results indicated that the interaction effect between gender and age cohort was significant for three-dimensional wisdom and all three wisdom dimensions. Compared with younger women and older men, older women tended to have less education and to score lower on the cognitive wisdom dimension, but they had similar average scores as older men on the compassionate wisdom dimension. Overall, the association between age and wisdom was only positive for men, due mainly to the positive relation between age and the reflective and compassionate wisdom dimensions for men after adjusting for education. The results are interpreted with reference to generation gaps, socialization of men versus women, and life experiences and opportunities. © The Author(s) 2015.

  4. Logic Model Checking of Time-Periodic Real-Time Systems

    Science.gov (United States)

    Florian, Mihai; Gamble, Ed; Holzmann, Gerard

    2012-01-01

    In this paper we report on the work we performed to extend the logic model checker SPIN with built-in support for the verification of periodic, real-time embedded software systems, as commonly used in aircraft, automobiles, and spacecraft. We first extended the SPIN verification algorithms to model priority based scheduling policies. Next, we added a library to support the modeling of periodic tasks. This library was used in a recent application of the SPIN model checker to verify the engine control software of an automobile, to study the feasibility of software triggers for unintended acceleration events.

  5. Trends in adolescent alcohol use: Effects of age, sex and cohort on prevalence and heritability

    NARCIS (Netherlands)

    Geels, L.M.; Bartels, M.; van Beijsterveldt, C.E.M.; Willemsen, G.; van der Aa, N.; Boomsma, D.I.; Vink, J.M.

    2012-01-01

    Aims To determine the effect of age, sex and cohort on the prevalence and genetic architecture of adolescent alcohol use (AAU). Design Survey study in participants registered with the Netherlands Twin Register. Setting Twins from the general population. Participants Two cohorts (data collected in

  6. HP Memristor mathematical model for periodic signals and DC

    KAUST Repository

    Radwan, Ahmed G.

    2012-07-28

    In this paper mathematical models of the HP Memristor for DC and periodic signal inputs are provided. The need for a rigid model for the Memristor using conventional current and voltage quantities is essential for the development of many promising Memristors\\' applications. Unlike the previous works, which focuses on the sinusoidal input waveform, we derived rules for any periodic signals in general in terms of voltage and current. Square and triangle waveforms are studied explicitly, extending the formulas for any general square wave. The limiting conditions for saturation are also provided in case of either DC or periodic signals. The derived equations are compared to the SPICE model of the Memristor showing a perfect match.

  7. Do social inequalities in health widen or converge with age? Longitudinal evidence from three cohorts in the West of Scotland

    Directory of Open Access Journals (Sweden)

    Benzeval Michaela

    2011-12-01

    Full Text Available Abstract Background Existing studies are divided as to whether social inequalities in health widen or converge as people age. In part this is due to reliance on cross-sectional data, but also among longitudinal studies to differences in the measurement of both socioeconomic status (SES and health and in the treatment of survival effects. The aim of this paper is to examine social inequalities in health as people age using longitudinal data from the West of Scotland Twenty-07 Study to investigate the effect of selective mortality, the timing of the SES measure and cohort on the inequality patterns. Methods The Twenty-07 Study has followed three cohorts, born around 1932, 1952 and 1972, from 1987/8 to 2007/8; 4,510 respondents were interviewed at baseline and, at the most recent follow-up, 2,604 were interviewed and 674 had died. Hierarchical repeated-measures models were estimated for self-assessed health status, with and without mortality, with baseline or time-varying social class, sex and cohort. Results Social inequalities in health emerge around the age of 30 after which they widen until the early 60s and then begin to narrow, converging around the age of 75. This pattern is a result of those in manual classes reporting poor health at younger ages, with the gap narrowing as the health of those in non-manual classes declines at older ages. However, employing a more proximal measure of SES reduces inequalities in middle age so that convergence of inequalities is not apparent in old age. Including death in the health outcome steepens the health trajectories at older ages, especially for manual classes, eliminating the convergence in health inequalities, suggesting that healthy survival effects are important. Cohort effects do not appear to affect the pattern of inequalities in health as people age in this study. Conclusions There is a general belief that social inequalities in health appear to narrow at older ages; however, taking account of

  8. Age in antiretroviral therapy programmes in South Africa: a retrospective, multicentre, observational cohort study.

    Science.gov (United States)

    Cornell, Morna; Johnson, Leigh F; Schomaker, Michael; Tanser, Frank; Maskew, Mhairi; Wood, Robin; Prozesky, Hans; Giddy, Janet; Stinson, Kathryn; Egger, Matthias; Boulle, Andrew; Myer, Landon

    2015-09-01

    As access to antiretroviral therapy (ART) expands, increasing numbers of older patients will start treatment and need specialised long-term care. However, the effect of age in ART programmes in resource-constrained settings is poorly understood. The HIV epidemic is ageing rapidly and South Africa has one of the highest HIV population prevalences worldwide. We explored the effect of age on mortality of patients on ART in South Africa and whether this effect is mediated by baseline immunological status. In this retrospective cohort analysis, we studied HIV-positive patients aged 16-80 years who started ART for the first time in six large South African cohorts of the International Epidemiologic Databases to Evaluate AIDS-Southern Africa collaboration, in KwaZulu-Natal, Gauteng, and Western Cape (two primary care clinics, three hospitals, and a large rural cohort). The primary outcome was mortality. We ascertained patients' vital status through linkage to the National Population Register. We used inverse probability weighting to correct mortality for loss to follow-up. We estimated mortality using Cox's proportional hazards and competing risks regression. We tested the interaction between baseline CD4 cell count and age. Between Jan 1, 2004, and Dec 31, 2013, 84,078 eligible adults started ART. Of these, we followed up 83,566 patients for 174,640 patient-years. 8% (1817 of 23,258) of patients aged 16-29 years died compared with 19% (93 of 492) of patients aged 65 years or older. The age adjusted mortality hazard ratio was 2·52 (95% CI 2·01-3·17) for people aged 65 years or older compared with those 16-29 years of age. In patients starting ART with a CD4 count of less than 50 cells per μL, the adjusted mortality hazard ratio was 2·52 (2·04-3·11) for people aged 50 years or older compared with those 16-39 years old. Mortality was highest in patients with CD4 counts of less than 50 cells per μL, and 15% (1103 of 7295) of all patients aged 50 years or older

  9. Risk evaluations of aging phenomena: The linear aging reliability model and its extensions

    International Nuclear Information System (INIS)

    Vesely, W.E.; Wolford, A.J.

    1988-01-01

    A model for component failure rates due to aging mechanisms is developed from basic phenomenological considerations. In the treatment, the occurrences of deterioration are modeled as following a Poisson process. The severity of damage is allowed to have any distribution, however the damage is assumed to accumulate independently. Finally, the failure rate is modeled as being proportional to the accumulated damage. Using this treatment, the linear aging failure rate model is obtained. The applicability of the linear aging model to various mechanisms is discussed. Extensions of the model to cover nonlinear and dependent aging phenomena are also described. The implementability of the linear aging model is demonstrated by applying it to the aging data collected in the U.S. NRC Nuclear Plant Aging Research (NPAR) Program. (orig./HP)

  10. Cohort Working Life Tables for Older Canadians

    Directory of Open Access Journals (Sweden)

    Frank T. Denton

    2010-12-01

    those based on the period tables, for both men and women, and that is reflected in increased retirement expectancies. For example, a male aged 50 in 1976 could have expected to live three years longer and to have almost four more years in retirement, based on the male cohort table under medium assumptions, as compared with the corresponding period table.

  11. PRIORITIES IN CONCEPT OF CARDIOVASCULAR RISK FACTORS IN IRRADIATED PATIENTS AT DISTANT PERIOD AFTER CHERNOBYL NUCLEAR DISASTER BASED ON PROSPECTIVE COHORT DATA

    Directory of Open Access Journals (Sweden)

    R. G. Oganov

    2008-01-01

    Full Text Available Aim. To study pathogenetic mechanisms and cardiovascular risk factors prospective cohort study in liquidators of consequences of Chernobyl Nuclear Disaster 13-20 years after an accident.Material and methods. 409 irradiated patients and 224 control patients comparable on the age and gender were involved into two-stage cohort prospective study with 4,5years period of observation. Database included results of standard questionnaires, social and demographic description, education, family status, smoking and alcohol habits, anthropometry, fasting lipids and glucose, blood pressure, ECG, arrhythmias on ECG monitoring, heart rhythm variability, Echocardiography, thyroid ultrasound image, spirometry, transesophageal electrophysiological study of heart conduction system, exercise tests, functional class of ischemic heart disease, stage of arterial hypertension, fatal/nonfatal end-points, as well as neurologist, endocrinologist and cardiologist conclusions. Totally 267 variables were included in the analysis.Results. Spectrum of active cardiovascular risk factors in cohort of irradiated patients was entirely different from this in control patients. Determinative value for irradiated patients was related with night hypersympathetic activity, ANDS syndrome (Autonomic Nervous Dysfunction on hyperSympathetic type and less related with decreased airway conductance in small bronchial tubes.Conclusion. Comparative prospective cohort study in liquidators of consequences of Chernobyl Nuclear Disaster 13-20 years after an accident revealed highly significant new and permanently acting cardiovascular risk factors. These data let to work out appropriate approaches to therapy and prevention of cardiovascular diseases.

  12. Revisiting the Dedifferentiation Hypothesis with Longitudinal Multi-Cohort Data

    Science.gov (United States)

    de Frias, Cindy M.; Lovden, Martin; Lindenberger, Ulman; Nilsson, Lars-Goran

    2007-01-01

    The present longitudinal multi-cohort study examines whether interindividual variability in cognitive performance and change increases in old age, and whether associations among developments of different cognitive functions increase with adult age. Multivariate multiple-group latent growth modeling was applied to data from narrow cohorts separated…

  13. Variations with time and age of the excess cancer risk among A-bomb survivors

    International Nuclear Information System (INIS)

    Pierce, D.A.; Vaeth, M.; Preston, D.L.

    1990-08-01

    This report has two aims: 1) to describe and analyze the age/time patterns of excess cancer risk in the atomic bomb survivor cohort followed up by RERF, and 2) to describe statistical methods which are used in RERF's analyses of data on mortality and morbidity in the cohort. In contrast to previous analyses of the cohort cancer mortality data, substantial use is made of Japanese national cancer rates for the purpose of investigation of the age/time variations in excess risk. This analysis considers mortality from all cancers except leukemia as a group. Primary attention is given to description in terms of the age-specific excess relative risk, but the importance of appropriate descriptions of the absolute excess risk is also emphasized. When models for the excess risk allow variation with age and time, both constant relative and absolute excess risk models provide very similar fits to the data. Previous reports have indicated that for a given age-at-exposure and sex, the excess age-specific relative risk is remarkably constant throughout the current follow-up period. Statistical analysis here indicates that for those less than about 35 years of age at exposure there is no departure from this pattern, beyond ordinary sampling variation. For those over about 35 years of age-at-exposure, there is modest evidence of an increasing trend in the excess relative risk, which could be plausibly attributed to effects related to minimal latent period. Some brief consideration is given to modeling the absolute excess risk as the product of an age-at-exposure and time-since-exposure effect. Interpretation of these results, particularly in regard to projections beyond the current follow-up, is discussed. (author)

  14. Shopper typologies amongst a Generation Y consumer cohort and variations in terms of age in the fashion apparel market

    Directory of Open Access Journals (Sweden)

    Chengedzai Mafini

    2014-04-01

    Rational: Marketers have ever been concerned with the behaviour of consumers. Generation Y consumers have emerged as an important marketing segment. Consequently, a need exists to investigate behavioural issues pertaining to this age cohort on a continuous basis. Methodology: A survey questionnaire was administered to a convenient sample of 230 Generation Y consumers of fashion apparel. Exploratory factor analysis was used to identify shopper typologies. The Kruskal-Wallis test was used to examine the influence of age on the identified shopper typologies. Findings: The study identified seven shopper typologies that are applicable to the Generation Y cohort. These are quality conscious, brand conscious, novelty seeking, hedonistic, confused by over-choice, habitual, brand loyal and fashion conscious shopper typologies. The study also revealed that younger consumers were found to be more confused by over-choice than their older counterparts. Value of research: These findings may enable marketers to understand and predict the purchase behaviour of Generation Y consumers, thereby facilitating the development and implementation of more effective marketing strategies.

  15. Cohort Fertility Patterns in the Nordic Countries

    Directory of Open Access Journals (Sweden)

    Gunnar Andersson

    2009-04-01

    Full Text Available Previous analyses of period fertility suggest that the trends of the Nordic countries are sufficiently similar to speak of a common "Nordic fertility regime". We investigate whether this assumption can be corroborated by comparing cohort fertility patterns in the Nordic countries. We study cumulated and completed fertility of Nordic birth cohorts based on the childbearing histories of women born in 1935 and later derived from the population registers of Denmark, Finland, Norway, and Sweden. We further explore childbearing behaviour by women's educational attainment. The results show remarkable similarities in postponement and recuperation between the countries and very small differences in completed fertility across educational groups. Median childbearing age is about 2-3 years higher in the 1960-64 cohort than in the 1950-54 cohort, but the younger cohort recuperates the fertility level of the older cohort at ages 30 and above. A similar pattern of recuperation can be observed for highly educated women as compared to women with less education. An interesting finding is that of a positive relationship between educational level and the final number of children when women who become mothers at similar ages are compared. Country differences in fertility outcome are generally rather low. Childlessness is highest in Finland and lowest in Norway, and the educational differentials are largest in Norway. Despite such differences, the cohort analyses in many ways support the notion of a common Nordic fertility regime.

  16. Decisions, decisions: analysis of age, cohort, and time of testing on framing of risky decision options.

    Science.gov (United States)

    Mayhorn, Christopher B; Fisk, Arthur D; Whittle, Justin D

    2002-01-01

    Decision making in uncertain environments is a daily challenge faced by adults of all ages. Framing decision options as either gains or losses is a common method of altering decision-making behavior. In the experiment reported here, benchmark decision-making data collected in the 1970s by Tversky and Kahneman (1981, 1988) were compared with data collected from current samples of young and older adults to determine whether behavior was consistent across time. Although differences did emerge between the benchmark and the present samples, the effect of framing on decision behavior was relatively stable. The present findings suggest that adults of all ages are susceptible to framing effects. Results also indicated that apparent age differences might be better explained by an analysis of cohort and time-of-testing effects. Actual or potential applications of this research include an understanding of how framing might influence the decision-making behavior of people of all ages in a number of applied contexts, such as product warning interactions and medical decision scenarios.

  17. Cohort profile: the Spanish WORKing life Social Security (WORKss) cohort study.

    Science.gov (United States)

    López Gómez, María Andrée; Durán, Xavier; Zaballa, Elena; Sanchez-Niubo, Albert; Delclos, George L; Benavides, Fernando G

    2016-03-07

    The global economy is changing the labour market and social protection systems in Europe. The effect of both changes on health needs to be monitored in view of an ageing population and the resulting increase in prevalence of chronic health conditions. The Spanish WORKing life Social Security (WORKss) cohort study provides unique longitudinal data to study the impact of labour trajectories and employment conditions on health, in terms of sickness absence, permanent disability and death. The WORKss cohort originated from the Continuous Working Life Sample (CWLS) generated by the General Directorate for the Organization of the Social Security in Spain. The CWLS contains a 4% representative sample of all individuals in contact with the Social Security system. The WORKss cohort exclusively includes individuals with a labour trajectory from 1981 or later. In 2004, the cohort was initiated with 1,022 ,79 Social Security members: 840,770 (82.2%) contributors and 182,009 (17.8%) beneficiaries aged 16 and older. The WORKss cohort includes demographic characteristics, chronological data about employment history, retirement, permanent disability and death. These data make possible the measurement of incidence of permanent disability, the number of potential years of working life lost, and the number of contracts and inactive periods with the Social Security system. The WORKss cohort was linked to temporary sickness absence registries to study medical diagnoses that lead to permanent disability and consequently to an earlier exit from the labour market in unhealthy conditions. Thanks to its administrative source, the WORKss cohort study will continue follow-up in the coming years, keeping the representativeness of the Spanish population affiliated to the Social Security system. The linkage between the WORKss cohort and temporary sickness absence registries is envisioned to continue. Future plans include the linkage of the cohort with mortality registries. Published by the BMJ

  18. Explaining the Wealth Holdings of Different Cohorts: Productivity Growth and Social Security

    NARCIS (Netherlands)

    Kapteyn, Arie; Alessie, R.J.M.; Lusardi, Annamaria

    1999-01-01

    It is well-known that individuals born in different periods of time (cohorts)exhibit different wealth accumulation paths. While previous studies have used cohort dummies to proxy for this fact, research in this area suffers from a serious identification problem, i.e., how to disentangle age, time,

  19. Occupational Characteristics and Cognitive Aging in the Glostrup 1914 Cohort

    DEFF Research Database (Denmark)

    Gow, Alan J; Avlund, Kirsten; Mortensen, Erik L

    2014-01-01

    Objectives.The effect of occupational characteristics on cognitive change over 20 years was examined.Method.Occupational characteristics-intellectual challenge, physical hazards, and psychological demands-were assessed in the Glostrup 1914 Cohort when aged 60 years, and cognitive ability...... was assessed by 4 cognitive ability tests at ages 60, 70, and 80. RESULTS: Individuals in more intellectually challenging occupations had higher cognitive ability (r = .27-.38, p occupations performed more poorly (r = -.12 and -.13 at ages 50 and 60, p ..., the one in the more intellectually challenging occupation had lower subsequent cognitive ability. The association of physical hazards with lower cognitive ability level did not remain after adjustment for the basic demographics, and none of the occupational characteristics were associated with cognitive...

  20. An evaluation of the 25 by 25 goal for premature cardiovascular disease mortality in Taiwan: an age-period-cohort analysis, population attributable fraction and national population-based study.

    Science.gov (United States)

    Su, Shih-Yung; Lee, Wen-Chung; Chen, Tzu-Ting; Wang, Hao-Chien; Su, Ta-Chen; Jeng, Jiann-Shing; Tu, Yu-Kang; Liao, Shu-Fen; Lu, Tzu-Pin; Chien, Kuo-Liong

    2017-01-01

    The aim of the 25 by 25 goal is to reduce mortality from premature non-communicable diseases by 25% before 2025. Studies have evaluated the 25 by 25 goal in many countries, but not in Taiwan. The aim of this study was to estimate the 25 by 25 goal for premature mortality from cardiovascular diseases in Taiwan. We applied the age-period-cohort model to project the incidence of premature death from cardiovascular disease from 2015 to 2024 and used the population attributable fraction to estimate the contributions of targeted risk factors. The probability of death was used to estimate the percent change. The percent change in business-as-usual trend during 2010-2024 was only a 6% (range 1.7-10.7%) lower risk of premature mortality from cardiovascular disease among men. The greatest reduction in the risk of mortality occurred with a 30% reduction in the prevalence of smoking; however, there was only a 14.5% (10.6-18.3%) decrease in percent change and in the corresponding number of men (3706: range 3543-3868) who were prevented from dying. More than a 25% reduction in the percent change of premature cardiovascular disease mortality among women was achieved without control of any risk factor. To reach a 25% reduction in men before 2025, there needs to be a 70% reduction in the prevalence of smoking to reduce mortality by 26.2% (22.9-29.3%). Cigarette smoking is the primary target in the prevention of cardiovascular disease. Through the stringent control of smoking, the goal of a 25% reduction in premature mortality from cardiovascular disease may be achieved before 2025 in Taiwan.

  1. Analyzing occupational cohort data: application to US uranium miners

    International Nuclear Information System (INIS)

    Whittemore, A.S.; McMillan, A.

    1982-01-01

    This paper presents methodological issues concerning the analysis of occupational mortality data. It summarizes pros and cons of three types of analysis: the person-years method, the cohort method, and the case-control method, and notes the common theoretical basis underlying cohort and case-control methods. Both these methods assume that occupational exposures act multiplicatively on either: (a) age-specific mortality rates; or (b) odds-ratios of death during follow-up. Both methods allow relative risk estimation by maximizing a partial or conditional likelihood under assumption (a), and an unconditional likelihood under assumption (b). the case-control method involves less data handling and computation than does the cohort method. This feature, useful when dealing with very large cohorts whose exposures vary with time, is purchased at the price of some decreased sensitivity to detect moderate to large relative risks associated with infrequently occurring exposure categories. The paper illustrates the utility and limitations of the case-control approach by applying it to lung cancer mortality versus exposures to radon-daughters and cigarette smoke among US uranium miners

  2. Language Delay and Externalizing Problems in Preschool Age: A Prospective Cohort Study.

    Science.gov (United States)

    Wang, Mari Vaage; Aarø, Leif Edvard; Ystrom, Eivind

    2018-01-10

    This study sought to examine the direction of causation between language delay and two externalizing problems; inattention and aggression. Autoregressive fixed effects models were fitted to data from 25,474 children (age 1.5 to 5 years; 50.8% boys) in the population-based longitudinal Norwegian Mother and Child Cohort Study (MoBa), to model the direction of causality for language delay and inattention and aggression, respectively. The most parsimonious model for the relationship between language delay and inattention was one where both common factors and reciprocal causation were estimated. Adjusted for common factors, language delay was estimated to have a non-significant effect on inattention by b = 0.12 (p = 0.06), and inattention to have a significant effect on language delay by b = 0.19 (p = 0.03). The most parsimonious model for the direction of causality for language delay and aggression was one where the entire association could be explained by language delay having effect on aggression b = 0.12 (p language delay can best be conceptualized as an epiphenomenon of inattention partly related to both common factors and causal processes, aggression can best be conceptualized as caused by language delay. This illumination of the hypothetical causal links between two common problem domains in preschool-aged children has clear implications on where to implement interventions to prevent co-occurrence of language delay and externalizing problems.

  3. Towards the application of precision medicine in Age-Related Macular Degeneration.

    Science.gov (United States)

    Cascella, Raffaella; Strafella, Claudia; Caputo, Valerio; Errichiello, Valeria; Zampatti, Stefania; Milano, Filippo; Potenza, Saverio; Mauriello, Silvestro; Novelli, Giuseppe; Ricci, Federico; Cusumano, Andrea; Giardina, Emiliano

    2018-03-01

    The review essentially describes genetic and non-genetic variables contributing to the onset and progression of exudative Age-related Macular Degeneration (AMD) in Italian population. In particular, AMD susceptibility within Italian population is contributed to by genetic variants, accounting for 23% of disease and non-genetic variants, accounting for 10% of AMD. Our data highlighted prominent differences concerning genetic and non-genetic contributors to AMD in our cohort with respect to worldwide populations. Among genetic variables, SNPs of CFH, ARMS2, IL-8, TIMP3, SLC16A8, RAD51B, VEGFA and COL8A1 were significantly associated with the risk of AMD in the Italian cohort. Surprisingly, other susceptibility variants described in European, American and Asiatic populations, did not reach the significance threshold in our cohort. As expected, advanced age, smoking and dietary habits were associated with the disease. In addition, we also describe a number of gene-gene and gene-phenotype interactions. In fact, AMD-associated genes may be involved in the alteration of Bruch's membrane and induction of angiogenesis, contributing to exacerbate the damage caused by aging and environmental factors. Our review provides an overview of genetic and non-genetic factors characterizing AMD susceptibility in Italian population, outlining the differences with respect to the worldwide populations. Altogether, these data reflect historical, geographic, demographic and lifestyle peculiarities of Italian population. The role of epigenetics, pharmacogenetics, comorbities and genetic counseling in the management of AMD patients have been described, in the perspective of the application of a "population-specific precision medicine" approach addressed to prevent AMD onset and improve patients' quality of life. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Plasma adiponectin and depressive symptoms during pregnancy and the postpartum period: A prospective cohort study.

    Science.gov (United States)

    Rebelo, Fernanda; Farias, Dayana R; Struchiner, Claudio J; Kac, Gilberto

    2016-04-01

    Some authors have described an inverse association between adiponectin and depression, but this association has not yet been investigated during the perinatal period. To evaluate the association between the plasma adiponectin levels and symptoms of depression in women from early pregnancy to 30-45 days postpartum. A prospective cohort of 235 women was analyzed, with four waves of follow-up: 5-13th, 22-26th, and 30-36th gestational weeks and 30-45 days postpartum. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS; cutoff ≥ 11). The plasma adiponectin concentrations were measured using an enzyme-linked immunosorbent assay. The statistical analyses included linear mixed effects regressions to model the association between these time-dependent variables. The prevalence of depressive symptoms was 35.5%, 22.8%, 21.8%, and 16.9% and the median (µg/mL) adiponectin levels were 4.8, 4.7, 4.4, and 7.5 in the 1st, 2nd, and 3rd trimesters and the postpartum period, respectively. Women who remained non-depressed throughout the study tended to have higher values of adiponectin throughout pregnancy and the postpartum period compared to those who had depressive symptoms at least once, but this difference was not statistically significant (β=-0.14; p=0.071). There was no statistically significant association between the plasma adiponectin levels and the EPDS scores in the multiple model (β=-0.07; p=0.320). Losses to follow-up, different procedures for the blood draws at the prenatal and postpartum visits, and the presence of a nested clinical trial with omega-3 supplementation. The plasma adiponectin levels were not associated with depressive symptoms during the perinatal period. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Height, age at menarche and risk of hormone receptor-positive and -negative breast cancer: a cohort study.

    Science.gov (United States)

    Ritte, Rebecca; Lukanova, Annekatrin; Tjønneland, Anne; Olsen, Anja; Overvad, Kim; Mesrine, Sylvie; Fagherazzi, Guy; Dossus, Laure; Teucher, Birgit; Steindorf, Karen; Boeing, Heiner; Aleksandrova, Krasimira; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; Palli, Domenico; Grioni, Sara; Mattiello, Amalia; Tumino, Rosario; Sacerdote, Carlotta; Quirós, José Ramón; Buckland, Genevieve; Molina-Montes, Esther; Chirlaque, María-Dolores; Ardanaz, Eva; Amiano, Pilar; Bueno-de-Mesquita, Bas; van Duijnhoven, Franzel; van Gils, Carla H; Peeters, Petra Hm; Wareham, Nick; Khaw, Kay-Tee; Key, Timothy J; Travis, Ruth C; Krum-Hansen, Sanda; Gram, Inger Torhild; Lund, Eiliv; Sund, Malin; Andersson, Anne; Romieu, Isabelle; Rinaldi, Sabina; McCormack, Valerie; Riboli, Elio; Kaaks, Rudolf

    2013-06-01

    Associations of breast cancer overall with indicators of exposures during puberty are reasonably well characterized; however, uncertainty remains regarding the associations of height, leg length, sitting height and menarcheal age with hormone receptor-defined malignancies. Within the European Prospective Investigation into Cancer and Nutrition cohort, Cox proportional hazards models were used to describe the relationships of adult height, leg length and sitting height and age at menarche with risk of estrogen and progesterone receptor negative (ER-PR-) (n = 990) and ER+PR+ (n = 3,524) breast tumors. Height as a single risk factor was compared to a model combining leg length and sitting height. The possible interactions of height, leg length and sitting height with menarche were also analyzed. Risk of both ER-PR- and ER+PR+ malignancies was positively associated with standing height, leg length and sitting height and inversely associated with increasing age at menarche. For ER+PR+ disease, sitting height (hazard ratios: 1.14[95% confidence interval: 1.08-1.20]) had a stronger risk association than leg length (1.05[1.00-1.11]). In comparison, for ER-PR- disease, no distinct differences were observed between leg length and sitting height. Women who were tall and had an early menarche (≤13 years) showed an almost twofold increase in risk of ER+PR+ tumors but no such increase in risk was observed for ER-PR- disease. Indicators of exposures during rapid growth periods were associated with risks of both HR-defined breast cancers. Exposures during childhood promoting faster development may establish risk associations for both HR-positive and -negative malignancies. The stronger associations of the components of height with ER+PR+ tumors among older women suggest possible hormonal links that could be specific for postmenopausal women. Copyright © 2012 UICC.

  6. The impact of obesity on US mortality levels: the importance of age and cohort factors in population estimates.

    Science.gov (United States)

    Masters, Ryan K; Reither, Eric N; Powers, Daniel A; Yang, Y Claire; Burger, Andrew E; Link, Bruce G

    2013-10-01

    To estimate the percentage of excess death for US Black and White men and women associated with high body mass, we examined the combined effects of age variation in the obesity-mortality relationship and cohort variation in age-specific obesity prevalence. We examined 19 National Health Interview Survey waves linked to individual National Death Index mortality records, 1986-2006, for age and cohort patterns in the population-level association between obesity and US adult mortality. The estimated percentage of adult deaths between 1986 and 2006 associated with overweight and obesity was 5.0% and 15.6% for Black and White men, and 26.8% and 21.7% for Black and White women, respectively. We found a substantially stronger association than previous research between obesity and mortality risk at older ages, and an increasing percentage of mortality attributable to obesity across birth cohorts. Previous research has likely underestimated obesity's impact on US mortality. Methods attentive to cohort variation in obesity prevalence and age variation in obesity's effect on mortality risk suggest that obesity significantly shapes US mortality levels, placing it at the forefront of concern for public health action.

  7. Cohort change and the diffusion of environmental concern: A cross-national analysis.

    Science.gov (United States)

    Nawrotzki, Raphael J; Pampel, Fred C

    2013-09-01

    This study explores value change across cohorts for a multinational population sample. Employing a diffusion-of-innovations approach, we combine competing theories predicting the relationship between socio-economic status (SES) and environmentalism: post-materialism and affluence theories, and global environmentalism theory. The diffusion argument suggests that high-SES groups first adopt pro-environmental views, but as time passes by, environmentalism diffuses to lower-SES groups. We test the diffusion argument using a sample of 18 countries for two waves (years 1993 and 2000) from the International Social Survey Project (ISSP). Cross-classified multilevel modeling allows us to identify a non-linear interaction between cohort and education, our core measure of SES, in predicting environmental concern, while controlling for age and period. We find support for the diffusion argument and demonstrate that the positive effect of education on environmental concern first increases among older cohorts, then starts to level off until a bend-point is reached for individuals born around 1940 and becomes progressively weaker for younger cohorts.

  8. Survival and its predictors from age 75 to 85 in men and women belonging to cohorts with marked survival differences to age 75

    DEFF Research Database (Denmark)

    Heikkinen, E; Kauppinen, M; Schroll, M

    2016-01-01

    focusing on different domains of health, functional capacity, and physical and social activities. RESULTS: The proportion of survivors to age 75 was markedly smaller among the Finnish men and women than Danish or Swedish subjects. In the local population no marked differences in survival from age 75 to 85...... among three local Nordic populations using survival data on national cohorts as background information. METHODS: The data were derived from national registers and from samples of 75-year old living in Denmark, Sweden, and Finland. The subjects were invited to take part in interviews and examinations...... were observed between the groups of men, while women survived longer than men and longer in Göteborg than in Glostrup or Jyväskylä. Univariate models revealed 12 predictors of survival. In the multivariate models, the significant predictors among men related to physical fitness, whereas among women...

  9. Health effects of low doses at low dose rates: dose-response relationship modeling in a cohort of workers of the nuclear industry

    International Nuclear Information System (INIS)

    Metz-Flamant, Camille

    2011-01-01

    The aim of this thesis is to contribute to a better understanding of the health effects of chronic external low doses of ionising radiation. This work is based on the French cohort of CEA-AREVA NC nuclear workers. The mains stages of this thesis were (1) conducting a review of epidemiological studies on nuclear workers, (2) completing the database and performing a descriptive analysis of the cohort, (3) quantifying risk by different statistical methods and (4) modelling the exposure-time-risk relationship. The cohort includes monitored workers employed more than one year between 1950 and 1994 at CEA or AREVA NC companies. Individual annual external exposure, history of work, vital status and causes of death were reconstructed for each worker. Standardized mortality ratios using French national mortality rates as external reference were computed. Exposure-risk analysis was conducted in the cohort using the linear excess relative risk model, based on both Poisson regression and Cox model. Time dependent modifying factors were investigated by adding an interaction term in the model or by using exposure time windows. The cohort includes 36, 769 workers, followed-up until age 60 in average. During the 1968- 2004 period, 5, 443 deaths, 2, 213 cancers, 62 leukemia and 1, 314 cardiovascular diseases were recorded. Among the 57% exposed workers, the mean cumulative dose was 21.5 milli-sieverts (mSv). A strong Healthy Worker Effect is observed in the cohort. Significant elevated risks of pleura cancer and melanoma deaths were observed in the cohort but not associated with dose. No significant association was observed with solid cancers, lung cancer and cardiovascular diseases. A significant dose-response relationship was observed for leukemia excluding chronic lymphatic leukemia, mainly for doses received less than 15 years before and for yearly dose rates higher than 10 mSv. This PhD work contributes to the evaluation of risks associated to chronic external radiation

  10. Comparison of the Rowe-Kahn Model of Successful Aging With Self-rated Health and Life Satisfaction: The West of Scotland Twenty-07 Prospective Cohort Study.

    Science.gov (United States)

    Whitley, Elise; Popham, Frank; Benzeval, Michaela

    2016-12-01

    With increasing longevity in industrialized populations, there is growing interest in what defines "successful aging" (SA). Various SA measures have been proposed but no consensus has been reached and many have been criticized for not representing the views and priorities of older people. We consider whether the Rowe-Kahn SA model captures older individual's perceptions of their own health and aging. Using two cohorts of 886 and 483 men and women from the West of Scotland Twenty-07 Study, aged around 57 and 76, respectively, we explored associations between Rowe-Kahn SA dimensions (absence of disease/disability; good physical/cognitive functioning; good interpersonal/productive social engagement) and four aspects of self-rated health and satisfaction (current general health; health for age; satisfaction with health; satisfaction with life). Respondents' self-rated health and satisfaction was generally good but few had all six Rowe-Kahn dimensions positive, the conventional definition of SA. All individual positive SA dimensions were associated with better self-rated health and satisfaction. This was consistent across age, gender, manual/nonmanual occupations, and personality. The prevalence of good self-rated health and satisfaction increased with increasing numbers of positive SA dimensions. The Rowe-Kahn model provides a functional definition of SA. Future work on ageing should include all Rowe-Kahn dimensions and consider SA as a continuum. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

  11. Apparent and internal validity of a Monte Carlo-Markov model for cardiovascular disease in a cohort follow-up study.

    Science.gov (United States)

    Nijhuis, Rogier L; Stijnen, Theo; Peeters, Anna; Witteman, Jacqueline C M; Hofman, Albert; Hunink, M G Myriam

    2006-01-01

    To determine the apparent and internal validity of the Rotterdam Ischemic heart disease & Stroke Computer (RISC) model, a Monte Carlo-Markov model, designed to evaluate the impact of cardiovascular disease (CVD) risk factors and their modification on life expectancy (LE) and cardiovascular disease-free LE (DFLE) in a general population (hereinafter, these will be referred to together as (DF)LE). The model is based on data from the Rotterdam Study, a cohort follow-up study of 6871 subjects aged 55 years and older who visited the research center for risk factor assessment at baseline (1990-1993) and completed a follow-up visit 7 years later (original cohort). The transition probabilities and risk factor trends used in the RISC model were based on data from 3501 subjects (the study cohort). To validate the RISC model, the number of simulated CVD events during 7 years' follow-up were compared with the observed number of events in the study cohort and the original cohort, respectively, and simulated (DF)LEs were compared with the (DF)LEs calculated from multistate life tables. Both in the study cohort and in the original cohort, the simulated distribution of CVD events was consistent with the observed number of events (CVD deaths: 7.1% v. 6.6% and 7.4% v. 7.6%, respectively; non-CVD deaths: 11.2% v. 11.5% and 12.9% v. 13.0%, respectively). The distribution of (DF)LEs estimated with the RISC model consistently encompassed the (DF)LEs calculated with multistate life tables. The simulated events and (DF)LE estimates from the RISC model are consistent with observed data from a cohort follow-up study.

  12. Impact of the age at menarche on body composition in adulthood: results from two birth cohort studies

    Directory of Open Access Journals (Sweden)

    Susana Bubach

    2016-09-01

    Full Text Available Abstract Background Evidence suggests that early menarche is positively associated with adiposity in adulthood. However, it is important to assess whether this association is due to early menarche or to the association of adiposity in late childhood with age at menarche. We evaluated the association between age at menarche and body composition in adolescence and adulthood, among subjects who have been prospectively followed in two Brazilian birth cohort studies. Methods In 1982 and 1993, the hospitals births in Pelotas were identified, and these subjects have been followed for several times. Information on age at menarche was obtained from the women (1982 cohort and their mothers (1993 cohort. At 30 and 18 years, the following body composition measures were evaluated: body mass index, waist circumference, fat-free mass index and fat mass index measured by dual-energy x-ray absorptiometry, and thickness of the abdominal visceral fat layer measured by ultrasound. The analyses were adjusted for: birth weight, maternal pregestational weight, gestational age, family income, household score index, maternal schooling, weight-for-height z-score at 4 years (1982, and body mass index at 11 years (1993. Results At 30 and 18 years, 2045 and 2092 women were evaluated, respectively. The prevalence of early menarche (≤11 years of age was 24.7 % in the 1982 and 27.6 % in the 1993 cohort. In the 1982 cohort, early menarche was positively associated with all body composition variables compared to those with late menarche (≥14 years of age even after adjusting for confounders (fat mass index: 2.33 kg/m2, 95 % Confidence interval: 1.64; 3.02. However, in the 1993 cohort, after adjusting for body mass index at 11 years, the regression coefficient for the association with fat mass index decreased from 2.2 kg/m2 (95 % Confidence interval: 1.7; 2.6 to 0.26 (95 % Confidence interval: −0.08; 0.60. Conclusions The association between age at menarche

  13. Childhood Risk Factors for Lifetime Anorexia Nervosa by Age 30 Years in a National Birth Cohort

    Science.gov (United States)

    Nicholls, Dasha E.; Viner, Russell M.

    2009-01-01

    Whether previously identified childhood risk factors for anorexia nervosa (AN) predict self-reported lifetime AN by age 30 is examined. The cohort confirmed four risk and two protective factors out of the 22 suggested risk factors. The study used data from the 1970 British Cohort Study.

  14. Identifying the age cohort responsible for transmission in a natural outbreak of Bordetella bronchiseptica.

    Directory of Open Access Journals (Sweden)

    Gráinne H Long

    2010-12-01

    Full Text Available Identifying the major routes of disease transmission and reservoirs of infection are needed to increase our understanding of disease dynamics and improve disease control. Despite this, transmission events are rarely observed directly. Here we had the unique opportunity to study natural transmission of Bordetella bronchiseptica--a directly transmitted respiratory pathogen with a wide mammalian host range, including sporadic infection of humans--within a commercial rabbitry to evaluate the relative effects of sex and age on the transmission dynamics therein. We did this by developing an a priori set of hypotheses outlining how natural B. bronchiseptica infections may be transmitted between rabbits. We discriminated between these hypotheses by using force-of-infection estimates coupled with random effects binomial regression analysis of B. bronchiseptica age-prevalence data from within our rabbit population. Force-of-infection analysis allowed us to quantify the apparent prevalence of B. bronchiseptica while correcting for age structure. To determine whether transmission is largely within social groups (in this case litter, or from an external group, we used random-effect binomial regression to evaluate the importance of social mixing in disease spread. Between these two approaches our results support young weanlings--as opposed to, for example, breeder or maternal cohorts--as the age cohort primarily responsible for B. bronchiseptica transmission. Thus age-prevalence data, which is relatively easy to gather in clinical or agricultural settings, can be used to evaluate contact patterns and infer the likely age-cohort responsible for transmission of directly transmitted infections. These insights shed light on the dynamics of disease spread and allow an assessment to be made of the best methods for effective long-term disease control.

  15. Differences in baseline lung cancer mortality between the German uranium miners cohort and the population of the former German Democratic Republic (1960-2003).

    Science.gov (United States)

    Walsh, Linda; Dufey, Florian; Möhner, Matthias; Schnelzer, Maria; Tschense, Annemarie; Kreuzer, Michaela

    2011-03-01

    A previous analysis of the radon-related lung cancer mortality risk, in the German uranium miners cohort, using Poisson modeling techniques, noted internal (spontaneous) rates that were higher on average than the external rates by 16.5% (95% CI: 9%; 24%). The main purpose of the present paper is to investigate the nature of, and possible reasons for, this difference by comparing patterns in spontaneous lung cancer mortality rates in a cohort of male miners involved in uranium extraction at the former Wismut mining company in East Germany with national male rates from the former German Democratic Republic. The analysis is based on miner data for 3,001 lung cancer deaths, 1.76 million person-years for the period 1960-2003, and national rates covering the same calendar-year range. Simple "age-period-cohort" graphical analyses were applied to assess the main qualitative differences between the national and cohort baseline lung cancer rates. Some differences were found to occur mainly at higher attained ages above 70 years. Although many occupational risk factors may have contributed to these observed age differences, only the effects of smoking have been assessed here by applying the Peto-Lopez indirect method for calculating smoking attributability. It is inferred that the observed age differences could be due to the greater prevalence of smoking and more mature smoking epidemic in the Wismut cohort compared to the general population of the former German Democratic Republic. In view of these observed differences between external population-based rates and internal (spontaneous) cohort baseline lung cancer rates, it is strongly recommended to apply only the internal rates in future analyses of uranium miner cohorts. © Springer-Verlag 2010

  16. Changing mortality and average cohort life expectancy

    Directory of Open Access Journals (Sweden)

    Robert Schoen

    2005-10-01

    Full Text Available Period life expectancy varies with changes in mortality, and should not be confused with the life expectancy of those alive during that period. Given past and likely future mortality changes, a recent debate has arisen on the usefulness of the period life expectancy as the leading measure of survivorship. An alternative aggregate measure of period mortality which has been seen as less sensitive to period changes, the cross-sectional average length of life (CAL has been proposed as an alternative, but has received only limited empirical or analytical examination. Here, we introduce a new measure, the average cohort life expectancy (ACLE, to provide a precise measure of the average length of life of cohorts alive at a given time. To compare the performance of ACLE with CAL and with period and cohort life expectancy, we first use population models with changing mortality. Then the four aggregate measures of mortality are calculated for England and Wales, Norway, and Switzerland for the years 1880 to 2000. CAL is found to be sensitive to past and present changes in death rates. ACLE requires the most data, but gives the best representation of the survivorship of cohorts present at a given time.

  17. Mortality in nuclear workers of the French electricity company: period 1968-2003; Cohorte des travailleurs du nucleaire a Electricite de France: mortalite des agents statutaires sur la periode 1968-2003

    Energy Technology Data Exchange (ETDEWEB)

    Rogel, A.; Joly, K.; Metz-Flamant, C.; Laurent, O.; Tirmarche, M.; Laurier, D. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Lab. d' Epidemiologie, DRPH/SRBE/LEPID, 92 - Fontenay-aux-roses (France); Hubert, D.; Garcier, Y. [Electricite de France (EDF), 93 - Saint-Denis (France)

    2009-08-15

    Background We conducted a mortality study on a cohort of French nuclear workers employed at Electricite de France (EDF). A first cancer mortality analysis had covered the period 1968-1994. This paper presents results from a mortality analysis including nine additional years of follow-up to cover workers employed from 1968 to 2003. Methods The cohort includes 22 393 workers, 97% of whom are males. Employment data were updated using the EDF personnel file. Vital status was ascertained using the French National Registry of Population, and further completed using EDF personnel and pension files. Causes of death were obtained from the National registry of causes of death. Standardised Mortality Ratios (S.M.R.) were computed using national rates as references. Variations of all causes and all cancers S.M.R.s were studied according to demographic and occupational characteristics. Results At the study end point (31/12/2003), 74% of workers are still in active employment. Only 0.3% of workers are lost to follow-up. The median duration of follow-up is 20 years. Causes are ascertained for 96% of deaths. The total number of deaths is 874, 307 of which are cancer deaths. S.M.R.s for all causes and cancers show a significant deficit compared to the French national mortality. No significant excess was observed for any of the cancer sites studied. Non-significant excesses are observed for pancreatic, pleural, kidney and brain cancer. Significant variations of all causes S.M.R.s according to age at study entry and attained age are observed. Significant variations of all causes and all cancers S.M.R.s according to diploma at employment are observed, with a reduced S.M.R. for a higher level of diploma. Conclusion There is a significant deficit of mortality compared to the general population, reflecting a strong Healthy Worker Effect. Although nine years of follow-up were added, this cohort is made up of young workers, most of whom are still in active service. Regular updating of the

  18. Joint modeling and registration of cell populations in cohorts of high-dimensional flow cytometric data.

    Directory of Open Access Journals (Sweden)

    Saumyadipta Pyne

    Full Text Available In biomedical applications, an experimenter encounters different potential sources of variation in data such as individual samples, multiple experimental conditions, and multivariate responses of a panel of markers such as from a signaling network. In multiparametric cytometry, which is often used for analyzing patient samples, such issues are critical. While computational methods can identify cell populations in individual samples, without the ability to automatically match them across samples, it is difficult to compare and characterize the populations in typical experiments, such as those responding to various stimulations or distinctive of particular patients or time-points, especially when there are many samples. Joint Clustering and Matching (JCM is a multi-level framework for simultaneous modeling and registration of populations across a cohort. JCM models every population with a robust multivariate probability distribution. Simultaneously, JCM fits a random-effects model to construct an overall batch template--used for registering populations across samples, and classifying new samples. By tackling systems-level variation, JCM supports practical biomedical applications involving large cohorts. Software for fitting the JCM models have been implemented in an R package EMMIX-JCM, available from http://www.maths.uq.edu.au/~gjm/mix_soft/EMMIX-JCM/.

  19. Advanced paternal age and risk of fetal death: a cohort study

    DEFF Research Database (Denmark)

    Nybo Andersen, Anne-Marie; Hansen, Kasper Daniel; Andersen, Per Kragh

    2004-01-01

    Cohort from 1997 to 1999 to assess the association between paternal age and fetal death. Fathers of the pregnancies were identified by record linkage to population registers. The paternal age-related risks of fetal death and its components, early and late fetal loss, were estimated using survival......A possible detrimental paternal age effect on offspring health due to mutations of paternal origin should be reflected in an association between paternal age and fetal loss. The authors used data from a prospective study of 23,821 pregnant women recruited consecutively to the Danish National Birth...... analysis. Pregnancies fathered by a man aged 50 or more years (n = 124) had almost twice the risk of ending in a fetal loss compared with pregnancies with younger fathers (hazard ratio = 1.88, 95% confidence interval: 0.93, 3.82), after adjustment for maternal age, reproductive history, and maternal...

  20. Cohort Measures of Internal Migration: Understanding Long-Term Trends.

    Science.gov (United States)

    Bernard, Aude

    2017-12-01

    Internal migration intensities fluctuate over time, but both migration levels and trends show great diversity. The dynamics underpinning these trends remain poorly understood because they are analyzed almost exclusively by applying period measures to cross-sectional data. This article proposes 10 cohort measures that can be applied to both prospective and retrospective data to systematically examine long-term trends. To demonstrate their benefits, the proposed measures are applied to retrospective survey data for England that provide residential histories from birth to age 50 for cohorts born between 1918 and 1957. The analysis reveals stable lifetime migration for men but increased lifetime migration for women associated with earlier ages at moving in adulthood and a compression of intervals between consecutive moves. The proposed cohort measures provide a more comprehensive picture of migration behavior and should be used to complement period measures in exploring long-term trends. Increasing availability of retrospective and longitudinal survey data means that researchers can now apply the proposed measures to a wide range of countries.

  1. A meta-analysis of four genome-wide association studies of survival to age 90 years or older: the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium.

    Science.gov (United States)

    Newman, Anne B; Walter, Stefan; Lunetta, Kathryn L; Garcia, Melissa E; Slagboom, P Eline; Christensen, Kaare; Arnold, Alice M; Aspelund, Thor; Aulchenko, Yurii S; Benjamin, Emelia J; Christiansen, Lene; D'Agostino, Ralph B; Fitzpatrick, Annette L; Franceschini, Nora; Glazer, Nicole L; Gudnason, Vilmundur; Hofman, Albert; Kaplan, Robert; Karasik, David; Kelly-Hayes, Margaret; Kiel, Douglas P; Launer, Lenore J; Marciante, Kristin D; Massaro, Joseph M; Miljkovic, Iva; Nalls, Michael A; Hernandez, Dena; Psaty, Bruce M; Rivadeneira, Fernando; Rotter, Jerome; Seshadri, Sudha; Smith, Albert V; Taylor, Kent D; Tiemeier, Henning; Uh, Hae-Won; Uitterlinden, André G; Vaupel, James W; Walston, Jeremy; Westendorp, Rudi G J; Harris, Tamara B; Lumley, Thomas; van Duijn, Cornelia M; Murabito, Joanne M

    2010-05-01

    Genome-wide association studies (GWAS) may yield insights into longevity. We performed a meta-analysis of GWAS in Caucasians from four prospective cohort studies: the Age, Gene/Environment Susceptibility-Reykjavik Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Rotterdam Study participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Longevity was defined as survival to age 90 years or older (n = 1,836); the comparison group comprised cohort members who died between the ages of 55 and 80 years (n = 1,955). In a second discovery stage, additional genotyping was conducted in the Leiden Longevity Study cohort and the Danish 1905 cohort. There were 273 single-nucleotide polymorphism (SNP) associations with p < .0001, but none reached the prespecified significance level of 5 x 10(-8). Of the most significant SNPs, 24 were independent signals, and 16 of these SNPs were successfully genotyped in the second discovery stage, with one association for rs9664222, reaching 6.77 x 10(-7) for the combined meta-analysis of CHARGE and the stage 2 cohorts. The SNP lies in a region near MINPP1 (chromosome 10), a well-conserved gene involved in regulation of cellular proliferation. The minor allele was associated with lower odds of survival past age 90 (odds ratio = 0.82). Associations of interest in a homologue of the longevity assurance gene (LASS3) and PAPPA2 were not strengthened in the second stage. Survival studies of larger size or more extreme or specific phenotypes may support or refine these initial findings.

  2. Early Father Involvement and Subsequent Child Behaviour at Ages 3, 5 and 7 Years: Prospective Analysis of the UK Millennium Cohort Study.

    Science.gov (United States)

    Kroll, Mary E; Carson, Claire; Redshaw, Maggie; Quigley, Maria A

    Fathers are increasingly involved in care of their babies and young children. We assessed the association of resident fathers' involvement with subsequent behaviour of their children, examining boys and girls separately. We used longitudinal data from the UK Millennium Cohort Study for children born in 2000-2001, divided into three separate analysis periods: ages 9 months to 3 years, 3 to 5 years, and 5 to 7 years. By exploratory factor analysis of self-reported attitudes and engagement in caring activities, we derived composite measures of various types of father involvement at 9 months, 3 and 5 years. Where possible we created equivalent measures of mother involvement. Child behaviour was assessed by the Strengths and Difficulties Questionnaire (SDQ), which was completed by the mother when the child was aged 3, 5 and 7 years. We estimated gender-specific odds ratios for behaviour problems per quintile of father involvement, using separate logistic regression models for boys and girls in each analysis period. We controlled for a wide range of potential confounders: characteristics of the child (temperament and development at 9 months, and illness and exact age at outcome), equivalent mother involvement where appropriate, and factors related to socioeconomic status, household change, and parental well-being, where statistically significant. Paternal positive parenting beliefs at age 9 months and increased frequency of creative play at age 5 years were significantly associated with lower risk of subsequent behaviour problems (SDQ total difficulties) in both boys and girls (pinvolvement. No associations were observed for other composite measures of caring activity by the father at 9 months, 3 years or 5 years. Quality of parenting, rather than the division of routine care between parents, was associated with child behavioural outcomes.

  3. Global stability, periodic solutions, and optimal control in a nonlinear differential delay model

    Directory of Open Access Journals (Sweden)

    Anatoli F. Ivanov

    2010-09-01

    Full Text Available A nonlinear differential equation with delay serving as a mathematical model of several applied problems is considered. Sufficient conditions for the global asymptotic stability and for the existence of periodic solutions are given. Two particular applications are treated in detail. The first one is a blood cell production model by Mackey, for which new periodicity criteria are derived. The second application is a modified economic model with delay due to Ramsey. An optimization problem for a maximal consumption is stated and solved for the latter.

  4. Multi-Period Natural Gas Market Modeling. Applications, Stochastic Extensions and Solution Approaches

    International Nuclear Information System (INIS)

    Egging, R.G.

    2010-11-01

    This dissertation develops deterministic and stochastic multi-period mixed complementarity problems (MCP) for the global natural gas market, as well as solution approaches for large-scale stochastic MCP. The deterministic model is unique in the combination of the level of detail of the actors in the natural gas markets and the transport options, the detailed regional and global coverage, the multi-period approach with endogenous capacity expansions for transportation and storage infrastructure, the seasonal variation in demand and the representation of market power according to Nash-Cournot theory. The model is applied to several scenarios for the natural gas market that cover the formation of a cartel by the members of the Gas Exporting Countries Forum, a low availability of unconventional gas in the United States, and cost reductions in long-distance gas transportation. The results provide insights in how different regions are affected by various developments, in terms of production, consumption, traded volumes, prices and profits of market participants. The stochastic MCP is developed and applied to a global natural gas market problem with four scenarios for a time horizon until 2050 with nineteen regions and containing 78,768 variables. The scenarios vary in the possibility of a gas market cartel formation and varying depletion rates of gas reserves in the major gas importing regions. Outcomes for hedging decisions of market participants show some significant shifts in the timing and location of infrastructure investments, thereby affecting local market situations. A first application of Benders decomposition (BD) is presented to solve a large-scale stochastic MCP for the global gas market with many hundreds of first-stage capacity expansion variables and market players exerting various levels of market power. The largest problem solved successfully using BD contained 47,373 variables of which 763 first-stage variables, however using BD did not result in

  5. Gestational age and newborn size according to parental social mobility: an intergenerational cohort study.

    Science.gov (United States)

    Gigante, Denise P; Horta, Bernardo L; Matijasevich, Alicia; Mola, Christian Loret de; Barros, Aluisio J D; Santos, Ina S; Barros, Fernando C; Victora, Cesar G

    2015-10-01

    We examined the associations between socioeconomic trajectories from birth to adulthood and gestational age and birth size in the next generation, using linked data from two population-based birth cohorts carried out in a Brazilian city. By comparing socioeconomic trajectories of mothers and fathers, we attempted to identify-specific effects of maternal and paternal socioeconomic trajectory on offspring birth weight, birth length, head circumference and gestational age at birth. 2 population-based birth cohort studies were carried out in 1982 and 2004 in Pelotas (Brazil); 156 mothers and 110 fathers from the earlier cohort had children in 2004. Gestational age and birth length, weight and head circumference were measured. Analyses were carried out separately for mothers and fathers. Mediation analyses assessed the role of birth weight and adult body mass index (BMI). Among mothers, but not for fathers, childhood poverty was strongly associated with smaller size in the next generation (about 400 g in weight and 1.5 cm in height) and shorter gestations (about 2 weeks). Adult poverty did not play a role. For mothers, the associations with gestational age, birth length and weight-but not with head circumference-persisted after adjusting for maternal birth weight and for the height and weight of the grandmother. Maternal birth weight did not mediate the observed associations, but high maternal BMI in adulthood was partly responsible for the association with gestational age. Strong effects of early poverty on gestational age and birth size in the next generation were observed among mothers, but not among fathers. These findings suggest a specific maternal effect of socioeconomic trajectory, and in particular of early poverty on offspring size and duration of pregnancy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Being Small for Gestational Age: Does it Matter for the Neurodevelopment of Premature Infants? A Cohort Study.

    Directory of Open Access Journals (Sweden)

    Myriam Bickle Graz

    Full Text Available Whether being small for gestational age (SGA increases the risk of adverse neurodevelopmental outcome in premature infants remains controversial.to study the impact of SGA (birthweight < percentile 10 on cognition, behavior, neurodevelopmental impairment and use of therapy at 5 years old.This population-based prospective cohort included infants born before 32 weeks of gestation. Cognition was evaluated with the K-ABC, and behavior with the Strengths and Difficulties Questionnaire (SDQ. Primary outcomes were cognitive and behavioral scores, as well as neurodevelopmental impairment (cognitive score < 2SD, hearing loss, blindness, or cerebral palsy. The need of therapy, an indirect indicator of neurodevelopmental impairment, was a secondary outcome. Linear and logistic regression models were used to analyze the association of SGA with neurodevelopment.342/515 (76% premature infants were assessed. SGA was significantly associated with hyperactivity scores of the SDQ (coefficient 0.81, p < 0.04, but not with cognitive scores, neurodevelopmental impairment or the need of therapy. Gestational age, socio-economic status, and major brain lesions were associated with cognitive outcome in the univariate and multivariate model, whereas asphyxia, sepsis and bronchopulmonary dysplasia were associated in the univariate model only. Severe impairment was associated with fetal tobacco exposition, asphyxia, gestational age and major brain lesions. Different neonatal factors were associated with the use of single or multiple therapies: children with one therapy were more likely to have suffered birth asphyxia or necrotizing enterocolitis, whereas the need for several therapies was predicted by major brain lesions.In this large cohort of premature infants, assessed at 5 years old with a complete panel of tests, SGA was associated with hyperactive behavior, but not with cognition, neurodevelopmental impairment or use of therapy. Birthweight <10th percentile alone

  7. Amyloid PET in European and North American cohorts; and exploring age as a limit to clinical use of amyloid imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chiotis, Konstantinos [Karolinska Institutet, Department of NVS, Center for Alzheimer Research, Translational Alzheimer Neurobiology, Stockholm (Sweden); Carter, Stephen F. [Karolinska Institutet, Department of NVS, Center for Alzheimer Research, Translational Alzheimer Neurobiology, Stockholm (Sweden); University of Manchester, Wolfson Molecular Imaging Centre, Institute of Brain, Behaviour and Mental Health, Manchester (United Kingdom); Farid, Karim [Karolinska Institutet, Department of NVS, Center for Alzheimer Research, Translational Alzheimer Neurobiology, Stockholm (Sweden); APHP, Hotel-Dieu Hospital, Department of Nuclear Medicine, Paris (France); Savitcheva, Irina [Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden); Nordberg, Agneta [Karolinska Institutet, Department of NVS, Center for Alzheimer Research, Translational Alzheimer Neurobiology, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Geriatric Medicine, Stockholm (Sweden); Collaboration: for the Diagnostic Molecular Imaging (DiMI) network and the Alzheimer' s Disease Neuroimaging Initiative

    2015-09-15

    Several radiotracers that bind to fibrillar amyloid-beta in the brain have been developed and used in various patient cohorts. This study aimed to investigate the comparability of two amyloid positron emission tomography (PET) tracers as well as examine how age affects the discriminative properties of amyloid PET imaging. Fifty-one healthy controls (HCs), 72 patients with mild cognitive impairment (MCI) and 90 patients with Alzheimer's disease (AD) from a European cohort were scanned with [11C]Pittsburgh compound-B (PIB) and compared with an age-, sex- and disease severity-matched population of 51 HC, 72 MCI and 84 AD patients from a North American cohort who were scanned with [18F]Florbetapir. An additional North American population of 246 HC, 342 MCI and 138 AD patients with a Florbetapir scan was split by age (55-75 vs 76-93 y) into groups matched for gender and disease severity. PET template-based analyses were used to quantify regional tracer uptake. The mean regional uptake patterns were similar and strong correlations were found between the two tracers across the regions of interest in HC (ρ = 0.671, p = 0.02), amyloid-positive MCI (ρ = 0.902, p < 0.001) and AD patients (ρ = 0.853, p < 0.001). The application of the Florbetapir cut-off point resulted in a higher proportion of amyloid-positive HC and a lower proportion of amyloid-positive AD patients in the older group (28 and 30 %, respectively) than in the younger group (19 and 20 %, respectively). These results illustrate the comparability of Florbetapir and PIB in unrelated but matched patient populations. The role of amyloid PET imaging becomes increasingly important with increasing age in the diagnostic assessment of clinically impaired patients. (orig.)

  8. Amyloid PET in European and North American cohorts; and exploring age as a limit to clinical use of amyloid imaging

    International Nuclear Information System (INIS)

    Chiotis, Konstantinos; Carter, Stephen F.; Farid, Karim; Savitcheva, Irina; Nordberg, Agneta

    2015-01-01

    Several radiotracers that bind to fibrillar amyloid-beta in the brain have been developed and used in various patient cohorts. This study aimed to investigate the comparability of two amyloid positron emission tomography (PET) tracers as well as examine how age affects the discriminative properties of amyloid PET imaging. Fifty-one healthy controls (HCs), 72 patients with mild cognitive impairment (MCI) and 90 patients with Alzheimer's disease (AD) from a European cohort were scanned with [11C]Pittsburgh compound-B (PIB) and compared with an age-, sex- and disease severity-matched population of 51 HC, 72 MCI and 84 AD patients from a North American cohort who were scanned with [18F]Florbetapir. An additional North American population of 246 HC, 342 MCI and 138 AD patients with a Florbetapir scan was split by age (55-75 vs 76-93 y) into groups matched for gender and disease severity. PET template-based analyses were used to quantify regional tracer uptake. The mean regional uptake patterns were similar and strong correlations were found between the two tracers across the regions of interest in HC (ρ = 0.671, p = 0.02), amyloid-positive MCI (ρ = 0.902, p < 0.001) and AD patients (ρ = 0.853, p < 0.001). The application of the Florbetapir cut-off point resulted in a higher proportion of amyloid-positive HC and a lower proportion of amyloid-positive AD patients in the older group (28 and 30 %, respectively) than in the younger group (19 and 20 %, respectively). These results illustrate the comparability of Florbetapir and PIB in unrelated but matched patient populations. The role of amyloid PET imaging becomes increasingly important with increasing age in the diagnostic assessment of clinically impaired patients. (orig.)

  9. Dental and Chronological Ages as Determinants of Peak Growth Period and Its Relationship with Dental Calcification Stages.

    Science.gov (United States)

    Litsas, George; Lucchese, Alessandra

    2016-01-01

    To investigate the relationship between dental, chronological, and cervical vertebral maturation growth in the peak growth period, as well as to study the association between the dental calcification phases and the skeletal maturity stages during the same growth period. Subjects were selected from orthodontic pre-treatment cohorts consisting of 420 subjects where 255 were identified and enrolled into the study, comprising 145 girls and 110 boys. The lateral cephalometric and panoramic radiographs were examined from the archives of the Department of Orthodontics, Aristotle University of Thessaloniki, Greece. Dental age was assessed according to the method of Demirjian, and skeletal maturation according to the Cervical Vertebral Maturation Method. Statistical elaboration included Spearman Brown formula, descriptive statistics, Pearson's correlation coefficient and regression analysis, paired samples t-test, and Spearman's rho correlation coefficient. Chronological and dental age showed a high correlation for both gender(r =0.741 for boys, r = 0.770 for girls, pStage IV for both males (r=0.554) and females (r=0.68). The lowest correlation was for the CVM Stage III in males (r=0.433, pStage II in females (r=0.393, p>0.001). The t-test revealed statistically significant differences between these variables (pstages was determined. The second molars showed the highest correlation with CVM stages (CVMS) (r= 0.65 for boys, r = 0.72 for girls). Dental age was more advanced than chronological for both boys and girls for all CVMS. During the peak period these differences were more pronounced. Moreover, all correlations between skeletal and dental stages were statistically significant. The second molars showed the highest correlation whereas the canines showed the lowest correlation for both gender.

  10. Risk of lower extremity arterial disease in a cohort of workers occupationally exposed to ionizing radiation over a prolonged period

    Energy Technology Data Exchange (ETDEWEB)

    Azizova, Tamara V.; Bannikova, Maria V.; Grigorieva, Evgenia S.; Bagaeva, Yaroslava P.; Azizova, Elena V. [Southern Urals Biophysics Institute, Ozyorsk Chelyabinsk Region (Russian Federation)

    2016-05-15

    In this study the incidence risk of lower extremity arterial disease (LEAD; international classification of diseases version 9 code 440.2) was assessed in a cohort of workers occupationally exposed to radiation over a prolonged period. The study cohort includes 22,377 workers of the Mayak Production Association (25 % of whom are females) first employed at one of the main facilities in 1948-1982 and followed up to the end of 2008. Dose estimates used in the study are provided by Mayak Worker Dosimetry System 2008. The mean total dose from external gamma-rays is 0.54 Gy for males and 0.44 Gy for females. The mean absorbed liver dose from internal alpha-radiation due to incorporated plutonium is 0.23 Gy in males and 0.44 Gy in females. Relative risks and excess relative risks per unit dose (ERR/Gy) are calculated based on maximum likelihood. A total of 943 cases of LEAD are registered in the study cohort during the follow-up of 512,801 person-years. A significant association of LEAD incidence with total dose from external gamma-rays (based on a linear model) was revealed, and the ERR/Gy is 0.27 (95 % confidence interval (CI) 0.11; 0.48). It turned out that a linear-exponential model provides a better fit of the data (∇AIC = 9.957). Inclusion of an adjustment for internal alpha-radiation dose resulted in the reduction of the ERR/Gy to 0.19 (95 % CI 0.05; 0.39), but the risk remains significant. No association of LEAD incidence with dose from internal alpha-radiation was found in the study worker cohort. It is concluded that this study provides evidence for an association of LEAD incidence with dose from external gamma-rays taking non-radiation factors into account. (orig.)

  11. Databases and statistical methods of cohort studies (1979-1995) in Yangjiang, China

    International Nuclear Information System (INIS)

    Sun Quanfu; Zou Jianming; Liu Yusheng

    1997-01-01

    There are epidemiological databases of some 40 MB available to risk analysis, mainly including databases of cohort follow-up and deaths of 12000 subject for the periods 1979-1986 and 1987-1995, and dosimetric database for 6783 households in 526 hamlets. Because of no strict projection relationship between database of the two periods of 1979-1986 and 1987-1995, the authors developed methods to combine the data of the two periods into one for risk analysis. The first one is to set up a theoretical cohort of 1979-1995 based on record linkage between the two periods. The other method is simply to sum up stratified person-year tables of different periods. It is suggested through extensive analysis of dosimetric data that indoor exposures should be divided further into two parts (exposure received on bed and those received during other indoor activities), outdoor exposure is homogeneous within a hamlet, and occupancy factors are sex-and-age-dependent. Cumulative dose estimates based upon hamlet-specific average of dose rates in bedroom, living room, and outdoor and sex-age-specific occupancy factors are derived for each cohort member. Person-years and number of deaths are tabulated with stratification by sex, attained age, calendar years, and dose. Cancer risks are analyzed for the period of 1979-1990. Conclusion: The epidemiological studies in high background radiation areas of Yangjiang, have been greatly improved by extensively using database management system and advanced statistical analysis with more attention paid to standardization and systematization of survey data management

  12. Effects of nitrogen application rate and leaf age on the distribution pattern of leaf SPAD readings in the rice canopy.

    Directory of Open Access Journals (Sweden)

    Hu Yang

    Full Text Available A Soil-Plant Analysis Development (SPAD chlorophyll meter can be used as a simple tool for evaluating N concentration of the leaf and investigating the combined effects of nitrogen rate and leaf age on N distribution. We conducted experiments in a paddy field over two consecutive years (2008-2009 using rice plants treated with six different N application levels. N distribution pattern was determined by SPAD readings based on the temporal dynamics of N concentrations in individual leaves. At 62 days after transplantation (DAT in 2008 and DAT 60 in 2009, leaf SPAD readings increased from the upper to lower in the rice canopy that received N levels of 150 to 375 kg ha(-1The differences in SPAD readings between the upper and lower leaf were larger under higher N application rates. However, as plants grew, this atypical distribution of SPAD readings in canopy leaf quickly reversed to the general order. In addition, temporal dynamics of the leaf SPAD readings (N concentrations were fitted to a piecewise function. In our model, changes in leaf SPAD readings were divided into three stages: growth, functioning, and senescence periods. The leaf growth period lasted approximately 6 days, and cumulative growing days were not affected by N application rates. The leaf functioning period was represented with a relatively stable SPAD reading related to N application rate, and cumulative growing days were extended with increasing N application rates. A quadratic equation was utilized to describe the relationship between SPAD readings and leaf age during the leaf senescence period. The rate of decrease in SPAD readings increased with the age of leaves, but the rate was slowed by N application. As leaves in the lower canopy were physiologically older than leaves in the upper canopy, the rate of decrease in SPAD readings was faster in the lower leaves.

  13. Decision support for life extension of technical systems through virtual age modelling

    International Nuclear Information System (INIS)

    Pérez Ramírez, Pedro A.; Utne, Ingrid Bouwer

    2013-01-01

    This article presents a virtual age model for decision support regarding life extension of ageing repairable systems. The aim of the model is to evaluate different life extension decision alternatives and their impact on the future performance of the system. The model can be applied to systems operated continuously (e.g., process systems) and systems operated on demand (e.g., safety systems). Deterioration and efficiency of imperfect maintenance is assessed when there is limited or no degradation data, and only failure and maintenance data is available. Systems that are in operation can be studied, meaning that the systems may be degraded. The current degradation is represented by a “current virtual age”, which is calculated from recorded maintenance data. The model parameters are estimated with the maximum likelihood method. A case study illustrates the application of the model for life extension of two fire water pumps in an oil and gas facility. The performance of the pump system is assessed with respect to number of failures, safety unavailability and costs during the life extension period. -- Highlights: ► Life extension assessment of technical systems using virtual age model is proposed. ► A virtual age model is generalised for systems in stand-by and continuous operation. ► The concept of current virtual age describes technical condition of the system. ► Different decision alternatives for life extension can be easily analysed. ► The decision process is improved even when only scarce failure data is available

  14. Effect of Age at Antiretroviral Therapy Initiation on Catch-Up Growth within the First 24 Months among HIV-Infected Children in the IeDEA West African Pediatric Cohort

    Science.gov (United States)

    Jesson, Julie; Koumakpaï, Sikiratou; Diagne, Ndeye R.; Amorissani-Folquet, Madeleine; Kouéta, Fla; Aka, Addi; Lawson-Evi, Koko; Dicko, Fatoumata; Kouakou, Kouadio; Pety, Touré; Renner, Lorna; Eboua, Tanoh; Coffie, Patrick A.; Desmonde, Sophie; Leroy, Valériane

    2015-01-01

    Background We described malnutrition and the effect of age at antiretroviral therapy (ART) initiation on catch-up growth over 24 months among HIV-infected children enrolled in the IeDEA West African paediatric cohort (pWADA). Methods Malnutrition was defined at ART initiation (baseline) by a Z-score malnutrition at ART initiation, ART regimen, time period and country, were compared by age at ART initiation. Cox proportional hazards regression models determined predictors of catch-up growth on ART over 24 months. Results Between 2001 and 2012, 2004 HIV-infected children Malnutrition among these children is an additional burden that has to be urgently managed. Despite a significant growth improvement after 24 months on ART, especially in children <5 years, a substantial proportion of children still never achieved catch-up growth. Nutritional care should be part of the global healthcare of HIV-infected children in sub-Saharan Africa. PMID:25955835

  15. Impact of age, sex, and indexation method on MR left ventricular reference values in the Framingham Heart Study offspring cohort.

    Science.gov (United States)

    Yeon, Susan B; Salton, Carol J; Gona, Philimon; Chuang, Michael L; Blease, Susan J; Han, Yuchi; Tsao, Connie W; Danias, Peter G; Levy, Daniel; O'Donnell, Christopher J; Manning, Warren J

    2015-04-01

    To determine normative values for left ventricular (LV) volumes, mass, concentricity, and ejection fraction (EF) and investigate associations between sex, age, and body size with LV parameters in community-dwelling adults. In all, 1794 Framingham Heart Study Offspring cohort members underwent LV short-axis oriented, contiguous multislice cine steady-state free precession MR of the left ventricle; from these a healthy referent group (n = 852, 61 ± 9 years, 40% men) free of clinical cardiac disease and hypertension (SBP 65 years); LV parameters were indexed to measures of body size. Men have greater LV volumes and mass than women both before and after indexation to height, powers of height, and body surface area (P J. Magn. Reson. Imaging 2015;41:1038-1045. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  16. Dynamic models for estimating the effect of HAART on CD4 in observational studies: Application to the Aquitaine Cohort and the Swiss HIV Cohort Study.

    Science.gov (United States)

    Prague, Mélanie; Commenges, Daniel; Gran, Jon Michael; Ledergerber, Bruno; Young, Jim; Furrer, Hansjakob; Thiébaut, Rodolphe

    2017-03-01

    Highly active antiretroviral therapy (HAART) has proved efficient in increasing CD4 counts in many randomized clinical trials. Because randomized trials have some limitations (e.g., short duration, highly selected subjects), it is interesting to assess the effect of treatments using observational studies. This is challenging because treatment is started preferentially in subjects with severe conditions. This general problem had been treated using Marginal Structural Models (MSM) relying on the counterfactual formulation. Another approach to causality is based on dynamical models. We present three discrete-time dynamic models based on linear increments models (LIM): the first one based on one difference equation for CD4 counts, the second with an equilibrium point, and the third based on a system of two difference equations, which allows jointly modeling CD4 counts and viral load. We also consider continuous-time models based on ordinary differential equations with non-linear mixed effects (ODE-NLME). These mechanistic models allow incorporating biological knowledge when available, which leads to increased statistical evidence for detecting treatment effect. Because inference in ODE-NLME is numerically challenging and requires specific methods and softwares, LIM are a valuable intermediary option in terms of consistency, precision, and complexity. We compare the different approaches in simulation and in illustration on the ANRS CO3 Aquitaine Cohort and the Swiss HIV Cohort Study. © 2016, The International Biometric Society.

  17. Effect of Birth Cohort on Risk of Hip Fracture: Age-Specific Incidence Rates in the Framingham Study

    Science.gov (United States)

    Samelson, Elizabeth J.; Zhang, Yuqing; Kiel, Douglas P.; Hannan, Marian T.; Felson, David T.

    2002-01-01

    Objectives. This study examined the effect of birth cohort on incidence rates of hip fracture among women and men in the Framingham Study. Methods. Age-specific incidence rates of first hip fracture were presented according to tertile of year of birth for 5209 participants of the Framingham Study, a population-based cohort followed since 1948. Sex-specific incidence rate ratios were calculated by Cox regression to assess the relation between birth cohort and hip fracture incidence. Results. An increasing trend in hip fracture incidence rates was observed with year of birth for women (trend, P = .05) and men (trend, P = .03). Relative to those born from 1887 to 1900 (incidence rate ratio [IRR] = 1.0), age-specific incidence rates were greatest in the most recent birth cohort, born from 1911 to 1921 (IRR = 1.4 for women, IRR = 2.0 for men), and intermediate in those born from 1901 to 1910 (IRR = 1.2 for women, IRR = 1.5 for men). Conclusions. Results suggest risk of hip fracture is increasing for successive birth cohorts. Projections that fail to account for the increase in rates associated with birth cohort underestimate the future public health impact of hip fracture in the United States. PMID:11988460

  18. Caffeine consumption and cognitive function at age 70: the Lothian Birth Cohort 1936 study.

    Science.gov (United States)

    Corley, Janie; Jia, Xueli; Kyle, Janet A M; Gow, Alan J; Brett, Caroline E; Starr, John M; McNeill, Geraldine; Deary, Ian J

    2010-02-01

    To investigate the association between caffeine consumption and cognitive outcomes in later life. Participants were 923 healthy adults from the Lothian Birth Cohort 1936 Study, on whom there were intelligence quotient (IQ) data from age 11 years. Cognitive function at age 70 years was assessed, using tests measuring general cognitive ability, speed of information processing, and memory. Current caffeine consumption (using multiple measures of tea, coffee, and total dietary caffeine) was obtained by self-report questionnaire, and demographic and health information was collected in a standardized interview. In age- and sex-adjusted models, there were significant positive associations between total caffeine intake and general cognitive ability and memory. After adjustment for age 11 IQ and social class, both individually and together, most of these associations became nonsignificant. A robust positive association, however, was found between drinking ground coffee (e.g., filter and espresso) and performance on the National Adult Reading Test (NART, p = .007), and the Wechsler Test of Adult Reading (WTAR, p = .02). No gender effects were observed, contrary to previous studies. Generally, higher cognitive scores were associated with coffee consumption, and lower cognitive scores with tea consumption, but these effects were not significant in the fully adjusted model. The present study is rare in having childhood IQ in a large sample of older people. The results suggest that the significant caffeine intake-cognitive ability associations are bidirectional-because childhood IQ and estimated prior IQ are associated with the type of caffeine intake in old age-and partly confounded by social class.

  19. Mother and child characteristics at birth and early age leukemia: a case-cohort population-based study.

    Science.gov (United States)

    Reis, Rejane de Souza; Silva, Neimar de Paula; Santos, Marceli de Oliveira; Oliveira, Julio Fernando Pinto; Thuler, Luiz Claudio Santos; de Camargo, Beatriz; Pombo-de-Oliveira, Maria S

    The population-based cancer registries (PBCR) and the Information System on Live Births in Brazil (Sistema de Informações sobre Nascidos Vivos [SINASC]) have information that enables the test for risk factors associated with leukemia at an early age. The aim of this study was to identify maternal and birth characteristics associated with early-age acute leukemia (EAL) in Brazil. A case-cohort study was performed using secondary dataset information of PBCR and SINASC. The risk association variables were grouped into (i) characteristics of the child at birth and (ii) characteristics of maternal exposure during pregnancy. The case-control ratio was 1:4. Linkage was performed using R software; odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression models. EAL was associated with maternal occupational exposure to chemicals (agricultural, chemical, and petrochemical industry; adjOR: 2.18, 95% CI: 1.16-4.10) and with birth defects (adjOR: 3.62, 95% CI: 1.19-11.00). The results of this study, with the identification of EAL risk factors in population-based case-cohort study, strengthen the knowledge and improve databases, contributing to investigations on risk factors associated with childhood leukemia worldwide. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  20. Mother and child characteristics at birth and early age leukemia: a case-cohort population-based study,

    Directory of Open Access Journals (Sweden)

    Rejane de Souza Reis

    Full Text Available Abstract Objective: The population-based cancer registries (PBCR and the Information System on Live Births in Brazil (Sistema de Informações sobre Nascidos Vivos [SINASC] have information that enables the test for risk factors associated with leukemia at an early age. The aim of this study was to identify maternal and birth characteristics associated with early-age acute leukemia (EAL in Brazil. Methods: A case-cohort study was performed using secondary dataset information of PBCR and SINASC. The risk association variables were grouped into (i characteristics of the child at birth and (ii characteristics of maternal exposure during pregnancy. The case-control ratio was 1:4. Linkage was performed using R software; odds ratio (OR and 95% confidence interval (CI were calculated by logistic regression models. Results: EAL was associated with maternal occupational exposure to chemicals (agricultural, chemical, and petrochemical industry; adjOR: 2.18, 95% CI: 1.16-4.10 and with birth defects (adjOR: 3.62, 95% CI: 1.19-11.00. Conclusions: The results of this study, with the identification of EAL risk factors in population-based case-cohort study, strengthen the knowledge and improve databases, contributing to investigations on risk factors associated with childhood leukemia worldwide.

  1. Significance of categorization and the modeling of age related factors for radiation protection

    International Nuclear Information System (INIS)

    Matsuoka, Osamu

    1987-01-01

    It is proposed that the categorization and modelling are necessary with regard to age related factors of radionuclide metabolism for the radiation protection of the public. In order to utilize the age related information as a model for life time risk estimate of public, it is necessary to generalize and simplify it according to the categorized model patterns. Since the patterns of age related changes in various parameters of radionuclide metabolism seem to be rather simple, it is possible to categorize them into eleven types of model patterns. Among these models, five are selected as positively significant models to be considered. Examples are shown as to the fitting of representative parameters of both physiological and metabolic parameter of radionuclides into the proposed model. The range of deviation from adult standard value is also analyzed for each model. The fitting of each parameter to categorized models, and its comparative consideration provide the effective information as to the physiological basis of radionuclide metabolism. Discussions are made on the problems encountered in the application of available age related information to radiation protection of the public, i.e. distribution of categorized parameter, period of life covered, range of deviation from adult value, implication to other dosimetric and pathological models and to the final estimation. 5 refs.; 3 figs.; 4 tabs

  2. Cognitive impacts of ambient air pollution in the National Social Health and Aging Project (NSHAP) cohort.

    Science.gov (United States)

    Tallon, Lindsay A; Manjourides, Justin; Pun, Vivian C; Salhi, Carmel; Suh, Helen

    2017-07-01

    Pathways through which air pollution may impact cognitive function are poorly understood, particularly with regard to whether and how air pollution interacts with social and emotional factors to influence cognitive health. To examine the association between air pollutant exposures and cognitive outcomes among older adults participating in the National Social Life, Health, and Aging Project (NSHAP) cohort study. Measures of cognitive function, social connectedness, and physical and mental health were obtained for each NSHAP participant starting with Wave 1 of the study in 2005. Cognitive function was assessed using the Chicago Cognitive Function Measure (CCFM) for 3377 participants. Exposures to fine particles (PM 2.5 ) were estimated for each participant using GIS-based spatio-temporal models, and exposures to nitrogen dioxide (NO 2 ) were obtained from the nearest EPA monitors. In adjusted linear regression models, IQR increases in 1 to 7year PM 2.5 exposures were associated with a 0.22 (95% CI: -0.44, -0.01) to a 0.25 (95% CI: -0.43, -0.06) point decrease in CCFM scores, equivalent to aging 1.6years, while exposures to NO 2 were equivalent to aging 1.9years. The impacts of PM 2.5 on cognition were modified by stroke, anxiety, and stress, and were mediated by depression. The impacts of NO 2 were mediated by stress and effect modification by impaired activities of daily living for NO 2 was found. Exposures to long-term PM 2.5 and NO 2 were associated with decreased cognitive function in our cohort of older Americans, and individuals who experienced a stroke or elevated anxiety were more susceptible to the effects of PM 2.5 on cognition. Additionally, mediation results suggest that PM 2.5 may impact cognition through pathways related to mood disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Impact of rotavirus vaccination on hospitalisations in Belgium: comparing model predictions with observed data.

    Directory of Open Access Journals (Sweden)

    Baudouin Standaert

    Full Text Available BACKGROUND: Published economic assessments of rotavirus vaccination typically use modelling, mainly static Markov cohort models with birth cohorts followed up to the age of 5 years. Rotavirus vaccination has now been available for several years in some countries, and data have been collected to evaluate the real-world impact of vaccination on rotavirus hospitalisations. This study compared the economic impact of vaccination between model estimates and observed data on disease-specific hospitalisation reductions in a country for which both modelled and observed datasets exist (Belgium. METHODS: A previously published Markov cohort model estimated the impact of rotavirus vaccination on the number of rotavirus hospitalisations in children aged <5 years in Belgium using vaccine efficacy data from clinical development trials. Data on the number of rotavirus-positive gastroenteritis hospitalisations in children aged <5 years between 1 June 2004 and 31 May 2006 (pre-vaccination study period or 1 June 2007 to 31 May 2010 (post-vaccination study period were analysed from nine hospitals in Belgium and compared with the modelled estimates. RESULTS: The model predicted a smaller decrease in hospitalisations over time, mainly explained by two factors. First, the observed data indicated indirect vaccine protection in children too old or too young for vaccination. This herd effect is difficult to capture in static Markov cohort models and therefore was not included in the model. Second, the model included a 'waning' effect, i.e. reduced vaccine effectiveness over time. The observed data suggested this waning effect did not occur during that period, and so the model systematically underestimated vaccine effectiveness during the first 4 years after vaccine implementation. CONCLUSIONS: Model predictions underestimated the direct medical economic value of rotavirus vaccination during the first 4 years of vaccination by approximately 10% when assessing

  4. Global attractivity of an almost periodic N-species nonlinear ecological competitive model

    Science.gov (United States)

    Xia, Yonghui; Han, Maoan; Huang, Zhenkun

    2008-01-01

    By using comparison theorem and constructing suitable Lyapunov functional, we study the following almost periodic nonlinear N-species competitive Lotka-Volterra model: A set of sufficient conditions is obtained for the existence and global attractivity of a unique positive almost periodic solution of the above model. As applications, some special competition models are studied again, our new results improve and generalize former results. Examples and their simulations show the feasibility of our main results.

  5. Pregnancy diet and offspring asthma risk over a 10-year period: the Lifeways Cross Generation Cohort Study, Ireland.

    Science.gov (United States)

    Viljoen, Karien; Segurado, Ricardo; O'Brien, John; Murrin, Celine; Mehegan, John; Kelleher, Cecily C

    2018-02-20

    The association of maternal pregnancy diet with offspring asthma risk have been reported. However, literature on longitudinal patterns of asthma risk relative to intrauterine nutrient exposure is limited. We aimed to establish whether vegetable, oily fish and vitamin D intake during pregnancy are associated with childhood asthma risk over a 10-year period in the Irish Republic. Mother-child pairs (n=897) from the Lifeways prospective birth cohort, with data on nutrient intake during pregnancy and asthma status, respectively, were eligible for inclusion in the analysis. Data on socioeconomic and morbidity indicators over 10 years of follow-up on mothers and the index child were collected through self-administered questionnaires. Asthma status as diagnosed by the general practitioner at any time point over 10 years was related to maternal vegetable, oily fish and vitamin D intake during pregnancy, while adjusting for gestational age, socioeconomic status, smoking at delivery, breast feeding, season of birth and supplement use. Data were modelled with a marginal model on correlated observations over time within individuals. In the fully adjusted model, asthma was inversely associated with higher daily average intake of oily fish (OR 0.23 per serving/day, 95% CI 0.04 to 1.41) and of vegetables (OR 0.96 per serving/day, 95% CI 0.88 to 1.05), but the confidence limits overlapped 1. A higher daily vitamin D intake was associated with reduced odds of asthma (OR 0.93 per μg/day, 95% CI 0.89 to 0.98). This analysis suggests higher daily average intake of vitamin D in pregnancy is associated with asthma risk in offspring over the first 10 years of life. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. Cohort change and the diffusion of environmental concern: A cross-national analysis

    Science.gov (United States)

    Nawrotzki, Raphael J.; Pampel, Fred C.

    2013-01-01

    This study explores value change across cohorts for a multinational population sample. Employing a diffusion-of-innovations approach, we combine competing theories predicting the relationship between socio-economic status (SES) and environmentalism: post-materialism and affluence theories, and global environmentalism theory. The diffusion argument suggests that high-SES groups first adopt pro-environmental views, but as time passes by, environmentalism diffuses to lower-SES groups. We test the diffusion argument using a sample of 18 countries for two waves (years 1993 and 2000) from the International Social Survey Project (ISSP). Cross-classified multilevel modeling allows us to identify a non-linear interaction between cohort and education, our core measure of SES, in predicting environmental concern, while controlling for age and period. We find support for the diffusion argument and demonstrate that the positive effect of education on environmental concern first increases among older cohorts, then starts to level off until a bend-point is reached for individuals born around 1940 and becomes progressively weaker for younger cohorts. PMID:24179313

  7. Vascular burden and brain aging in a senior volunteer cohort: A pilot study

    Directory of Open Access Journals (Sweden)

    Raymond Y Lo

    2017-01-01

    Full Text Available Objective: To test the feasibility of establishing a senior volunteer cohort and describe vascular risks, cognitive function, and brain aging indices in a pilot study. Materials and Methods: We enrolled 40 senior volunteers from the Tzu Chi Foundation and other organizations in Hualien in 2014–2015. We conducted in-person interviews to collect information on demographic features, physical fitness, dietary habits, comorbidities, and narratives of aging. Vascular risks including blood pressure, body mass index (BMI, serum glucose level, and lipid profile were examined. Each participant underwent a comprehensive battery of neuropsychological tests and structural brain magnetic resonance imaging (MRI. Descriptive statistics and tabulation were applied to characterize this pilot cohort. Results: There were more volunteers from the Tzu Chi Foundation (n = 25 than other organizations. The mean age was 66.7 years (standard deviation = 5.1 and there was a female predominance (M:F = 13:27. The mean number of comorbid chronic diseases was 2.1 and the mean BMI was 24.5. Most participants (77.5% engaged in outdoor walking activities every week. Nutrient intake in vegetarians (n = 18 did not differ from nonvegetarians except for lower Vitamin B12 levels (mean = 0.9 μg. All participants but one scored 26 or above in the Mini–Mental State Examination (mean = 28.4. Among the other cognitive tests, only one task related to inhibition and switching abilities was at the low average level. The mean values of vascular risk markers were within the normal ranges. The most common genotype of apolipoprotein E was μ3/μ3 (n = 32. The quality of MRI was sufficient for volumetric analysis. Conclusion: It is feasible to establish a volunteer-based cohort to study brain aging in Taiwan. The senior volunteers were physically active and cognitively healthy. Vascular risks were well distributed among these participants. Future longitudinal study will allow us to observe

  8. Maternal age and offspring developmental vulnerability at age five: A population-based cohort study of Australian children.

    Directory of Open Access Journals (Sweden)

    Kathleen Falster

    2018-04-01

    Full Text Available In recent decades, there has been a shift to later childbearing in high-income countries. There is limited large-scale evidence of the relationship between maternal age and child outcomes beyond the perinatal period. The objective of this study is to quantify a child's risk of developmental vulnerability at age five, according to their mother's age at childbirth.Linkage of population-level perinatal, hospital, and birth registration datasets to data from the Australian Early Development Census (AEDC and school enrolments in Australia's most populous state, New South Wales (NSW, enabled us to follow a cohort of 99,530 children from birth to their first year of school in 2009 or 2012. The study outcome was teacher-reported child development on five domains measured by the AEDC, including physical health and well-being, emotional maturity, social competence, language and cognitive skills, and communication skills and general knowledge. Developmental vulnerability was defined as domain scores below the 2009 AEDC 10th percentile cut point. The mean maternal age at childbirth was 29.6 years (standard deviation [SD], 5.7, with 4,382 children (4.4% born to mothers aged <20 years and 20,026 children (20.1% born to mothers aged ≥35 years. The proportion vulnerable on ≥1 domains was 21% overall and followed a reverse J-shaped distribution according to maternal age: it was highest in children born to mothers aged ≤15 years, at 40% (95% CI, 32-49, and was lowest in children born to mothers aged between 30 years and ≤35 years, at 17%-18%. For maternal ages 36 years to ≥45 years, the proportion vulnerable on ≥1 domains increased to 17%-24%. Adjustment for sociodemographic characteristics significantly attenuated vulnerability risk in children born to younger mothers, while adjustment for potentially modifiable factors, such as antenatal visits, had little additional impact across all ages. Although the multi-agency linkage yielded a broad range of

  9. Multi-period natural gas market modeling Applications, stochastic extensions and solution approaches

    Science.gov (United States)

    Egging, Rudolf Gerardus

    This dissertation develops deterministic and stochastic multi-period mixed complementarity problems (MCP) for the global natural gas market, as well as solution approaches for large-scale stochastic MCP. The deterministic model is unique in the combination of the level of detail of the actors in the natural gas markets and the transport options, the detailed regional and global coverage, the multi-period approach with endogenous capacity expansions for transportation and storage infrastructure, the seasonal variation in demand and the representation of market power according to Nash-Cournot theory. The model is applied to several scenarios for the natural gas market that cover the formation of a cartel by the members of the Gas Exporting Countries Forum, a low availability of unconventional gas in the United States, and cost reductions in long-distance gas transportation. 1 The results provide insights in how different regions are affected by various developments, in terms of production, consumption, traded volumes, prices and profits of market participants. The stochastic MCP is developed and applied to a global natural gas market problem with four scenarios for a time horizon until 2050 with nineteen regions and containing 78,768 variables. The scenarios vary in the possibility of a gas market cartel formation and varying depletion rates of gas reserves in the major gas importing regions. Outcomes for hedging decisions of market participants show some significant shifts in the timing and location of infrastructure investments, thereby affecting local market situations. A first application of Benders decomposition (BD) is presented to solve a large-scale stochastic MCP for the global gas market with many hundreds of first-stage capacity expansion variables and market players exerting various levels of market power. The largest problem solved successfully using BD contained 47,373 variables of which 763 first-stage variables, however using BD did not result in

  10. Cohort Profile Update: The TRacking Adolescents’ Individual Lives Survey (TRAILS)

    Science.gov (United States)

    Oldehinkel, Albertine J; Rosmalen, Judith GM; Buitelaar, Jan K; Hoek, Hans W; Ormel, Johan; Raven, Dennis; Reijneveld, Sijmen A; Veenstra, René; Verhulst, Frank C; Vollebergh, Wilma AM; Hartman, Catharina A

    2015-01-01

    TRAILS consists of a population cohort (N = 2230) and a clinical cohort (N = 543), both of which were followed from about age 11 years onwards. To date, the population cohort has been assessed five times over a period of 11 years, with retention rates ranging between 80% and 96%. The clinical cohort has been assessed four times over a period of 8 years, with retention rates ranging between 77% and 85%. Since the IJE published a cohort profile on the TRAILS in 2008, the participants have matured from adolescents into young adults. The focus shifted from parents and school to entry into the labour market and family formation, including offspring. Furthermore, psychiatric diagnostic interviews were administered, the database was linked to a Psychiatric Case Registry, and the availability of genome-wide SNP variations opened the door to genome-wide association studies regarding a wide range of (endo)phenotypes. With some delay, TRAILS data are available to researchers outside the TRAILS consortium without costs; access can be obtained by submitting a publication proposal (see www.trails.nl). PMID:25431468

  11. Features of high-speed and strength qualities development in young biathlonists aged 14–15 in the preparatory period

    Directory of Open Access Journals (Sweden)

    Artem Burla

    2015-04-01

    Full Text Available Purpose: to substantiate a methodology of high-speed and strength qualities development of young biathlonists aged 14–15 during the preparatory period. Material and Methods: young biathlonists aged 14–15 from control and experimental groups took part in the research. There were 12 athletes in each group. Pedagogical methods and methods of mathematical statistics were used in the work. Pedagogical methods of researches were used for level definition of high-speed and strength qualities development of young biathlonists. Results: reliable increase of motive qualities and polydynamometry results testing of young biathlonists from the experimental group due to implementation of the experimental methodology in the preparatory period is established. Conclusions: application of the developed complexes in the preparatory period in the experimental group of young biathlonists aged 14–15 allows to raise indices of motive qualities and polydynamometry testing statistically significantly.

  12. Comprehensive Analysis of Large Sets of Age-Related Physiological Indicators Reveals Rapid Aging around the Age of 55 Years.

    Science.gov (United States)

    Lixie, Erin; Edgeworth, Jameson; Shamir, Lior

    2015-01-01

    While many studies show a correlation between chronological age and physiological indicators, the nature of this correlation is not fully understood. To perform a comprehensive analysis of the correlation between chronological age and age-related physiological indicators. Physiological aging scores were deduced using principal component analysis from a large dataset of 1,227 variables measured in a cohort of 4,796 human subjects, and the correlation between the physiological aging scores and chronological age was assessed. Physiological age does not progress linearly or exponentially with chronological age: a more rapid physiological change is observed around the age of 55 years, followed by a mild decline until around the age of 70 years. These findings provide evidence that the progression of physiological age is not linear with that of chronological age, and that periods of mild change in physiological age are separated by periods of more rapid aging. © 2015 S. Karger AG, Basel.

  13. Structural social relations and cognitive ageing trajectories: evidence from the Whitehall II cohort study.

    Science.gov (United States)

    Elovainio, Marko; Sommerlad, Andrew; Hakulinen, Christian; Pulkki-Råback, Laura; Virtanen, Marianna; Kivimäki, Mika; Singh-Manoux, Archana

    2017-11-07

    Social relations are important for health, particularly at older ages. We examined the salience of frequency of social contacts and marital status for cognitive ageing trajectories over 21 years, from midlife to early old age. Data are from the Whitehall II cohort study, including 4290 men and 1776 women aged 35-55 years at baseline (1985-88). Frequency of social contacts and marital status were measured in 1985-88 and 1989-90. Assessment of cognitive function on five occasions (1991-94, 1997-99, 2003-04, 2007-09 and 2012-13) included the following tests: short-term memory, inductive reasoning, verbal fluency (phonemic and semantic) and a combined global score. Cognitive trajectories over the study period were analysed using longitudinal latent growth class analyses, and the associations of these latent classes (trajectory memberships) with social relations were analysed using multinominal logistic regression. More frequent social contacts [relative risk (RRR) 0.96, 95% confidence interval (CI) 0.94 - 0.98] and being married (RRR 0.70, 95% CI 0.58 - 0.84) were associated with lower probability of being on a low rather than high cognitive performance trajectory over the subsequent 21 years. These associations persisted after adjustment for covariates. Of the sub-tests, social relations variables had the strongest association with phonemic fluency (RRR 0.95, 95% CI 0.94 - 0.97 for frequent contact; RRR 0.59, 95% CI 0.48 - 0.71 for being married). More frequent social contacts and having a spouse were associated with more favourable cognitive ageing trajectories. Further studies are needed to examine whether interventions designed to improve social connections affect cognitive ageing. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

  14. Neuropsychologic status at the age 4 years and atopy in a population-based birth cohort.

    Science.gov (United States)

    Julvez, J; Torrent, M; Guxens, M; Antó, J M; Guerra, S; Sunyer, J

    2009-09-01

    Mental health has been reported to be associated with allergy, but only a few cohort studies have assessed if neurodevelopment predicts atopy. To investigate if neurobehavioral status of healthy 4-year-old children was associated with specific immunoglobulin E (IgE) at the same age and skin prick test results 2 years later. A population-based birth cohort enrolled 482 children, 422 of them (87%) provided neurobehavioral data, 341 (71%) had specific IgE measured at the age of 4 years; and 395 (82%) had skin prick tests completed at the age of 6 years. Atopy was defined as IgE levels higher than 0.35 kU/l to any of the three tested allergens at the age of 4 or as a positive skin prick test to any of the six tested allergens at the age of 6. McCarthy Scales of Child Abilities and California Preschool Social Competence Scale were the psychometric instruments used. Twelve percent of children at the age of 4 and 17% at the age of 6 were atopic. Neurobehavioral scores were negatively associated with 6-year-old atopy after adjustment for socio-demographic and allergic factors, A relative risk of 3.06 (95% CI: 1.30-7.24) was associated with the lowest tertile (scorings eczema at the age of 6, but not at the age of 4, were associated with neurodevelopment at the age of 4. Neuropsychologic functioning and later atopy are negatively associated in preschool age children.

  15. Decreases in Smoking-Related Cancer Mortality Rates Are Associated with Birth Cohort Effects in Korean Men.

    Science.gov (United States)

    Jee, Yon Ho; Shin, Aesun; Lee, Jong-Keun; Oh, Chang-Mo

    2016-12-05

    Background: This study aimed to examine trends in smoking-related cancer mortality rates and to investigate the effect birth cohort on smoking-related cancer mortality in Korean men. Methods: The number of smoking-related cancer deaths and corresponding population numbers were obtained from Statistics Korea for the period 1984-2013. Joinpoint regression analysis was used to detect changes in trends in age-standardized mortality rates. Birth-cohort specific mortality rates were illustrated by 5 year age groups. Results: The age-standardized mortality rates for oropharyngeal decreased from 2003 to 2013 (annual percent change (APC): -3.1 (95% CI, -4.6 to -1.6)) and lung cancers decreased from 2002 to 2013 (APC -2.4 (95% CI -2.7 to -2.2)). The mortality rates for esophageal declined from 1994 to 2002 (APC -2.5 (95% CI -4.1 to -0.8)) and from 2002 to 2013 (APC -5.2 (95% CI -5.7 to -4.7)) and laryngeal cancer declined from 1995 to 2013 (average annual percent change (AAPC): -3.3 (95% CI -4.7 to -1.8)). By the age group, the trends for the smoking-related cancer mortality except for oropharyngeal cancer have changed earlier to decrease in the younger age group. The birth-cohort specific mortality rates and age-period-cohort analysis consistently showed that all birth cohorts born after 1930 showed reduced mortality of smoking-related cancers. Conclusions: In Korean men, smoking-related cancer mortality rates have decreased. Our findings also indicate that current decreases in smoking-related cancer mortality rates have mainly been due to a decrease in the birth cohort effect, which suggest that decrease in smoking rates.

  16. Effects of age, gender, and stimulus presentation period on visual short-term memory.

    Science.gov (United States)

    Kunimi, Mitsunobu

    2016-01-01

    This study focused on age-related changes in visual short-term memory using visual stimuli that did not allow verbal encoding. Experiment 1 examined the effects of age and the length of the stimulus presentation period on visual short-term memory function. Experiment 2 examined the effects of age, gender, and the length of the stimulus presentation period on visual short-term memory function. The worst memory performance and the largest performance difference between the age groups were observed in the shortest stimulus presentation period conditions. The performance difference between the age groups became smaller as the stimulus presentation period became longer; however, it did not completely disappear. Although gender did not have a significant effect on d' regardless of the presentation period in the young group, a significant gender-based difference was observed for stimulus presentation periods of 500 ms and 1,000 ms in the older group. This study indicates that the decline in visual short-term memory observed in the older group is due to the interaction of several factors.

  17. Phenotyping asthma, rhinitis and eczema in MeDALL population-based birth cohorts

    DEFF Research Database (Denmark)

    Garcia-Aymerich, J; Benet, M; Saeys, Y

    2015-01-01

    at 4 years and 14 585 at 8 years from seven European population-based birth cohorts (MeDALL project). At each age period, children were grouped, using partitioning cluster analysis, according to the distribution of 23 variables covering symptoms 'ever' and 'in the last 12 months', doctor diagnosis, age...

  18. Retrospective cohort study of all deaths among infants born between 22 and 27 completed weeks of gestation in Switzerland over a 3-year period.

    Science.gov (United States)

    Berger, T M; Steurer, M A; Bucher, H U; Fauchère, J C; Adams, M; Pfister, R E; Baumann-Hölzle, R; Bassler, D

    2017-06-15

    The aim of this research is to assess causes and circumstances of deaths in extremely low gestational age neonates (ELGANs) born in Switzerland over a 3-year period. Population-based, retrospective cohort study. All nine level III perinatal centres (neonatal intensive care units (NICUs) and affiliated obstetrical services) in Switzerland. ELGANs with a gestational age (GA) Switzerland, most deaths among infants born at less than 24 weeks of gestation occurred in the delivery room. In contrast, most deaths of ELGANs with a GA ≥24 weeks were observed following unrestricted provisional intensive care, end-of-life decision-making and redirection of care in the NICU regardless of the degree of immaturity. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. Active aging - resilience and external support as modifiers of the disablement outcome: AGNES cohort study protocol.

    Science.gov (United States)

    Rantanen, Taina; Saajanaho, Milla; Karavirta, Laura; Siltanen, Sini; Rantakokko, Merja; Viljanen, Anne; Rantalainen, Timo; Pynnönen, Katja; Karvonen, Anu; Lisko, Inna; Palmberg, Lotta; Eronen, Johanna; Palonen, Eeva-Maija; Hinrichs, Timo; Kauppinen, Markku; Kokko, Katja; Portegijs, Erja

    2018-05-02

    Population aging increases the need for knowledge on positive aspects of aging, and contributions of older people to their own wellbeing and that of others. We defined active aging as an individual's striving for elements of wellbeing with activities as per their goals, abilities and opportunities. This study examines associations of health, health behaviors, health literacy and functional abilities, environmental and social support with active aging and wellbeing. We will develop and validate assessment methods for physical activity and physical resilience suitable for research on older people, and examine their associations with active aging and wellbeing. We will examine cohort effects on functional phenotypes underlying active aging and disability. For this population-based study, we plan to recruit 1000 participants aged 75, 80 or 85 years living in central Finland, by drawing personal details from the population register. Participants are interviewed on active aging, wellbeing, disability, environmental and social support, mobility, health behavior and health literacy. Physical activity and heart rate are monitored for 7 days with wearable sensors. Functional tests include hearing, vision, muscle strength, reaction time, exercise tolerance, mobility, and cognitive performance. Clinical examination by a nurse and physician includes an electrocardiogram, tests of blood pressure, orthostatic regulation, arterial stiffness, and lung function, as well as a review of chronic and acute conditions and prescribed medications. C-reactive protein, small blood count, cholesterol and vitamin D are analyzed from blood samples. Associations of factors potentially underlying active aging and wellbeing will be studied using multivariate methods. Cohort effects will be studied by comparing test results of physical and cognitive functioning with results of a cohort examined in 1989-90. The current study will renew research on positive gerontology through the novel approach to

  20. Trends and determinants of mortality in women of reproductive age in rural Guinea-Bissau, West Africa--a cohort study

    DEFF Research Database (Denmark)

    Mane, Maram; Fisker, Ane B; Ravn, Henrik

    2013-01-01

    mortality between 1996-2000 followed by 14% increase in mortality [Hazard rate ratio (HRR) = 1.14; 95% confidence interval (CI): 0.98-1.32; p = 0.08] between 2001-2003, and then in the last period from 2004-2007 a 25% decline (HRR = 0.75; 95% CI: 0.64-0.87; p ...BACKGROUND: There are few studies reporting mortality of women of reproductive age (WRA) in developing countries. The trend and patterns of their mortality may be important for documenting the health status of the population in general. METHODS: We used a prospective open cohort of women aged 12...... to 49 years living in the Bandim Health Project's rural Health and Demographic Surveillance System (HDSS) in 5 regions of Guinea-Bissau from 1996 to 2007. Information on in- and out-migration and deaths were collected through the HDSS routine procedures. We assessed the trends in mortality...

  1. Association of prenatal exposure to benzodiazepines and child internalizing problems: A sibling-controlled cohort study.

    Directory of Open Access Journals (Sweden)

    Ragnhild E Brandlistuen

    Full Text Available During pregnancy, many women experience sleep problems and anxiety that require treatment. The long-term safety for the child of maternal benzodiazepine (BZD and z-hypnotic use during pregnancy remains controversial.We conducted a cohort and a sibling control study using data from the Norwegian Mother and Child Cohort Study. Data on use of BZD and z-hypnotics, internalizing and externalizing outcomes, and covariates were collected from mothers at gestational weeks 17 and 30 and when children were 0.5, 1.5, and 3 years of age. The total sample consisted of 71,996 children (19,297 siblings at 1.5 years and 55,081 children (13,779 siblings at 3 years. Short-term use was defined as use in one pregnancy period only. Long-term use was defined as use in two or more pregnancy periods. Linear full cohort random-effect and sibling-matched fixed-effect regression models were used to compare internalizing and externalizing behavior in children prenatally exposed compared to those unexposed in the full cohort of pregnancies accounting for family clusters, as well as within sibling clusters comparing pregnancies with discordant exposures. Propensity score (PS adjustment included variables on indication for use (sleep problems, symptoms of anxiety and depression and other potential confounding factors.Long-term prenatal exposure to BZD or z-hypnotics was associated with increased internalizing behavior in crude cohort analyses and at age 1.5 years after PS adjustment in sibling-matched fixed-effect models [β 0.60, 95% confidence interval 0.17-0.95]. Analyses on specific drug groups showed that prenatal exposure to BZD-anxiolytics was associated with increased internalizing problems at both 1.5 years [β 0.25, 0.01-0.49] and 3 years [β 0.26, 0.002-0.52] while exposure to z-hypnotics was not associated with any adverse outcomes after adjustment.The findings suggest a moderate association between BZD-anxiolytic exposure and child internalizing problems that is

  2. Measuring trends in age at first sex and age at marriage in Manicaland, Zimbabwe.

    Science.gov (United States)

    Cremin, I; Mushati, P; Hallett, T; Mupambireyi, Z; Nyamukapa, C; Garnett, G P; Gregson, S

    2009-04-01

    To identify reporting biases and to determine the influence of inconsistent reporting on observed trends in the timing of age at first sex and age at marriage. Longitudinal data from three rounds of a population-based cohort in eastern Zimbabwe were analysed. Reports of age at first sex and age at marriage from 6837 individuals attending multiple rounds were classified according to consistency. Survival analysis was used to identify trends in the timing of first sex and marriage. In this population, women initiate sex and enter marriage at younger ages than men but spend much less time between first sex and marriage. Among those surveyed between 1998 and 2005, median ages at first sex and first marriage were 18.5 years and 21.4 years for men and 18.2 years and 18.5 years, respectively, for women aged 15-54 years. High levels of reports of both age at first sex and age at marriage among those attending multiple surveys were found to be unreliable. Excluding reports identified as unreliable from these analyses did not alter the observed trends in either age at first sex or age at marriage. Tracing birth cohorts as they aged revealed reporting biases, particularly among the youngest cohorts. Comparisons by birth cohorts, which span a period of >40 years, indicate that median age at first sex has remained constant over time for women but has declined gradually for men. Although many reports of age at first sex and age at marriage were found to be unreliable, inclusion of such reports did not result in artificial generation or suppression of trends.

  3. Prediction of BMI at age 11 in a longitudinal sample of the Ulm Birth Cohort Study.

    Directory of Open Access Journals (Sweden)

    Hanna Christiansen

    Full Text Available Obesity is one of the greatest public health challenges in the world with childhood prevalence rates between 20-26% and numerous associated health risks. The aim of the current study was to analyze the 11-year follow-up data of the Ulm Birth Cohort Study (UBCS, to identify whether abnormal eating behavior patterns, especially restrained eating, predict body mass index (BMI at 11 years of age and to explore other factors known to be longitudinally associated with it. Of the original UBCS, n = 422 children (~ 40% of the original sample and their parents participated in the 11-year follow-up. BMI at age 8 and 11 as well as information on restrained eating, psychological problems, depressive symptoms, lifestyle, and IQ at age 8 were assessed. Partial Least Squares Structural Equation Modeling (PLS-SEM was used to predict children's BMI scores at age 11. PLS-SEM explained 68% of the variance of BMI at age 11, with BMI at age 8 being the most important predictor. Restrained eating, via BMI at age 8 as well as parental BMI, had further weak associations with BMI at age 11; no other predictor was statistically significant. Since established overweight at age 8 already predicts BMI scores at age 11 longitudinally, obesity interventions should be implemented in early childhood.

  4. Health effects of low doses at low dose rates: dose-response relationship modeling in a cohort of workers of the nuclear industry; Effets sanitaires des faibles doses a faibles debits de dose: modelisation de la relation dose-reponse dans une cohorte de travailleurs du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Metz-Flamant, Camille

    2011-09-19

    The aim of this thesis is to contribute to a better understanding of the health effects of chronic external low doses of ionising radiation. This work is based on the French cohort of CEA-AREVA NC nuclear workers. The mains stages of this thesis were (1) conducting a review of epidemiological studies on nuclear workers, (2) completing the database and performing a descriptive analysis of the cohort, (3) quantifying risk by different statistical methods and (4) modelling the exposure-time-risk relationship. The cohort includes monitored workers employed more than one year between 1950 and 1994 at CEA or AREVA NC companies. Individual annual external exposure, history of work, vital status and causes of death were reconstructed for each worker. Standardized mortality ratios using French national mortality rates as external reference were computed. Exposure-risk analysis was conducted in the cohort using the linear excess relative risk model, based on both Poisson regression and Cox model. Time dependent modifying factors were investigated by adding an interaction term in the model or by using exposure time windows. The cohort includes 36, 769 workers, followed-up until age 60 in average. During the 1968- 2004 period, 5, 443 deaths, 2, 213 cancers, 62 leukemia and 1, 314 cardiovascular diseases were recorded. Among the 57% exposed workers, the mean cumulative dose was 21.5 milli-sieverts (mSv). A strong Healthy Worker Effect is observed in the cohort. Significant elevated risks of pleura cancer and melanoma deaths were observed in the cohort but not associated with dose. No significant association was observed with solid cancers, lung cancer and cardiovascular diseases. A significant dose-response relationship was observed for leukemia excluding chronic lymphatic leukemia, mainly for doses received less than 15 years before and for yearly dose rates higher than 10 mSv. This PhD work contributes to the evaluation of risks associated to chronic external radiation

  5. Delineating the third age: joint models of older people's quality of life and attrition in Britain 2002-2010.

    Science.gov (United States)

    Tampubolon, Gindo

    2015-07-01

    In the public mind, later life is being transformed by the emerging possibility of a flourishing third age with sustained quality of life. We draw trajectories of life quality measured using CASP-19 over eight years. We refine these trajectories by jointly modelling attrition, since older people tend to leave longitudinal studies (attrite) not at random. Growth curve models are applied to the English Longitudinal Study of Ageing waves 1 to 5. Then joint model is estimated where attrition is considered. Extensive predictors are entered including demographic attributes, social and economic status, health conditions, and behaviours. Strong non-linear age trajectory of life quality is revealed by the growth curve models where the peak is achieved in the late 60s. Then the joint model uncovers the peak somewhat later in time, and also reveals secular improvement in life quality experienced by recent cohorts. Sharp estimates for many predictors of higher levels of life quality are also found. For the first time, the trajectories of life quality in the third age are drawn and improvement across cohorts is demonstrated. The contributions are estimated for predictors amenable to intervention such as social capital. This can help in policy discussion on improving the lives of older people in the third age.

  6. Health returns to education by family socioeconomic origins, 1980–2008: Testing the importance of gender, cohort, and age

    Directory of Open Access Journals (Sweden)

    Matthew A. Andersson

    2016-12-01

    Full Text Available Recent studies find that health returns to education are elevated among those who come from disadvantaged families. These findings suggest that education may be a health resource that compensates or “substitutes” for lower parental socioeconomic status. Alternatively, some studies find support for a cumulative (disadvantage perspective, such that educational health returns are higher among those who already were advantaged, widening initial health (disadvantages across the life course. However, it remains unclear whether these findings are dependent on gender or cohort, and this is a fundamental oversight given marked differences between men and women in educational and health inequalities across the twentieth century. Drawing on national US data (1980–2002 General Social Survey with 2008 National Death Index Link, I indeed find that the presence or strength of resource substitution or cumulative (disadvantage depends upon health measure as well as gender and cohort. For self-rated health, cumulative (disadvantage explains educational health disparities, but among men only. Cumulative (disadvantage in avoiding fair or poor health is partly explained by cohort and age variation in health returns to education, and cumulative (disadvantage in excellent health is more robust in earlier cohorts and at older ages. For mortality, resource substitution is instead supported, but for women only. Among those from disadvantaged families, educational mortality buffering increases with cohort but diminishes with age. Taken together, these findings confirm prior research showing that adult health inequalities linked to education depend on family background, and extend this work by demonstrating that the nature and extent of these dynamics differ considerably depending on the health outcome being assessed and on an individual's historical context, life course stage, and gender. Keywords: Self-rated health, Mortality, Education, Gender, Cohort, Age

  7. Infant BMI peak as a predictor of overweight and obesity at age 2 years in a Chinese community-based cohort

    Science.gov (United States)

    Sun, Jie; Nwaru, Bright I; Hua, Jing; Li, Xiaohong; Wu, Zhuochun

    2017-01-01

    Objectives Infant body mass index (BMI) peak has proven to be a useful indicator for predicting childhood obesity risk in American and European populations. However, it has not been assessed in China. We characterised infant BMI trajectories in a Chinese longitudinal cohort and evaluated whether BMI peak can predict overweight and obesity at age 2 years. Methods Serial measurements (n=6–12) of weight and length were taken from healthy term infants (n=2073) in a birth cohort established in urban Shanghai. Measurements were used to estimate BMI growth curves from birth to 13.5 months using a polynomial regression model. BMI peak characteristics, including age (in months) and magnitude (BMI, in kg/m2) at peak and prepeak velocities (in kg/m2/month), were estimated. The relationship between infant BMI peak and childhood BMI at age 2 years was examined using binary logistic analysis. Results Mean age at peak BMI was 7.61 months, with a magnitude of 18.33 kg/m2. Boys (n=1022) had a higher average peak BMI (18.60 vs 18.07 kg/m2, pBMI and 1 month increase in peak time, the risk of overweight at age 2 years increased by 2.11 times (OR 3.11; 95% CI 2.64 to 3.66) and 35% (OR 1.35; 95% CI 1.21 to 1.50), respectively. Similarly, higher BMI magnitude (OR 2.69; 95% CI 2.00 to 3.61) and later timing of infant BMI peak (OR 1.35; 95% CI 1.08 to 1.68) were associated with an increased risk of childhood obesity at age 2 years. Conclusions We have shown that infant BMI peak is valuable for predicting early childhood overweight and obesity in urban Shanghai. Because this is the first Chinese community-based cohort study of this nature, future research is required to examine infant populations in other areas of China. PMID:28988164

  8. The short-lived African turquoise killifish: an emerging experimental model for ageing.

    Science.gov (United States)

    Kim, Yumi; Nam, Hong Gil; Valenzano, Dario Riccardo

    2016-02-01

    Human ageing is a fundamental biological process that leads to functional decay, increased risk for various diseases and, ultimately, death. Some of the basic biological mechanisms underlying human ageing are shared with other organisms; thus, animal models have been invaluable in providing key mechanistic and molecular insights into the common bases of biological ageing. In this Review, we briefly summarise the major applications of the most commonly used model organisms adopted in ageing research and highlight their relevance in understanding human ageing. We compare the strengths and limitations of different model organisms and discuss in detail an emerging ageing model, the short-lived African turquoise killifish. We review the recent progress made in using the turquoise killifish to study the biology of ageing and discuss potential future applications of this promising animal model. © 2016. Published by The Company of Biologists Ltd.

  9. The use of bone age for bone mineral density interpretation in a cohort of pediatric brain tumor patients

    International Nuclear Information System (INIS)

    Morris, E.B.; Shelso, John; Smeltzer, Matthew P.; Li, Chin-Shang; Thomas, Nicole A.; Karimova, E.J.; Merchant, Thomas; Gajjar, Amar; Kaste, Sue C.

    2008-01-01

    Skeletal bone accretion occurs throughout childhood. The integrity of this process can influence future adult bone health and the risk of osteoporosis. Although surveillance of children who are at risk of poor bone accretion is important, the most appropriate method to monitor childhood bone health has not been established. Previous investigators have proposed using bone age (BA) rather than chronological age (CA) when interpreting bone mineral density (BMD) values in children. To investigate the value of BA assessment for BMD measurement in a cohort of children at risk of poor accretion. A cohort of 163 children with brain tumors who completed both a BMD assessment (quantitative computed tomography, QCT) and who had a BA within a 6-month interval were identified. The difference in BMD Z-scores determined by CA and BA was determined. The impact of salient clinical features was assessed. No significant difference between CA and BA Z-scores was detected in the overall cohort (P 0.056). However, the scores in 18 children (all boys between the ages of 11 years and 15 years) were statistically determined to be outliers from the values in the rest of the cohort. Interpretation of BMD with BA measurement might be appropriate and affect treatment decisions in peripubertal males. (orig.)

  10. Virtual age model for equipment aging plant based on operation environment and service state

    International Nuclear Information System (INIS)

    Zhang Liming; Cai Qi; Zhao Xinwen; Chen Ling

    2010-01-01

    The accelerated life model based on the operation environment and service state was established by taking the virtual age as the equipment aging indices. The effect of different operation environments and service states on the reliability and virtual age under the continuum operation conditions and cycle operation conditions were analyzed, and the sensitivities of virtual age on operational environments and service states were studied. The results of the example application show that the effect of NPP equipment lifetime and the key parameters related to the reliability can be quantified by this model, and the result is in accordance with the reality.(authors)

  11. Periconceptional multivitamin use and risk of preterm or small-for-gestational-age births in the Danish National Birth Cohort.

    Science.gov (United States)

    Catov, Janet M; Bodnar, Lisa M; Olsen, Jorn; Olsen, Sjurdur; Nohr, Ellen A

    2011-09-01

    The intake of periconceptional multivitamins may decrease the risk of preterm births (PTBs) or small-for-gestational-age (SGA) births. We related the timing and frequency of periconceptional multivitamin use to SGA births and PTBs and its clinical presentations (ie, preterm labor, premature rupture of membranes, and medical induction). Women in the Danish National Birth Cohort (n = 35,897) reported the number of weeks of multivitamin use during a 12-wk periconceptional period. Cox regression was used to estimate the relation between any multivitamin use and PTBs (2 SDs below the mean on the basis of fetal growth curves). The timing (preconception and postconception) and frequency of use were also analyzed. Regular users (4-6 wk) and partial users (1-3 wk) in each period were compared with nonusers. The association between periconceptional multivitamin use and PTBs varied according to prepregnancy overweight status (P-interaction = 0.07). Regular preconception and postconception multivitamin use in women with a prepregnancy BMI (in kg/m(2)) PTBs in nonoverweight women.

  12. Effect of maternal age on the risk of preterm birth: A large cohort study.

    Science.gov (United States)

    Fuchs, Florent; Monet, Barbara; Ducruet, Thierry; Chaillet, Nils; Audibert, Francois

    2018-01-01

    Maternal age at pregnancy is increasing worldwide as well as preterm birth. However, the association between prematurity and advanced maternal age remains controversial. To evaluate the impact of maternal age on the occurrence of preterm birth after controlling for multiple known confounders in a large birth cohort. Retrospective cohort study using data from the QUARISMA study, a large Canadian randomized controlled trial, which collected data from 184,000 births in 32 hospitals. Inclusion criteria were maternal age over 20 years. Exclusion criteria were multiple pregnancy, fetal malformation and intra-uterine fetal death. Five maternal age categories were defined and compared for maternal characteristics, gestational and obstetric complications, and risk factors for prematurity. Risk factors for preterm birth births were included in the study. Chronic hypertension, assisted reproduction techniques, pre-gestational diabetes, invasive procedure in pregnancy, gestational diabetes and placenta praevia were linearly associated with increasing maternal age whereas hypertensive disorders of pregnancy followed a "U" shaped distribution according to maternal age. Crude rates of preterm birth before 37 weeks followed a "U" shaped curve with a nadir at 5.7% for the group of 30-34 years. In multivariate analysis, the adjusted odds ratio (aOR) of prematurity stratified by age group followed a "U" shaped distribution with an aOR of 1.08 (95%CI; 1.01-1.15) for 20-24 years, and 1.20 (95% CI; 1.06-1.36) for 40 years and older. Confounders found to have the greatest impact were placenta praevia, hypertensive complications, and maternal medical history. Even after adjustment for confounders, advanced maternal age (40 years and over) was associated with preterm birth. A maternal age of 30-34 years was associated with the lowest risk of prematurity.

  13. Decreases in Smoking-Related Cancer Mortality Rates Are Associated with Birth Cohort Effects in Korean Men

    Directory of Open Access Journals (Sweden)

    Yon Ho Jee

    2016-12-01

    Full Text Available Background: This study aimed to examine trends in smoking-related cancer mortality rates and to investigate the effect birth cohort on smoking-related cancer mortality in Korean men. Methods: The number of smoking-related cancer deaths and corresponding population numbers were obtained from Statistics Korea for the period 1984–2013. Joinpoint regression analysis was used to detect changes in trends in age-standardized mortality rates. Birth-cohort specific mortality rates were illustrated by 5 year age groups. Results: The age-standardized mortality rates for oropharyngeal decreased from 2003 to 2013 (annual percent change (APC: −3.1 (95% CI, −4.6 to −1.6 and lung cancers decreased from 2002 to 2013 (APC −2.4 (95% CI −2.7 to −2.2. The mortality rates for esophageal declined from 1994 to 2002 (APC −2.5 (95% CI −4.1 to −0.8 and from 2002 to 2013 (APC −5.2 (95% CI −5.7 to −4.7 and laryngeal cancer declined from 1995 to 2013 (average annual percent change (AAPC: −3.3 (95% CI −4.7 to −1.8. By the age group, the trends for the smoking-related cancer mortality except for oropharyngeal cancer have changed earlier to decrease in the younger age group. The birth-cohort specific mortality rates and age-period-cohort analysis consistently showed that all birth cohorts born after 1930 showed reduced mortality of smoking-related cancers. Conclusions: In Korean men, smoking-related cancer mortality rates have decreased. Our findings also indicate that current decreases in smoking-related cancer mortality rates have mainly been due to a decrease in the birth cohort effect, which suggest that decrease in smoking rates.

  14. Life review in advanced age: qualitative research on the 'start in life' of 90-year-olds in the Lothian Birth Cohort 1921.

    Science.gov (United States)

    Lapsley, Hilary; Pattie, Alison; Starr, John M; Deary, Ian J

    2016-04-01

    into the relationship between child risk and resilience factors that may influence ageing. It demonstrates the utility and wider application of the Life Review Questionnaire. Although the surviving cohort is not representative of their childhood peers, their words provide insight into the processes of weaving experience and memory into a rich texture of meanings that may help create wellbeing across a lifetime.

  15. Graduating the age-specific fertility pattern using Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Anastasia Kostaki

    2009-06-01

    Full Text Available A topic of interest in demographic literature is the graduation of the age-specific fertility pattern. A standard graduation technique extensively used by demographers is to fit parametric models that accurately reproduce it. Non-parametric statistical methodology might be alternatively used for this graduation purpose. Support Vector Machines (SVM is a non-parametric methodology that could be utilized for fertility graduation purposes. This paper evaluates the SVM techniques as tools for graduating fertility rates In that we apply these techniques to empirical age specific fertility rates from a variety of populations, time period, and cohorts. Additionally, for comparison reasons we also fit known parametric models to the same empirical data sets.

  16. Establishment and baseline characteristics of a nationwide Danish cohort of patients with Ehlers-Danlos syndrome.

    Science.gov (United States)

    Kulas Søborg, Marie-Louise; Leganger, Julie; Quitzau Mortensen, Laura; Rosenberg, Jacob; Burcharth, Jakob

    2017-05-01

    The aim of this study was to investigate national prevalence, general demographic characteristics and survival of Danish patients with Ehlers-Danlos syndrome (EDS). A population-based cohort study was conducted using a database consisting of the entire Danish population alive at any given time between 1 January 2000 and 31 December 2012, based upon longitudinal Danish national registers. All patients with EDS were identified, and the cohort was described by disease prevalence, basic demographic characteristics, mean age at death and mortality for the observational period of 13 years. The cohort held 1427 unique persons with EDS, giving a national prevalence of 0.02%. The EDS population had a mean ( s . d .) age of 34.9 (18.6) years and comprised 73.9% females and 26.1% males. Of the cohort, 95.9% originated from Denmark and 57% were unmarried. We found that 31.6% of the cohort received state-granted subsidies, of which 77% were in the form of early retirement pension. Regarding educational status, 28.1% of the EDS cohort had completed primary education (⩽10th grade) as their highest educational level, while 71.9% had completed a higher level. During the observation period, 42 patients died, with a mean ( s . d .) age at death of 53.6 (21.7) years. This study confirmed a small national prevalence of patients diagnosed with EDS and showed that the majority of patients diagnosed are female. The EDS cohort had a lower educational level, mean age and life expectancy compared with the background population and showed a predisposition for receiving state-granted subsidies. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  17. The natural course of eczema from birth to age 7 years and the association with asthma and allergic rhinitis: a population-based birth cohort study.

    Science.gov (United States)

    Shen, Chian-Yin; Lin, Ming-Chih; Lin, Heng-Kuei; Lin, Ching-Heng; Fu, Lin-Shien; Fu, Yun-Chin

    2013-01-01

    Although "atopic march" is a popular concept, the relationship between eczema and subsequent asthma is far from clear. However, some cohort studies have shown the possibility of two different allergic phenotypes in those who present with early eczema in terms of their persistency. We checked the cohort data from 308,849 children born in 2000 in Taiwan, to evaluate the different courses of eczema and their relationships to subsequent asthma and allergic rhinitis (AR) at age 7 years. We examined the age prevalence of eczema, asthma, and AR up to 7 years of age. We grouped all cases according to their course of eczema, as well as wheezing, and determined the rates of asthma and AR at age 7 years. We checked the adjusted risk factors by multiple logistic regression model. We also examined the distributions of wheezing types in different eczema groups. We found the "atopic march" pattern of allergic diseases based on their age prevalence. Early eczema was associated with asthma and AR at the age of 7 years. Those with eczema symptoms persisting after 36 months of age had a higher risk than those with transient eczema. Early wheeze also contributed to asthma and AR later in childhood. In addition, late-onset eczema had a completely different wheeze distribution compared with other groups and also had a higher risk for asthma and AR than transient eczema. In conclusion, different eczema phenotypes could be found in this population-based cohort. This article emphasizes the special attention to the persistency and late-onset eczema in clinical practice.

  18. With friends like these…: peer delinquency influences across age cohorts on smoking, alcohol and illegal substance use.

    Science.gov (United States)

    Ferguson, C J; Meehan, D C

    2011-01-01

    Discussions and debate about youth smoking, alcohol use, and illegal substance use (collectively referred to as youth substance use) continue to receive wide attention among researchers, policymakers, and the general public. Previous research has suggested that peer delinquency is a particularly strong correlate of youth substance use. The current study focuses on the influence of delinquent peers on substance use, and how peer delinquency influences change across age cohorts of youth. The current study examines multiple correlates for youth substance use in a sample of 8,256 youth (mean age 14), with the goal of identifying the influence of delinquent peers across age cohorts while controlling for other correlates. Data was collected from the Ohio version of the Youth Risk Behavior Surveillance System (YRBSS) developed by the Centers for Disease Control. Results from multiple regression analyses identified peer delinquency as the strongest correlate of youth substance use even when other relevant factors related to family, neighborhood, and media use were controlled. Correlations between peer delinquency and substance use behavior increased across age cohorts and for individuals who first used in middle teen years (13-16) irrespective of current age. Age appears to be a moderating factor regarding the correlation between peer delinquency and youth substance abuse. Primary and secondary prevention and intervention strategies that focus on peers are potentially more likely to reduce youth substance use and improve peer relationships than those focused on other areas such as schools or media. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  19. Transitions in cognitive test scores over 5 and 10 years in elderly people: Evidence for a model of age-related deficit accumulation

    Directory of Open Access Journals (Sweden)

    Rockwood Kenneth

    2008-02-01

    Full Text Available Abstract Background On average, health worsens with age, but many people have periods of improvement. A stochastic model provides an excellent description of how such changes occur. Given that cognition also changes with age, we wondered whether the same model might also describe the accumulation of errors in cognitive test scores in community-dwelling older adults. Methods In this prospective cohort study, 8954 older people (aged 65+ at baseline from the Canadian Study of Health and Aging were followed for 10 years. Cognitive status was defined by the number of errors on the 100-point Modified Min-Mental State Examination. The error count was chosen to parallel the deficit count in the general model of aging, which is based on deficit accumulation. As with the deficit count, a Markov chain transition model was employed, with 4 parameters. Results On average, the chance of making errors increased linearly with the number of errors present at each time interval. Changes in cognitive states were described with high accuracy (R2 = 0.96 by a modified Poisson distribution, using four parameters: the background chance of accumulating additional errors, the chance of incurring more or fewer errors, given the existing number, and the corresponding background and incremental chances of dying. Conclusion The change in the number of errors in a cognitive test corresponded to a general model that also summarizes age-related changes in deficits. The model accounts for both improvement and deterioration and appears to represent a clinically relevant means of quantifying how various aspects of health status change with age.

  20. Cohort Profile Update: the TRacking Adolescents' Individual Lives Survey (TRAILS).

    Science.gov (United States)

    Oldehinkel, Albertine J; Rosmalen, Judith Gm; Buitelaar, Jan K; Hoek, Hans W; Ormel, Johan; Raven, Dennis; Reijneveld, Sijmen A; Veenstra, René; Verhulst, Frank C; Vollebergh, Wilma Am; Hartman, Catharina A

    2015-02-01

    TRAILS consists of a population cohort (N=2230) and a clinical cohort (N=543), both of which were followed from about age 11 years onwards. To date, the population cohort has been assessed five times over a period of 11 years, with retention rates ranging between 80% and 96%. The clinical cohort has been assessed four times over a period of 8 years, with retention rates ranging between 77% and 85%. Since the IJE published a cohort profile on the TRAILS in 2008, the participants have matured from adolescents into young adults. The focus shifted from parents and school to entry into the labour market and family formation, including offspring. Furthermore, psychiatric diagnostic interviews were administered, the database was linked to a Psychiatric Case Registry, and the availability of genome-wide SNP variations opened the door to genome-wide association studies regarding a wide range of (endo)phenotypes. With some delay, TRAILS data are available to researchers outside the TRAILS consortium without costs; access can be obtained by submitting a publication proposal (see www.trails.nl). © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  1. Changes in the age pattern of childbearing in Serbia and EU countries - comparative analysis

    Directory of Open Access Journals (Sweden)

    Magdalenić Ivana

    2015-01-01

    Full Text Available Most European countries nowadays are characterized by a fertility level, which by earlier theoretical considerations was not even assumed as the lower limit for childbearing. The focus of this paper are the changes in reproductive behavior of women during the second half of the 20th and beginning of the 21st century as well as the changes in the age model of childbearing which resulted from that. The comparative analysis between Serbia and 28 EU member countries covers the period 1960-2012. The distribution of live births according to mother's age was analyzed, as well as the phenomena of postponing births and increasing the average age of mothers at childbirth, changes in the structure of female population according to the number of live births, and the decrease of higher birth orders. Demographic potentials of fertility through age structures of the fertile cohort were also pointed out. The similarities and differences in the fertility patterns in the Republic of Serbia and the EU countries were considered in order to determine the specificities of the reproductive model of women in Serbia and the widespread phenomena of postponing births. The fertility transition in Serbia in the second half of the 20th century had the same trend as in the EU countries evolving in the direction of constant lowering of the childbirth levels. Nevertheless, in relation to the sixties of the 20th century, Serbia shifted towards the lower part of the scale at which the EU countries are ranked according to total fertility rate. Almost all EU member countries (except for Luxembourg, Malta, Cyprus and Portugal marked an increase in fertility in the 2000-2011 period, while the fertility level in Serbia, with some oscillations, continued to decrease. The turnabout in total fertility rate registered in most European countries is attributed to the effect of postponed childbirths, while it is assumed that its impact will be marked in Serbia during the next decade. Changes

  2. A Three-period Samuelson-Diamond Growth Model

    DEFF Research Database (Denmark)

    Blomgren-Hansen, Niels

    2005-01-01

    Samuelson (1958) analyses a three-period model, whereas Diamod (1965) considers a two-period model. This difference poses the question whether the insights derived by analysing the simple two-period model carry over in the more complicated three-period case. They do. The Samuelson model (no produ...

  3. [Induced thymus aging: radiation model and application perspective for low intensive laser radiation].

    Science.gov (United States)

    Sevost'ianova, N N; Trofimov, A V; Lin'kova, N S; Poliakova, V O; Kvetnoĭ, I M

    2010-01-01

    The influence of gamma-radiation on morphofunctional state of thymus is rather like as natural thymus aging. However gamma-radiation model of thymus aging widely used to investigate geroprotectors has many shortcomings and limitations. Gamma-radiation can induce irreversible changes in thymus very often. These changes are more intensive in comparison with changes, which can be observed at natural thymus aging. Low intensive laser radiation can not destroy structure of thymus and its effects are rather like as natural thymus aging in comparison with gamma-radiation effects. There are many parameters of low intensive laser radiation, which can be changed to improve morphofunctional thymus characteristics in aging model. Using low intensive laser radiation in thymus aging model can be very perspective for investigations of aging immune system.

  4. Algebraic models of local period maps and Yukawa algebras

    Science.gov (United States)

    Bandiera, Ruggero; Manetti, Marco

    2018-02-01

    We describe some L_{∞} model for the local period map of a compact Kähler manifold. Applications include the study of deformations with associated variation of Hodge structure constrained by certain closed strata of the Grassmannian of the de Rham cohomology. As a by-product, we obtain an interpretation in the framework of deformation theory of the Yukawa coupling.

  5. Age-Related Changes of Intraocular Pressure in Elderly People in Southern China: Lingtou Eye Cohort Study.

    Directory of Open Access Journals (Sweden)

    Xiaotong Han

    Full Text Available To study age-related changes of intraocular pressure (IOP and assess the cohort effect in both cross-sectional and longitudinal settings among elderly Chinese adults.Participants were enrolled from the Lingtou Eye Cohort Study with Chinese government officials aged 40 years and older at baseline and received physical check-up and ocular examinations from 2010 to 2012. IOP was measured using a non-contact tonometer according to standardized protocols, as well as systolic blood pressure (SBP, diastolic blood pressure (DBP and body mass index (BMI. Participants who had attended IOP measurements in both 2010 and 2012 were included in this study. Cross-sectional association of IOP with age was assessed using multivariate liner regression analyses and based on the data of 2010. Longitudinal changes in IOP were assessed by paired t-test.A total of 3372 subjects were enrolled in the current analysis (2010 mean [SD] age, 61.9 [7.1] years; 60.2% men. The mean IOP in 2010 was 15.4 ± 2.3 mmHg for women and 15.2 ± 2.3 mmHg for men with an intersex difference (P = 0.029. Cross-sectional analysis showed that IOP was negatively associated with age (P = 0.003, β = -0.033 for women and P<0.001, β = -0.061 for men adjusted for baseline SBP, DBP and BMI. Paired t-test suggested that IOP was higher in the year 2012 than 2010 in women (P = 0.006 but did not change significantly in men within 2 years (P = 0.345. In addition, the 2-year changes of IOP were not associated with age adjusted for baseline IOP in 2010 (P = 0.249.Cross-sectional data suggests that IOP is lower in people with older age. Longitudinal data does not support such findings and thus the identified decreasing pattern with age in cross-sectional analysis is likely caused by cohort effects.

  6. The prevalence of SDQ-measured mental health problems at age 5-7 years and identification of predictors from birth to preschool age in a Danish birth cohort: the Copenhagen Child Cohort 2000

    DEFF Research Database (Denmark)

    Elberling, Hanne; Linneberg, Allan; Olsen, Else Marie

    2010-01-01

    version of the Strengths and Difficulties Questionnaire (SDQ) was answered by parents and pre-school teachers. Data from Danish national registers included perinatal data, socioeconomic data and data on child mental illness diagnosed at hospital in preschool age. Register data from the first year of life......The objective of the study is to investigate the prevalence, distribution and predictors of mental health problems in 5-7-year-old Danish children in the general population. This study is a 5-7-year follow-up study of a birth cohort of 6,090 children, the Copenhagen Child Cohort 2000. The extended...... was obtained from 99.7% of the children in the cohort. Of 5,898 eligible children, 3,501 participated in the SDQ assessment (59%). The overall estimated 6-month prevalence of mental health problems was 4.8% (95% CI 4.1-5.6). Conduct problems were found in 3.0% (95% CI 2.4-3.6), problems of hyperactivity...

  7. Aging-related trajectories of lung function in the general population-The Doetinchem Cohort Study.

    NARCIS (Netherlands)

    van Oostrom, Sandra H; Engelfriet, Peter M; Verschuren, W M Monique; Schipper, Maarten; Wouters, Inge M; Boezen, Marike; Smit, Henriëtte A; Kerstjens, Huib A M; Picavet, H Susan J

    2018-01-01

    The objective of this study was to explore trajectories of lung function decline with age in the general population, and to study the effect of sociodemographic and life style related risk factors, in particular smoking and BMI. For this purpose, we used data from the Doetinchem Cohort Study (DCS)

  8. The History of Stuttering by 7 Years of Age: Follow-Up of a Prospective Community Cohort

    Science.gov (United States)

    Kefalianos, Elaina; Onslow, Mark; Packman, Ann; Vogel, Adam; Pezic, Angela; Mensah, Fiona; Conway, Laura; Bavin, Edith; Block, Susan; Reilly, Sheena

    2017-01-01

    Purpose: For a community cohort of children confirmed to have stuttered by the age of 4 years, we report (a) the recovery rate from stuttering, (b) predictors of recovery, and (c) comorbidities at the age of 7 years. Method: This study was nested in the Early Language in Victoria Study. Predictors of stuttering recovery included child, family, and…

  9. Modeling the Impact of Uganda's Safe Male Circumcision Program: Implications for Age and Regional Targeting.

    Science.gov (United States)

    Kripke, Katharine; Vazzano, Andrea; Kirungi, William; Musinguzi, Joshua; Opio, Alex; Ssempebwa, Rhobbinah; Nakawunde, Susan; Kyobutungi, Sheila; Akao, Juliet N; Magala, Fred; Mwidu, George; Castor, Delivette; Njeuhmeli, Emmanuel

    2016-01-01

    Uganda aims to provide safe male circumcision (SMC) to 80% of men ages 15-49 by 2016. To date, only 2 million men have received SMC of the 4.2 million men required. In response to age and regional trends in SMC uptake, the country sought to re-examine its targets with respect to age and subnational region, to assess the program's progress, and to refine the implementation approach. The Decision Makers' Program Planning Tool, Version 2.0 (DMPPT 2.0), was used in conjunction with incidence projections from the Spectrum/AIDS Impact Module (AIM) to conduct this analysis. Population, births, deaths, and HIV incidence and prevalence were used to populate the model. Baseline male circumcision prevalence was derived from the 2011 AIDS Indicator Survey. Uganda can achieve the most immediate impact on HIV incidence by circumcising men ages 20-34. This group will also require the fewest circumcisions for each HIV infection averted. Focusing on men ages 10-19 will offer the greatest impact over a 15-year period, while focusing on men ages 15-34 offers the most cost-effective strategy over the same period. A regional analysis showed little variation in cost-effectiveness of scaling up SMC across eight regions. Scale-up is cost-saving in all regions. There is geographic variability in program progress, highlighting two regions with low baseline rates of circumcision where additional efforts will be needed. Focusing SMC efforts on specific age groups and regions may help to accelerate Uganda's SMC program progress. Policy makers in Uganda have already used model outputs in planning efforts, proposing males ages 10-34 as a priority group for SMC in the 2014 application to the Global Fund's new funding model. As scale-up continues, the country should also consider a greater effort to expand SMC in regions with low MC prevalence.

  10. Modeling the Impact of Uganda's Safe Male Circumcision Program: Implications for Age and Regional Targeting.

    Directory of Open Access Journals (Sweden)

    Katharine Kripke

    Full Text Available Uganda aims to provide safe male circumcision (SMC to 80% of men ages 15-49 by 2016. To date, only 2 million men have received SMC of the 4.2 million men required. In response to age and regional trends in SMC uptake, the country sought to re-examine its targets with respect to age and subnational region, to assess the program's progress, and to refine the implementation approach.The Decision Makers' Program Planning Tool, Version 2.0 (DMPPT 2.0, was used in conjunction with incidence projections from the Spectrum/AIDS Impact Module (AIM to conduct this analysis. Population, births, deaths, and HIV incidence and prevalence were used to populate the model. Baseline male circumcision prevalence was derived from the 2011 AIDS Indicator Survey. Uganda can achieve the most immediate impact on HIV incidence by circumcising men ages 20-34. This group will also require the fewest circumcisions for each HIV infection averted. Focusing on men ages 10-19 will offer the greatest impact over a 15-year period, while focusing on men ages 15-34 offers the most cost-effective strategy over the same period. A regional analysis showed little variation in cost-effectiveness of scaling up SMC across eight regions. Scale-up is cost-saving in all regions. There is geographic variability in program progress, highlighting two regions with low baseline rates of circumcision where additional efforts will be needed.Focusing SMC efforts on specific age groups and regions may help to accelerate Uganda's SMC program progress. Policy makers in Uganda have already used model outputs in planning efforts, proposing males ages 10-34 as a priority group for SMC in the 2014 application to the Global Fund's new funding model. As scale-up continues, the country should also consider a greater effort to expand SMC in regions with low MC prevalence.

  11. Cost-effectiveness of inactivated seasonal influenza vaccination in a cohort of Thai children ≤60 months of age.

    Science.gov (United States)

    Kittikraisak, Wanitchaya; Suntarattiwong, Piyarat; Ditsungnoen, Darunee; Pallas, Sarah E; Abimbola, Taiwo O; Klungthong, Chonticha; Fernandez, Stefan; Srisarang, Suchada; Chotpitayasunondh, Tawee; Dawood, Fatimah S; Olsen, Sonja J; Lindblade, Kim A

    2017-01-01

    Vaccination is the best measure to prevent influenza. We conducted a cost-effectiveness evaluation of trivalent inactivated seasonal influenza vaccination, compared to no vaccination, in children ≤60 months of age participating in a prospective cohort study in Bangkok, Thailand. A static decision tree model was constructed to simulate the population of children in the cohort. Proportions of children with laboratory-confirmed influenza were derived from children followed weekly. The societal perspective and one-year analytic horizon were used for each influenza season; the model was repeated for three influenza seasons (2012-2014). Direct and indirect costs associated with influenza illness were collected and summed. Cost of the trivalent inactivated seasonal influenza vaccine (IIV3) including promotion, administration, and supervision cost was added for children who were vaccinated. Quality-adjusted life years (QALY), derived from literature, were used to quantify health outcomes. The incremental cost-effectiveness ratio (ICER) was calculated as the difference in the expected total costs between the vaccinated and unvaccinated groups divided by the difference in QALYs for both groups. Compared to no vaccination, IIV3 vaccination among children ≤60 months in our cohort was not cost-effective in the introductory year (2012 season; 24,450 USD/QALY gained), highly cost-effective in the 2013 season (554 USD/QALY gained), and cost-effective in the 2014 season (16,200 USD/QALY gained). The cost-effectiveness of IIV3 vaccination among children participating in the cohort study varied by influenza season, with vaccine cost and proportion of high-risk children demonstrating the greatest influence in sensitivity analyses. Vaccinating children against influenza can be economically favorable depending on the maturity of the program, influenza vaccine performance, and target population.

  12. Cost-effectiveness of inactivated seasonal influenza vaccination in a cohort of Thai children ≤60 months of age.

    Directory of Open Access Journals (Sweden)

    Wanitchaya Kittikraisak

    Full Text Available Vaccination is the best measure to prevent influenza. We conducted a cost-effectiveness evaluation of trivalent inactivated seasonal influenza vaccination, compared to no vaccination, in children ≤60 months of age participating in a prospective cohort study in Bangkok, Thailand.A static decision tree model was constructed to simulate the population of children in the cohort. Proportions of children with laboratory-confirmed influenza were derived from children followed weekly. The societal perspective and one-year analytic horizon were used for each influenza season; the model was repeated for three influenza seasons (2012-2014. Direct and indirect costs associated with influenza illness were collected and summed. Cost of the trivalent inactivated seasonal influenza vaccine (IIV3 including promotion, administration, and supervision cost was added for children who were vaccinated. Quality-adjusted life years (QALY, derived from literature, were used to quantify health outcomes. The incremental cost-effectiveness ratio (ICER was calculated as the difference in the expected total costs between the vaccinated and unvaccinated groups divided by the difference in QALYs for both groups.Compared to no vaccination, IIV3 vaccination among children ≤60 months in our cohort was not cost-effective in the introductory year (2012 season; 24,450 USD/QALY gained, highly cost-effective in the 2013 season (554 USD/QALY gained, and cost-effective in the 2014 season (16,200 USD/QALY gained.The cost-effectiveness of IIV3 vaccination among children participating in the cohort study varied by influenza season, with vaccine cost and proportion of high-risk children demonstrating the greatest influence in sensitivity analyses. Vaccinating children against influenza can be economically favorable depending on the maturity of the program, influenza vaccine performance, and target population.

  13. Chemical extraction to assess the bioavailability of chlorobenzenes in soil with different aging periods

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yang; Wang, Fang; Yang, Xinglun; Liu, Cuiying; Jin, Xin; Jiang, Xin [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Kengara, Fredrick Orori [Maseno Univ. (Kenya). Dept. of Chemistry

    2011-12-15

    Bioavailability is mainly influenced by aging and desorption of contaminants in soil. The purpose of this study was to investigate the desorption kinetics of chlorobenzenes (CBs) in soil and to investigate whether chemical extractions are suitable for the bioavailability assessment of CBs in soil. A soil spiked with CBs and aged for different periods was extracted with Tenax, hydroxypropyl-{beta}-cyclodextrin (HPCD), and butanol to assess the bioavailability of CBs in soil, respectively. Earthworm (Eisenia foetida) accumulation was used as bioassay in parallel experiments to evaluate the chemical extractions. The results showed that desorption of CBs from soil with consecutive Tenax extraction fitted into triphasic kinetics model. Different chemical methods extracted different amounts of CBs over different aging periods. For hexachlorobenzene (HCB), the extraction efficiency was in the order of butanol > Tenax-6h > HPCD extraction, while the order of butanol > HPCD > Tenax-6h extraction for pentachlorobenzene (PeCB). The bioaccumulation by earthworm decreased with increasing aging period and was significantly higher for HCB than for PeCB (p < 0.05). Earthworm accumulated CBs correlated well with all the three chemical extracted CBs. However, HPCD extraction showed the converse extraction tendency with earthworm uptake of CBs. Chemical extraction could be used to assess the bioavailability of contaminants in soil; however, they were method and compound specific. Tenax and butanol extractions were more reliable than HPCD extraction for bioavailability assessment of the tested CBs and the soil used since they showed the consistent extraction tendency with earthworm uptake of CBs.

  14. Risk prediction for breast, endometrial, and ovarian cancer in white women aged 50 y or older: derivation and validation from population-based cohort studies.

    Directory of Open Access Journals (Sweden)

    Ruth M Pfeiffer

    Full Text Available Breast, endometrial, and ovarian cancers share some hormonal and epidemiologic risk factors. While several models predict absolute risk of breast cancer, there are few models for ovarian cancer in the general population, and none for endometrial cancer.Using data on white, non-Hispanic women aged 50+ y from two large population-based cohorts (the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial [PLCO] and the National Institutes of Health-AARP Diet and Health Study [NIH-AARP], we estimated relative and attributable risks and combined them with age-specific US-population incidence and competing mortality rates. All models included parity. The breast cancer model additionally included estrogen and progestin menopausal hormone therapy (MHT use, other MHT use, age at first live birth, menopausal status, age at menopause, family history of breast or ovarian cancer, benign breast disease/biopsies, alcohol consumption, and body mass index (BMI; the endometrial model included menopausal status, age at menopause, BMI, smoking, oral contraceptive use, MHT use, and an interaction term between BMI and MHT use; the ovarian model included oral contraceptive use, MHT use, and family history or breast or ovarian cancer. In independent validation data (Nurses' Health Study cohort the breast and ovarian cancer models were well calibrated; expected to observed cancer ratios were 1.00 (95% confidence interval [CI]: 0.96-1.04 for breast cancer and 1.08 (95% CI: 0.97-1.19 for ovarian cancer. The number of endometrial cancers was significantly overestimated, expected/observed = 1.20 (95% CI: 1.11-1.29. The areas under the receiver operating characteristic curves (AUCs; discriminatory power were 0.58 (95% CI: 0.57-0.59, 0.59 (95% CI: 0.56-0.63, and 0.68 (95% CI: 0.66-0.70 for the breast, ovarian, and endometrial models, respectively.These models predict absolute risks for breast, endometrial, and ovarian cancers from easily obtainable risk factors and may

  15. Effect of year of birth on the breast cancer age-incidence curve in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Bjarnason, O [Univ. of Iceland, Reykjavik; Day, N; Snaedal, G; Tulinius, H

    1974-01-01

    Among different populations, the shape of the age-incidence curve for breast cancer is strongly related to the overall incidence of breast cancer in the respective population. Data are available from Iceland for the period 1911--1972. These data show that breast cancer has increased very markedly in Iceland during this period, and that as the overall incidence has risen, so the age-incidence curve has changed in shape, the relation between the shape and the overall incidence being the same as that now observed in other countries. The change in shape is shown to be explicable entirely as a cohort phenomenon, each decade of birth cohort having an age-incidence curve of similar shape, but with different overall incidence. Data from some other regions of the world indicate that many of the present differences in the shape of the age-incidence curve may be the reflection of cohort phenomena.

  16. Factors that affect skin aging: a cohort-based survey on twins.

    Science.gov (United States)

    Martires, Kathryn J; Fu, Pingfu; Polster, Amy M; Cooper, Kevin D; Baron, Elma D

    2009-12-01

    To identify environmental factors that correlate with skin photoaging, controlling for genetic susceptibility by using a questionnaire administered to twins. The survey collected information about each participant's Fitzpatrick type, history of skin cancer, smoking and drinking habits, and weight from a cohort of twins. Clinicians then assigned a clinical photodamage score to each participant. The annual Twins Days Festival in Twinsburg, Ohio. A voluntary cohort of twins from the general community, mostly from Ohio, Pennsylvania, and the northeastern United States. The survey was completed on a voluntary basis by sets of monozygotic (MZ) and dizygotic (DZ) twins. A total of 130 surveys taken by 65 complete twin pairs were analyzed. Skin aging was assessed using a validated photographic scale of photodamage, graded by such characteristics as wrinkling and pigmentation change. Photodamage scores among twins of a pair, whether MZ or DZ, were highly correlated (P = .92). Factors found to predict higher photodamage include history of skin cancer (P < .001), zygosity status (MZ vs DZ) (P = .001), weight (P = .02), and cigarette smoking (P = .046). Alcohol consumption was significantly associated with lower photodamage scores (P = .003). The study of twins provides a unique opportunity to control for genetic susceptibility in order to elucidate environmental influences on skin aging. The relationships found between smoking, weight, sunscreen use, skin cancer, and photodamage in these twin pairs may help to motivate the reduction of risky behaviors.

  17. Effects of externally rated job demand and control on depression diagnosis claims in an industrial cohort.

    Science.gov (United States)

    DeSanto Iennaco, Joanne; Cullen, Mark R; Cantley, Linda; Slade, Martin D; Fiellin, Martha; Kasl, Stanislav V

    2010-02-01

    This study examined whether externally rated job demand and control were associated with depression diagnosis claims in a heavy industrial cohort. The retrospective cohort sample consisted of 7,566 hourly workers aged 18-64 years who were actively employed at 11 US plants between January 1, 1996, and December 31, 2003, and free of depression diagnosis claims during an initial 2-year run-in period. Logistic regression analysis was used to model the effect of tertiles of demand and control exposure on depression diagnosis claims. Demand had a significant positive association with depression diagnosis claims in bivariate models and models adjusted for demographic (age, gender, race, education, job grade, tenure) and lifestyle (smoking status, body mass index, cholesterol level) variables (high demand odds ratio = 1.39, 95% confidence interval: 1.04, 1.86). Control was associated with greater risk of depression diagnosis at moderate levels in unadjusted models only (odds ratio = 1.47, 95% confidence interval: 1.12, 1.93), while low control, contrary to expectation, was not associated with depression. The effects of the externally rated demand exposure were lost with adjustment for location. This may reflect differences in measurement or classification of exposure, differences in depression diagnosis by location, or other location-specific factors.

  18. Prediction of five-year all-cause mortality in Chinese patients with type 2 diabetes mellitus - A population-based retrospective cohort study.

    Science.gov (United States)

    Wan, Eric Yuk Fai; Fong, Daniel Yee Tak; Fung, Colman Siu Cheung; Yu, Esther Yee Tak; Chin, Weng Yee; Chan, Anca Ka Chun; Lam, Cindy Lo Kuen

    2017-06-01

    This study aimed to develop and validate an all-cause mortality risk prediction model for Chinese primary care patients with type 2 diabetes mellitus(T2DM) in Hong Kong. A population-based retrospective cohort study was conducted on 132,462 Chinese patients who had received public primary care services during 2010. Each gender sample was randomly split on a 2:1 basis into derivation and validation cohorts and was followed-up for a median period of 5years. Gender-specific mortality risk prediction models showing the interaction effect between predictors and age were derived using Cox proportional hazards regression with forward stepwise approach. Developed models were compared with pre-existing models by Harrell's C-statistic and calibration plot using validation cohort. Common predictors of increased mortality risk in both genders included: age; smoking habit; diabetes duration; use of anti-hypertensive agents, insulin and lipid-lowering drugs; body mass index; hemoglobin A1c; systolic blood pressure(BP); total cholesterol to high-density lipoprotein-cholesterol ratio; urine albumin to creatinine ratio(urine ACR); and estimated glomerular filtration rate(eGFR). Prediction models showed better discrimination with Harrell"'s C-statistics of 0.768(males) and 0.782(females) and calibration power from the plots than previously established models. Our newly developed gender-specific models provide a more accurate predicted 5-year mortality risk for Chinese diabetic patients than other established models. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A shared frailty model for case-cohort samples: parent and offspring relations in an adoption study

    DEFF Research Database (Denmark)

    Petersen, Liselotte; Sørensen, Thorkild I A; Andersen, Per Kragh

    2010-01-01

    of their biological and adoptive parents were collected with the purpose of studying the association of survival between the adoptee and his/her biological or adoptive parents. Motivated by this study, we explored how to make inference in a shared frailty model for case-cohort data. Our approach was to use inverse......The Danish adoption register contains data on the 12 301 Danish nonfamilial adoptions during 1924-1947. From that register a case-cohort sample was selected consisting of all case adoptees, that is those adoptees dying before age 70 years, and a random sample of 1683 adoptees. The survival data...... probability weighting to account for the sampling in a conditional, shared frailty Poisson model and to use the robust variance estimator proposed by Moger et al. (Statist. Med. 2008; 27:1062-1074).To explore the performance of the estimation procedure, a simulation study was conducted. We studied situations...

  20. External validation of a normal tissue complication probability model for radiation-induced hypothyroidism in an independent cohort

    DEFF Research Database (Denmark)

    Rønjom, Marianne F; Brink, Carsten; Bentzen, Søren M

    2015-01-01

    blood tests in the validation cohort relative to the original cohort. However, Pearson's correlation coefficients between model and clinical outcome were high: r = 0.97 estimated by the original model versus the original cohort, and r = 0.97 estimated by the original model versus the new cohort....... CONCLUSION: Dmean and Vthyroid were significant predictors of RIHT in both cohorts. The original NTCP model demonstrated external validity owing to high Pearson's correlation coefficients between estimated and observed incidence rates of RIHT in the original as well as in the validation cohort. This model...

  1. Application of First Trimester Screening in the Prognostication of Small for Gestational Age

    Directory of Open Access Journals (Sweden)

    Reza Saeidi

    2018-05-01

    Full Text Available Background: Fetal growth restriction is defined as the failure of the fetus to achieve its full growth potential. The present study aimed to investigate the application of first trimester screening in the prediction of small for gestational age (SGA.Methods: This cohort study was conducted on the consecutive and unselected women with singleton pregnancies undergoing routine first-trimester examinations in a health center affiliated to Neyshabur University of Medical Sciences in Razavi Khorasan Iran during February 2014-March 2016. Subjects received a first-trimester visit by a physician, which included the entry of basic maternal characteristics, medical history, measurement of maternal weight and height, ultrasound examination for fetal anatomy, and measurement of crown-rump length to assess gestational age.Results: SGA was significantly correlated with maternal age, parity, and body mass index. Furthermore, a significant association was observed between SGA and smoking habits in the mothers.Conclusion: According to the results, first trimester screening was a useful method for the prediction of SGA.

  2. POLAND AND UKRAINE IN THE LIGHT OF PARADYSZ'S PERIOD FERTILITY MODEL

    Directory of Open Access Journals (Sweden)

    J. Paradysz

    2015-04-01

    Full Text Available The article reflects research issues, which are currently considered to be of utmost importance in methodology of period fertility analysis. In the cohort analysis we dispose many possibilities to describe human reproduction process. The period analysis is not so reach and we would like to use the same methods in the both one. Many years ago one of us have proposed a decomposition of the period total fertility rate in order to calculate period “theoretical” birth intervals. Combining the two systems demographic analysis (parity progression ration and increment–decrement tables we decompose the “classic” total fertility rate (TFR on the last and non–last children in period analysis.

  3. Social Mobility and Mental Disorders at 30 Years of Age in Participants of the 1982 Cohort, Pelotas, Rio Grande Do Sul - RS.

    Directory of Open Access Journals (Sweden)

    Lenice de Castro Muniz de Quadros

    Full Text Available This study aimed to evaluate the relationship between mental disorders at 30 years of age and social mobility by formally testing three hypotheses: Risk Accumulation; Critical Period; and Social Mobility. The study was performed using data from the 30-year follow-up of the Pelotas Birth Cohort Study, conducted in 1982, and data from previous follow-ups. The tool used to evaluate mental health was the Self Report Questionnaire (SRQ-20. For the statistical analysis, the chi-square test with the Yates correction was used to estimate the prevalence of mental disorder, and the Poisson regression with robust variance was used to formally test the hypotheses according to the Risk Accumulation, Critical Period and Social Mobility Models. The analyses were stratified by gender. The prevalence of Common Mental Disorders (CMDs was 24.3% (95% CI 22.9-25.7 when the whole sample was considered. The highest prevalence, 27.1% (95% CI 25.1-29.2, was found in women, and the difference between genders was significant (p < 0.001. CMDs were more frequent in participants who remained "poor" in the three follow-ups. In both men and women, the best fit was obtained with the Risk Accumulation Model, with p = 0.6348 and p = 0.2105, respectively. The results indicate the need to rethink public income maintenance policies. Finally, we suggest further studies to investigate the role of different public policies in decreasing the prevalence of mental disorders and thus contribute proposals of new policies that may contribute to the prevention of these disorders.

  4. Incremental Value of Repeated Risk Factor Measurements for Cardiovascular Disease Prediction in Middle-Aged Korean Adults: Results From the NHIS-HEALS (National Health Insurance System-National Health Screening Cohort).

    Science.gov (United States)

    Cho, In-Jeong; Sung, Ji Min; Chang, Hyuk-Jae; Chung, Namsik; Kim, Hyeon Chang

    2017-11-01

    Increasing evidence suggests that repeatedly measured cardiovascular disease (CVD) risk factors may have an additive predictive value compared with single measured levels. Thus, we evaluated the incremental predictive value of incorporating periodic health screening data for CVD prediction in a large nationwide cohort with periodic health screening tests. A total of 467 708 persons aged 40 to 79 years and free from CVD were randomly divided into development (70%) and validation subcohorts (30%). We developed 3 different CVD prediction models: a single measure model using single time point screening data; a longitudinal average model using average risk factor values from periodic screening data; and a longitudinal summary model using average values and the variability of risk factors. The development subcohort included 327 396 persons who had 3.2 health screenings on average and 25 765 cases of CVD over 12 years. The C statistics (95% confidence interval [CI]) for the single measure, longitudinal average, and longitudinal summary models were 0.690 (95% CI, 0.682-0.698), 0.695 (95% CI, 0.687-0.703), and 0.752 (95% CI, 0.744-0.760) in men and 0.732 (95% CI, 0.722-0.742), 0.735 (95% CI, 0.725-0.745), and 0.790 (95% CI, 0.780-0.800) in women, respectively. The net reclassification index from the single measure model to the longitudinal average model was 1.78% in men and 1.33% in women, and the index from the longitudinal average model to the longitudinal summary model was 32.71% in men and 34.98% in women. Using averages of repeatedly measured risk factor values modestly improves CVD predictability compared with single measurement values. Incorporating the average and variability information of repeated measurements can lead to great improvements in disease prediction. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02931500. © 2017 American Heart Association, Inc.

  5. FORMATION OF THE PRECONDITIONS FOR THE EMERGENCE OF GENDER PSYCHOLOGY IN MIDDLE AGES PERIOD

    Directory of Open Access Journals (Sweden)

    Veronika Olegovna Mokhova

    2013-10-01

    of the Middle Ages, relevant to the establishment of the gender psychology.Results: With the use of a qualitative content analysis significant ideas of the Middle Ages for the formation and development of gender psychology were revealed. In Europe: the continuation of the ancient thesis of the initial androgyny of a human being; impact of the woman's education on her ability for development; consideration of sexuality as sinful; the issue of women's emancipation, the declining value of the large numerous families despite of a ban on interference in the reproductive cycle in the middle of the Medieval period. In Russia: the perception of inter-sexual characteristics as defined by the God; unconditional obedience of a woman to her husband; androgyny in the distribution of the farmers responsibilities.The area of application of the results: the history of gender psychology.DOI: http://dx.doi.org/10.12731/2218-7405-2013-7-34

  6. Increased subsequent risk of erectile dysfunction among middle and old age males with chronic osteomyelitis: a nationwide population-based cohort study.

    Science.gov (United States)

    Wang, H-Y; Chao, C-H; Lin, C-L; Tseng, C-H; Kao, C-H

    2016-07-01

    Chronic inflammation may cause endothelial dysfunction and atherosclerosis, resulting in subsequent erectile dysfunction (ED). We examined the relationship between chronic osteomyelitis, which is a chronic inflammatory disease, and ED. A retrospective cohort study was conducted using data from the National Health Insurance Research Database. After excluding patients <40 years of age, 677 male patients newly diagnosed with chronic osteomyelitis (COM) from 1 January 2000 to 31 December 2011 were identified for the study. The non-osteomyelitis comparison cohort consisted of 2706 male participants. The incidence of ED was 2.66-fold higher in the COM cohort than in the non-osteomyelitis cohort (4.01 vs 1.51 per 10 000 person-years). After adjusting for age and comorbidities of coronary heart disease, hypertension, hyperlipidemia, depression, stroke, diabetes, peripheral vascular disease, chronic kidney disease, chronic obstructive pulmonary disease and asthma, the patients with COM had a 2.82-fold risk of ED (95% confidence interval=1.44-5.56). The incidence of ED increased with that of comorbidities in both cohorts. The highest hazard ratio was in patients between 40 and 59 years of age who had COM. Our data showed, for the first time, that COM is a possible risk factor for the development of ED.

  7. Impact on the physical and sensory properties of salt-and fat-reduced traditional Irish breakfast sausages on various age cohorts acceptance.

    Science.gov (United States)

    Conroy, Paula M; O'Sullivan, Maurice G; Hamill, Ruth M; Kerry, Joseph P

    2018-09-01

    The properties of varying salt and fat levels in traditional breakfast sausages were investigated. Sausages were produced with fat levels of: 30%, 20% and 15%. Fat was replaced with pea extract. Salt levels employed were: 2.5%, 1.1% and 0.0%. A reduced sodium salt which contains 45% less sodium than standard salt was used. Sensory analysis was conducted on consumers (n = 228): 18-40 yrs., 41-64 yrs. and 65-85 yrs. The 18-40 yr. olds preferred sausages containing 20% fat, 41-64 yr. olds preferred sausages with 15% fat, 65+ age group preferred sausages containing 30% fat. The 18-40 yr. olds preferred high salt samples, 41-64 yr. olds displayed no salt preference, while the 65+ age group preferred high salt sausages. Sausage formulation choice was found to be driven by texture for the younger age cohort, flavour for the middle age cohort and visual aspects from the oldest age cohort. There is a need to understand how meat products might be reformulated different age palates. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. How Has the Age-Related Process of Overweight or Obesity Development Changed over Time? Co-ordinated Analyses of Individual Participant Data from Five United Kingdom Birth Cohorts.

    Directory of Open Access Journals (Sweden)

    William Johnson

    2015-05-01

    Full Text Available There is a paucity of information on secular trends in the age-related process by which people develop overweight or obesity. Utilizing longitudinal data in the United Kingdom birth cohort studies, we investigated shifts over the past nearly 70 years in the distribution of body mass index (BMI and development of overweight or obesity across childhood and adulthood.The sample comprised 56,632 participants with 273,843 BMI observations in the 1946 Medical Research Council National Survey of Health and Development (NSHD; ages 2-64 years, 1958 National Child Development Study (NCDS; 7-50, 1970 British Cohort Study (BCS; 10-42, 1991 Avon Longitudinal Study of Parents and Children (ALSPAC; 7-18, or 2001 Millennium Cohort Study (MCS; 3-11. Growth references showed a secular trend toward positive skewing of the BMI distribution at younger ages. During childhood, the 50th centiles for all studies lay in the middle of the International Obesity Task Force normal weight range, but during adulthood, the age when a 50th centile first entered the overweight range (i.e., 25-29.9 kg/m2 decreased across NSHD, NCDS, and BCS from 41 to 33 to 30 years in males and 48 to 44 to 41 years in females. Trajectories of overweight or obesity showed that more recently born cohorts developed greater probabilities of overweight or obesity at younger ages. Overweight or obesity became more probable in NCDS than NSHD in early adulthood, but more probable in BCS than NCDS and NSHD in adolescence, for example. By age 10 years, the estimated probabilities of overweight or obesity in cohorts born after the 1980s were 2-3 times greater than those born before the 1980s (e.g., 0.229 [95% CI 0.219-0.240] in MCS males; 0.071 [0.065-0.078] in NSHD males. It was not possible to (1 model separate trajectories for overweight and obesity, because there were few obesity cases at young ages in the earliest-born cohorts, or (2 consider ethnic minority groups. The end date for analyses was August

  9. Rebuilding after collapse: evidence for long-term cohort dynamics in the native Hawaiian rain forest

    Science.gov (United States)

    Boehmer, Hans Juergen; Wagner, Helene H.; Jacobi, James D.; Gerrish, Grant C.; Mueller-Dombois, Dieter

    2013-01-01

    Questions: Do long-term observations in permanent plots confirm the conceptual model of Metrosideros polymorpha cohort dynamics as postulated in 1987? Do regeneration patterns occur independently of substrate age, i.e. of direct volcanic disturbance impact? Location: The windward mountain slopes of the younger Mauna Loa and the older Mauna Kea volcanoes (island of Hawaii, USA). Methods: After widespread forest decline (dieback), permanent plots were established in 1976 in 13 dieback and 13 non-dieback patches to monitor the population structure of M. polymorpha at ca. 5-yr intervals. Within each plot of 20 × 20 m, all trees with DBH >2.5 cm were individually tagged, measured and tree vigour assessed; regeneration was quantified in 16 systematically placed subplots of 3 × 5 m. Data collected in the subplots included the total number of M. polymorpha seedlings and saplings (five stem height classes). Here we analyse monitoring data from six time steps from 1976 to 2003 using repeated measures ANOVA to test specific predictions derived from the 1987 conceptual model. Results: Regeneration was significantly different between dieback and non-dieback plots. In dieback plots, the collapse in the 1970s was followed by a ‘sapling wave’ that by 2003 led to new cohort stands of M. polymorpha. In non-dieback stands, seedling emergence did not result in sapling waves over the same period. Instead, a ‘sapling gap’ (i.e. very few or no M. polymorpha saplings) prevailed as typical for mature stands. Canopy dieback in 1976, degree of recovery by 2003 and the number of living trees in 2003 were unrelated to substrate age. Conclusions: Population development of M. polymorpha supports the cohort dynamics model, which predicts rebuilding of the forest with the same canopy species after dieback. The lack of association with substrate age suggests that the long-term maintenance of cohort structure in M. polymorpha does not depend on volcanic disturbance but may be related to

  10. Risk factors for deformational plagiocephaly at birth and at 7 weeks of age: a prospective cohort study

    NARCIS (Netherlands)

    van Vlimmeren, Leo A.; van der Graaf, Yolanda; Boere-Boonekamp, Magda M.; L'Hoir, Monique P.; Helders, Paul J. M.; Engelbert, Raoul H. H.

    2007-01-01

    The purpose of this work was to identify risk factors for deformational plagiocephaly within 48 hours of birth and at 7 weeks of age. This was a prospective cohort study in which 380 healthy neonates born at term in Bernhoven Hospital in Veghel were followed at birth and at 7 weeks of age. Data

  11. Groundwater flow modelling of periods with temperate climate conditions - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Swan, David (Serco Technical Consulting Services (United Kingdom)); Marsic, Niko (Kemakta Konsult AB (Sweden)); Follin, Sven (SF GeoLogic AB (Sweden))

    2010-11-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Forsmark site during temperate conditions; i.e. from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 12,000 AD. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a hydrogeological base case (reference case conceptualisation) and then in an examination of various areas of uncertainty within the current understanding by a series of model variants. The hydrogeological base case models at three different scales, 'repository', 'site' and 'regional', make use of continuous porous medium (CPM), equivalent continuous porous medium (ECPM) and discrete fracture network (DFN) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  12. Periodic solutions for a non-monotone family of delayed differential equations with applications to Nicholson systems

    Science.gov (United States)

    Faria, Teresa

    2017-07-01

    For a family of n-dimensional periodic delay differential equations which encompasses a broad set of models used in structured population dynamics, the existence of a positive periodic solution is obtained under very mild conditions. The proof uses the Schauder fixed point theorem and relies on the permanence of the system. A general criterion for the existence of a positive periodic solution for Nicholson's blowflies periodic systems (with both distributed and discrete time-varying delays) is derived as a simple application of our main result, generalizing the few existing results concerning multi-dimensional Nicholson models. In the case of a Nicholson system with discrete delays all multiples of the period, the global attractivity of the positive periodic solution is further analyzed, improving results in recent literature.

  13. Risk of erectile dysfunction in transfusion-naive thalassemia men: a nationwide population-based retrospective cohort study.

    Science.gov (United States)

    Chen, Yu-Guang; Lin, Te-Yu; Lin, Cheng-Li; Dai, Ming-Shen; Ho, Ching-Liang; Kao, Chia-Hung

    2015-04-01

    Based on the mechanism of pathophysiology, thalassemia major or transfusion-dependent thalassemia patients may have an increased risk of developing organic erectile dysfunction resulting from hypogonadism. However, there have been few studies investigating the association between erectile dysfunction and transfusion-naive thalassemia populations. We constructed a population-based cohort study to elucidate the association between transfusion-naive thalassemia populations and organic erectile dysfunction. This nationwide population-based cohort study involved analyzing data from 1998 to 2010 obtained from the Taiwanese National Health Insurance Research Database, with a follow-up period extending to the end of 2011. We identified men with transfusion-naive thalassemia and selected a comparison cohort that was frequency-matched with these according to age, and year of diagnosis thalassemia at a ratio of 1 thalassemia man to 4 control men. We analyzed the risks for transfusion-naive thalassemia men and organic erectile dysfunction by using Cox proportional hazards regression models. In this study, 588 transfusion-naive thalassemia men and 2337 controls were included. Total 12 patients were identified within the thalassaemia group and 10 within the control group. The overall risks for developing organic erectile dysfunction were 4.56-fold in patients with transfusion-naive thalassemia men compared with the comparison cohort after we adjusted for age and comorbidities. Our long-term cohort study results showed that in transfusion-naive thalassemia men, there was a higher risk for the development of organic erectile dysfunction, particularly in those patients with comorbidities.

  14. Male sleep duration and fecundability in a North American preconception cohort study

    DEFF Research Database (Denmark)

    Wise, Lauren Anne; Rothman, Kenneth Jay; Wesselink, Amelia Kent

    2018-01-01

    OBJECTIVE: To evaluate prospectively the association between male sleep duration and fecundability. DESIGN: Pregnancy Online Study (PRESTO), a Web-based prospective cohort study of North American couples enrolled during the preconception period (2013-2017). SETTING: Not applicable. PATIENT(S): Male...

  15. COHORT CHANGE, DIFFUSION, AND SUPPORT FOR ENVIRONMENTAL SPENDING IN THE UNITED STATES.

    Science.gov (United States)

    Pampel, Fred C; Hunter, Lori M

    2012-09-01

    The long-standing and sometimes heated debates over the direction and size of the effect of socioeconomic status (SES) on environmental concern contrast post-materialist and affluence arguments, suggesting a positive relationship in high-income nations, with counter arguments for a negative or near zero relationship. A diffusion-of-innovations approach adapts parts of both arguments by predicting that high SES groups first adopt pro-environmental views, which produces a positive relationship. Like other innovations, however, environmentalism diffuses over time to other SES groups, which subsequently weakens the association. We test this argument using the General Social Survey from 1973 to 2008 to compare support for environmental spending across 83 cohorts born from around 1900 to 1982. In developing attitudes before, during, and after the emergence of environmentalism, varying cohorts provide the contrast needed to identify long-term changes in environmental concern. Multilevel age, period, and cohort models support diffusion arguments by demonstrating the effects, across cohorts, of three common indicators of SES - education, income and occupational prestige - first strengthen and then weaken. This finding suggests that diffusion of environmental concern first produces positive relationships consistent with postmaterialism arguments and later produces null or negative relationships consistent with global environmentalism arguments.

  16. Cardiovascular disease: Risk factors and applicability of a risk model in a Greek cohort of renal transplant recipients.

    Science.gov (United States)

    Anastasopoulos, Nikolaos-Andreas; Dounousi, Evangelia; Papachristou, Evangelos; Pappas, Charalampos; Leontaridou, Eleni; Savvidaki, Eirini; Goumenos, Dimitrios; Mitsis, Michael

    2017-02-24

    To investigate the incidence and the determinants of cardiovascular morbidity in Greek renal transplant recipients (RTRs) expressed as major advance cardiac event (MACE) rate. Two hundred and forty-two adult patients with a functioning graft for at least three months and available data that were followed up on the August 31, 2015 at two transplant centers of Western Greece were included in this study. Baseline recipients' data elements included demographics, clinical characteristics, history of comorbid conditions and laboratory parameters. Follow-up data regarding MACE occurrence were collected retrospectively from the patients' records and MACE risk score was calculated for each patient. The mean age was 53 years (63.6% males) and 47 patients (19.4%) had a pre-existing cardiovascular disease (CVD) before transplantation. The mean estimated glomerular filtration rate was 52 ± 17 mL/min per 1.73 m 2 . During follow-up 36 patients (14.9%) suffered a MACE with a median time to MACE 5 years (interquartile range: 2.2-10 years). Recipients with a MACE compared to recipients without a MACE had a significantly higher mean age (59 years vs 52 years, P Greek database of RTRs was good with an area under the receiver operating characteristics curve of 0.68 (95%CI: 0.58-0.78). In this Greek cohort of RTRs, MACE occurred in 14.9% of the patients, pre-existing CVD was the main risk factor, while MACE risk model was proved a dependable utility in predicting CVD post RT.

  17. The effects of model complexity and calibration period on groundwater recharge simulations

    Science.gov (United States)

    Moeck, Christian; Van Freyberg, Jana; Schirmer, Mario

    2017-04-01

    A significant number of groundwater recharge models exist that vary in terms of complexity (i.e., structure and parametrization). Typically, model selection and conceptualization is very subjective and can be a key source of uncertainty in the recharge simulations. Another source of uncertainty is the implicit assumption that model parameters, calibrated over historical periods, are also valid for the simulation period. To the best of our knowledge there is no systematic evaluation of the effect of the model complexity and calibration strategy on the performance of recharge models. To address this gap, we utilized a long-term recharge data set (20 years) from a large weighting lysimeter. We performed a differential split sample test with four groundwater recharge models that vary in terms of complexity. They were calibrated using six calibration periods with climatically contrasting conditions in a constrained Monte Carlo approach. Despite the climatically contrasting conditions, all models performed similarly well during the calibration. However, during validation a clear effect of the model structure on model performance was evident. The more complex, physically-based models predicted recharge best, even when calibration and prediction periods had very different climatic conditions. In contrast, more simplistic soil-water balance and lumped model performed poorly under such conditions. For these models we found a strong dependency on the chosen calibration period. In particular, our analysis showed that this can have relevant implications when using recharge models as decision-making tools in a broad range of applications (e.g. water availability, climate change impact studies, water resource management, etc.).

  18. Temporal diagnostic analysis of the SWAT model to detect dominant periods of poor model performance

    Science.gov (United States)

    Guse, Björn; Reusser, Dominik E.; Fohrer, Nicola

    2013-04-01

    four reoccurring patterns of typical model performance, which can be related to different phases of the hydrograph. Overall, the baseflow cluster has the lowest performance. By combining the periods with poor model performance with the dominant model components during these phases, the groundwater module was detected as the model part with the highest potential for model improvements. The detection of dominant processes in periods of poor model performance enhances the understanding of the SWAT model. Based on this, concepts how to improve the SWAT model structure for the application in German lowland catchment are derived.

  19. Early growth patterns and cardiometabolic function at the age of 5 in a multiethnic birth cohort: the ABCD study

    Directory of Open Access Journals (Sweden)

    Vrijkotte Tanja GM

    2009-03-01

    Full Text Available Abstract Background The relation between fetal growth retardation and cardiovascular and metabolic diseases in later life has been demonstrated in many studies. However, debate exists around the potential independent role of postnatal growth acceleration. Furthermore, it is unknown whether a potential effect of growth acceleration on cardiovascular and metabolic function is confined to certain timeframes. The present study assesses the (predictive role of prenatal and postnatal growth on 5 components of cardiovascular and metabolic function in children aged 5. The potential association of timing of postnatal growth acceleration with these outcomes will be explored. Methods and design Prospective multiethnic community-based cohort study of 8266 pregnancies (Amsterdam Born Children and their Development, ABCD study. Up till now, anthropometry of 5104 children from the original cohort was followed during the first 5 years of life, with additional information about birth weight, pregnancy duration, and various potential confounding variables. At age 5, various components of cardiovascular and metabolic function are being measured. Outcome variables are body size, body composition and fat distribution, insulin sensitivity, lipid profile, blood pressure and autonomic regulation of cardiovascular function. Discussion This study will be one of the first population-based prospective cohort studies to address the association between measures of both prenatal and postnatal growth and various components of cardiovascular and metabolic function. Specific attention is paid to the timing of acceleration in growth and its potential association with the outcome variables. Importantly, the longitudinal design of this study gives us the opportunity to gain more insight into growth trajectories associated with adverse outcomes in later life. If identified as an independent risk factor, this provides further basis for the hypothesis that accelerated growth during

  20. Micronutrient intake and risk of prostate cancer in a cohort of middle-aged, Danish men

    DEFF Research Database (Denmark)

    Roswall, Nina; Larsen, Signe B.; Friis, Søren

    2013-01-01

    intake of vitamin C, E, folate, and beta-carotene and prostate cancer risk, focusing on possible different effects of dietary, supplemental, or total intake and on potential effect modification by alcohol intake and BMI. Methods: Danish prospective cohort study of 26,856 men aged 50-64 years...

  1. Growth trajectories from conception through middle childhood and cognitive achievement at age 8 years: Evidence from four low- and middle-income countries

    Directory of Open Access Journals (Sweden)

    Andreas Georgiadis

    2016-12-01

    Full Text Available Child chronic malnutrition is endemic in low- and middle-income countries and deleterious for child development. Studies investigating the relationship between nutrition at different periods of childhood, as measured by growth in these periods (growth trajectories, and cognitive development have produced mixed evidence. Although an explanation of this has been that different studies use different approaches to model growth trajectories, the differences across approaches are not well understood. Furthermore, little is known about the pathways linking growth trajectories and cognitive achievement. In this paper, we develop and estimate a general path model of the relationship between growth trajectories and cognitive achievement using data on four cohorts from Ethiopia, India, Peru, and Vietnam. The model is used to: (a compare two of the most common approaches to modelling growth trajectories in the literature, namely the lifecourse plot and the conditional body size model, and (b investigate the potential channels via which the association between growth in each period and cognitive achievement manifests. We show that the two approaches are expected to produce systematically different results that have distinct interpretations. Results suggest that growth from conception through age 1 year, between age 1 and 5 years, and between 5 and 8 years, are each positively and significantly associated with cognitive achievement at age 8 years and that this may be partly explained by the fact that faster-growing children start school earlier. We also find that a significant share of the association between early growth and later cognitive achievement is mediated through growth in interim periods. Keywords: Nutrition, Cognitive achievement, Path analysis, Cohort study, Ethiopia, India, Peru, Vietnam

  2. Shift work and overall and cause-specific mortality in the Danish nurse cohort

    DEFF Research Database (Denmark)

    Jørgensen, Jeanette Therming; Karlsen, Sashia; Stayner, Leslie T.

    2017-01-01

    Objectives: Evidence of an effect of shift work on all-cause and cause-specific mortality is inconsistent. This study aims to examine whether shift work is associated with increased all-cause and cause-specific mortality.  Methods: We linked 28 731 female nurses (age ≥44 years), recruited in 1993...... or 1999 from the Danish nurse cohort where they reported information on shift work (night, evening, rotating, or day), to the Danish Register of Causes of Death to identify deaths up to 2013. We used Cox regression models with age as the underlying scale to examine the associations between night, evening......, and rotating shift work (compared to day shift work) and all-cause and cause-specific mortality in models adjusted for potentially confounding variables.  Results: Of 18 015 nurses included in this study, 1616 died during the study time period from the following causes: cardiovascular disease (N=217), cancer...

  3. Lung cancer risk from radon - a joint analysis of three Czech miners cohorts

    International Nuclear Information System (INIS)

    Tomasek, L.; Placek, V.; Heribanova, A.

    1998-01-01

    The three cohorts were as follows: 4320 uranium miners first exposed in 1948-1959; 5624 miners who were working in uranium mines in 1968-1974, and 914 burnt-clay miners employed underground in 1960-1980. The statistical analyses were based on relative risk models in the general form O cE(1+ERR(W,Z)) where O is the observed number of cases, E is the number expected based on nationwide mortality data, and ERR is the excessive relative risk function depending on exposure (W) and modifying variables (Z). By the end of 1995, 888 cases of lung cancer were observed in the 3 cohorts, most of them in cohort 1, reflecting thus the high exposures and age. The simple model gives an ERR/WLM estimate (WLM = Working level Month; 1 WLM 3.54 = mJh/m 3 ) of 0.014 for the entire range of cumulative exposures (1-860 WLM), the intercept is 1.58. A somewhat steeper slope is seen at very low exposures. When the exposure range is restricted to less than 100 WLM, the ERR/WLM and intercept estimates are 0.023 and 1,25, respectively. Even at 10-20 WLM, the relative risk is significantly different from the baseline rate. The main reasons for the differences between the two global estimates of ERR/WLM are (i) the exposure rate effect, (ii) the different periods of follow-up after exposure, and (iii) the age structure of miners at work. The effect of smoking was also taken into account. (P.A.)

  4. Dental care for the elderly through a Capped-fee funding model: Optimising outcomes for primary government dental services.

    Science.gov (United States)

    Conquest, Jennifer H; Skinner, John; Kruger, Estie; Tennant, Marc

    2017-12-01

    The objectives of this study were to (i) compare a Capped Payment formula for adults, to the fee-for-service model and the New South Wales Government services payment model; (ii) identify the presenting oral health needs of a 65+ years of age cohort during the period January 2011 to March 2015. Australia faces an ageing population with the vast majority accessing free market dental care, whilst the poor access Government services. This cohort retains most of their dentition increasing demand on Government services. The analysis of New South Wales Government adult de-identified patients' record unit data was from 2011 to 2015, for the three payment models and undertaken in three stages; (i) development of the Capped Payment Model; (ii) evaluation of twenty (20) case studies of adults 65+ years of age; (iii) analyse the cost efficiency of the three payment models. This study found that the Government model was the most cost effective. The Capped-fee model performed less efficiently, particularly in the 75+ age group, with the fee-for-service model generally more costly. It was $2580 (85%) more costly for the 65-74 age cohort, and $4619 (66%) for the 75+ age cohort. Policy makers in partnership with Government and private service providers should seek to develop partnerships with Government, private services and universities, scope opportunities in applying a Capped-fee funding model, and one that helps address the oral needs of the elderly. © 2017 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  5. Is 27 really a dangerous age for famous musicians? Retrospective cohort study.

    Science.gov (United States)

    Wolkewitz, Martin; Allignol, Arthur; Graves, Nicholas; Barnett, Adrian G

    2011-12-20

    To test the "27 club" hypothesis that famous musicians are at an increased risk of death at age 27. Design Cohort study using survival analysis with age as a time dependent exposure. Comparison was primarily made within musicians, and secondarily relative to the general UK population. The popular music scene from a UK perspective. Musicians (solo artists and band members) who had a number one album in the UK between 1956 and 2007 (n = 1046 musicians, with 71 deaths, 7%). Risk of death by age of musician, accounting for time dependent study entry and the number of musicians at risk. Risk was estimated using a flexible spline which would allow a bump at age 27 to appear. We identified three deaths at age 27 amongst 522 musicians at risk, giving a rate of 0.57 deaths per 100 musician years. Similar death rates were observed at ages 25 (rate = 0.56) and 32 (0.54). There was no peak in risk around age 27, but the risk of death for famous musicians throughout their 20s and 30s was two to three times higher than the general UK population. The 27 club is unlikely to be a real phenomenon. Fame may increase the risk of death among musicians, but this risk is not limited to age 27.

  6. Early childhood development when second-trimester ultrasound dating disagrees with last menstrual period: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Grewal Jagteshwar

    2012-04-01

    Full Text Available Abstract Background When an ultrasound-based estimate of gestational age (GA is less (greater than an estimate based on a definite last menstrual period, the fetus may grow slower (faster than average. While the association between these discrepancies in GA estimates and adverse perinatal outcomes has been examined extensively, there is scant evidence about long-term effects, such as child neurodevelopment. Methods Using data from a prospective cohort study titled, NICHD Study of Successive Small-for-Gestational Age Births, we examined if GA discrepancies in early second trimester of pregnancy (17 weeks’ gestation are associated with: (1 impaired motor and mental function at 13 months (measured using Bayley Scales of Infant Development (Bayley, and (2 impaired cognitive development at five years (assessed by Wechsler Preschool and Primary Scale of Intelligence – Revised Intelligence Quotient (WPPSI-R in the infant. The study population consisted of 572 (30% of the overall sample of 1,945 women who presented for prenatal care in Norway and Sweden between 1986 and 1988. Results Our results showed that GA discrepancies in early second trimester are significantly associated with birthweight. We found no significant relationship, however, with the Bayley development scores at 13 months and with the WPPSI-R IQ measures at five years. Conclusions GA discrepancies at 17 weeks’ gestation are not associated child neurodevelopment. These discrepancies do, however, relate to birthweights, providing a basis for detecting fetal growth patterns early in the second trimester of pregnancy. Our study, however, was unable to evaluate the impact of first-trimester discrepancies on impaired neurodevelopment in the infant.

  7. Chronic Obstructive Pulmonary Disease (COPD as a disease of early aging: Evidence from the EpiChron Cohort.

    Directory of Open Access Journals (Sweden)

    Miguel J Divo

    Full Text Available Aging is an important risk factor for most chronic diseases. Patients with COPD develop more comorbidities than non-COPD subjects. We hypothesized that the development of comorbidities characteristically affecting the elderly occur at an earlier age in subjects with the diagnosis of COPD.We included all subjects carrying the diagnosis of COPD (n = 27,617, and a similar number of age and sex matched individuals without the diagnosis, extracted from the 727,241 records of individuals 40 years and older included in the EpiChron Cohort (Aragon, Spain. We compared the cumulative number of comorbidities, their prevalence and the mortality risk between both groups. Using network analysis, we explored the connectivity between comorbidities and the most influential comorbidities in both groups. We divided the groups into 5 incremental age categories and compared their comorbidity networks. We then selected those comorbidities known to affect primarily the elderly and compared their prevalence across the 5 age groups. In addition, we replicated the analysis in the smokers' subgroup to correct for the confounding effect of cigarette smoking. Subjects with COPD had more comorbidities and died at a younger age compared to controls. Comparison of both cohorts across 5 incremental age groups showed that the number of comorbidities, the prevalence of diseases characteristic of aging and network's density for the COPD group aged 56-65 were similar to those of non-COPD 15 to 20 years older. The findings persisted after adjusting for smoking.Multimorbidity increases with age but in patients carrying the diagnosis of COPD, these comorbidities are seen at an earlier age.

  8. Chronic Obstructive Pulmonary Disease (COPD) as a disease of early aging: Evidence from the EpiChron Cohort.

    Science.gov (United States)

    Divo, Miguel J; Celli, Bartolome R; Poblador-Plou, Beatriz; Calderón-Larrañaga, Amaia; de-Torres, Juan Pablo; Gimeno-Feliu, Luis A; Bertó, Juan; Zulueta, Javier J; Casanova, Ciro; Pinto-Plata, Victor M; Cabrera-Lopez, Carlos; Polverino, Francesca; Carmona Píréz, Jonás; Prados-Torres, Alexandra; Marin, Jose M

    2018-01-01

    Aging is an important risk factor for most chronic diseases. Patients with COPD develop more comorbidities than non-COPD subjects. We hypothesized that the development of comorbidities characteristically affecting the elderly occur at an earlier age in subjects with the diagnosis of COPD. We included all subjects carrying the diagnosis of COPD (n = 27,617), and a similar number of age and sex matched individuals without the diagnosis, extracted from the 727,241 records of individuals 40 years and older included in the EpiChron Cohort (Aragon, Spain). We compared the cumulative number of comorbidities, their prevalence and the mortality risk between both groups. Using network analysis, we explored the connectivity between comorbidities and the most influential comorbidities in both groups. We divided the groups into 5 incremental age categories and compared their comorbidity networks. We then selected those comorbidities known to affect primarily the elderly and compared their prevalence across the 5 age groups. In addition, we replicated the analysis in the smokers' subgroup to correct for the confounding effect of cigarette smoking. Subjects with COPD had more comorbidities and died at a younger age compared to controls. Comparison of both cohorts across 5 incremental age groups showed that the number of comorbidities, the prevalence of diseases characteristic of aging and network's density for the COPD group aged 56-65 were similar to those of non-COPD 15 to 20 years older. The findings persisted after adjusting for smoking. Multimorbidity increases with age but in patients carrying the diagnosis of COPD, these comorbidities are seen at an earlier age.

  9. Model linear absolute and relative risk estimates for cancer induced by ionizing radiation in Mexican cohort of occupationally exposed

    International Nuclear Information System (INIS)

    Alvarez, R.J.T.; Trovar, M.V.M; González, J.F.

    2015-01-01

    From the rate of natural mortality m s cancer (t) for every 100 thousand habitants, modeled by a fourth-degree polynomial function of the age data of the Mexican population (2008), and assuming: a) a relationship 1: 5 of cancer induced radiation respect to presented spontaneously, b) a size of initial cohort No = 100 k SOPs, c) a speed of H E = (2 ± 1) mSv / received by the SOPs from 18 to 65 years, d) a latency of 8 years for cancer induction after irradiation, e) a time tracking cohort to 75 years, f) and taking the coefficients absolute and relative risk BEIRs induction of cancer models II and VII (excluding leukemia); It determined: BEIR II for a total of 125 and 400 deaths from cancer for absolute and relative linear models respectively. For BEIR VII has a number of fatal cases of 345 and 927 deaths respectively for absolute and relative linear model cancer. [es

  10. Changing Racial/Ethnic Disparities in Heavy Drinking Trajectories Through Young Adulthood: A Comparative Cohort Study.

    Science.gov (United States)

    Williams, Edwina; Mulia, Nina; Karriker-Jaffe, Katherine J; Lui, Camillia K

    2018-01-01

    There is evidence of racial/ethnic differences in the age at which young adults age out of heavy drinking. Some studies have found Black and Hispanic drinkers engage in more frequent heavy drinking than White people beyond adulthood. Yet, the alcohol-related disparities literature has produced contradictory findings on whether an age-crossover effect is evident among racial/ethnic groups; that is, whether racial/ethnic minorities' drinking levels or trajectories are lower than White people at young ages but later exceed (or crossover) those of White people. This study extends this scant literature by assessing whether racial/ethnic differences in heavy drinking have changed over time (possibly accounting for mixed findings from prior research); and tests for an age-crossover effect in heavy drinking using longitudinal data from 2 cohorts born 20 years apart. Data are from the 1979 (n = 10,963) and 1997 (n = 8,852) cohorts of the National Longitudinal Survey of Youth (NLSY). Generalized estimating equations were used to model trajectories of heavy drinking frequency from ages 17 to 31. Racial/ethnic differences were determined using sex-stratified models and 3-way interactions of race/ethnicity with age, age-squared, and cohort. Racial/ethnic differences in heavy drinking trajectories have changed over time in men and women. In the older NLSY cohort, Hispanic men and Black women surpassed White men's and women's heavy drinking frequency by age 31. This crossover was absent in the younger cohort, where trajectories of all racial-sex groups converged by age 31. Normative trajectories have changed in Hispanics and White people of both sexes, with a delay in age of peak frequency, and greater levels of heavy drinking in the younger cohort of women. Changes in heavy drinking trajectories over time suggest the need for targeted interventions during young adulthood. While disparities in young adult heavy drinking were no longer apparent in the more recent birth cohort

  11. Sexual Assault, Sexual Harassment, and Physical Victimization during Military Service across Age Cohorts of Women Veterans.

    Science.gov (United States)

    Gibson, Carolyn J; Gray, Kristen E; Katon, Jodie G; Simpson, Tracy L; Lehavot, Keren

    2016-01-01

    Exposure to sexual and physical trauma during military service is associated with adverse mental and physical health outcomes. Little is known about their prevalence and impact in women veterans across age cohorts. Data from a 2013 national online survey of women veterans was used to examine associations between age and trauma during military service, including sexual assault, sexual harassment, and physical victimization. Analyses were conducted using logistic regression, adjusting for service duration and demographic factors. In secondary analyses, the moderating role of age in the relationship between trauma and self-reported health was examined. The sample included 781 women veterans. Compared with the oldest age group (≥ 65), all except the youngest age group had consistently higher odds of reporting trauma during military service. These differences were most pronounced in women aged 45 to 54 years (sexual assault odds ratio [OR], 3.81 [95% CI, 2.77-6.71]; sexual harassment, OR, 3.99 [95% CI, 2.25-7.08]; and physical victimization, OR, 5.72 [95% CI, 3.32-9.85]). The association between trauma during military service and self-reported health status also varied by age group, with the strongest negative impact observed among women aged 45 to 54 and 55 to 64. Compared with other age groups, women in midlife were the most likely to report trauma during military service, and these experiences were associated with greater negative impact on their self-reported health. Providers should be aware that trauma during military service may be particularly problematic for the cohort of women currently in midlife, who represent the largest proportion of women who use Department of Veterans Affairs health care. Published by Elsevier Inc.

  12. Primary stability of a cementless acetabular cup in a cohort of patient-specific finite element models.

    Science.gov (United States)

    O'Rourke, Dermot; Al-Dirini, Rami Ma; Taylor, Mark

    2018-03-01

    The primary stability achieved during total hip arthroplasty determines the long-term success of cementless acetabular cups. Pre-clinical finite element testing of cups typically use a model of a single patient and assume the results can be extrapolated to the general population. This study explored the variability in predicted primary stability of a Pinnacle ® cementless acetabular cup in 103 patient-specific finite element models of the hemipelvis and examined the association between patient-related factors and the observed variability. Cups were inserted by displacement-control into the FE models and then a loading configuration simulating a complete level gait cycle was applied. The cohort showed a range of polar gap of 284-1112 μm and 95th percentile composite peak micromotion (CPM) of 18-624 μm. Regression analysis was not conclusive on the relationship between patient-related factors and primary stability. No relationship was found between polar gap and micromotion. However, when the patient-related factors were categorised into quartile groups, trends suggested higher polar gaps occurred in subjects with small and shallow acetabular geometries and cup motion during gait was affected most by low elastic modulus and high bodyweight. The variation in primary stability in the cohort for an acetabular cup with a proven clinical track record may provide benchmark data when evaluating new cup designs. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1012-1023, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  13. Forward Period Analysis Method of the Periodic Hamiltonian System.

    Directory of Open Access Journals (Sweden)

    Pengfei Wang

    Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

  14. A cohort study of developmental polychlorinated biphenyl (PCB) exposure in relation to post-vaccination antibody response at 6-months of age

    International Nuclear Information System (INIS)

    Jusko, Todd A.; De Roos, Anneclaire J.; Schwartz, Stephen M.; Paige Lawrence, B.; Palkovicova, Lubica; Nemessanyi, Tomas; Drobna, Beata; Fabisikova, Anna; Kocan, Anton; Sonneborn, Dean; Jahnova, Eva; Kavanagh, Terrance J.; Trnovec, Tomas; Hertz-Picciotto, Irva

    2010-01-01

    Background: Extensive experimental data in animals indicate that exposure to polychlorinated biphenyls (PCBs) during pregnancy leads to changes in offspring immune function during the postnatal period. Whether developmental PCB exposure influences immunologic development in humans has received little study. Methods: The study population was 384 mother-infant pairs recruited from two districts of eastern Slovakia for whom prospectively collected maternal, cord, and 6-month infant blood specimens were available. Several PCB congeners were measured in maternal, cord, and 6-month infant sera by high-resolution gas chromatography with electron capture detection. Concentrations of IgG-specific anti-haemophilus influenzae type b, tetanus toxoid, and diphtheria toxoid were assayed in 6-month infant sera using ELISA methods. Multiple linear regression was used to estimate the relation between maternal, cord, and 6-month infant PCB concentrations and the antibody concentrations evaluated at 6-months of age. Results: Overall, there was little evidence of an association between infant antibody concentrations and PCB measures during the pre- and early postnatal period. In addition, our results did not show specificity in terms of associations limited to a particular developmental period (e.g. pre- vs. postnatal), a particular antibody, or a particular PCB congener. Conclusions: At the PCB concentrations measured in this cohort, which are high relative to most human populations today, we did not detect an association between maternal or early postnatal PCB exposure and specific antibody responses at 6-months of age.

  15. A cohort study of developmental polychlorinated biphenyl (PCB) exposure in relation to post-vaccination antibody response at 6-months of age

    Energy Technology Data Exchange (ETDEWEB)

    Jusko, Todd A., E-mail: juskota@niehs.nih.gov [Epidemiology Branch, National Institute of Environmental Health Sciences, PO Box 12233, MD A3-05, 111 T.W. Alexander Dr, Rall Bldg 101, Rm A361, Research Triangle Park, NC 27709-2233 (United States); Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); De Roos, Anneclaire J.; Schwartz, Stephen M. [Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Program in Epidemiology, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Paige Lawrence, B. [Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY (United States); Palkovicova, Lubica [Department of Environmental Medicine, Slovak Medical University, Bratislava (Slovakia); Nemessanyi, Tomas [Department of Immunology and Immunotoxicology, Slovak Medical University, Bratislava (Slovakia); Drobna, Beata; Fabisikova, Anna; Kocan, Anton [Department of Toxic Organic Pollutants, Slovak Medical University, Bratislava (Slovakia); Sonneborn, Dean [Department of Public Health Sciences, University of California, Davis, CA (United States); Jahnova, Eva [Department of Immunology and Immunotoxicology, Slovak Medical University, Bratislava (Slovakia); Kavanagh, Terrance J. [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA (United States); Trnovec, Tomas [Department of Toxic Organic Pollutants, Slovak Medical University, Bratislava (Slovakia); Hertz-Picciotto, Irva [Department of Public Health Sciences, University of California, Davis, CA (United States)

    2010-05-15

    Background: Extensive experimental data in animals indicate that exposure to polychlorinated biphenyls (PCBs) during pregnancy leads to changes in offspring immune function during the postnatal period. Whether developmental PCB exposure influences immunologic development in humans has received little study. Methods: The study population was 384 mother-infant pairs recruited from two districts of eastern Slovakia for whom prospectively collected maternal, cord, and 6-month infant blood specimens were available. Several PCB congeners were measured in maternal, cord, and 6-month infant sera by high-resolution gas chromatography with electron capture detection. Concentrations of IgG-specific anti-haemophilus influenzae type b, tetanus toxoid, and diphtheria toxoid were assayed in 6-month infant sera using ELISA methods. Multiple linear regression was used to estimate the relation between maternal, cord, and 6-month infant PCB concentrations and the antibody concentrations evaluated at 6-months of age. Results: Overall, there was little evidence of an association between infant antibody concentrations and PCB measures during the pre- and early postnatal period. In addition, our results did not show specificity in terms of associations limited to a particular developmental period (e.g. pre- vs. postnatal), a particular antibody, or a particular PCB congener. Conclusions: At the PCB concentrations measured in this cohort, which are high relative to most human populations today, we did not detect an association between maternal or early postnatal PCB exposure and specific antibody responses at 6-months of age.

  16. Econometric model for age- and population-dependent radiation exposures

    International Nuclear Information System (INIS)

    Sandquist, G.M.; Slaughter, D.M.; Rogers, V.C.

    1991-01-01

    The economic impact associated with ionizing radiation exposures in a given human population depends on numerous factors including the individual's mean economic status as a function age, the age distribution of the population, the future life expectancy at each age, and the latency period for the occurrence of radiation-induced health effects. A simple mathematical model has been developed that provides an analytical methodology for estimating the societal econometrics associated with radiation effects are to be assessed and compared for economic evaluation

  17. Age at exposure and attained age variations of cancer risk in the Japanese A-bomb and radiotherapy cohorts.

    Science.gov (United States)

    Schneider, Uwe; Walsh, Linda

    2015-08-01

    Phenomenological risk models for radiation-induced cancer are frequently applied to estimate the risk of radiation-induced cancers at radiotherapy doses. Such models often include the effect modification, of the main risk to radiation dose response, by age at exposure and attained age. The aim of this paper is to compare the patterns in risk effect modification by age, between models obtained from the Japanese atomic-bomb (A-bomb) survivor data and models for cancer risks previously reported for radiotherapy patients. Patterns in risk effect modification by age from the epidemiological studies of radiotherapy patients were also used to refine and extend the risk effect modification by age obtained from the A-bomb survivor data, so that more universal models can be presented here. Simple log-linear and power functions of age for the risk effect modification applied in models of the A-bomb survivor data are compared to risks from epidemiological studies of second cancers after radiotherapy. These functions of age were also refined and fitted to radiotherapy risks. The resulting age models provide a refined and extended functional dependence of risk with age at exposure and attained age especially beyond 40 and 65 yr, respectively, and provide a better representation than the currently available simple age functions. It was found that the A-bomb models predict risk similarly to the outcomes of testicular cancer survivors. The survivors of Hodgkin's disease show steeper variations of risk with both age at exposure and attained age. The extended models predict solid cancer risk increase as a function of age at exposure beyond 40 yr and the risk decrease as a function of attained age beyond 65 yr better than the simple models. The standard functions for risk effect modification by age, based on the A-bomb survivor data, predict second cancer risk in radiotherapy patients for ages at exposure prior to 40 yr and attained ages before 55 yr reasonably well. However, for

  18. Seasonal modulation of the Asian summer monsoon between the Medieval Warm Period and Little Ice Age: a multi model study

    Science.gov (United States)

    Kamae, Youichi; Kawana, Toshi; Oshiro, Megumi; Ueda, Hiroaki

    2017-12-01

    Instrumental and proxy records indicate remarkable global climate variability over the last millennium, influenced by solar irradiance, Earth's orbital parameters, volcanic eruptions and human activities. Numerical model simulations and proxy data suggest an enhanced Asian summer monsoon during the Medieval Warm Period (MWP) compared to the Little Ice Age (LIA). Using multiple climate model simulations, we show that anomalous seasonal insolation over the Northern Hemisphere due to a long cycle of orbital parameters results in a modulation of the Asian summer monsoon transition between the MWP and LIA. Ten climate model simulations prescribing historical radiative forcing that includes orbital parameters consistently reproduce an enhanced MWP Asian monsoon in late summer and a weakened monsoon in early summer. Weakened, then enhanced Northern Hemisphere insolation before and after June leads to a seasonally asymmetric temperature response over the Eurasian continent, resulting in a seasonal reversal of the signs of MWP-LIA anomalies in land-sea thermal contrast, atmospheric circulation, and rainfall from early to late summer. This seasonal asymmetry in monsoon response is consistently found among the different climate models and is reproduced by an idealized model simulation forced solely by orbital parameters. The results of this study indicate that slow variation in the Earth's orbital parameters contributes to centennial variability in the Asian monsoon transition.[Figure not available: see fulltext.

  19. A constitutive model accounting for strain ageing effects on work-hardening. Application to a C-Mn steel

    Science.gov (United States)

    Ren, Sicong; Mazière, Matthieu; Forest, Samuel; Morgeneyer, Thilo F.; Rousselier, Gilles

    2017-12-01

    One of the most successful models for describing the Portevin-Le Chatelier effect in engineering applications is the Kubin-Estrin-McCormick model (KEMC). In the present work, the influence of dynamic strain ageing on dynamic recovery due to dislocation annihilation is introduced in order to improve the KEMC model. This modification accounts for additional strain hardening rate due to limited dislocation annihilation by the diffusion of solute atoms and dislocation pinning at low strain rate and/or high temperature. The parameters associated with this novel formulation are identified based on tensile tests for a C-Mn steel at seven temperatures ranging from 20 °C to 350 °C. The validity of the model and the improvement compared to existing models are tested using 2D and 3D finite element simulations of the Portevin-Le Chatelier effect in tension.

  20. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    International Nuclear Information System (INIS)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Roberts, David; Swan, David; Gylling, Bjoern; Marsic, Niko; Rhen, Ingvar

    2010-12-01

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a Hydrogeological base case (reference case conceptualisation) and then an examination of various areas of uncertainty within the current understanding by a series of model variants. The Hydrogeological base case models at three different scales, 'repository', 'site' and 'regional' make use of a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 15,000 AD. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  1. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Roberts, David; Swan, David (Serco Technical Consulting Services (United Kingdom)); Gylling, Bjoern; Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a Hydrogeological base case (reference case conceptualisation) and then an examination of various areas of uncertainty within the current understanding by a series of model variants. The Hydrogeological base case models at three different scales, 'repository', 'site' and 'regional' make use of a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 15,000 AD. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  2. Relating smoking, obesity, insulin resistance and ovarian biomarker changes to the final menstrual period (FMP)

    OpenAIRE

    Sowers, MaryFran R.; McConnell, Daniel; Yosef, Matheos; Jannausch, Mary L.; Harlow, Sioban D.; Randolph, John F.

    2010-01-01

    In order to determine if smoking, obesity, and insulin resistance mediated age at final menstrual period (FMP), we examined anti-Müllerian hormone (AMH), inhibin B, and follicle-stimulating hormone as biomarkers of changing follicle status and ovarian aging. We performed a longitudinal data analysis from a cohort of premenopausal women followed to their FMP. Our results found that smokers had an earlier age at FMP (p

  3. An Agent-Based Modeling Template for a Cohort of Veterans with Diabetic Retinopathy.

    Directory of Open Access Journals (Sweden)

    Theodore Eugene Day

    Full Text Available Agent-based models are valuable for examining systems where large numbers of discrete individuals interact with each other, or with some environment. Diabetic Veterans seeking eye care at a Veterans Administration hospital represent one such cohort.The objective of this study was to develop an agent-based template to be used as a model for a patient with diabetic retinopathy (DR. This template may be replicated arbitrarily many times in order to generate a large cohort which is representative of a real-world population, upon which in-silico experimentation may be conducted.Agent-based template development was performed in java-based computer simulation suite AnyLogic Professional 6.6. The model was informed by medical data abstracted from 535 patient records representing a retrospective cohort of current patients of the VA St. Louis Healthcare System Eye clinic. Logistic regression was performed to determine the predictors associated with advancing stages of DR. Predicted probabilities obtained from logistic regression were used to generate the stage of DR in the simulated cohort.The simulated cohort of DR patients exhibited no significant deviation from the test population of real-world patients in proportion of stage of DR, duration of diabetes mellitus (DM, or the other abstracted predictors. Simulated patients after 10 years were significantly more likely to exhibit proliferative DR (P<0.001.Agent-based modeling is an emerging platform, capable of simulating large cohorts of individuals based on manageable data abstraction efforts. The modeling method described may be useful in simulating many different conditions where course of disease is described in categorical stages.

  4. Modelling BSE trend over time in Europe, a risk assessment perspective

    NARCIS (Netherlands)

    Ducrot, C.; Sala, C.; Ru, G.; Koeijer, de A.A.; Sheridan, H.; Saegerman, C.; Selhorst, T.; Arnold, M.; Polak, M.P.; Calavas, D.

    2010-01-01

    BSE is a zoonotic disease that caused the emergence of variant Creuzfeldt-Jakob disease in the mid 1990s. The trend of the BSE epidemic in seven European countries was assessed and compared, using Age-Period-Cohort and Reproduction Ratio modelling applied to surveillance data 2001-2007. A strong

  5. Features of Physical and Neuro-Psychological Development of Children with Low, Very Low and Extremely Low Birth Weight in Different Age Periods of Life

    Directory of Open Access Journals (Sweden)

    I. A. Deev

    2016-01-01

    Full Text Available Analysis of features of physical and neuro-psychological development of children with low, very low and extremely low birth weight in different age periods is carried out according to cohort studies of newborns with different gestational age and birth weight, presented in electronic databases PubMed and Medscape. It is revealed that the overwhelming number of children with low, very low and extremely low birth weight, gain physical and neuro- psychological development impairments, hearing and vision disorders of varying severity, violation of motor function, intelligence and cognitive skills infringement in an older age. In this regard, it is actual not only to develop new neonatal reanimation and intensive care technologies, but also to ensure adequate prevention of preterm birth in the group of women with a high degree of perinatal risk. All this will further allow preventing increase in children with disabling conditions number among premature infants.

  6. Periconceptional multivitamin use and risk of preterm or small-for-gestational-age births in the Danish National Birth Cohort1234

    Science.gov (United States)

    Bodnar, Lisa M; Olsen, Jorn; Olsen, Sjurdur; Nohr, Ellen A

    2011-01-01

    Background: The intake of periconceptional multivitamins may decrease the risk of preterm births (PTBs) or small-for-gestational-age (SGA) births. Objective: We related the timing and frequency of periconceptional multivitamin use to SGA births and PTBs and its clinical presentations (ie, preterm labor, premature rupture of membranes, and medical induction). Design: Women in the Danish National Birth Cohort (n = 35,897) reported the number of weeks of multivitamin use during a 12-wk periconceptional period. Cox regression was used to estimate the relation between any multivitamin use and PTBs (2 SDs below the mean on the basis of fetal growth curves). The timing (preconception and postconception) and frequency of use were also analyzed. Regular users (4–6 wk) and partial users (1–3 wk) in each period were compared with nonusers. Results: The association between periconceptional multivitamin use and PTBs varied according to prepregnancy overweight status (P-interaction = 0.07). Regular preconception and postconception multivitamin use in women with a prepregnancy BMI (in kg/m2) PTBs in nonoverweight women. PMID:21795441

  7. Development and Validation of a Risk-Score Model for Type 2 Diabetes: A Cohort Study of a Rural Adult Chinese Population.

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    Full Text Available Some global models to predict the risk of diabetes may not be applicable to local populations. We aimed to develop and validate a score to predict type 2 diabetes mellitus (T2DM in a rural adult Chinese population. Data for a cohort of 12,849 participants were randomly divided into derivation (n = 11,564 and validation (n = 1285 datasets. A questionnaire interview and physical and blood biochemical examinations were performed at baseline (July to August 2007 and July to August 2008 and follow-up (July to August 2013 and July to October 2014. A Cox regression model was used to weigh each variable in the derivation dataset. For each significant variable, a score was calculated by multiplying β by 100 and rounding to the nearest integer. Age, body mass index, triglycerides and fasting plasma glucose (scores 3, 12, 24 and 76, respectively were predictors of incident T2DM. The model accuracy was assessed by the area under the receiver operating characteristic curve (AUC, with optimal cut-off value 936. With the derivation dataset, sensitivity, specificity and AUC of the model were 66.7%, 74.0% and 0.768 (95% CI 0.760-0.776, respectively. With the validation dataset, the performance of the model was superior to the Chinese (simple, FINDRISC, Oman and IDRS models of T2DM risk but equivalent to the Framingham model, which is widely applicable in a variety of populations. Our model for predicting 6-year risk of T2DM could be used in a rural adult Chinese population.

  8. Gene expression markers of age-related inflammation in two human cohorts.

    Science.gov (United States)

    Pilling, Luke C; Joehanes, Roby; Melzer, David; Harries, Lorna W; Henley, William; Dupuis, Josée; Lin, Honghuang; Mitchell, Marcus; Hernandez, Dena; Ying, Sai-Xia; Lunetta, Kathryn L; Benjamin, Emelia J; Singleton, Andrew; Levy, Daniel; Munson, Peter; Murabito, Joanne M; Ferrucci, Luigi

    2015-10-01

    Chronically elevated circulating inflammatory markers are common in older persons but mechanisms are unclear. Many blood transcripts (>800 genes) are associated with interleukin-6 protein levels (IL6) independent of age. We aimed to identify gene transcripts statistically mediating, as drivers or responders, the increasing levels of IL6 protein in blood at older ages. Blood derived in-vivo RNA from the Framingham Heart Study (FHS, n=2422, ages 40-92 yrs) and InCHIANTI study (n=694, ages 30-104 yrs), with Affymetrix and Illumina expression arrays respectively (>17,000 genes tested), were tested for statistical mediation of the age-IL6 association using resampling techniques, adjusted for confounders and multiple testing. In FHS, IL6 expression was not associated with IL6 protein levels in blood. 102 genes (0.6% of 17,324 expressed) statistically mediated the age-IL6 association of which 25 replicated in InCHIANTI (including 5 of the 10 largest effect genes). The largest effect gene (SLC4A10, coding for NCBE, a sodium bicarbonate transporter) mediated 19% (adjusted CI 8.9 to 34.1%) and replicated by PCR in InCHIANTI (n=194, 35.6% mediated, p=0.01). Other replicated mediators included PRF1 (perforin, a cytolytic protein in cytotoxic T lymphocytes and NK cells) and IL1B (Interleukin 1 beta): few other cytokines were significant mediators. This transcriptome-wide study on human blood identified a small distinct set of genes that statistically mediate the age-IL6 association. Findings are robust across two cohorts and different expression technologies. Raised IL6 levels may not derive from circulating white cells in age related inflammation. Published by Elsevier Inc.

  9. Age at exposure and attained age variations of cancer risk in the Japanese A-bomb and radiotherapy cohorts

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Uwe, E-mail: uwe.schneider@uzh.ch [Institute of Physics, Science Faculty, University of Zürich, Zürich 8057, Switzerland and Radiotherapy Hirslanden, Uwe Schneider Institute of Radiotherapy, Witellikerstr. 40, Zürich 8032 (Switzerland); Walsh, Linda [Institute of Physics, Science Faculty, University of Zürich, Zürich 8057, Switzerland and BfS - Federal Office for Radiation Protection, Radiation Protection and Health, Neuherberg 85764 (Germany)

    2015-08-15

    Purpose: Phenomenological risk models for radiation-induced cancer are frequently applied to estimate the risk of radiation-induced cancers at radiotherapy doses. Such models often include the effect modification, of the main risk to radiation dose response, by age at exposure and attained age. The aim of this paper is to compare the patterns in risk effect modification by age, between models obtained from the Japanese atomic-bomb (A-bomb) survivor data and models for cancer risks previously reported for radiotherapy patients. Patterns in risk effect modification by age from the epidemiological studies of radiotherapy patients were also used to refine and extend the risk effect modification by age obtained from the A-bomb survivor data, so that more universal models can be presented here. Methods: Simple log-linear and power functions of age for the risk effect modification applied in models of the A-bomb survivor data are compared to risks from epidemiological studies of second cancers after radiotherapy. These functions of age were also refined and fitted to radiotherapy risks. The resulting age models provide a refined and extended functional dependence of risk with age at exposure and attained age especially beyond 40 and 65 yr, respectively, and provide a better representation than the currently available simple age functions. Results: It was found that the A-bomb models predict risk similarly to the outcomes of testicular cancer survivors. The survivors of Hodgkin’s disease show steeper variations of risk with both age at exposure and attained age. The extended models predict solid cancer risk increase as a function of age at exposure beyond 40 yr and the risk decrease as a function of attained age beyond 65 yr better than the simple models. Conclusions: The standard functions for risk effect modification by age, based on the A-bomb survivor data, predict second cancer risk in radiotherapy patients for ages at exposure prior to 40 yr and attained ages

  10. Increasing incidence of testicular cancer--birth cohort effects.

    Science.gov (United States)

    Ekbom, A; Akre, O

    1998-01-01

    The incidence of testicular cancer is rising in most Western populations. A collaborative study between nine population-based cancer registries in countries around the Baltic Sea was utilized in order to analyze in detail geographic variations and temporal trends in the occurrence of testicular cancer. There were 34,309 cases registered up until 1989 starting in Denmark in 1942 and most recently in Latvia in 1977. From the descriptive epidemiology it was obvious that there was a substantial variation in the age-standardized incidence amounting to about a 10-fold difference between the different countries ranging from 0.8 per 100,000 person-years in Lithuania to 7.6 per 100,000 person-years in Denmark. Previous studies have indicated that this increase is due to birth cohort effects. A more detailed analysis was therefore performed in those six countries with a sufficiently long period of cancer registration; Poland, former East Germany, Norway, Finland, Denmark and Sweden. This analysis showed that birth cohort is a more important determinant of testicular cancer risk than year of diagnosis. In Poland, former East Germany and Finland, there was an increasing risk for all birth cohorts. Among men born in Denmark, Norway or Sweden between 1930 and 1945, this increasing trend in risk was interrupted in these birth cohorts but followed thereafter by an uninterrupted increase by birth cohort. In conclusion, life time exposure to environmental factors which are associated with the incidence of testicular cancer appear to be more related to birth cohort than to year of diagnosis. Because testicular cancer typically occurs at an early age, major etiological factors therefore need to operate early in life, perhaps even in utero.

  11. Childhood maltreatment preceding depressive disorder at age 18 years: A prospective Brazilian birth cohort study.

    Science.gov (United States)

    Gallo, Erika Alejandra Giraldo; De Mola, Christian Loret; Wehrmeister, Fernando; Gonçalves, Helen; Kieling, Christian; Murray, Joseph

    2017-08-01

    Childhood maltreatment is linked with increased risk for mental illness in adolescence and adulthood. However, little evidence is available on whether different forms of maltreatment have specific effects, and no prospective studies in low- or middle-income countries have addressed this issue. Participants in a population-based, birth cohort study in Pelotas, Brazil (N=3715) self-reported exposure to maltreatment (emotional abuse, physical neglect, physical abuse, sexual abuse, domestic violence) in confidential questionnaires at age 15 years, and were assessed for major depression in interviews at age 18 years, using the MINI. Confounding variables concerning family characteristics were measured in interviews with mothers in the perinatal period and at age 11 years. Females exposed to emotional abuse (OR=2.7; 95%CI=1.9, 3.8) and domestic violence (OR=1.9; 95%CI=1.2, 2.9) were at increased risk for depression after adjustment for confounders and other types of maltreatment. Females exposed to two or more forms of maltreatment were at particularly high risk for depression (OR=4.1; 95%Cl=2.8, 6.1) compared with females not exposed to maltreatment. In adjusted analyses, maltreatment was not associated with depression for males. Detailed information about maltreatment such as timing and frequency was not available, and 1534 individuals were not included in the analyses, who had poorer and less educated mothers. Emotional abuse and domestic violence are strong risk factors for major depression for females. Early intervention to prevent maltreatment and its consequences is critical, especially for girls exposed to poly-maltreatment. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Cohort profile: Ho Chi Minh City Youth Cohort--changes in diet, physical activity, sedentary behaviour and relationship with overweight/obesity in adolescents.

    Science.gov (United States)

    Trang, Nguyen Hoang Hanh Doan; Hong, Tang Kim; Dibley, Michael John

    2012-01-01

    The Ho Chi Minh Youth cohort study aimed to assess the change in nutritional status; indicators of adiposity; diet; physical activity and sedentary behaviours; home, neighbourhood and school microenvironments and their complex relationships in adolescents in urban areas of Ho Chi Minh City. Prospective 5-year cohort. Systematic random sampling was used to select 18 schools in urban districts. Children were followed up over 5 years with an assessment in each year. Consent, from both adolescents and their parents, was required. At baseline, 759 students were recruited into the cohort, and of these students, 740 remained in the cohort for the first round, 712 for the second round, 630 for the third round and 585 for the last round of follow-up. Anthropometric measurements were taken using established guidelines. Six main groups of exposure factors including dietary intake and behaviours, physical activity and sedentary behaviours, family social and physical environment, school environment, socioeconomic status and parental characteristics were measured. Retention rate was high (77%). Within 5-year period, the prevalence of combined overweight and obesity using International Obesity Task Force cut-off values increased from 14.2% to 21.8%. Time spent on physical activity decreased significantly in the 5-year period from 87 to 50 min/day. Time spent on sedentary behaviours increased in the 5-year period from 512 to 600 min/day. The complete data analysis of this cohort study will allow a full exploration of the role of environmental and lifestyle behaviours on adolescent overweight and obesity and also identify the factors most strongly associated with excess weight gain and the appearance of overweight and obesity in different age groups of adolescents from this large city in Vietnam.

  13. Loneliness and the rate of motor decline in old age: the rush memory and aging project, a community-based cohort study

    Directory of Open Access Journals (Sweden)

    Arnold Steven E

    2010-10-01

    Full Text Available Abstract Background Being alone, as measured by less frequent social interactions, has been reported to be associated with a more rapid rate of motor decline in older persons. We tested the hypothesis that feeling alone is associated with the rate of motor decline in community-dwelling older persons. Methods At baseline, loneliness was assessed with a 5-item scale in 985 persons without dementia participating in the Rush Memory and Aging Project, a longitudinal community-based cohort study. Annual detailed assessment of 9 measures of muscle strength and 9 motor performances were summarized in a composite measure of global motor function. Results Linear mixed-effects models which controlled for age, sex and education, showed that the level of loneliness at baseline was associated with the rate of motor decline (Estimate, -0.016; S.E. 0.006, p = 0.005. For each 1-point higher level of loneliness at baseline, motor decline was 40% more rapid; this effect was similar to the rate of motor decline observed in an average participant 4 years older at baseline. Furthermore, this amount of motor decline per year was associated with about a 50% increased risk of death. When terms for both feeling alone (loneliness and being alone were considered together in a single model, both were relatively independent predictors of motor decline. The association between loneliness and motor decline persisted even after controlling for depressive symptoms, cognition, physical and cognitive activities, chronic conditions, as well as baseline disability or a history of stroke or Parkinson's disease. Conclusions Among community-dwelling older persons, both feeling alone and being alone are associated with more rapid motor decline, underscoring the importance of psychosocial factors and motor decline in old age.

  14. Parenting style in childhood and mortality risk at older ages: a longitudinal cohort study.

    Science.gov (United States)

    Demakakos, Panayotes; Pillas, Demetris; Marmot, Michael; Steptoe, Andrew

    2016-08-01

    Parenting style is associated with offspring health, but whether it is associated with offspring mortality at older ages remains unknown. We examined whether childhood experiences of suboptimal parenting style are associated with increased risk of death at older ages. Longitudinal cohort study of 1964 community-dwelling adults aged 65-79 years. The association between parenting style and mortality was inverse and graded. Participants in the poorest parenting style score quartile had increased risk of death (hazard ratio (HR) = 1.72, 95% CI 1.20-2.48) compared with those in the optimal parenting style score quartile after adjustment for age and gender. Full adjustment for covariates partially explained this association (HR = 1.49, 95% CI 1.02-2.18). Parenting style was inversely associated with cancer and other mortality, but not cardiovascular mortality. Maternal and paternal parenting styles were individually associated with mortality. Experiences of suboptimal parenting in childhood are associated with increased risk of death at older ages. © The Royal College of Psychiatrists 2016.

  15. Value of neuropsychological tests, neuroimaging, and biomarkers for diagnosing Alzheimer's disease in younger and older age cohorts

    NARCIS (Netherlands)

    Schmand, B.; Eikelenboom, P.; van Gool, W.A.

    2011-01-01

    OBJECTIVES: To examine the influence of age on the value of four techniques for diagnosing Alzheimer's disease (AD). DESIGN: Observational cohort study. SETTING: Alzheimer's Disease Neuroimaging Initiative. PARTICIPANTS: Individuals with mild cognitive impairment (MCI; n=179), individuals with AD

  16. A brief dietary assessment predicts executive dysfunction in an elderly cohort: results from the Einstein Aging Study

    Science.gov (United States)

    Objectives: To examine the association between diet and executive function, episodic memory and global verbal cognition in the Einstein Aging Study (EAS) cohort and determine whether race modifies this relationship. Design: Cross-sectional. Setting: Community. Participants: EAS participants without ...

  17. Using a Gradient Vector to Find Multiple Periodic Oscillations in Suspension Bridge Models

    Science.gov (United States)

    Humphreys, L. D.; McKenna, P. J.

    2005-01-01

    This paper describes how the method of steepest descent can be used to find periodic solutions of differential equations. Applications to two suspension bridge models are discussed, and the method is used to find non-obvious large-amplitude solutions.

  18. Modeled tephra ages from lake sediments, base of Redoubt Volcano, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Schiff, C J; Kaufman, D S; Wallace, K L; Werner, A; Ku, T L; Brown, T A

    2007-02-25

    A 5.6-m-long lake sediment core from Bear Lake, Alaska, located 22 km southeast of Redoubt Volcano, contains 67 tephra layers deposited over the last 8750 cal yr, comprising 15% of the total thickness of recovered sediment. Using 12 AMS {sup 14}C ages, along with the {sup 137}Cs and {sup 210}Pb activities of recent sediment, we evaluated different models to determine the age-depth relation of sediment, and to determine the age of each tephra deposit. The age model is based on a cubic smooth spline function that was passed through the adjusted tephra-free depth of each dated layer. The estimated age uncertainty of the 67 tephras averages {+-} 105 yr (1{sigma}). Tephra-fall frequency at Bear Lake was among the highest during the past 500 yr, with eight tephras deposited compared to an average of 3.7 per 500 yr over the last 8500 yr. Other periods of increased tephra fall occurred 2500-3500, 4500-5000, and 7000-7500 cal yr. Our record suggests that Bear Lake experienced extended periods (1000-2000 yr) of increased tephra fall separated by shorter periods (500-1000 yr) of apparent quiescence. The Bear Lake sediment core affords the most comprehensive tephrochronology from the base of the Redoubt Volcano to date, with an average tephra-fall frequency of once every 130 yr.

  19. Dietary Pattern Trajectories from 6 to 12 Months of Age in a Multi-Ethnic Asian Cohort.

    Science.gov (United States)

    Lim, Geraldine Huini; Toh, Jia Ying; Aris, Izzuddin M; Chia, Ai-Ru; Han, Wee Meng; Saw, Seang Mei; Godfrey, Keith M; Gluckman, Peter D; Chong, Yap-Seng; Yap, Fabian; Lee, Yung Seng; Kramer, Michael S; Chong, Mary Foong-Fong

    2016-06-15

    Little is known about the dietary patterns of Asian infants in the first year of life, nor of their associations with maternal socio-demographic factors. Based on the Growing Up in Singapore towards healthy Outcomes (GUSTO) mother-offspring cohort, cross-sectional dietary patterns were derived by factor analysis using 24-h recalls and food diaries of infants at 6-, 9- and 12-months of age. Dietary pattern trajectories were modeled by mapping similar dietary patterns across each age using multilevel mixed models. Associations with maternal socio-demographic variables, collected through questionnaires during pregnancy, were assessed using general linear models. In n = 486 infants, four dietary pattern trajectories were established from 6- to 12-months. Predominantly breastmilk: mainly breastmilk and less formula milk, rice porridge, vegetables, fruits and low-fat fish and meat, Easy-to-prepare foods: infant cereals, juices, cakes and biscuits and Noodles (in soup) and seafood: noodle and common accompaniments. In adjusted models, higher maternal education attainment was correlated with higher start scores on Predominantly breastmilk, but lowest education attainment increased its adherence over time. Older mothers had higher start scores on Easy-to-prepare foods, but younger mothers had increased adherence over time. Chinese mothers had higher start scores on Predominantly breastmilk but greater adherence to GUIDELINES over time, while Indian mothers had higher start scores on Easy-to-prepare foods but greater adherence to Predominantly breastmilk with time (p dietary patterns established during weaning are strongly influenced by maternal socio-demographic factors and remain stable over the first year of life.

  20. Prospective Relationships Between Physical Activity and Optimism in Young and Mid-aged Women.

    Science.gov (United States)

    Pavey, Toby G; Burton, Nicola W; Brown, Wendy J

    2015-07-01

    There is growing evidence that regular physical activity (PA) reduces the risk of poor mental health. Less research has focused on the relationship between PA and positive wellbeing. The study aims were to assess the prospective associations between PA and optimism, in both young and mid-aged women. 9688 young women (born 1973-1978) completed self-report surveys in 2000 (age 22 to 27), 2003, 2006, and 2009; and 11,226 mid-aged women (born 1946-1951) completed surveys in 2001 (age 50-55) 2004, 2007, and 2010, as part of the Australian Longitudinal Study on Women's Health. Generalized estimating equation models (with 3-year time lag) were used to examine the relationship between PA and optimism in both cohorts. In both cohorts, women reporting higher levels of PA had greater odds of reporting higher optimism over the 9-year period, (young, OR = 5.04, 95% CI: 3.85-6.59; mid-age, OR = 5.77, 95% CI: 4.76-7.00) than women who reported no PA. Odds were attenuated in adjusted models, with depression accounting for a large amount of this attenuation (young, OR = 2.00, 95% CI: 1.57-2.55; mid-age, OR = 1.64 95% CI: 1.38-1.94). Physical activity can promote optimism in young and mid-aged women over time, even after accounting for the negative effects of other psychosocial indicators such as depression.

  1. Time trends in heavy drinking among middle-aged and older adults in Denmark

    DEFF Research Database (Denmark)

    Bjørk, Christina; Thygesen, Lau Caspar; Vinther-Larsen, Mathilde

    2008-01-01

    BACKGROUND: Studies have indicated an increasing proportion of heavy drinking among middle-aged and older Danes. Trends in consumption are often extremely sensitive to influence from various components of the time trends but only few have explored the age, period and cohort-related influences...... that the proportion of heavy drinking women increases in younger birth cohorts. This trend is not observed for men as their drinking pattern mainly increase slightly by calendar year. CONCLUSIONS: Our Danish observations for older aged individuals correspond to the social and cultural changes in the 1960s and 1970s...

  2. Effect of women's age on embryo morphology, cleavage rate and competence-A multicenter cohort study

    DEFF Research Database (Denmark)

    Grøndahl, Marie Louise; Christiansen, Sofie Lindgren; Kesmodel, Ulrik Schiøler

    2017-01-01

    This multicenter cohort study on embryo assessment and outcome data from 11,744 IVF/ICSI cycles with 104,830 oocytes and 42,074 embryos, presents the effect of women's age on oocyte, zygote, embryo morphology and cleavage parameters, as well as cycle outcome measures corrected for confounding.......0001) with increasing age. Maternal age had no effect on cleavage parameters or on the morphology of the embryo day 2 post insemination. Interestingly, initial hCG value after single embryo transfer followed by ongoing pregnancy was increased with age in both IVF (p = 0.007) and ICSI (p = 0.001) cycles. For the first...... time, we show that a woman's age does impose a significant footprint on early embryo morphological development (3PN). In addition, the developmentally competent embryos were associated with increased initial hCG values as the age of the women increased. Further studies are needed to elucidate...

  3. Premature death of adult adoptees: analyses of a case-cohort sample.

    Science.gov (United States)

    Petersen, Liselotte; Andersen, Per Kragh; Sørensen, Thorkild I A

    2005-05-01

    Genetic and environmental influence on risk of premature death in adulthood was investigated by estimating the associations in total and cause-specific mortality of adult Danish adoptees and their biological and adoptive parents. Among all 14,425 non-familial adoptions formally granted in Denmark during the period 1924 through 1947, we selected the study population according to a case-cohort sampling design. As the case-control design, the case-cohort design has the advantage of economic data collection and little loss in statistical efficiency, but the case-cohort sample has the additional advantages that rate ratio estimates may be obtained, and re-use of the cohort sample in future studies of other outcomes is possible. Analyses were performed using Kalbfleisch and Lawless's estimator for hazard ratio, and robust estimation for variances. In the main analyses the sample was restricted to birth years of the adoptees 1924 and after, and age of transfer to the adoptive parents before 7 years, and age at death was restricted to 16 to 70 years. The results showed a higher mortality among adoptees, whose biological parents died in the age range of 16 to 70 years; this was significant for deaths from natural causes, vascular causes and all causes. No influence was seen from early death of adoptive parents, regardless of cause of death. (c) 2005 Wiley-Liss, Inc.

  4. Mortality risk attributable to smoking, hypertension and diabetes among English and Brazilian older adults (The ELSA and Bambui cohort ageing studies)

    Science.gov (United States)

    Marmot, Michael G.; Demakakos, Panayotes; Vaz de Melo Mambrini, Juliana; Peixoto, Sérgio Viana; Lima-Costa, Maria Fernanda

    2016-01-01

    Background: The main aim of this study was to quantify and compare 6-year mortality risk attributable to smoking, hypertension and diabetes among English and Brazilian older adults. This study represents a rare opportunity to approach the subject in two different social and economic contexts. Methods: Data from the data from the English Longitudinal Study of Ageing (ELSA) and the Bambuí Cohort Study of Ageing (Brazil) were used. Deaths in both cohorts were identified through mortality registers. Risk factors considered in this study were baseline smoking, hypertension and diabetes mellitus. Both age–sex adjusted hazard ratios and population attributable risks (PAR) of all-cause mortality and their 95% confidence intervals for the association between risk factors and mortality were estimated using Cox proportional hazards models. Results: Participants were 3205 English and 1382 Brazilians aged 60 years and over. First, Brazilians showed much higher absolute risk of mortality than English and this finding was consistent in all age, independently of sex. Second, as a rule, hazard ratios for mortality to smoking, hypertension and diabetes showed more similarities than differences between these two populations. Third, there was strong difference among English and Brazilians on attributable deaths to hypertension. Conclusions: The findings indicate that, despite of being in more recent transitions, the attributable deaths to one or more risk factors was twofold among Brazilians relative to the English. These findings call attention for the challenge imposed to health systems to prevent and treat non-communicable diseases, particularly in populations with low socioeconomic level. PMID:26666869

  5. Modeling the brain morphology distribution in the general aging population

    Science.gov (United States)

    Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.

    2016-03-01

    Both normal aging and neurodegenerative diseases such as Alzheimer's disease cause morphological changes of the brain. To better distinguish between normal and abnormal cases, it is necessary to model changes in brain morphology owing to normal aging. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general aging population. The method is applied to 1000 subjects from a large population imaging study in the elderly, from which 900 were used to train the model and 100 were used for testing. The results of the 100 test subjects show that the model generalizes to subjects outside the model population. Smooth percentile curves showing the brain morphology changes as a function of age and spatiotemporal atlases derived from the model population are publicly available via an interactive web application at agingbrain.bigr.nl.

  6. Association between midlife health behaviours and transitions out of employment from midlife to early old age: Whitehall II cohort study

    Directory of Open Access Journals (Sweden)

    Gareth Hagger-Johnson

    2017-01-01

    Full Text Available Abstract Background It is important to determine whether unhealthy behaviours might influence transitions out of employment from midlife to old age, given the anticipated need for adults to work for longer. Our aim was to determine the association between repeated assessments of cigarette smoking, heavy/problem alcohol drinking, low physical activity and poor diet at midlife, in relation to work exit from midlife to old age. Methods Data from 7704 participants (5392 men from the Whitehall II cohort study in employment at midlife were used to evaluate the association between unhealthy behaviours and a subsequent transition out of work during 22 years follow-up, using logistic regression models. Results Men who smoked cigarettes, consistently drank alcohol heavily, or reported problem drinking, were more likely to leave employment over follow-up. Women with a consistently poor diet were more likely to leave employment. Associations were stronger when the reason for leaving was health grounds, and stronger among those with persistently unhealthy behaviours over follow-up. The size of the effects were broadly equivalent to one advancing year of age on employment. Physical health functioning over follow-up only partly accounted for the associations with work exit, whereas physical and mental functioning accounted for most of the associations with work exit on health grounds. Conclusions Unhealthy behaviours in midlife are associated with transitions out of employment into old age. Promoting healthy behaviours at midlife might support current policy initiatives aimed at extending working life. Future research should consider possible mechanisms that link behaviours to transitions out of employment, and consider sex differences in larger cohorts.

  7. Strength and muscle quality in a well-functioning cohort of older adults : the Health, Aging and Body Composition Study

    NARCIS (Netherlands)

    Newman, Anne B; Haggerty, Catherine L; Goodpaster, Bret H; Harris, Tamara B; Kritchevsky, Steve; Nevitt, Michael; Miles, Toni P; Visser, Marjolein

    OBJECTIVES: To determine whether lower lean mass and higher fat mass have independent effects on the loss of strength and muscle quality in older adults and might explain part of the effect of age. DESIGN: Single-episode, cross-sectional analyses of a cohort of subjects in the Health, Aging and Body

  8. 47 CFR 0.489 - Applications for ship radio inspection and periodical survey.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Applications for ship radio inspection and... Taking Examinations § 0.489 Applications for ship radio inspection and periodical survey. Applications for ship radio inspection or for periodical survey shall be forwarded to the radio district office...

  9. A Multi-Period Optimization Model for Service Providers Using Online Reservation Systems: An Application to Hotels.

    Science.gov (United States)

    Xu, Ming; Jiao, Yan; Li, Xiaoming; Cao, Qingfeng; Wang, Xiaoyang

    2015-01-01

    This paper presents a multi-period optimization model for high margin and zero salvage products in online distribution channels with classifying customers based on number of products required. Taking hotel customers as an example, one is regular customers who reserve rooms for one day, and the other is long term stay (LTS) customers who reserve rooms for a number of days. LTS may guarantee a specific amount of demand and generate opportunity income for a certain number of periods, meanwhile with risk of punishment incurred by overselling. By developing an operational optimization model and exploring the effects of parameters on optimal decisions, we suggest that service providers should make decisions based on the types of customers, number of products required, and duration of multi-period to reduce the loss of reputation and obtain more profit; at the same time, multi-period buying customers should buy products early. Finally, the paper conducts a numerical experiment, and the results are consistent with prevailing situations.

  10. A Multi-Period Optimization Model for Service Providers Using Online Reservation Systems: An Application to Hotels

    Science.gov (United States)

    Xu, Ming; Jiao, Yan; Li, Xiaoming; Cao, Qingfeng; Wang, Xiaoyang

    2015-01-01

    This paper presents a multi-period optimization model for high margin and zero salvage products in online distribution channels with classifying customers based on number of products required. Taking hotel customers as an example, one is regular customers who reserve rooms for one day, and the other is long term stay (LTS) customers who reserve rooms for a number of days. LTS may guarantee a specific amount of demand and generate opportunity income for a certain number of periods, meanwhile with risk of punishment incurred by overselling. By developing an operational optimization model and exploring the effects of parameters on optimal decisions, we suggest that service providers should make decisions based on the types of customers, number of products required, and duration of multi-period to reduce the loss of reputation and obtain more profit; at the same time, multi-period buying customers should buy products early. Finally, the paper conducts a numerical experiment, and the results are consistent with prevailing situations. PMID:26147663

  11. Model selection in periodic autoregressions

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)

    1994-01-01

    textabstractThis paper focuses on the issue of period autoagressive time series models (PAR) selection in practice. One aspect of model selection is the choice for the appropriate PAR order. This can be of interest for the valuation of economic models. Further, the appropriate PAR order is important

  12. The diagnostic yield of the first episode of a periodic health evaluation: a descriptive epidemiology study

    Directory of Open Access Journals (Sweden)

    Kermott Cindy A

    2012-05-01

    Full Text Available Abstract Background The benefits of a periodic health evaluation remain debatable. The incremental value added by such evaluations beyond the delivery of age appropriate screening and preventive medicine recommendations is unclear. Methods We retrospectively collected data on a cohort of consecutive patients presenting for their first episode of a comprehensive periodic health evaluation. We abstracted data on new diagnoses that were identified during this single episode of care and that were not trivial (i.e., required additional testing or intervention. Results The cohort consisted of 491 patients. The rate of new diagnoses per this single episode of care was 0.9 diagnoses per patient. The majority of these diagnoses was not prompted by patients’ complaints (71% and would not have been identified by screening guidelines (51%. Men (odds ratio 2.67; 95% CI, 1.76, 4.03 and those with multiple complaints at presentation (odds ratio 1.12; 95% CI, 1.05, 1.19 were more likely to receive a clinically relevant diagnosis at the conclusion of the visit. Age was not a predictor of receiving a diagnosis in this cohort. Conclusion The first episode of a comprehensive periodic health evaluation may reveal numerous important diagnoses or risk factors that are not always identified through routine screening.

  13. Thyroid Cancer Incidence in New Jersey: Time Trend, Birth Cohort and Socioeconomic Status Analysis (1979-2006)

    International Nuclear Information System (INIS)

    Roche, L.M.; Niu, X.; Pawlish, K.S.; Henry, K.A.

    2011-01-01

    The study's purpose was to investigate thyroid cancer incidence time trends, birth cohort effects, and association with socioeconomic status (SES) in New Jersey (NJ), a high incidence state, using NJ State Cancer Registry data. Thyroid cancer incidence rates in each sex, nearly all age groups, two major histologists and all stages significantly increased between 1979 and 2006. For each sex, age-specific incidence rates began greatly increasing in the 1924 birth cohort and, generally, the highest thyroid cancer incidence rate for each five-year age group occurred in the latest birth cohort and diagnosis period. Thyroid cancer incidence rates were significantly higher in NJ Census tracts with higher SES and in counties with a higher percentage of insured residents. These results support further investigation into the relationship between rising thyroid cancer incidence and increasing population exposure to medical (including diagnostic) radiation, as well as widespread use of more sensitive diagnostic techniques

  14. Modeling the Impact of Uganda’s Safe Male Circumcision Program: Implications for Age and Regional Targeting

    Science.gov (United States)

    Kripke, Katharine; Vazzano, Andrea; Kirungi, William; Musinguzi, Joshua; Opio, Alex; Ssempebwa, Rhobbinah; Nakawunde, Susan; Kyobutungi, Sheila; Akao, Juliet N.; Magala, Fred; Mwidu, George; Castor, Delivette

    2016-01-01

    Background Uganda aims to provide safe male circumcision (SMC) to 80% of men ages 15–49 by 2016. To date, only 2 million men have received SMC of the 4.2 million men required. In response to age and regional trends in SMC uptake, the country sought to re-examine its targets with respect to age and subnational region, to assess the program’s progress, and to refine the implementation approach. Methods and Findings The Decision Makers’ Program Planning Tool, Version 2.0 (DMPPT 2.0), was used in conjunction with incidence projections from the Spectrum/AIDS Impact Module (AIM) to conduct this analysis. Population, births, deaths, and HIV incidence and prevalence were used to populate the model. Baseline male circumcision prevalence was derived from the 2011 AIDS Indicator Survey. Uganda can achieve the most immediate impact on HIV incidence by circumcising men ages 20–34. This group will also require the fewest circumcisions for each HIV infection averted. Focusing on men ages 10–19 will offer the greatest impact over a 15-year period, while focusing on men ages 15–34 offers the most cost-effective strategy over the same period. A regional analysis showed little variation in cost-effectiveness of scaling up SMC across eight regions. Scale-up is cost-saving in all regions. There is geographic variability in program progress, highlighting two regions with low baseline rates of circumcision where additional efforts will be needed. Conclusion Focusing SMC efforts on specific age groups and regions may help to accelerate Uganda’s SMC program progress. Policy makers in Uganda have already used model outputs in planning efforts, proposing males ages 10–34 as a priority group for SMC in the 2014 application to the Global Fund’s new funding model. As scale-up continues, the country should also consider a greater effort to expand SMC in regions with low MC prevalence. PMID:27410234

  15. Value of neuropsychological tests, neuroimaging, and biomarkers for diagnosing Alzheimer's disease in younger and older age cohorts

    NARCIS (Netherlands)

    Schmand, Ben; Eikelenboom, Piet; van Gool, Willem A.

    2011-01-01

    To examine the influence of age on the value of four techniques for diagnosing Alzheimer's disease (AD). Observational cohort study. Alzheimer's Disease Neuroimaging Initiative. Individuals with mild cognitive impairment (MCI; n = 179), individuals with AD (n = 91), and normal controls (n = 105).

  16. Teenage pregnancy and mental health beyond the postpartum period: a systematic review.

    Science.gov (United States)

    Xavier, Chloé; Benoit, Anita; Brown, Hilary K

    2018-02-08

    Teenage mothers are at increased risk for adverse social outcomes and short-term health problems, but long-term impacts on mental health are poorly understood. The aims of our systematic review were to determine the association between teenage pregnancy and mental health beyond the postpartum period, critically appraise the literature's quality and guide future research. We systematically searched MEDLINE, Embase, PsycINFO, CINAHL, Scopus and Web of Science from inception to June 2017 for peer-reviewed articles written in English or French. Data were collected using a modified Cochrane Data Extraction Form. Study quality was assessed using the Effective Public Health Practice Project critical appraisal tool. Heterogeneity of studies permitted only a qualitative synthesis. Nine quantitative studies comprising the results from analyses of 11 cohorts met our criteria and were rated as strong (n=5), moderate (n=2) or weak (n=2). Three cohorts found a statistically significant association between teenage pregnancy and poor long-term mental health after adjustment, three found a statistically significant association before but not after adjustment and five did not find a statistically significant association. Studies observed varying degrees of attenuation after considering social context. Studies with statistically significant findings tended to comprise earlier cohorts, with outcomes measured at older ages. The association between teenage pregnancy and mental health beyond the postpartum period remains unclear. Future studies should employ age-period-cohort frameworks to disentangle effects of normative patterns and stress accumulation. Social factors are important in determining long-term mental health of teenage mothers and should be prioritised in prevention and intervention strategies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly

  17. An "age"-structured model of hematopoietic stem cell organization with application to chronic myeloid leukemia.

    Science.gov (United States)

    Roeder, Ingo; Herberg, Maria; Horn, Matthias

    2009-04-01

    Previously, we have modeled hematopoietic stem cell organization by a stochastic, single cell-based approach. Applications to different experimental systems demonstrated that this model consistently explains a broad variety of in vivo and in vitro data. A major advantage of the agent-based model (ABM) is the representation of heterogeneity within the hematopoietic stem cell population. However, this advantage comes at the price of time-consuming simulations if the systems become large. One example in this respect is the modeling of disease and treatment dynamics in patients with chronic myeloid leukemia (CML), where the realistic number of individual cells to be considered exceeds 10(6). To overcome this deficiency, without losing the representation of the inherent heterogeneity of the stem cell population, we here propose to approximate the ABM by a system of partial differential equations (PDEs). The major benefit of such an approach is its independence from the size of the system. Although this mean field approach includes a number of simplifying assumptions compared to the ABM, it retains the key structure of the model including the "age"-structure of stem cells. We show that the PDE model qualitatively and quantitatively reproduces the results of the agent-based approach.

  18. Oxidative Stress-Mediated Aging during the Fetal and Perinatal Periods

    Directory of Open Access Journals (Sweden)

    Lucia Marseglia

    2014-01-01

    Full Text Available Oxidative stress is worldwide recognized as a fundamental component of the aging, a process that begins before birth. There is a critical balance between free radical generation and antioxidant defenses. Oxidative stress is caused by an imbalance between the production of free radicals and the ability of antioxidant system to detoxify them. Oxidative stress can occur early in pregnancy and continue in the postnatal period; this damage is implicated in the pathophysiology of pregnancy-related disorders, including recurrent pregnancy loss, preeclampsia and preterm premature rupture of membranes. Moreover, diseases of the neonatal period such as bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and periventricular leukomalacia are related to free radical damage. The specific contribution of oxidative stress to the pathogenesis and progression of these neonatal diseases is only partially understood. This review summarizes what is known about the role of oxidative stress in pregnancy and in the pathogenesis of common disorders of the newborn, as a component of the early aging process.

  19. U-ages in soils and groundwater evidencing wet periods 400-600 kyr ago in southeast Brazil

    International Nuclear Information System (INIS)

    Bonotto, D.M.; Jimenez-Rueda, J.R.

    2007-01-01

    238 U and its radiogenic daughter 234 U have been utilized for dating soil formation and groundwater residence time during the last 1.5 million years, in this case based on the U-dissolution/precipitation occurring during modifications of the oxidation-reduction conditions. In this paper, we report a 400-600 kyr proxy of wet periods from sediments occurring in a soil profile developed over rocks outcropping at the Parana sedimentary basin in Brazil, and from groundwater exploited of Guarani aquifer at the same basin. The approaches indicated successful use of the U-modeled ages for suggesting wet periods exceeding the past 116-210 kyr from previous studies

  20. Personality traits in old age: measurement and rank-order stability and some mean-level change.

    Science.gov (United States)

    Mõttus, René; Johnson, Wendy; Deary, Ian J

    2012-03-01

    Lothian Birth Cohorts, 1936 and 1921 were used to study the longitudinal comparability of Five-Factor Model (McCrae & John, 1992) personality traits from ages 69 to 72 years and from ages 81 to 87 years, and cross-cohort comparability between ages 69 and 81 years. Personality was measured using the 50-item International Personality Item Pool (Goldberg, 1999). Satisfactory measurement invariance was established across time and cohorts. High rank-order stability was observed in both cohorts. Almost no mean-level change was observed in the younger cohort, whereas Extraversion, Agreeableness, Conscientiousness, and Intellect declined significantly in the older cohort. The older cohort scored higher on Agreeableness and Conscientiousness. In these cohorts, individual differences in personality traits continued to be stable even in very old age, mean-level changes accelerated.

  1. Cohort Profile : LifeLines, a three-generation cohort study and biobank

    NARCIS (Netherlands)

    Scholtens, Salome; Smidt, Nynke; Swertz, Morris A.; Bakker, Stephan J. L.; Dotinga, Aafje; Vonk, Judith M.; van Dijk, Freerk; van Zon, Sander K. R.; Wijmenga, Cisca; Wolffenbuttel, Bruce H. R.; Stolk, Ronald P.

    The LifeLines Cohort Study is a large population-based cohort study and biobank that was established as a resource for research on complex interactions between environmental, phenotypic and genomic factors in the development of chronic diseases and healthy ageing. Between 2006 and 2013, inhabitants

  2. Groundwater flow modelling of periods with periglacial and glacial climate conditions - Forsmark

    International Nuclear Information System (INIS)

    Vidstrand, Patrik; Follin, Sven; Zugec, Nada

    2010-12-01

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The groundwater flow modelling study reported here comprises a coupled thermal-hydraulic-chemical (T-H-C) analysis of periods with periglacial and glacial climate conditions. Hydraulic-mechanical (H-M) issues are also handled but no coupled flow modelling is done. The objective of the report is to provide bounding hydrogeological estimates at different stages during glaciation and deglaciation of a glacial cycle for subsequent use in safety assessment applications within SKB's project SR-Site. Three cases with different climate conditions are analysed here: (i) Temperate case, (ii) Glacial case without permafrost, and (iii) Glacial case with permafrost. The glacial periods are transient and encompass approximately 19,000 years. The simulation results comprise residual fluid pressures, Darcy fluxes, and water salinities, as well as advective transport performance measures obtained by particle tracking such as flow path lengths, travel times and flow-related transport resistances. The modelling is accompanied by a sensitivity study that addresses the impact of the following matters: the direction of the ice sheet advance, the speed of the ice sheet margin, the bedrock hydraulic and transport properties, the temperature at the ice-subsurface interface close to the ice sheet margin, and the initial hydrochemical conditions

  3. Groundwater flow modelling of periods with periglacial and glacial climate conditions - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik (TerraSolve AB, Floda (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden)); Zugec, Nada (Bergab, Stockholm (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The groundwater flow modelling study reported here comprises a coupled thermal-hydraulic-chemical (T-H-C) analysis of periods with periglacial and glacial climate conditions. Hydraulic-mechanical (H-M) issues are also handled but no coupled flow modelling is done. The objective of the report is to provide bounding hydrogeological estimates at different stages during glaciation and deglaciation of a glacial cycle for subsequent use in safety assessment applications within SKB's project SR-Site. Three cases with different climate conditions are analysed here: (i) Temperate case, (ii) Glacial case without permafrost, and (iii) Glacial case with permafrost. The glacial periods are transient and encompass approximately 19,000 years. The simulation results comprise residual fluid pressures, Darcy fluxes, and water salinities, as well as advective transport performance measures obtained by particle tracking such as flow path lengths, travel times and flow-related transport resistances. The modelling is accompanied by a sensitivity study that addresses the impact of the following matters: the direction of the ice sheet advance, the speed of the ice sheet margin, the bedrock hydraulic and transport properties, the temperature at the ice-subsurface interface close to the ice sheet margin, and the initial hydrochemical conditions.

  4. Convergence dynamics and pseudo almost periodicity of a class of nonautonomous RFDEs with applications

    Science.gov (United States)

    Fan, Meng; Ye, Dan

    2005-09-01

    This paper studies the dynamics of a system of retarded functional differential equations (i.e., RF=Es), which generalize the Hopfield neural network models, the bidirectional associative memory neural networks, the hybrid network models of the cellular neural network type, and some population growth model. Sufficient criteria are established for the globally exponential stability and the existence and uniqueness of pseudo almost periodic solution. The approaches are based on constructing suitable Lyapunov functionals and the well-known Banach contraction mapping principle. The paper ends with some applications of the main results to some neural network models and population growth models and numerical simulations.

  5. Effective mechanical means of uterine cervix accelerating maturity in pregnant women of first mature age period of different somatotypes

    Directory of Open Access Journals (Sweden)

    Yakovleva О.V.

    2013-03-01

    Full Text Available The purpose is to evaluate the effectiveness of stimulation of delivery in first mature age period of pregnant women mechanically in different somatotypes. Materials and Methods: 658 patients at 38-41 weeks of gestation of the first period of mature age (22-35 years have been considered. Differentiation by somatotypes has been performed by the method of HT Kaarma (1991. All patients of each somatotype have been divided into primiparous (n = 402 and multiparous (n = 256. Preparation for delivery by mechanical means: on the 1 st day it was introduced into the cervical canal for 16 hours, on the 2nd day — Foley catheter for 8-16 hours (before the birth. Results: In multiparous women the application of mechanical preparation of the birth canal has been effective regardless of somatotype. The percentage of operative delivery in mechanical induction has been lower in multiparous women and also not related to somatotype. In nulliparous women of asthenic and normosthenic type greater efficiency of mechanical induction in preparation for delivery has been revealed. In asthenic and pyknictype mechanical induction has been inefficient and therefore has not been recommended for the use. Conclusion: Application of mechanical means of stimulation of delivery in nulliparous pregnant women should be performed according to their somatotype.

  6. [Application of cohort study in cancer prevention and control].

    Science.gov (United States)

    Dai, Min; Bai, Yana; Pu, Hongquan; Cheng, Ning; Li, Haiyan; He, Jie

    2016-03-01

    Cancer control is a long-term work. Cancer research and intervention really need the support of cohort study. In the recent years, more and more cohort studies on cancer control were conducted in China along with the increased ability of scientific research in China. Since 2010, Cancer Hospital, Chinese Academy of Medical Sciences, collaborated with Lanzhou University and the Worker' s Hospital of Jinchuan Group Company Limited, have carried out a large-scale cohort study on cancer, which covered a population of more than 50 000 called " Jinchang cohort". Since 2012, a National Key Public Health Project, "cancer screening in urban China" , has been conducted in Jinchang, which strengthened the Jinchang cohort study. Based on the Jinchang cohort study, historical cohort study, cross-sectional study and prospective cohort study have been conducted, which would provide a lot of evidence for the cancer control in China.

  7. Mixture models for undiagnosed prevalent disease and interval-censored incident disease: applications to a cohort assembled from electronic health records.

    Science.gov (United States)

    Cheung, Li C; Pan, Qing; Hyun, Noorie; Schiffman, Mark; Fetterman, Barbara; Castle, Philip E; Lorey, Thomas; Katki, Hormuzd A

    2017-09-30

    For cost-effectiveness and efficiency, many large-scale general-purpose cohort studies are being assembled within large health-care providers who use electronic health records. Two key features of such data are that incident disease is interval-censored between irregular visits and there can be pre-existing (prevalent) disease. Because prevalent disease is not always immediately diagnosed, some disease diagnosed at later visits are actually undiagnosed prevalent disease. We consider prevalent disease as a point mass at time zero for clinical applications where there is no interest in time of prevalent disease onset. We demonstrate that the naive Kaplan-Meier cumulative risk estimator underestimates risks at early time points and overestimates later risks. We propose a general family of mixture models for undiagnosed prevalent disease and interval-censored incident disease that we call prevalence-incidence models. Parameters for parametric prevalence-incidence models, such as the logistic regression and Weibull survival (logistic-Weibull) model, are estimated by direct likelihood maximization or by EM algorithm. Non-parametric methods are proposed to calculate cumulative risks for cases without covariates. We compare naive Kaplan-Meier, logistic-Weibull, and non-parametric estimates of cumulative risk in the cervical cancer screening program at Kaiser Permanente Northern California. Kaplan-Meier provided poor estimates while the logistic-Weibull model was a close fit to the non-parametric. Our findings support our use of logistic-Weibull models to develop the risk estimates that underlie current US risk-based cervical cancer screening guidelines. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  8. Development of a bioenergetics model for age-0 American Shad

    Science.gov (United States)

    Sauter, Sally T.

    2011-01-01

    predatory fishes encountered in the lower Columbia River (Petersen and Ward 1999). The Wisconsin bioenergetics model has not been developed for American shad, however Limburg (1996) parameterized a simplified bioenergetics growth model for this species. A common application for the Wisconsin bioenergetics model is to estimate the consumption or growth of a fish population under different temperature and feeding scenarios (Ney 1993). One advantage of the bioenergetics approach is that consumption can be estimated without direct field measurements of predation rate (prey·predator-1· day-1; Petersen and Ward 1999). Field estimates of fish consumption are time consuming and costly to determine, and estimates may show wide variance due to environmental and sampling variability. However, the consumption parameters used in a newly developed bioenergetics model must be verified with field and laboratory estimates of consumption (Ney 1993). The objective of this research was to parameterize a Wisconsin bioenergetics model for age-0 American shad using published physiological data on American shad and closely related alosine species. The American shad bioenergetics model will be used as a tool to explore various hypotheses about how age-0 American shad directly and indirectly affect Columbia River salmon through ecological interactions in lower Columbia River food webs. One over-arching focus of the larger research project was to identify potential interactions between age-0 American shad and juvenile salmonids, addressing potential outcomes through bioenergetics modeling scenarios. This report contains two bioenergetics modeling applications to demonstrate how these models can be used to address management questions and direct research effort. The first modeling application uses the American shad bioenergetics model described in this report to explore prey consumption by age-0 American shad (Chapter 1, this report). Dietary data on age-0 American shad and previously published

  9. The associations of parity and maternal age with small-for-gestational-age, preterm, and neonatal and infant mortality: a meta-analysis

    Science.gov (United States)

    2013-01-01

    Background Previous studies have reported on adverse neonatal outcomes associated with parity and maternal age. Many of these studies have relied on cross-sectional data, from which drawing causal inference is complex. We explore the associations between parity/maternal age and adverse neonatal outcomes using data from cohort studies conducted in low- and middle-income countries (LMIC). Methods Data from 14 cohort studies were included. Parity (nulliparous, parity 1-2, parity ≥3) and maternal age (gestational-age (SGA), preterm, neonatal and infant mortality. Adjusted odds ratios (aOR) were calculated per study and meta-analyzed. Results Nulliparous, age mothers, suggesting that reproductive health interventions need to address the entirety of a woman’s reproductive period. Funding Funding was provided by the Bill & Melinda Gates Foundation (810-2054) by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group. PMID:24564800

  10. Cigarette smoking and the risk of adult leukemia: results from the Three Mile Island cohort study.

    Science.gov (United States)

    Xu, Xiaohui; Talbott, Evelyn O; Zborowski, Jeanne V; Rager, Judith R

    2007-01-01

    Smoking is an unconfirmed risk factor for the development of leukemia. The authors examined the potential link using data from the Three Mile Island cohort for the period 1979-1995. Eligible for analysis were 24,539 individuals aged 14 years or older who were followed up over 16 years from the Three Mile Island cohort. The authors identified all incident leukemia cases through the Pennsylvania Department of Health Cancer Registry. They used the Cox proportional hazards model to evaluate the relationships and observed 42 incident leukemia cases, including 15 acute myeloid leukemia (AML) cases, in the cohort. After controlling for other confounding factors, the authors found current smoking to be associated with an increased risk of adult AML (relative risk = 3.47; 95% confidence interval = 1.002-11.99). The authors also observed a marginally significant linear trend of risk of AML associated with the number of years smoked (p = .06). The results from this study suggested that cigarette smoking was associated with an increased risk of adult AML. Further investigation is required to confirm these findings.

  11. Developmental outcome at 18 and 24 months of age in very preterm children: a cohort study from 1996 to 1997

    NARCIS (Netherlands)

    Stoelhorst, Gerlinde M. S. J.; Rijken, Monique; Martens, Shirley E.; van Zwieten, Paul H. T.; Feenstra, J.; Zwinderman, Aeilko H.; Wit, Jan Maarten; Veen, Sylvia

    2003-01-01

    Objective: To determine the effect of prematurity (gestational age (GA) <32 weeks) on developmental outcome at the corrected age of 18 and 24 months in a regionally defined, prospective cohort study. Study design: The Leiden Follow-Up Project on Prematurity (LFUPP) includes all liveborn infants <32

  12. Childhood psychological distress and youth unemployment: evidence from two British cohort studies.

    Science.gov (United States)

    Egan, Mark; Daly, Michael; Delaney, Liam

    2015-01-01

    The effect of childhood mental health on later unemployment has not yet been established. In this article we assess whether childhood psychological distress places young people at high risk of subsequent unemployment and whether the presence of economic recession strengthens this relationship. This study was based on 19,217 individuals drawn from two nationally-representative British prospective cohort studies; the Longitudinal Study of Young People in England (LSYPE) and the National Child Development Study (NCDS). Both cohorts contain rich contemporaneous information detailing the participants' early life socioeconomic background, household characteristics, and physical health. In adjusted analyses in the LSYPE sample (N = 10,232) those who reported high levels of distress at age 14 were 2 percentage points more likely than those with low distress to be unemployed between ages 16 and 21. In adjusted analyses of the NCDS sample (N = 8985) children rated as having high distress levels by their teachers at age 7 and 11 were 3 percentage points more likely than those with low distress to be unemployed between ages 16 and 23. Our examination of the 1980 UK recession in the NCDS cohort found the difference in average unemployment level between those with high versus low distress rose from 2.6 pct points in the pre-recession period to 3.9 points in the post-recession period. These findings point to a previously neglected contribution of childhood mental health to youth unemployment, which may be particularly pronounced during times of economic recession. Our findings also suggest a further economic benefit to enhancing the provision of mental health services early in life. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Use of atomoxetine and suicidal ideation in children and adolescents: Results of an observational cohort study within general practice in England.

    Science.gov (United States)

    Davies, M; Coughtrie, A; Layton, D; Shakir, S A S

    2017-01-01

    To investigate the association between atomoxetine, a drug used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), and suicidal ideation, within a cohort of 2-18-year-old patients in England. The study was conducted using the observational cohort technique of Modified prescription event monitoring (M-PEM). Patients prescribed atomoxetine were identified from dispensed prescriptions issued by primary care physicians. A customised postal GP questionnaire was used to capture outcome data for suicidal ideation. A matched pair cohort analysis was performed within patients to compare the risk of suicidal ideation in the period after starting atomoxetine with the risk prior to starting atomoxetine; this was stratified by age and concomitant use of methylphenidate. Additional information on patient characteristics, and events of interest was also collected; individual cases of suicidal ideation were qualitatively assessed for drug relatedness. Of the final cohort (n=4509); 85.5% male (n=3857), median age 11 years (IQR: 9,14). Primary prescribing indication for atomoxetine was ADHD (n=4261, 94.6%). Almost a quarter of the cohort had been co-prescribed methylphenidate. Results of the matched pair cohort analysis indicated that the period after starting atomoxetine was not associated with an increase in the incidence of suicidal ideation compared to the period prior to starting treatment (RR: 0.71; CI: 0.48-1.07; P-value: 0.104). Individual case assessment of suicidal ideation suggested a causal association within a number of cases. This study found no evidence of an increased risk of suicidal ideation during treatment with atomoxetine, compared to the period prior to starting treatment. Amongst age specific subgroups, this risk may change. Nonetheless, individual case assessment suggested a causal relationship in some patients, hence physicians need to be aware of the possibility of developing this event, and furthermore consider how best to detect it in

  14. A probit- log- skew-normal mixture model for repeated measures data with excess zeros, with application to a cohort study of paediatric respiratory symptoms

    Directory of Open Access Journals (Sweden)

    Johnston Neil W

    2010-06-01

    Full Text Available Abstract Background A zero-inflated continuous outcome is characterized by occurrence of "excess" zeros that more than a single distribution can explain, with the positive observations forming a skewed distribution. Mixture models are employed for regression analysis of zero-inflated data. Moreover, for repeated measures zero-inflated data the clustering structure should also be modeled for an adequate analysis. Methods Diary of Asthma and Viral Infections Study (DAVIS was a one year (2004 cohort study conducted at McMaster University to monitor viral infection and respiratory symptoms in children aged 5-11 years with and without asthma. Respiratory symptoms were recorded daily using either an Internet or paper-based diary. Changes in symptoms were assessed by study staff and led to collection of nasal fluid specimens for virological testing. The study objectives included investigating the response of respiratory symptoms to respiratory viral infection in children with and without asthma over a one year period. Due to sparse data daily respiratory symptom scores were aggregated into weekly average scores. More than 70% of the weekly average scores were zero, with the positive scores forming a skewed distribution. We propose a random effects probit/log-skew-normal mixture model to analyze the DAVIS data. The model parameters were estimated using a maximum marginal likelihood approach. A simulation study was conducted to assess the performance of the proposed mixture model if the underlying distribution of the positive response is different from log-skew normal. Results Viral infection status was highly significant in both probit and log-skew normal model components respectively. The probability of being symptom free was much lower for the week a child was viral positive relative to the week she/he was viral negative. The severity of the symptoms was also greater for the week a child was viral positive. The probability of being symptom free was

  15. Impact of weight change after quitting cigarettes on all-cause and cause-specific mortality in middle-aged male smokers: national health screening cohort study

    OpenAIRE

    Kyuwoong Kim; Seulggie Choi; Mi Hee Cho; Ji Hye Jun; Jooyoung Chang; Sung Min Kim; Kiheon Lee; Sang Min Park

    2018-01-01

    Background We aimed to investigate the association between weight change after smoking cessation and the risk of all-cause and cause-specific mortality among middle-aged male smokers. Methods We conducted a prospective cohort study using the National Health Insurance Service National Health Screening Cohort (NHIS-HealS) database. Male Participants (n=102,403) without critical conditions aged between 40 and 79 at baseline who underwent biennial health examination ...

  16. The influence of age on the exploitation period in broiler ...

    African Journals Online (AJOL)

    These investigations were intended to identify the influence of parental flock age at heavy hybrid Ross 308 (usage period) on more important reproductive capabilities (carrying eggs intensity of brood eggs, egg mass, one day old chick mass, relative chick mass share in complete egg mass) and consumption of food per ...

  17. Age peculiarities of reproductive morbidity in female participants of the ChNPP accident consequences clean-up (according to the figures from SRU, 1988-2012 survey period)

    International Nuclear Information System (INIS)

    Majevs'ka, Yo.O.; Buzunov, V.O.

    2015-01-01

    Data on the Chernobyl disaster survivors received from the State Registry of Ukraine are out line in the paper. Review of the level and pattern of genital system morbidity was carried out for the 17,237 female participants of the ChNPP accident cleanup works in 1986-1987 depending on time under risk upon radiation expo sure and reproductive age at exposure. Survey period lasted since 1988 till 2012. Assessment of morbidity level, confidential intervals, and statistical significance was carried out using the trial version of OpenEpiversion 2.3.1. software. Statistical significance was also rated using the z-score and t- criterion. The results of this cohort epidemiological study showed that there are some peculiarities of natural course of the female genital system disease depending on reproductive age at exposure and time under risk upon radiation impact. Comparative statistical review of the level and pattern of genital system morbidity at different times within a survey period. Exposure to ionizing radiation in the childbearing age (18-45 years old) can be a risk factor of elevated incidence of uterine leiomyoma, benign mammary dysplasia (i.e. benign breast disease), and salpingooophoritis. It is far to assume that uterine and mammary tissues are more sensitive to impact of ionizing radiation in females of the childbearing age vs. in persons exposed in premenopause or menopause

  18. Local Stability Analysis of an Infection-Age Mathematical Model for ...

    African Journals Online (AJOL)

    Timothy

    1Department of Mathematics/Statistics/Computer Science, Federal University of Agriculture, Makurdi, ... ABSTRACT: An infection age structured mathematical model for tuberculosis disease ...... its applications to optimal vaccination strategies.

  19. Impact of gestational weight gain and prepregnancy body mass index on the prevalence of large-for-gestational age infants in two cohorts of women with type 1 insulin-dependent diabetes: a cross-sectional population study

    Science.gov (United States)

    Bowers, Katherine; Dolan, Lawrence M; Deka, Ranjan; Jackson, Chandra L; Khoury, Jane C

    2018-01-01

    Objectives Despite improvements in treatment modalities, large-for-gestational age (LGA) prevalence has remained between 30% and 40% among infants of mothers with type 1 insulin-dependent diabetes mellitus (TIDM). Our objective was to estimate LGA prevalence and examine the association between gestational weight gain (GWG) and prepregnancy body mass index (BMI) with LGA among mothers with TIDM. Design Cross-sectional study. Setting Regional data in Cincinnati, Ohio, from the Diabetes in Pregnancy Program Project (PPG), a prospective cohort for the period 1978–1993; national data from Consortium on Safe Labor (CSL), a multicentre cross-sectional study for the period 2002–2008. Participants The study included 333 pregnancies in the PPG and 358 pregnancies in the CSL. Pregnancies delivered prior to 23 weeks’ gestation were excluded. Women with TIDM in the PPG were identified according to physician confirmation of ketoacidosis, and/or c-peptide levels, and by International Classification of Diseases, ninth version codes within the CSL. LGA was identified as birth weight >90th percentile according to gestational age, race and sex. Main outcome measures LGA at birth. Results Mean±SD maternal age at delivery was 26.4±5.1 years for PPG women and 27.5±6.0 years for CSL women, p=0.008. LGA prevalence did not significantly differ between cohorts (PPG: 40.2% vs CSL: 36.6%, p=0.32). More women began pregnancy as overweight in the later cohort (PPG (16.8%) vs CSL (27.1%), pIOM) guidelines was higher in the later CSL (56.2%) vs PPG (42.3%) cohort, pIOM guidelines had a lower LGA prevalence in CSL (PPG: 30.6% vs CSL: 13.7%), p=0.001. Conclusions Normal-weight women with GWG within IOM guidelines experienced a lower LGA prevalence, supporting the importance of adherence to IOM guidelines for GWG to reduce LGA. High BMI and GWG may be hindering a reduction in LGA prevalence. PMID:29602844

  20. Frailty, HIV infection, and mortality in an aging cohort of injection drug users.

    Directory of Open Access Journals (Sweden)

    Damani A Piggott

    Full Text Available Frailty is associated with morbidity and premature mortality among elderly HIV-uninfected adults, but the determinants and consequences of frailty in HIV-infected populations remain unclear. We evaluated the correlates of frailty, and the impact of frailty on mortality in a cohort of aging injection drug users (IDUs.Frailty was assessed using standard criteria among HIV-infected and uninfected IDUs in 6-month intervals from 2005 to 2008. Generalized linear mixed-model analyses assessed correlates of frailty. Cox proportional hazards models estimated risk for all-cause mortality.Of 1230 participants at baseline, the median age was 48 years and 29% were HIV-infected; the frailty prevalence was 12.3%. In multivariable analysis of 3,365 frailty measures, HIV-infected IDUs had an increased likelihood of frailty (OR, 1.66; 95% CI, 1.24-2.21 compared to HIV-uninfected IDUs; the association was strongest (OR, 2.37; 95% CI, 1.62-3.48 among HIV-infected IDUs with advanced HIV disease (CD4<350 cells/mm3 and detectable HIV RNA. No significant association was seen with less advanced disease. Sociodemographic factors, comorbidity, depressive symptoms, and prescription drug abuse were also independently associated with frailty. Mortality risk was increased with frailty alone (HR 2.63, 95% CI, 1.23-5.66, HIV infection alone (HR 3.29, 95% CI, 1.85-5.88, and being both HIV-infected and frail (HR, 7.06; 95%CI 3.49-14.3.Frailty was strongly associated with advanced HIV disease, but IDUs with well-controlled HIV had a similar prevalence to HIV-uninfected IDUs. Frailty was independently associated with mortality, with a marked increase in mortality risk for IDUs with both frailty and HIV infection.

  1. Disparities of time trends and birth cohort effects on invasive breast cancer incidence in Shanghai and Hong Kong pre- and post-menopausal women.

    Science.gov (United States)

    Wang, Feng; Tse, Lap Ah; Chan, Wing-Cheong; Kwok, Carol Chi-Hei; Leung, Siu-Lan; Wu, Cherry; Mang, Oscar Wai-Kong; Ngan, Roger Kai-Cheong; Li, Mengjie; Yu, Wai-Cho; Tsang, Koon-Ho; Law, Sze-Hong; Miao, Xiaoping; Wu, Chunxiao; Zheng, Ying; Wu, Fan; Yang, Xiaohong R; Yu, Ignatius Tak-Sun

    2017-05-23

    Breast cancer is the leading cause of cancer morbidity among Shanghai and Hong Kong women, which contributes to 20-25% of new female cancer incidents. This study aimed to describe the temporal trend of breast cancer and interpret the potential effects on the observed secular trends. Cancer incident data were obtained from the cancer registries. Age-standardized incidence rate was computed by the direct method using the World population of 2000. Average annual percentage change (AAPC) in incidence rate was estimated by the Joinpoint regression. Age, period and cohort effects were assessed by using a log-linear model with Poisson regression. During 1976-2009, an increasing trend of breast cancer incidence was observed, with an AAPC of 1.73 [95% confidence interval (CI): 1.54-1.92)] for women in Hong Kong and 2.83 (95% CI, 2.26-3.40) in Shanghai. Greater upward trends were revealed in Shanghai women aged 50 years old or above (AAPC = 3.09; 95% CI, 1.48-4.73). Using age at 50 years old as cut-point, strong birth cohort effects were shown in both pre- and post-menopausal women, though a more remarkable effect was suggested in Shanghai post-menopausal women. No evidence for a period effect was indicated. Incidence rate of breast cancer has been more speedy in Shanghai post-menopausal women than that of the Hong Kong women over the past 30 years. Decreased birth rate and increasing environmental exposures (e.g., light-at-night) over successive generations may have constituted major impacts on the birth cohort effects, especially for the post-menopausal breast cancer; further analytic studies are warranted.

  2. Fragile DNA Repair Mechanism Reduces Ageing in Multicellular Model

    DEFF Research Database (Denmark)

    Bendtsen, Kristian Moss; Juul, Jeppe Søgaard; Trusina, Ala

    2012-01-01

    increases the amount of unrepaired DNA damage. Despite this vicious circle, we ask, can cells maintain a high DNA repair capacity for some time or is repair capacity bound to continuously decline with age? We here present a simple mathematical model for ageing in multicellular systems where cells subjected...... to DNA damage can undergo full repair, go apoptotic, or accumulate mutations thus reducing DNA repair capacity. Our model predicts that at the tissue level repair rate does not continuously decline with age, but instead has a characteristic extended period of high and non-declining DNA repair capacity......DNA damages, as well as mutations, increase with age. It is believed that these result from increased genotoxic stress and decreased capacity for DNA repair. The two causes are not independent, DNA damage can, for example, through mutations, compromise the capacity for DNA repair, which in turn...

  3. Decreasing Sports Activity with Increasing Age? Findings from a 20-Year Longitudinal and Cohort Sequence Analysis

    Science.gov (United States)

    Breuer, Christoph; Wicker, Pamela

    2009-01-01

    According to cross-sectional studies in sport science literature, decreasing sports activity with increasing age is generally assumed. In this paper, the validity of this assumption is checked by applying more effective methods of analysis, such as longitudinal and cohort sequence analyses. With the help of 20 years' worth of data records from the…

  4. Are incident gallstones associated to sex-dependent changes with age? A cohort study

    DEFF Research Database (Denmark)

    Shabanzadeh, D M; Holmboe, S A; Sørensen, L T

    2017-01-01

    Age and female sex have repeatedly been identified as gallstone determinants but the underlying mechanisms are not clarified. The objectives of this study were to determine if changes with age in physiology, lifestyle, or reproductive hormones were associated with incident gallstones. A cohort...... pressure, blood lipids, self-rated health), lifestyle (smoking, alcohol and coffee consumption, dietary habits, physical activity level), and indices of reproductive function (number of births, oral contraceptive use, hormone replacement therapy, male reproductive hormones) were explored in females...... (OR) 0.94, 95% confidence interval (CI) [0.90; 0.98]) and the cessation of hormone replacement therapy (OR 0.29, 95% CI [0.10; 0.83]) inversely determined incident gallstones. In males, increasing levels of SHBG (OR 0.97, 95% CI [0.94; 0.998]) inversely determined incident gallstones. Other changes...

  5. Age dependencies in the modelling of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Kellerer, A.M.; GSF, Neuherberg; Barclay, D.

    1992-01-01

    Models for the dose and age dependence of radiation induced cancer have been based primarily on the follow-up of the atomic bomb survivors. Two different concepts have been deduced for leukaemias and for other cancers. The excess leukaemias appear in a distinct temporal wave with a maximum 5 to 10 years after radiation exposure; the distribution is more narrow for younger ages, but there is little dependence of the total attributable risk on age at exposure. For other cancers the latent periods are longer and, according to the current interpretation, the excess rates are then proportional to the age specific spontaneous rates, so that most excess cases would arise at old age. The factors of proportionality, and thus the attributable risks, are assumed to be markedly higher for young ages at exposure. It is argued here, that there is no firm support for this interpretation. (author)

  6. Parenting style in childhood and mortality risk at old age: a longitudinal cohort study

    Science.gov (United States)

    Demakakos, Panayotes; Pillas, Demetris; Marmot, Michael; Steptoe, Andrew

    2018-01-01

    Background Parenting style is associated with offspring health, but whether it is associated with offspring mortality at older ages remains unknown. Aims We examined whether childhood experiences of suboptimal parenting style are associated with increased risk of death at older ages. Method Longitudinal cohort study of 1,964 community-dwelling adults aged 65 to 79 years. Results The association between parenting style and mortality was inverse and graded. Participants in the poorest parenting style score quartile had increased risk of death (hazard ratio (HR) 1.72; 95% CI, 1.20-2.48) compared with those in the optimal parenting style score quartile after adjustment for age and sex. Full adjustment for covariates partially explained this association (HR 1.49; 95% CI, 1.02-2.18). Parenting style was inversely associated with cancer and other mortality, but not cardiovascular mortality. Maternal and paternal parenting styles were individually associated with mortality. Conclusions Experiences of suboptimal parenting in childhood are associated with increased risk of death at older ages. PMID:26941265

  7. Longitudinal associations between social relationships at age 30 and internalising symptoms at age 42: findings from the Northern Swedish Cohort.

    Science.gov (United States)

    Landstedt, Evelina; Gustafsson, Per E; Johansson, Klara; Hammarström, Anne

    2016-01-01

    Little is known on long-term consequences of poor social relationships in adulthood. The study aimed to examine associations between social relationships at age 30 and internalising symptoms at age 42. Data was drawn from four waves of the Northern Swedish cohort (n = 1001, 94 % response rate). The outcome internalising symptoms was measured by a composite index of depressiveness and anxiety. A cumulative measure was constructed to reflect various aspects of social relationships. Multivariate ordinal logistic regressions were used, controlling for socioeconomic indicators and previous level of internalising symptoms. An accumulation of poor social relationships indicators at age 30 is related to internalising symptoms at age 42 in women (OR 1.30; CI 1.11-1.52) and men (OR 1.17; CI 1.02-1.36). The associations remained significant after adjustment for covariates. Poor quality of social relationships at age 30 can predict internalising symptoms 12 years later in both men and women even when previous mental health as well as financial disadvantage is accounted for. More research is required to further examine pathways and mechanisms as well as suitable interventions.

  8. Gestational age and adolescent mental health: evidence from Hong Kong's 'Children of 1997' birth cohort.

    Science.gov (United States)

    Wang, Hui; Leung, Gabriel M; Lam, H S; Schooling, C Mary

    2015-09-01

    Preterm, and more recently early term, birth has been identified as a risk factor for poor health. Whether the sequelae of late preterm or early term birth extends to poor mental health and well-being in adolescence is unclear and has not been systematically assessed. Linear regression was used to assess the adjusted associations of gestational age (very/moderate preterm (self-reported self-esteem at ∼11 years (n=6935), parent-reported Rutter score assessing the common emotional and behavioural problems at ∼7 years (n=6292) and ∼11 years (n=5596) and self-reported depressive symptoms at ∼13 years (n=5795) in a population-representative Hong Kong Chinese birth cohort 'Children of 1997' where gestational age has little social patterning. Very/moderate preterm birth was associated with higher Rutter subscore for hyperactivity (ß coefficients 0.5, 95% CI 0.01 to 1.00) at ∼7 years but not at ∼11 years, adjusted for sex, age, socio-economic position, parents' age at birth, birth order and secondhand smoke exposure. Similarly adjusted, late preterm, early term, late term and post-term birth were not associated with self-esteem or depressive symptoms. In a population-representative birth cohort from a non-Western-developed setting, gestational age had few associations with mental health and well-being in adolescence, whereas very preterm birth was specifically associated with hyperactivity in childhood. Inconsistencies with studies from Western settings suggest setting specific unmeasured confounding may underlie any observed associations. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Specific infant feeding practices do not consistently explain variation in anthropometry at age 1 year in urban United States, Mexico, and China cohorts.

    Science.gov (United States)

    Woo, Jessica G; Guerrero, M Lourdes; Ruiz-Palacios, Guillermo M; Peng, Yong-mei; Herbers, Patricia M; Yao, Wen; Ortega, Hilda; Davidson, Barbara S; McMahon, Robert J; Morrow, Ardythe L

    2013-02-01

    Infant feeding practices generally influence infant growth, but it is unclear how introduction of specific foods affects growth across global populations. We studied 3 urban populations in the Global Exploration of Human Milk study to determine the association between infant feeding and anthropometry at 1 y of age. Three hundred sixty-five breastfeeding mother-infant pairs (120 US, 120 China, and 125 Mexico) were recruited soon after the infant's birth. Enrollment required agreement to breastfeed ≥75% for at least 3 mo. Weekly, 24-h, food frequency data were conducted on infants for 1 y and exclusive breastfeeding (EBF) duration and timing of specific complementary food introduction were calculated. Weight and length were measured at age 1 y and anthropometry Z-scores calculated using WHO standards. Cohorts in the 3 urban populations (Shanghai, China; Cincinnati, USA; and Mexico City, Mexico) differed by median EBF duration (5, 14, and 7 wk, respectively; P Mexico City infants (P < 0.001). Adjusting for nonfeeding covariates, the only feeding variable associated with anthropometry was EBF duration, which was modestly inversely associated with weight-for-age but not length-for-age or BMI Z-scores at 1 y. Although feeding variables differed by cohort, their impact on anthropometry differences was not consistent among cohorts. Overall, across these urban, international, breast-fed cohorts, differences in specific feeding practices did not explain the significant variation in anthropometry.

  10. Copenhagen Airport Cohort

    DEFF Research Database (Denmark)

    Møller, Karina Lauenborg; Brauer, Charlotte; Mikkelsen, Sigurd

    2017-01-01

    TO DATE: The cohort includes environmental Global Positioning System (GPS) measurements in Copenhagen Airport, information on job function/task for each calendar year of employment between 1990 and 2012, exposure to air pollution at residence, average weight of baggage lifted per day and lifestyle...... covers 69 175 men in unskilled positions. The exposed cohort includes men in unskilled jobs employed at Copenhagen Airport in the period 1990-2012 either as baggage handlers or in other outdoor work. The reference cohort includes men in unskilled jobs working in the greater Copenhagen area. FINDINGS...

  11. Aging evaluation methodology of periodic safety review in Korea

    International Nuclear Information System (INIS)

    Park, Heung-Bae; Jung, Sung-Gyu; Jin, Tae-Eun; Jeong, Ill-Seok

    2002-01-01

    In Korea plant lifetime management (PLIM) study for Kori Unit 1 has been performed since 1993. Meanwhile, periodic safety review (PSR) for all operating nuclear power plants (NPPs) has been started with Kori Unit 1 since 2000 per IAEA recommendation. The evaluation period is 10 years, and safety (evaluation) factors are 11 per IAEA guidelines as represented in table 1. The relationship between PSR factors and PLIM is also represented. Among these factors evaluation of 'management of aging' is one of the most important and difficult factor. This factor is related to 'actual condition of the NPP', 'use of experience from other nuclear NPPs and of research findings', and 'management of aging'. The object of 'management of aging' is to obtain plant safety through identifying actual condition of system, structure and components (SSCs) and evaluating aging phenomena and residual life of SSCs using operating experience and research findings. The paper describes the scope and procedure of valuation of 'management of aging', such as, screening criteria of SSCs, Code and Standards, evaluation of SSCs and safety issues as represented. Evaluating SSCs are determined using final safety analysis report (FSAR) and power unit maintenance system for Nuclear Ver. III (PUMAS/N-III). The screening criteria of SSCs are safety-related items (quality class Q), safety-impact items (quality class T), backfitting rule items (fire protection (10CFR50.48), environmental qualification (10CFR50.49), pressurized thermal shock (10CFR50.61), anticipated transient without scram (10CFR50.62), and station blackout (10CFR50.63)) and regulating authority requiring items[1∼3]. The purpose of review of Code and Standards is identifying actual condition of the NPP and evaluating aging management using effective Code and Standards corresponding to reactor facilities. Code and Standards is composed of regulating laws, FSAR items, administrative actions, regulating actions, agreement items, and other

  12. Cohort Working Life Tables for Older Canadians

    Directory of Open Access Journals (Sweden)

    Spencer, Byron G.

    2010-01-01

    Full Text Available AbstractWe construct cohort working life tables for Canadian men and women aged 50and older and, for comparison, corresponding period tables. The tables arederived using annual single-age time series of participation rates for 1976-2006from the master files of the Statistics Canada Labour Force Survey. The cohortcalculations are based on stochastic projections of mortality coupled withalternative assumptions about future participation rates. Separate tables areprovided for the years 1976, 1991, and 2006, thus spanning a period ofsubstantial gains in life expectancy and strong upward trends in femaleparticipation. Life expectancies based on the cohort tables are greater thanthose based on the period tables, for both men and women, and that is reflectedin increased retirement expectancies. For example, a male aged 50 in 1976could have expected to live three years longer and to have almost four moreyears in retirement, based on the male cohort table under medium assumptions,as compared with the corresponding period table.RésuméNous avons établis des tables de vie active par génération pour les Canadiens etCanadiennes âgés de 50 ans ou plus ainsi que des tables du momentcorrespondantes pour servir de comparaison. Les tables sont dérivées à l'aidede séries chronologiques annuelles d'un seul âge pour le taux d'activité pour lesannées 1976 à 2006 provenant des fichiers maîtres de l'Enquête sur lapopulation active de Statistique Canada. Les calculs par génération sont baséessur des projections stochastiques de mortalité et sur des suppositions quant àde futurs taux d'activité possibles. Des tables séparées ont été établies pour lesannées 1976, 1991 et 2006 ; ce qui représente une période qui a vu des gainssubstantiels en ce qui concerne l'espérance de vie et une forte hausse d'activitéchez les femmes. Les espérance de vie basées sur les tables par génération sontplus élevées que celles basées sur les tables du

  13. Unstable employment and health in middle age in the longitudinal 1970 British Birth Cohort Study.

    Science.gov (United States)

    Waynforth, David

    2018-01-01

    Jobs for life have become increasingly rare in industrialized economies, and have been replaced by shorter-term employment contracts and freelancing. This labour market change is likely to be accompanied by physiological changes in individuals who have experienced little job stability. Evolved responses to increased environmental instability or stochasticity include increased fat deposition and fight-or-flight responses, such as glucose mobilization and increased blood pressure. These responses may have evolved by natural selection as beneficial to individuals in the short-term, but are damaging in the longer term. This study tested whether job losses experienced between ages 30 and 42 are associated with increased body weight, hypertension and diabetes diagnosis in the 1970 British Birth Cohort, which consists of all registered births in a one-week period in April 1970. Each job loss experienced increased the odds of developing diabetes by 1.39 times (CI 1.08-1.80), and of hypertension by 1.28 times (CI 1.07-1.53). Another economic variable, higher personal debt, was associated with all three of these health outcomes: every £100 000 of debt roughly doubled the odds of gaining at least 5 kg between ages 30 and 42. These associations between job loss and health-risk factors suggest that our changing economy results in increases in the prevalence of risk factors for cardiovascular disease. At a broader level, they are consistent with evolutionary understandings of environmental stochasticity, and are a reminder that economic policy is also health policy.

  14. Establishment and baseline characteristics of a nationwide Danish cohort of patients with Ehlers-Danlos syndrome

    DEFF Research Database (Denmark)

    Kulas Søborg, Marie-Louise; Leganger, Julie; Quitzau Mortensen, Laura

    2017-01-01

    at any given time between 1 January 2000 and 31 December 2012, based upon longitudinal Danish national registers. All patients with EDS were identified, and the cohort was described by disease prevalence, basic demographic characteristics, mean age at death and mortality for the observational period...

  15. Treatment of a long-acting anticoagulant rodenticide poisoning cohort with vitamin K1 during the maintenance period

    Science.gov (United States)

    Long, Jianhai; Peng, Xiaobo; Luo, Yuan; Sun, Yawei; Lin, Guodong; Wang, Yongan; Qiu, Zewu

    2016-01-01

    Abstract Currently, there are few guidelines for the use of vitamin K1 in the maintenance treatment of long-acting anticoagulant rodenticide (LAAR) poisonings. We explored factors in the treatment of LAAR poisoning during the maintenance period in order to suggest feasible treatment models. Data from 24 cases of anticoagulant rodenticide poisoning in our hospital were collected from January 2013 to May 2016. The patients’ sex, age, coagulation function, total time from poisoning to treatment with vitamin K1 (prehospital time), vitamin K1 sustained treatment time (VKSTT), anticoagulant rodenticide category, and specific poison dosage were collected. Multivariate analysis was used to evaluate the correlation between vitamin K1 dosage and other factors during the maintenance period. Only VKSTT (partial regression coefficient −1.133, 0.59, P = 0.035) had an obvious influence on the therapeutic dose of vitamin K1 required during the maintenance period. After an initial pulse therapy, the bleeding and coagulation functions were stabilized, and the patients were subsequently treated with vitamin K1 during the maintenance period. Over time, the maintenance dose of vitamin K1 (10–120 mg/d, intravenous drip) was gradually decreased and was not related to toxicant concentration. PMID:28002326

  16. Surgery during holiday periods and prognosis in oesophageal cancer: a population-based nationwide Swedish cohort study.

    Science.gov (United States)

    Markar, Sheraz R; Wahlin, Karl; Mattsson, Fredrik; Lagergren, Pernilla; Lagergren, Jesper

    2016-09-06

    Previous studies indicate an increased short-term and long-term mortality from major cancer surgery performed towards the end of the working week or during the weekend. We hypothesised that the prognosis after major cancer surgery is also negatively influenced by surgery conducted during holiday periods. Population-based nationwide Swedish cohort study. Patients undergoing oesophagectomy for oesophageal cancer between 1987 and 2010. Among 1820 included patients, 206 (11.3%) and 373 (20.5%) patients were operated on during narrow and wide holiday periods, respectively. Narrow (7 weeks) and wide (14 weeks) Swedish holiday periods. 90-day all-cause, 5-year all-cause and 5-year disease-specific mortality. Narrow holiday period did not increase all-cause 90-day (HR=0.84, 95% CI 0.53 to 1.33), all-cause 5-year (HR=1.01, 95% CI 0.85 to 1.21) or disease-specific 5-year mortality (HR=1.04, 95% CI 0.87 to 1.26). Similarly, wide holiday period did not increase the risk of 90-day (HR=0.79, 95% CI 0.55 to 1.13), all-cause 5-year (HR=0.96, 95% CI 0.84 to 1.1) or disease-specific 5-year mortality (HR=1.03, 95% CI 0.89 to 1.19). No measurable effects of holiday periods on short-term or longer term mortality following surgery for oesophageal cancer were observed in this population-based study, indicating that an adequate surgical experience was maintained during holiday periods. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Representing anthropogenic gross land use change, wood harvest, and forest age dynamics in a global vegetation model ORCHIDEE-MICT v8.4.2

    Science.gov (United States)

    Yue, Chao; Ciais, Philippe; Luyssaert, Sebastiaan; Li, Wei; McGrath, Matthew J.; Chang, Jinfeng; Peng, Shushi

    2018-01-01

    Land use change (LUC) is among the main anthropogenic disturbances in the global carbon cycle. Here we present the model developments in a global dynamic vegetation model ORCHIDEE-MICT v8.4.2 for a more realistic representation of LUC processes. First, we included gross land use change (primarily shifting cultivation) and forest wood harvest in addition to net land use change. Second, we included sub-grid evenly aged land cohorts to represent secondary forests and to keep track of the transient stage of agricultural lands since LUC. Combination of these two features allows the simulation of shifting cultivation with a rotation length involving mainly secondary forests instead of primary ones. Furthermore, a set of decision rules regarding the land cohorts to be targeted in different LUC processes have been implemented. Idealized site-scale simulation has been performed for miombo woodlands in southern Africa assuming an annual land turnover rate of 5 % grid cell area between forest and cropland. The result shows that the model can correctly represent forest recovery and cohort aging arising from agricultural abandonment. Such a land turnover process, even though without a net change in land cover, yields carbon emissions largely due to the imbalance between the fast release from forest clearing and the slow uptake from agricultural abandonment. The simulation with sub-grid land cohorts gives lower emissions than without, mainly because the cleared secondary forests have a lower biomass carbon stock than the mature forests that are otherwise cleared when sub-grid land cohorts are not considered. Over the region of southern Africa, the model is able to account for changes in different forest cohort areas along with the historical changes in different LUC activities, including regrowth of old forests when LUC area decreases. Our developments provide possibilities to account for continental or global forest demographic change resulting from past anthropogenic and

  18. Variance components models for physical activity with age as modifier: a comparative twin study in seven countries

    DEFF Research Database (Denmark)

    Vink, Jacqueline M; Boomsma, Dorret I; Medland, Sarah E

    2011-01-01

    -reported data from twins aged 19 to 50 from seven countries that collaborated in the GenomEUtwin project: Australia, Denmark, Finland, Norway, Netherlands, Sweden and United Kingdom. Results confirmed the importance of genetic influences on physical activity in all countries and showed an age-related decrease......Physical activity is influenced by genetic factors whose expression may change with age. We employed an extension to the classical twin model that allows a modifier variable, age, to interact with the effects of the latent genetic and environmental factors. The model was applied to self...... into account when exploring the genetic and environmental contribution to physical activity. It also suggests that the power of genome-wide association studies to identify the genetic variants contributing to physical activity may be larger in young adult cohorts....

  19. Younger age as a prognostic indicator in breast cancer: A cohort study

    LENUS (Irish Health Repository)

    Kheirelseid, Elrasheid A.H.

    2011-08-28

    Abstract Background The debate continues as to whether younger women who present with breast cancer have a more aggressive form of disease and a worse prognosis. The objectives of this study were to determine the incidence of breast cancer in women under 40 years old and to analyse the clinicopathological characteristics and outcome compared to an older patient cohort. Methods Data was acquired from a review of charts and the prospectively reviewed GUH Department of Surgery database. Included in the study were 276 women diagnosed with breast cancer under the age of forty and 2869 women over forty. For survival analysis each women less than 40 was matched with two women over forty for both disease stage and grade. Results The proportion of women diagnosed with breast cancer under the age of forty in our cohort was 8.8%. In comparison to their older counterparts, those under forty had a higher tumour grade (p = 0.044) and stage (p = 0.046), a lower incidence of lobular tumours (p < 0.001), higher estrogen receptor negativity (p < 0.001) and higher HER2 over-expression (p = 0.002); there was no statistical difference as regards tumour size (p = 0.477). There was no significant difference in overall survival (OS) for both groups; and factors like tumour size (p = 0.026), invasion (p = 0.026) and histological type (p = 0.027), PR (p = 0.031) and HER2 (p = 0.002) status and treatment received were independent predictors of OS Conclusion Breast cancer in younger women has distinct histopathological characteristics; however, this does not result in a reduced survival in this population.

  20. Younger age as a prognostic indicator in breast cancer: A cohort study

    International Nuclear Information System (INIS)

    H Kheirelseid, Elrasheid A; Boggs, Jennifer ME; Curran, Catherine; Glynn, Ronan W; Dooley, Cara; Sweeney, Karl J; Kerin, Michael J

    2011-01-01

    The debate continues as to whether younger women who present with breast cancer have a more aggressive form of disease and a worse prognosis. The objectives of this study were to determine the incidence of breast cancer in women under 40 years old and to analyse the clinicopathological characteristics and outcome compared to an older patient cohort. Data was acquired from a review of charts and the prospectively reviewed GUH Department of Surgery database. Included in the study were 276 women diagnosed with breast cancer under the age of forty and 2869 women over forty. For survival analysis each women less than 40 was matched with two women over forty for both disease stage and grade. The proportion of women diagnosed with breast cancer under the age of forty in our cohort was 8.8%. In comparison to their older counterparts, those under forty had a higher tumour grade (p = 0.044) and stage (p = 0.046), a lower incidence of lobular tumours (p < 0.001), higher estrogen receptor negativity (p < 0.001) and higher HER2 over-expression (p = 0.002); there was no statistical difference as regards tumour size (p = 0.477). There was no significant difference in overall survival (OS) for both groups; and factors like tumour size (p = 0.026), invasion (p = 0.026) and histological type (p = 0.027), PR (p = 0.031) and HER2 (p = 0.002) status and treatment received were independent predictors of OS Breast cancer in younger women has distinct histopathological characteristics; however, this does not result in a reduced survival in this population

  1. Predicting the 6-month risk of severe hypoglycemia among adults with diabetes: Development and external validation of a prediction model.

    Science.gov (United States)

    Schroeder, Emily B; Xu, Stan; Goodrich, Glenn K; Nichols, Gregory A; O'Connor, Patrick J; Steiner, John F

    2017-07-01

    To develop and externally validate a prediction model for the 6-month risk of a severe hypoglycemic event among individuals with pharmacologically treated diabetes. The development cohort consisted of 31,674 Kaiser Permanente Colorado members with pharmacologically treated diabetes (2007-2015). The validation cohorts consisted of 38,764 Kaiser Permanente Northwest members and 12,035 HealthPartners members. Variables were chosen that would be available in electronic health records. We developed 16-variable and 6-variable models, using a Cox counting model process that allows for the inclusion of multiple 6-month observation periods per person. Across the three cohorts, there were 850,992 6-month observation periods, and 10,448 periods with at least one severe hypoglycemic event. The six-variable model contained age, diabetes type, HgbA1c, eGFR, history of a hypoglycemic event in the prior year, and insulin use. Both prediction models performed well, with good calibration and c-statistics of 0.84 and 0.81 for the 16-variable and 6-variable models, respectively. In the external validation cohorts, the c-statistics were 0.80-0.84. We developed and validated two prediction models for predicting the 6-month risk of hypoglycemia. The 16-variable model had slightly better performance than the 6-variable model, but in some practice settings, use of the simpler model may be preferred. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Multicenter cohort association study of SLC2A1 single nucleotide polymorphisms and age-related macular degeneration

    Science.gov (United States)

    Baas, Dominique C.; Ho, Lintje; Tanck, Michael W.T.; Fritsche, Lars G.; Merriam, Joanna E.; van het Slot, Ruben; Koeleman, Bobby P.C.; Gorgels, Theo G.M.F.; van Duijn, Cornelia M.; Uitterlinden, André G.; de Jong, Paulus T.V.M.; Hofman, Albert; ten Brink, Jacoline B.; Vingerling, Johannes R.; Klaver, Caroline C.W.; Dean, Michael; Weber, Bernhard H. F.; Allikmets, Rando; Hageman, Gregory S.

    2012-01-01

    Purpose Age-related macular degeneration (AMD) is a major cause of blindness in older adults and has a genetically complex background. This study examines the potential association between single nucleotide polymorphisms (SNPs) in the glucose transporter 1 (SLC2A1) gene and AMD. SLC2A1 regulates the bioavailability of glucose in the retinal pigment epithelium (RPE), which might influence oxidative stress–mediated AMD pathology. Methods Twenty-two SNPs spanning the SLC2A1 gene were genotyped in 375 cases and 199 controls from an initial discovery cohort (the Amsterdam-Rotterdam-Netherlands study). Replication testing was performed in The Rotterdam Study (the Netherlands) and study populations from Würzburg (Germany), the Age Related Eye Disease Study (AREDS; United States), Columbia University (United States), and Iowa University (United States). Subsequently, a meta-analysis of SNP association was performed. Results In the discovery cohort, significant genotypic association between three SNPs (rs3754219, rs4660687, and rs841853) and AMD was found. Replication in five large independent (Caucasian) cohorts (4,860 cases and 4,004 controls) did not yield consistent association results. The genotype frequencies for these SNPs were significantly different for the controls and/or cases among the six individual populations. Meta-analysis revealed significant heterogeneity of effect between the studies. Conclusions No overall association between SLC2A1 SNPs and AMD was demonstrated. Since the genotype frequencies for the three SLC2A1 SNPs were significantly different for the controls and/or cases between the six cohorts, this study corroborates previous evidence that population dependent genetic risk heterogeneity in AMD exists. PMID:22509097

  3. Colorectal cancer mortality trends in Córdoba, Argentina.

    Science.gov (United States)

    Pou, Sonia Alejandra; Osella, Alberto Rubén; Eynard, Aldo Renato; Niclis, Camila; Diaz, María del Pilar

    2009-12-01

    Colorectal cancer is a leading cause of death worldwide for men and women, and one of the most commonly diagnosed in Córdoba, Argentina. The aim of this work was to provide an up-to-date approach to descriptive epidemiology of colorectal cancer in Córdoba throughout the estimation of mortality trends in the period 1986-2006, using Joinpoint and age-period-cohort (APC) models. Age-standardized (world population) mortality rates (ASMR), overall and truncated (35-64 years), were calculated and Joinpoint regression performed to compute the estimated annual percentage changes (EAPC). Poisson sequential models were fitted to estimate the effect of age (11 age groups), period (1986-1990, 1991-1995, 1996-2000 or 2001-2006) and cohort (13 ten-years cohorts overlapping each other by five-years) on colorectal cancer mortality rates. ASMR showed an overall significant decrease (EAPC -0.9 95%CI: -1.7, -0.2) for women, being more noticeable from 1996 onwards (EAPC -2.1 95%CI: -4.0, -0.1). Age-effect showed an important rise in both sexes, but more evident in males. Birth cohort- and period effects reflected increasing and decreasing tendencies for men and women, respectively. Differences in mortality rates were found according to sex and could be related to age-period-cohort effects linked to the ageing process, health care and lifestyle. Further research is needed to elucidate the specific age-, period- and cohort-related factors.

  4. Long sleep duration is associated with lower cognitive function among middle-age adults - the Doetinchem Cohort Study.

    Science.gov (United States)

    van Oostrom, Sandra H; Nooyens, Astrid C J; van Boxtel, Martin P J; Verschuren, W M Monique

    2018-01-01

    In older adults, both short and long sleep duration are associated with lower cognitive function, suggesting an inverted U-shaped association between sleep duration and cognitive outcomes. This study examined whether sleep duration is associated with (changes in) cognitive function in a middle-aged population. In the Doetinchem Cohort Study, the cognitive function of 2970 men and women aged 41-75 years at baseline (1995-2007) was examined 2-3 times, with 5-year time intervals. Global cognitive function and the domains memory, information processing speed, and cognitive flexibility were assessed. In multivariable linear regression models, (change in) self-reported sleep duration was studied in association with the level and change in cognitive function. In a subsample of the population (n = 2587), the association of sleep duration and feeling rested with cognitive function was studied. Sleep duration of 9 h and more was statistically significantly associated with lower global cognitive function (p cognitive function. An inverted U-shaped association between sleep duration and cognitive function was observed for speed, flexibility, and global cognitive function. Sleep duration was not associated with change in cognitive function. Middle-age adults with long sleep duration had a lower cognitive function. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. An Evaluation of Functional Sit-to-Stand Power in Cohorts of Healthy Adults Aged 18-97 Years.

    Science.gov (United States)

    Glenn, Jordan M; Gray, Michelle; Vincenzo, Jennifer; Paulson, Sally; Powers, Melissa

    2017-04-01

    This investigation examined differences in functional sit-to-stand power/velocity between cohorts of adults aged 18-97 years. This study included 264 healthy adults classified into four cohorts (18-40, C1; 60-69, C2; 70-79, C2; ≥ 80, C4). Participants completed the sit-to-stand task five times. Power and velocity were measured via the TENDO power analyzer. Absolute average power was maintained from C1-C3, but decreased (p power decreased between C1-C2 (p power decreased between C1-C2 (p power may plateau during the seventh and eighth decades, accelerating after 80 years.

  6. Validation of the IHE Cohort Model of Type 2 Diabetes and the impact of choice of macrovascular risk equations.

    Directory of Open Access Journals (Sweden)

    Adam Lundqvist

    Full Text Available Health-economic models of diabetes are complex since the disease is chronic, progressive and there are many diabetic complications. External validation of these models helps building trust and satisfies demands from decision makers. We evaluated the external validity of the IHE Cohort Model of Type 2 Diabetes; the impact of using alternative macrovascular risk equations; and compared the results to those from microsimulation models.The external validity of the model was analysed from 12 clinical trials and observational studies by comparing 167 predicted microvascular, macrovascular and mortality outcomes to the observed study outcomes. Concordance was examined using visual inspection of scatterplots and regression-based analysis, where an intercept of 0 and a slope of 1 indicate perfect concordance. Additional subgroup analyses were conducted on 'dependent' vs. 'independent' endpoints and microvascular vs. macrovascular vs. mortality endpoints.Visual inspection indicates that the model predicts outcomes well. The UKPDS-OM1 equations showed almost perfect concordance with observed values (slope 0.996, whereas Swedish NDR (0.952 and UKPDS-OM2 (0.899 had a slight tendency to underestimate. The R2 values were uniformly high (>0.96. There were no major differences between 'dependent' and 'independent' outcomes, nor for microvascular and mortality outcomes. Macrovascular outcomes tended to be underestimated, most so for UKPDS-OM2 and least so for NDR risk equations.External validation indicates that the IHE Cohort Model of Type 2 Diabetes has predictive accuracy in line with microsimulation models, indicating that the trade-off in accuracy using cohort simulation might not be that large. While the choice of risk equations was seen to matter, each were associated with generally reasonable results, indicating that the choice must reflect the specifics of the application. The largest variation was observed for macrovascular outcomes. There, NDR

  7. Determination of timescales of nitrate contamination by groundwater age models in a complex aquifer system

    Science.gov (United States)

    Koh, E. H.; Lee, E.; Kaown, D.; Lee, K. K.; Green, C. T.

    2017-12-01

    Timing and magnitudes of nitrate contamination are determined by various factors like contaminant loading, recharge characteristics and geologic system. Information of an elapsed time since recharged water traveling to a certain outlet location, which is defined as groundwater age, can provide indirect interpretation related to the hydrologic characteristics of the aquifer system. There are three major methods (apparent ages, lumped parameter model, and numerical model) to date groundwater ages, which differently characterize groundwater mixing resulted by various groundwater flow pathways in a heterogeneous aquifer system. Therefore, in this study, we compared the three age models in a complex aquifer system by using observed age tracer data and reconstructed history of nitrate contamination by long-term source loading. The 3H-3He and CFC-12 apparent ages, which did not consider the groundwater mixing, estimated the most delayed response time and a highest period of the nitrate loading had not reached yet. However, the lumped parameter model could generate more recent loading response than the apparent ages and the peak loading period influenced the water quality. The numerical model could delineate various groundwater mixing components and its different impacts on nitrate dynamics in the complex aquifer system. The different age estimation methods lead to variations in the estimated contaminant loading history, in which the discrepancy in the age estimation was dominantly observed in the complex aquifer system.

  8. Is schizophrenia associated with an increased risk of chronic kidney disease? A nationwide matched-cohort study.

    Science.gov (United States)

    Tzeng, Nian-Sheng; Hsu, Yung-Ho; Ho, Shinn-Ying; Kuo, Yu-Ching; Lee, Hua-Chin; Yin, Yun-Ju; Chen, Hong-An; Chen, Wen-Liang; Chu, William Cheng-Chung; Huang, Hui-Ling

    2015-01-27

    The impact of schizophrenia on vital diseases, such as chronic kidney disease (CKD), has not as yet been verified. This study aims to establish whether there is an association between schizophrenia and CKD. A nationwide matched cohort study. Taiwan's National Health Insurance Research Database. A total of 2338 patients with schizophrenia, and 7014 controls without schizophrenia (1:3), matched cohort for sex, age group, geography, urbanisation and monthly income, between 1 January 2003 and 31 December 2007, based on the International Classifications of Disease Ninth Edition (ICD-9), Clinical Modification codes. After making adjustments for confounding risk factors, a Cox proportional hazards model was used to compare the risk of developing CKD during a 3-year follow-up period from the index date. Of the 2338-subject case cohort, 163 (6.97%) developed a CKD, as did 365 (5.20%) of the 7014 control participants. Cox proportional hazards regression analysis revealed that patients with schizophrenia were more likely to develop CKD (HR=1.36, 95% CI 1.13 to 1.63; pschizophrenia was 1.25 (95% CI 1.04 to 1.50; prisk of CKD in patients with schizophrenia. The findings from this population-based retrospective cohort study suggest that schizophrenia is associated with a 25% increase in the risk of developing CKD within only a 3-year follow-up period. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Applications of computer modeling to fusion research

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1989-01-01

    Progress achieved during this report period is presented on the following topics: Development and application of gyrokinetic particle codes to tokamak transport, development of techniques to take advantage of parallel computers; model dynamo and bootstrap current drive; and in general maintain our broad-based program in basic plasma physics and computer modeling

  10. Optimizing Implementation of Hepatitis C Birth-Cohort Screening and Treatment Strategies

    Directory of Open Access Journals (Sweden)

    Yuankun Li MS

    2017-01-01

    Full Text Available Background: Chronic hepatitis C (HCV is a significant public health problem affecting more than three million Americans. The US health care systems are ramping up costly HCV screening and treatment efforts with limited budget. We determine the optimal implementation of HCV birth-cohort screening and treatment strategies under budget constraints and health care payer’s perspective. Methods: Markov model and scenario-based simulation optimization. The target population is birth cohort born between 1945 and 1975. The interventions are allocating annual budget to screen a proportion of the target population and treat a proportion of the identified chronic HCV-positive patients over 10 years. Outcomes measure is to maximize lifetime discounted quality-adjusted life-years. Results: Allocate a percentage of the annual budget to screening, then treat patients with the remaining budget and prioritize the sickest patients. When the budget is $1 billion/year, the best strategy is to allocate the entire budget to treatment. When the budget is $5 billion/year, it is optimal to allocate 60% of the budget to screening in the first 2 years and 0% thereafter for age cohort 40 to 49; and allocate 20% of the budget to screening starting in year 3 for age cohorts 50 to 59 and 60 to 69. Health benefits are sensitive to budget in the first 2 years. Results are not sensitive to distribution of fibrosis stages by awareness of HCV. Conclusion: When budget is limited, all efforts should be focused on early treatment. With higher budget, better population health outcomes are achieved by reserving some budget for HCV screening while implementing a priority-based treatment strategy. This work has broad applicability to diverse health care systems and helps determine how much effort should be devoted to screening versus treatment under resource limitations.

  11. Periodically patterned structures for nanoplasmonic and biomedical applications

    Science.gov (United States)

    Peer, Akshit

    Periodically patterned nanostructures have imparted profound impact on diverse scientific disciplines. In physics, chemistry, and materials science, artificially engineered photonic crystals have demonstrated an unprecedented ability to control the propagation of photons through light concentration and diffraction. The field of photonic crystals has led to many technical advances in fabricating periodically patterned nanostructures in dielectric/metallic materials and controlling the light-matter interactions at the nanoscale. In the field of biomaterials, it is of great interest to apply our knowledge base of photonic materials and explore how such periodically patterned structures control diverse biological functions by varying the available surface area, which is a key attribute for surface hydrophobicity, cell growth and drug delivery. Here we describe closely related scientific applications of large-scale periodically patterned polymers and metal nanostructures. The dissertation starts with nanoplasmonics for improving photovoltaic devices, where we design and optimize experimentally realizable light-trapping nanostructures using rigorous scattering matrix simulations for enhancing the performance of organic and perovskite solar cells. The use of periodically patterned plasmonic metal cathode in conjunction with polymer microlens array significantly improves the absorption in solar cells, providing new opportunities for photovoltaic device design. We further show the unprecedented ability of nanoplasmonics to concentrate light at the nanoscale by designing a large-area plasmonic nanocup array with frequency-selective optical transmission. The fabrication of nanostructure is achieved by coating non-uniform gold layer over a submicron periodic nanocup array imprinted on polystyrene using soft lithography. The gold nanocup array shows extraordinary optical transmission at a wavelength close to the structure period. The resonance wavelength for transmission can be

  12. Why did the breast cancer lymph node status distribution improve in Denmark in the pre-mammography screening period of 1978-1994?

    International Nuclear Information System (INIS)

    Rostgaard, Klaus; Lynge, Elsebeth; Vaeth, Michael; Rootzen, Helle

    2010-01-01

    Background. Danish breast cancer patients diagnosed in 1978-1994 experienced a trend over time towards a more favourable distribution of lymph node status at time of diagnosis, which was not due to mammography screening. We investigated how this trend could be explained by patient characteristics at diagnosis: age (biological processes), calendar period (e.g. environmental changes), birth cohort (living conditions over a life time), post-menopausal status (a predictor of less favourable nodal status), and tumour diameter (a marker of detection time). Material and methods. The data set consisted of 22 955 patients aged 30-69 years at time of diagnosis with known lymph node status, known tumour diameter, known menopausal status, and clinically detected tumours, available from the Danish Breast Cancer Cooperative Group (DBCG). Age, period, cohort, menopausal status, and tumour diameter were used as predictors in generalised linear models with either node-positive status (at least one of the excised lymph nodes being tumour-positive) or severely node-positive status (at least half of the excised lymph nodes being tumour-positive) as outcomes. Lymph node status was assessed both empirically and estimated using an EM algorithm in order to reduce misclassification. Results and discussion. We found that the improved lymph node status distribution was most likely a period effect due to a combination of earlier detection of clinical tumours, explaining most of the trend in node-positive breast cancer and half of the trend in severely node-positive breast cancer, and some unknown factor affecting lymph node status but not necessarily other tumour characteristics

  13. Age Adjusted D-Dimer for exclusion of Pulmonary Embolism: a retrospective cohort study.

    LENUS (Irish Health Repository)

    Monks, D

    2017-08-01

    D-Dimer (DD) will increase with age and recent studies have shown the upper limit of normal can be raised in those who are low risk and over 50. We studied age adjusted D-dimer (AADD) levels to assess whether pulmonary embolism (PE) could be safely excluded. This study analysed the Emergency Department (ED) Computed Tomographic Pulmonary Angiography (CTPA) requests. There were 756 requests. The parameters studied were; age, DD value, calculated AADD, CT result and Simplified Geneva Score (SGS). The primary outcome was the diagnostic performance of AADD. One hundred and eighty-five patients were included in the final cohort. Twenty-one patients had a negative DD after age adjustment. Of these one had a PE, corresponding to a failure rate of 4.76% (1 in 22). The sensitivity of AADD was 0.96 (95% CI 0.76 to 0.99) and its specificity was 0.12 (95% CI 0.08- 0.19). AADD demonstrated a reduction in false positives with one false negative, giving rise to a failure rate higher than that of other larger studies. Further study is indicated to accurately define the diagnostic characteristics for the Irish context.

  14. Smaller global and regional carbon emissions from gross land use change when considering sub-grid secondary land cohorts in a global dynamic vegetation model

    Science.gov (United States)

    Yue, Chao; Ciais, Philippe; Li, Wei

    2018-02-01

    Several modelling studies reported elevated carbon emissions from historical land use change (ELUC) by including bidirectional transitions on the sub-grid scale (termed gross land use change), dominated by shifting cultivation and other land turnover processes. However, most dynamic global vegetation models (DGVMs) that have implemented gross land use change either do not account for sub-grid secondary lands, or often have only one single secondary land tile over a model grid cell and thus cannot account for various rotation lengths in shifting cultivation and associated secondary forest age dynamics. Therefore, it remains uncertain how realistic the past ELUC estimations are and how estimated ELUC will differ between the two modelling approaches with and without multiple sub-grid secondary land cohorts - in particular secondary forest cohorts. Here we investigated historical ELUC over 1501-2005 by including sub-grid forest age dynamics in a DGVM. We run two simulations, one with no secondary forests (Sageless) and the other with sub-grid secondary forests of six age classes whose demography is driven by historical land use change (Sage). Estimated global ELUC for 1501-2005 is 176 Pg C in Sage compared to 197 Pg C in Sageless. The lower ELUC values in Sage arise mainly from shifting cultivation in the tropics under an assumed constant rotation length of 15 years, being 27 Pg C in Sage in contrast to 46 Pg C in Sageless. Estimated cumulative ELUC values from wood harvest in the Sage simulation (31 Pg C) are however slightly higher than Sageless (27 Pg C) when the model is forced by reconstructed harvested areas because secondary forests targeted in Sage for harvest priority are insufficient to meet the prescribed harvest area, leading to wood harvest being dominated by old primary forests. An alternative approach to quantify wood harvest ELUC, i.e. always harvesting the close-to-mature forests in both Sageless and Sage, yields similar values of 33 Pg C by both

  15. Copenhagen Airport Cohort

    DEFF Research Database (Denmark)

    Møller, Karina Lauenborg; Brauer, Charlotte; Mikkelsen, Sigurd

    2017-01-01

    PURPOSE: Copenhagen Airport Cohort 1990-2012 presents a unique data source for studies of health effects of occupational exposure to air pollution (ultrafine particles) and manual baggage handling among airport employees. We describe the extent of information in the cohort and in the follow...... covers 69 175 men in unskilled positions. The exposed cohort includes men in unskilled jobs employed at Copenhagen Airport in the period 1990-2012 either as baggage handlers or in other outdoor work. The reference cohort includes men in unskilled jobs working in the greater Copenhagen area. FINDINGS...... TO DATE: The cohort includes environmental Global Positioning System (GPS) measurements in Copenhagen Airport, information on job function/task for each calendar year of employment between 1990 and 2012, exposure to air pollution at residence, average weight of baggage lifted per day and lifestyle...

  16. Risk factors for deformational plagiocephaly at birth and at seven weeks of age - A prospective cohort study-

    NARCIS (Netherlands)

    van Vlimmeren, Leo A.; van der Graaf, Jolanda; Boere-Boonekamp, Magdalena M.; L'Hoir, Monique P.; Helders, Paul J.M.; Engelbert, Raoul H.H.

    2007-01-01

    OBJECTIVE. The purpose of this work was to identify risk factors for deformational plagiocephaly within 48 hours of birth and at 7 weeks of age. PATIENTS AND METHODS. This was a prospective cohort study in which 380 healthy neonates born at term in Bernhoven Hospital in Veghel were followed at birth

  17. Serum Folate Shows an Inverse Association with Blood Pressure in a Cohort of Chinese Women of Childbearing Age: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Minxue Shen

    Full Text Available It has been reported that higher folate intake from food and supplementation is associated with decreased blood pressure (BP. The association between serum folate concentration and BP has been examined in few studies. We aim to examine the association between serum folate and BP levels in a cohort of young Chinese women.We used the baseline data from a pre-conception cohort of women of childbearing age in Liuyang, China, for this study. Demographic data were collected by structured interview. Serum folate concentration was measured by immunoassay, and homocysteine, blood glucose, triglyceride and total cholesterol were measured through standardized clinical procedures. Multiple linear regression and principal component regression model were applied in the analysis.A total of 1,532 healthy normotensive non-pregnant women were included in the final analysis. The mean concentration of serum folate was 7.5 ± 5.4 nmol/L and 55% of the women presented with folate deficiency (< 6.8 nmol/L. Multiple linear regression and principal component regression showed that serum folate levels were inversely associated with systolic and diastolic BP, after adjusting for demographic, anthropometric, and biochemical factors.Serum folate is inversely associated with BP in non-pregnant women of childbearing age with high prevalence of folate deficiency.

  18. Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot.

    Science.gov (United States)

    Dobson, Richard J; Mordi, Ify; Danton, Mark H; Walker, Niki L; Walker, Hamish A; Tzemos, Nikolaos

    2017-01-01

    Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes. Single centre cohort study SETTING: National tertiary referral center Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29). Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database. Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion. Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (P = .027). However, when adjusted for age at scan the significant variables included NYHA class (P = .006), peak oxygen uptake (P = .028), number of prior sternotomies (P = .044), and higher indexed RV and LV end diastolic volumes (P = .002 and P tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future. © 2016 Wiley Periodicals, Inc.

  19. Role of BMI and age in predicting pathologic vertebral fractures in newly diagnosed multiple myeloma patients: A retrospective cohort study.

    Science.gov (United States)

    Chen, Yi-Lun; Liu, Yao-Chung; Wu, Chia-Hung; Yeh, Chiu-Mei; Chiu, Hsun-I; Lee, Gin-Yi; Lee, Yu-Ting; Hsu, Pei; Lin, Ting-Wei; Gau, Jyh-Pyng; Hsiao, Liang-Tsai; Chiou, Tzeon-Jye; Liu, Jin-Hwang; Liu, Chia-Jen

    2018-04-01

    Vertebral fractures affect approximately 30% of myeloma patients and lead to a poor impact on survival and life quality. In general, age and body mass index (BMI) are reported to have an important role in vertebral fractures. However, the triangle relationship among age, BMI, and vertebral fractures is still unclear in newly diagnosed multiple myeloma (NDMM) patients. This study recruited consecutive 394 patients with NDMM at Taipei Veterans General Hospital between January 1, 2005 and December 31, 2015. Risk factors for vertebral fractures in NDMM patients were collected and analyzed. The survival curves were demonstrated using Kaplan-Meier estimate. In total, 301 (76.4%) NDMM patients were enrolled in the cohort. In the median follow-up period of 18.0 months, the median survival duration in those with vertebral fractures ≥ 2 was shorter than those with vertebral fracture BMI BMI ≥ 24.0 kg/m 2 (adjusted RR, 2.79; 95% CI, 1.44-5.43). In multivariable logistic regression, BMI BMI ≥ 24.0 kg/m 2 (adjusted OR, 6.05; 95% CI, 2.43-15.08). Among age stratifications, patients with both old age and low BMI were at a greater risk suffering from increased vertebral fractures, especially in patients > 75 years and BMI BMI. Elder patients with low BMI should consider to routinely receive spinal radiographic examinations and regular follow-up. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Periodic safety review of the experimental fast reactor JOYO. Review of aging management

    International Nuclear Information System (INIS)

    Isozaki, Kazunori; Ogawa, To-ru; Nishino, Kazunari

    2005-05-01

    Periodic safety review (Review of the aging management) which consisted of ''Technical review on aging for the safety related structures, systems and components'' and ''Establishment a long term maintenance program'' was carried out up to April 2005. 1. Technical review on aging for the safety related structures, systems and components. It was technically confirmed to prevent the loss of function of the safety related structures, systems and components due to aging phenomena, which (1) irradiation damage, (2) corrosion, (3) abrasion and erosion, (4) thermal aging, (5) creep and fatigue, (6) Stress Corrosion Cracking, (7) insulation deterioration and (8) general deterioration, under the periodic monitoring or renewal of them. 2. Establishment of long term maintenance program. The long term maintenance during JFY2005 to 2014 were established based on the technical review on aging for the safety related structures, systems and components. It was evaluated that the inspection and renewal based on the long term maintenance program, in addition to the spontaneous inspection of the long term voluntary long-term inspection plan, could prevent the loss of function of the safety related structures, systems and components. (author)

  1. Základní pojmy a principy konstrukce modelů typu věk-období-kohorta

    Czech Academy of Sciences Publication Activity Database

    Reissigová, Jindra; Rychtaříková, J.

    2015-01-01

    Roč. 57, č. 1 (2015), s. 21-39 ISSN 0011-8265 Grant - others:GA ČR(CZ) GAP404/12/0883 Institutional support: RVO:67985807 Keywords : Lexis diagram * age-period-cohort * identification problem * generalised linear model * prediction * male mortality * Czech Republic Subject RIV: BB - Applied Statistics, Operational Research

  2. Statin adherence and the risk of Parkinson's disease: A population-based cohort study.

    Science.gov (United States)

    Rozani, Violetta; Giladi, Nir; El-Ad, Baruch; Gurevich, Tanya; Tsamir, Judith; Hemo, Beatriz; Peretz, Chava

    2017-01-01

    While experimental data provided some compelling evidence on the benefits of statins on dopaminergic neurons, observational studies reported conflicting results regarding the potential of statins to effect the risk of Parkinson's disease (PD). To evaluate the association between changes in statin adherence over time and PD risk. A population-based cohort of new statin users (ages 40-79, years 1999-2012) was derived from a large Israeli healthcare services organization. Data included history of statin purchases and low density lipoprotein cholesterol (LDL-C) levels. Personal statin adherence was measured annually by the proportion of days covered (PDC). PD was detected employing a drug-tracer approach. Stratified (by sex, LDL-C levels at baseline and age) Cox proportional hazards models with time-dependent covariates were used to compute adjusted Hazard Ratio (HR) with 95%CI. The cohort included 232,877 individuals, 49.3% men. Mean age at first statin purchase was 56.5 (±9.8) years for men and 58.7 (±9.2) years for women. PDC distribution for the whole follow up period differed between men and women: medians 58.3% and 54.1% respectively. During a mean follow up of 7.6 (±3.4) years, 2,550 (1.1%) PD cases were identified. In a 1-year lagged analysis, we found no association between annual statin adherence and PD risk in all age-groups regardless of statin type and potency. Age-pooled HR (95%CI) for men and women with LDL-C levels at baseline ≤160mg/dL were: 0.99 (0.99-1.01), 1.01 (1.00-1.02); and for men and women with LDL-C >160mg/dL levels: 0.99 (0.98-1.01), 0.97 (0.98-1.01). Our findings suggest that statin adherence over time does not affect PD risk. Future studies should use large-scale cohorts and refining assessments of long-term profiles in statin adherence.

  3. Population aging and the extended family in Taiwan

    Directory of Open Access Journals (Sweden)

    2004-05-01

    Full Text Available Population aging produces changes in the availability of kin with uncertain implications for extended living arrangements. We propose a highly stylized model that can be used to analyze and project age-specific proportions of adults living in extended and nuclear households. The model is applied to Taiwan using annual data from 1978-1998. We estimate cohort and age effects showing that more recently born cohorts of seniors are less likely to live in extended households, but that as seniors age the proportion living in extended households increases. The effect of individual aging has diminished over time, however. The proportion of non-senior adults living in extended households has increased steadily because changes in the age structure have increased the availability of older kin. The model is used to project living arrangements and we conclude that the proportion living in extended households will begin to decline gradually for both seniors and non-seniors. The extended family is becoming less important in Taiwan, but it is not on the way out.

  4. Thyroid Cancer Incidence in New Jersey: Time Trend, Birth Cohort and Socioeconomic Status Analysis (1979–2006

    Directory of Open Access Journals (Sweden)

    Lisa M. Roche

    2011-01-01

    Full Text Available The study's purpose was to investigate thyroid cancer incidence time trends, birth cohort effects, and association with socioeconomic status (SES in New Jersey (NJ, a high incidence state, using NJ State Cancer Registry data. Thyroid cancer incidence rates in each sex, nearly all age groups, two major histologies and all stages significantly increased between 1979 and 2006. For each sex, age-specific incidence rates began greatly increasing in the 1924 birth cohort and, generally, the highest thyroid cancer incidence rate for each five-year age group occurred in the latest birth cohort and diagnosis period. Thyroid cancer incidence rates were significantly higher in NJ Census tracts with higher SES and in counties with a higher percentage of insured residents. These results support further investigation into the relationship between rising thyroid cancer incidence and increasing population exposure to medical (including diagnostic radiation, as well as widespread use of more sensitive diagnostic techniques.

  5. Associations of anthropometry since birth with sagittal posture at age 7 in a prospective birth cohort: the Generation XXI Study.

    Science.gov (United States)

    Araújo, Fábio A; Lucas, Raquel; Simpkin, Andrew J; Heron, Jon; Alegrete, Nuno; Tilling, Kate; Howe, Laura D; Barros, Henrique

    2017-07-26

    Adult sagittal posture is established during childhood and adolescence. A flattened or hypercurved spine is associated with poorer musculoskeletal health in adulthood. Although anthropometry from birth onwards is expected to be a key influence on sagittal posture design, this has never been assessed during childhood. Our aim was to estimate the association between body size throughout childhood with sagittal postural patterns at age 7. Prospective cohort study. A subsample of 1029 girls and 1101 boys taking part in the 7-year-old follow-up of the birth cohort Generation XXI (Porto, Portugal) was included. We assessed the associations between anthropometric measurements (weight, height and body mass index) at birth, 4 and 7 years of age and postural patterns at age 7. Postural patterns were defined using latent profile analysis, a probabilistic model-based technique which allows for simultaneously including anthropometrics as predictors of latent profiles by means of logistic regression. Postural patterns identified were sway, flat and "neutral to hyperlordotic"in girls, and "sway to neutral", flat and hyperlordotic in boys; with flat and hyperlordotic postures representing a straightened and a rounded spine, respectively. In both girls and boys, higher weight was associated with lower odds of a flat pattern compared with a sway/"sway to neutral"pattern, with stronger associations at older ages: for example, ORs were 0.68 (95% CI 0.53 to 0.88) per SD increase in birth weight and 0.36 (95% CI 0.19 to 0.68) per SD increase in weight at age 7 in girls, with similar findings in boys. Boys with higher ponderal index at birth were more frequently assigned to the hyperlordotic pattern (OR=1.44 per SD; p=0.043). Our findings support a prospective sculpting role of body size and therefore of load on musculoskeletal spinopelvic structures, with stronger associations as children get older. © Article author(s) (or their employer(s) unless otherwise stated in the text of the

  6. ADRB2, brain white matter integrity and cognitive ageing in the Lothian Birth Cohort 1936.

    Science.gov (United States)

    Lyall, Donald M; Lopez, Lorna M; Bastin, Mark E; Maniega, Susana Muñoz; Penke, Lars; Valdés Hernández, Maria del C; Royle, Natalie A; Starr, John M; Porteous, David J; Wardlaw, Joanna M; Deary, Ian J

    2013-01-01

    The non-synonymous mutations arg16gly (rs1042713) and gln27glu (rs1042714) in the adrenergic β-2 receptor gene (ADRB2) have been associated with cognitive function and brain white matter integrity. The current study aimed to replicate these findings and expand them to a broader range of cognitive and brain phenotypes. The sample used is a community-dwelling group of older people, the Lothian Birth Cohort 1936. They had been assessed cognitively at age 11 years, and undertook further cognitive assessments and brain diffusion MRI tractography in older age. The sample size range for cognitive function variables was N = 686-765, and for neuroimaging variables was N = 488-587. Previously-reported findings with these genetic variants did not replicate in this cohort. Novel, nominally significant associations were observed; notably, the integrity of the left arcuate fasciculus mediated the association between rs1042714 and the Digit Symbol Coding test of information processing speed. No significant associations of cognitive and brain phenotypes with ADRB2 variants survived correction for false discovery rate. Previous findings may therefore have been subject to type 1 error. Further study into links between ADRB2, cognitive function and brain white matter integrity is required.

  7. Modeling the Association Between Home Care Service Use and Entry Into Residential Aged Care: A Cohort Study Using Routinely Collected Data.

    Science.gov (United States)

    Jorgensen, Mikaela; Siette, Joyce; Georgiou, Andrew; Warland, Andrew; Westbrook, Johanna

    2018-02-01

    To examine home care service-related and person-based factors associated with time to entry into permanent residential aged care. Longitudinal cohort study using routinely collected client management data. A large aged care service provider in New South Wales and the Australian Capital Territory, Australia. A total of 1116 people aged 60 years and older who commenced home care services for higher-level needs between July 1, 2015 and June 30, 2016. Survival analysis methods were used to examine service-related and person-based factors that were associated with time between first home care service and entry into permanent residential aged care. Predictors included service hours per week, combination of service types, demographics, needs, hospital leave, and change in care level. Cluster analysis was used to determine patterns of types of services used. By December 31, 2016, 21.1% of people using home care services had entered into permanent residential care (n = 235). After adjusting for significant factors such as age and care needs, each hour of service received per week was associated with a 6% lower risk of entry into residential care (hazard ratio = 0.94, 95% confidence interval 0.90-0.98). People who were predominant users of social support services, those with an identified carer, and those born in a non-main English-speaking country also remained in their own homes for longer. Greater volume of home care services was associated with significantly delayed entry into permanent residential care. This study provides much-needed evidence about service outcomes that could be used to inform older adults' care choices. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  8. Changes in Leisure-Time Physical Activity From the Prepregnancy to the Postpartum Period: 2004 Pelotas (Brazil) Birth Cohort Study.

    Science.gov (United States)

    Coll, Carolina; Domingues, Marlos; Santos, Iná; Matijasevich, Alicia; Horta, Bernardo Lessa; Hallal, Pedro C

    2016-04-01

    The aim of this study was to evaluate changes in leisure-time physical activity (LTPA) and its correlates from prepregnancy to the postpartum period in mothers enrolled in a Brazilian birth cohort study. Our hypothesis was that LTPA would decline considerably during pregnancy. Maternal LTPA in the 3 months before pregnancy and during each trimester of pregnancy was assessed soon after delivery. A follow-up visit was conducted 3 months later. Weekly frequency and duration of each session of LTPA in a typical week were assessed for each period and a cut-off point of 150 minutes per week was used to classify women as active or not. The proportion of women active in leisure time declined from 11.3% in the prepregnancy to 2.3% in pregnancy and 0.1% in the postpartum period (P for trend benefits of LTPA prepregnancy, during, and postpregnancy.

  9. Age Related Macular Degeneration and Total Hip Replacement Due to Osteoarthritis or Fracture: Melbourne Collaborative Cohort Study.

    Directory of Open Access Journals (Sweden)

    Elaine W Chong

    Full Text Available Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003-2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001-2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00-1.49. Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25-12.02. The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured

  10. Incidence of atrial fibrillation and its risk prediction model based on a prospective urban Han Chinese cohort.

    Science.gov (United States)

    Ding, L; Li, J; Wang, C; Li, X; Su, Q; Zhang, G; Xue, F

    2017-09-01

    Prediction models of atrial fibrillation (AF) have been developed; however, there was no AF prediction model validated in Chinese population. Therefore, we aimed to investigate the incidence of AF in urban Han Chinese health check-up population, as well as to develop AF prediction models using behavioral, anthropometric, biochemical, electrocardiogram (ECG) markers, as well as visit-to-visit variability (VVV) in blood pressures available in the routine health check-up. A total of 33 186 participants aged 45-85 years and free of AF at baseline were included in this cohort, to follow up for incident AF with an annually routine health check-up. Cox regression models were used to develop AF prediction model and 10-fold cross-validation was used to test the discriminatory accuracy of prediction model. We developed three prediction models, with age, sex, history of coronary heart disease (CHD), hypertension as predictors for simple model, with left high-amplitude waves, premature beats added for ECG model, and with age, sex, history of CHD and VVV in systolic and diabolic blood pressures as predictors for VVV model, to estimate risk of incident AF. The calibration of our models ranged from 1.001 to 1.004 (P for Hosmer Lemeshow test >0.05). The area under receiver operator characteristics curve were 78%, 80% and 82%, respectively, for predicting risk of AF. In conclusion, we have identified predictors of incident AF and developed prediction models for AF with variables readily available in routine health check-up.

  11. Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil

    OpenAIRE

    Matos, SM; Jesus, SR; Saldiva, SR; Prado, MS; D'Innocenzo, S; Assis, AM; Rodrigues, LC; Alcantara-Neves, NM; Cruz, Á, A; Simões, SdeM; Barreto, ML; SCAALA (Social Change, Asthma and Allergy in Latin America) Stud,

    2011-01-01

    : To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005. : Cross-sectional study nested in a cohort. : The metropolitan region of Salvador, Bahia, Brazil. : The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. ...

  12. The physical and mental health of a large military cohort: baseline functional health status of the Millennium Cohort

    Directory of Open Access Journals (Sweden)

    Engel Charles C

    2007-11-01

    Full Text Available Abstract Background: The US military is currently involved in large, lengthy, and complex combat operations around the world. Effective military operations require optimal health of deployed service members, and both mental and physical health can be affected by military operations. Methods: Baseline data were collected from 77,047 US service members during 2001–2003 as part of a large, longitudinal, population-based military health study (the Millennium Cohort Study. The authors calculated unadjusted, adjusted, and weighted means for the Medical Outcomes Study Short Form 36-item Survey for Veterans physical (PCS and mental component summary (MCS scores over a variety of demographic and military characteristics at baseline. Results: The unadjusted mean PCS and MCS scores for this study were 53.4 (95% confidence interval: 53.3–53.4 and 52.8 (95% confidence interval: 52.7–52.9. Average PCS and MCS scores were slightly more favorable in this military sample compared to those of the US general population of the same age and sex. Factors independently associated with more favorable health status included male gender, being married, higher educational attainment, higher military rank, and Air Force service. Combat specialists had similar health status compared to other military occupations. Having been deployed to Southwest Asia, Bosnia, or Kosovo between 1998 and 2000 was not associated with diminished health status. Conclusion: The baseline health status of this large population-based military cohort is better than that of the US general population of the same age and sex distribution over the same time period, especially in older age groups. Deployment experiences during the period of 1998–2001 were not associated with decreased health status. These data will serve as a useful reference for other military health studies and for future longitudinal analyses.

  13. The Danish National Birth Cohort

    DEFF Research Database (Denmark)

    Andersen, Anne-Marie Nybo; Olsen, Jørn

    2011-01-01

    , physical exercise, working conditions, medication and infections during pregnancy, and environmental possible toxins. The study designs cover straightforward cohort analyses, case-control studies and sub-cohort analyses with enriched data collection. CONCLUSION: So far, the Danish National Birth Cohort has......INTRODUCTION: In this review a selection of studies published during the period 2002-2010, based on data from the Danish National Birth Cohort linked with other health registers, is described. Illustrative examples of studies addressing perinatal health outcomes (pregnancy complications and fetal...... that this investment in epidemiologic infrastructure was well spent. The existence of the Danish National Birth Cohort together with other cohorts and national registers has given Denmark a leading position in reproductive epidemiology....

  14. Student experiences of the PhD cohort model: Working within or ...

    African Journals Online (AJOL)

    The Collaborative Cohort Model (CCM) of higher degrees supervision is gaining increasing popularity internationally and, in some contexts, replacing the conventional Apprentice Master Model (AMM). Among the motivations advanced for this shift is that the CCM improves completion rates and enhances the quality of ...

  15. Challenges estimating the return period of extreme floods for reinsurance applications

    Science.gov (United States)

    Raven, Emma; Busby, Kathryn; Liu, Ye

    2013-04-01

    Mapping and modelling extreme natural events is fundamental within the insurance and reinsurance industry for assessing risk. For example, insurers might use a 1 in 100-year flood hazard map to set the annual premium of a property, whilst a reinsurer might assess the national scale loss associated with the 1 in 200-year return period for capital and regulatory requirements. Using examples from a range of international flood projects, we focus on exploring how to define what the n-year flood looks like for predictive uses in re/insurance applications, whilst considering challenges posed by short historical flow records and the spatial and temporal complexities of flood. First, we shall explore the use of extreme value theory (EVT) statistics for extrapolating data beyond the range of observations in a marginal analysis. In particular, we discuss how to estimate the return period of historical flood events and explore the impact that a range of statistical decisions have on these estimates. Decisions include: (1) selecting which distribution type to apply (e.g. generalised Pareto distribution (GPD) vs. generalised extreme value distribution (GEV)); (2) if former, the choice of the threshold above which the GPD is fitted to the data; and (3) the necessity to perform a cluster analysis to group flow peaks to temporally represent individual flood events. Second, we summarise a specialised multivariate extreme value model, which combines the marginal analysis above with dependence modelling to generate industry standard event sets containing thousands of simulated, equi-probable floods across a region/country. These events represent the typical range of anticipated flooding across a region and can be used to estimate the largest or most widespread events that are expected to occur. Finally, we summarise how a reinsurance catastrophe model combines the event set with detailed flood hazard maps to estimate the financial cost of floods; both the full event set and also

  16. Masking Period Patterns & Forward Masking for Speech-Shaped Noise: Age-related effects

    Science.gov (United States)

    Grose, John H.; Menezes, Denise C.; Porter, Heather L.; Griz, Silvana

    2015-01-01

    Objective The purpose of this study was to assess age-related changes in temporal resolution in listeners with relatively normal audiograms. The hypothesis was that increased susceptibility to non-simultaneous masking contributes to the hearing difficulties experienced by older listeners in complex fluctuating backgrounds. Design Participants included younger (n = 11), middle-aged (n = 12), and older (n = 11) listeners with relatively normal audiograms. The first phase of the study measured masking period patterns for speech-shaped noise maskers and signals. From these data, temporal window shapes were derived. The second phase measured forward-masking functions, and assessed how well the temporal window fits accounted for these data. Results The masking period patterns demonstrated increased susceptibility to backward masking in the older listeners, compatible with a more symmetric temporal window in this group. The forward-masking functions exhibited an age-related decline in recovery to baseline thresholds, and there was also an increase in the variability of the temporal window fits to these data. Conclusions This study demonstrated an age-related increase in susceptibility to non-simultaneous masking, supporting the hypothesis that exacerbated non-simultaneous masking contributes to age-related difficulties understanding speech in fluctuating noise. Further support for this hypothesis comes from limited speech-in-noise data suggesting an association between susceptibility to forward masking and speech understanding in modulated noise. PMID:26230495

  17. Models for predicting turnover of residential aged care nurses: a structural equation modelling analysis of secondary data.

    Science.gov (United States)

    Gao, Fengsong; Newcombe, Peter; Tilse, Cheryl; Wilson, Jill; Tuckett, Anthony

    2014-09-01

    Nurse turnover in the residential aged care industry is a pressing issue. Researchers have shown ongoing interest in exploring how the factors that are amendable to change in aged care policy, regulation and funding and in organizational procedures (e.g. job demands, coping resources and psychological health of nurses) impact on turnover. However, the findings are mixed. This study tested two theoretical models of turnover to examine the structural relationships among job demands, coping resources, psychological health and turnover of residential aged care nurses. Although many previous studies operationalized turnover as intention to leave, the present study investigated actual turnover by following up with the same individuals over time, and thus provided more accurate predictive models of turnover behaviour. The sample, 239 Australian residential aged care nurses, came from the Nurses and Midwives e-cohort Study. Job demands, coping resources, and psychological health were measured using standardized instruments. Structural equation modelling was used to test the measurement and structural models. Controlling for a number of workforce and individual characteristics, coping resources (measured by job control, supervisor support, and co-worker support) were negatively and directly associated with turnover. Additionally, the findings supported the Job Demand-Control-Support model in that higher coping resources and lower job demands (indicated by psychological demands, physical demands, and effort) were related to better psychological health (measured by vitality, social functioning, role emotional, and mental health), and higher job demands were related to lower coping resources. Findings suggest that aged care policy makers and service providers might consider increasing coping resources available to nurses and minimizing job demands of care work to reduce turnover and improve nurses' psychological health. Moreover, findings from this Australian study may provide

  18. Dual-component model of respiratory motion based on the periodic autoregressive moving average (periodic ARMA) method

    International Nuclear Information System (INIS)

    McCall, K C; Jeraj, R

    2007-01-01

    A new approach to the problem of modelling and predicting respiration motion has been implemented. This is a dual-component model, which describes the respiration motion as a non-periodic time series superimposed onto a periodic waveform. A periodic autoregressive moving average algorithm has been used to define a mathematical model of the periodic and non-periodic components of the respiration motion. The periodic components of the motion were found by projecting multiple inhale-exhale cycles onto a common subspace. The component of the respiration signal that is left after removing this periodicity is a partially autocorrelated time series and was modelled as an autoregressive moving average (ARMA) process. The accuracy of the periodic ARMA model with respect to fluctuation in amplitude and variation in length of cycles has been assessed. A respiration phantom was developed to simulate the inter-cycle variations seen in free-breathing and coached respiration patterns. At ±14% variability in cycle length and maximum amplitude of motion, the prediction errors were 4.8% of the total motion extent for a 0.5 s ahead prediction, and 9.4% at 1.0 s lag. The prediction errors increased to 11.6% at 0.5 s and 21.6% at 1.0 s when the respiration pattern had ±34% variations in both these parameters. Our results have shown that the accuracy of the periodic ARMA model is more strongly dependent on the variations in cycle length than the amplitude of the respiration cycles

  19. Mortality increase in late-middle and early-old age: heterogeneity in death processes as a new explanation.

    Science.gov (United States)

    Li, Ting; Yang, Yang Claire; Anderson, James J

    2013-10-01

    Deviations from the Gompertz law of exponential mortality increases in late-middle and early-old age are commonly neglected in overall mortality analyses. In this study, we examined mortality increase patterns between ages 40 and 85 in 16 low-mortality countries and demonstrated sex differences in these patterns, which also changed across period and cohort. These results suggest that the interaction between aging and death is more complicated than what is usually assumed from the Gompertz law and also challenge existing biodemographic hypotheses about the origin and mechanisms of sex differences in mortality. We propose a two-mortality model that explains these patterns as the change in the composition of intrinsic and extrinsic death rates with age. We show that the age pattern of overall mortality and the population heterogeneity therein are possibly generated by multiple dynamics specified by a two-mortality model instead of a uniform process throughout most adult ages.

  20. Evaluation of mammographic surveillance services in women aged 40-49 years with a moderate family history of breast cancer: a single-arm cohort study.

    Science.gov (United States)

    Duffy, S W; Mackay, J; Thomas, S; Anderson, E; Chen, T H H; Ellis, I; Evans, G; Fielder, H; Fox, R; Gui, G; Macmillan, D; Moss, S; Rogers, C; Sibbering, M; Wallis, M; Warren, R; Watson, E; Whynes, D; Allgood, P; Caunt, J

    2013-03-01

    Women with a significant family history of breast cancer are often offered more intensive and earlier surveillance than is offered to the general population in the National Breast Screening Programme. Up to now, this strategy has not been fully evaluated. To evaluate the benefit of mammographic surveillance for women aged 40-49 years at moderate risk of breast cancer due to family history. The study is referred to as FH01. This was a single-arm cohort study with recruitment taking place between January 2003 and February 2007. Recruits were women aged women were offered annual mammography for at least 5 years and observed for the occurrence of breast cancer during the surveillance period. The age group 40-44 years was targeted so that they would still be aged women, 94% of whom were aged women aged 40-49 years with a significant family history of breast or ovarian cancer is both clinically effective in reducing breast cancer mortality and cost-effective. There is a need to further standardise familial risk assessment, to research the impact of digital mammography and to clarify the role of breast density in this population. National Research Register N0484114809. This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 11. See the HTA programme website for further project information.

  1. Understanding and Harnessing the Power of the Cohort Model in Preparing Educational Leaders.

    Science.gov (United States)

    Teitel, Lee

    1997-01-01

    The University of Massachusetts at Boston (UMB) shifted all of its school leadership programs to the cohort model. This article reviews UMB's school leadership programs, describes the survey methodology used to take stock of the program and its cohort design, then summarizes survey findings to identify five different types of impacts reported by…

  2. Lung cancer risk comparison among male smokers between the "six-prefecture cohort" in Japan and the British physicians' cohort.

    Science.gov (United States)

    Mizuno, S; Akiba, S; Hirayama, T

    1989-12-01

    We estimated the effective duration of cigarette smoking using the data of lung cancer mortality among male smokers of a large-scale cohort study in Japan and evaluated its role in the lung cancer risk difference between male smokers of the Japanese cohort and the British physicians' cohort. By selecting male cohort members who answered that they had started smoking at ages 18-22 (average = 20.3), the subjects of our analysis, which numbered 49,013, were made relatively homogeneous in terms of age at which smoking was started. Assuming lung cancer mortality to be proportional to the 4.5th power of the effective duration of cigarette smoking, i.e., (age-theta)4.5, as was proposed on the basis of the British cohort study by Doll and Peto, the parameter theta was estimated to be 29.4 for male smokers aged 40-64 in 1966; therefore, the estimated duration of cigarette smoking was, on average, 9.1 years (95% confidence interval = 5.8-11.6) shorter than that calculated from the reported age at which smoking was started. Our findings suggested that the low lung cancer mortality relative to daily cigarette consumption in Japan resulted from the shorter duration of cigarette smoking in the Japanese cohort, possibly due to the severe shortage of cigarettes during and shortly after World War II. Once the effective duration of cigarette smoking was adjusted, lung cancer mortality in the range of 5-34 cigarettes per day was fairly comparable to that observed among the cohort of male British physicians.

  3. Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

    Science.gov (United States)

    Assefa, Yibeltal; Worku, Alemayehu; Wouters, Edwin; Koole, Olivier; Haile Mariam, Damen; Van Damme, Wim

    2012-01-01

    Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

  4. Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

    Directory of Open Access Journals (Sweden)

    Yibeltal Assefa

    Full Text Available INTRODUCTION: Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. METHODS: Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. RESULTS: We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. CONCLUSION: The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

  5. Basis for the ICRP's age-specific biokinetic model for uranium

    International Nuclear Information System (INIS)

    Leggett, R.W.

    1994-01-01

    In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is developing age-specific biokinetic models and dose coefficients for environmentally important radionuclides. This paper describes the ICRP's age-specific biokinetic model for uranium. The model is constructed within a physiologically based framework originally developed for application to the alkaline earth elements but sufficiently general to apply to the larger class of bone-volume-seeking elements. Transfer rates for a reference adult are based mainly on: (1) measurements of uranium in blood and excreta of several human subjects who were intravenously injected with uranium; (2) postmortem measurements of uranium in tissues of some of those subjects; (3) postmortem measurements of uranium in tissues of occupationally and non-occupationally exposed subjects; (4) data on baboons, dogs, and smaller laboratory animals exposed to uranium for experimental purposes; and (5) consideration of the physiological processes thought to control retention and translocation of uranium in the body. Transfer rates for the adult are extended to children by application of a set of generic assumptions applied by the ICRP to calcium-like elements. These assumptions were derived mainly from observations of the age-specific biokinetics of the alkaline earth elements and lead in humans and laboratory animals but are consistent with available age-specific biokinetic data on uranium. 82 refs., 17 figs., 8 tabs

  6. Periodic Properties and Inquiry: Student Mental Models Observed during a Periodic Table Puzzle Activity

    Science.gov (United States)

    Larson, Kathleen G.; Long, George R.; Briggs, Michael W.

    2012-01-01

    The mental models of both novice and advanced chemistry students were observed while the students performed a periodic table activity. The mental model framework seems to be an effective way of analyzing student behavior during learning activities. The analysis suggests that students do not recognize periodic trends through the examination of…

  7. More active pre-school children have better motor competence at school starting age: an observational cohort study.

    Science.gov (United States)

    Barnett, Lisa M; Salmon, Jo; Hesketh, Kylie D

    2016-10-10

    Almost half of young children do not achieve minimum recommendations of 60 daily minutes in physical activity. Physical activity is potentially an important determinant of the development of motor competence in children. This study is one of very few longitudinal studies in this area and the first to investigate early childhood physical activity as a predictor of subsequent motor skill competence. Children were assessed as part of the Melbourne InFANT Program longitudinal cohort study at 19 months, 3.5 years and 5 years. Moderate-to-vigorous physical activity (MVPA) (accelerometry) was assessed at each time point. At age 5, children were also assessed in actual (Test of Gross Motor Development-2) and perceived motor competence (Pictorial Scale of Perceived Movement Skill Competence). General linear models were performed with all 12 skills (six object control and six locomotor skills), both actual and perceived, at age 5 as the respective outcome variables. Predictor variables alternated between MVPA at 19 months, 3.5 years and 5 years. Based on standardized TGMD-2 scores most children were average or below in their skill level at age 5. MVPA at 19 months was not a predictor of actual or perceived skill at age 5. MVPA at 3.5 years was associated with actual locomotor skill (B = 0.073, p = 0.033) and perceived total skill at 5 years of age (B = 0.059, p = 0.044). MVPA was not a predictor of actual or perceived object control skill at any age. Parents and preschool staff should be informed that more time in MVPA as a preschool child contributes to locomotor skill and to perceptions of skill ability in a child of school starting age. Understanding this relationship will assist in intervention development.

  8. More active pre-school children have better motor competence at school starting age: an observational cohort study

    Directory of Open Access Journals (Sweden)

    Lisa M. Barnett

    2016-10-01

    Full Text Available Abstract Background Almost half of young children do not achieve minimum recommendations of 60 daily minutes in physical activity. Physical activity is potentially an important determinant of the development of motor competence in children. This study is one of very few longitudinal studies in this area and the first to investigate early childhood physical activity as a predictor of subsequent motor skill competence. Methods Children were assessed as part of the Melbourne InFANT Program longitudinal cohort study at 19 months, 3.5 years and 5 years. Moderate-to-vigorous physical activity (MVPA (accelerometry was assessed at each time point. At age 5, children were also assessed in actual (Test of Gross Motor Development-2 and perceived motor competence (Pictorial Scale of Perceived Movement Skill Competence. General linear models were performed with all 12 skills (six object control and six locomotor skills, both actual and perceived, at age 5 as the respective outcome variables. Predictor variables alternated between MVPA at 19 months, 3.5 years and 5 years. Results Based on standardized TGMD-2 scores most children were average or below in their skill level at age 5. MVPA at 19 months was not a predictor of actual or perceived skill at age 5. MVPA at 3.5 years was associated with actual locomotor skill (B = 0.073, p = 0.033 and perceived total skill at 5 years of age (B = 0.059, p = 0.044. MVPA was not a predictor of actual or perceived object control skill at any age. Conclusion Parents and preschool staff should be informed that more time in MVPA as a preschool child contributes to locomotor skill and to perceptions of skill ability in a child of school starting age. Understanding this relationship will assist in intervention development.

  9. Burden of Clostridium difficile infection: Associated hospitalization in a cohort of middle-aged and older adults.

    Science.gov (United States)

    Chen, Yingxi; Glass, Kathryn; Liu, Bette; Korda, Rosemary J; Riley, Thomas V; Kirk, Martyn D

    2017-05-01

    Clostridium difficile is the principal cause of infectious diarrhea in hospitalized patients. The aim of this study was to describe and compare length of stay (LOS), costs, and in-hospital deaths for C difficile infection (CDI) and non-CDI hospitalizations, in a cohort of middle-aged and older Australians. We used survey data from the 45 and Up Study, linked to hospitalization and death data. We calculated the average LOS and costs per hospitalization, and the proportion of in-hospital deaths for CDI and non-CDI hospitalizations. We then compared hospitalizations with CDI as a secondary diagnosis to non-CDI hospitalizations by stratifying hospitalizations based on principal diagnosis and then using generalized linear models to compare LOS and in-hospital costs, and logistic regression for in-hospital deaths, adjusting for age and sex. There were 641 CDI hospitalizations during 2006-2012. The average LOS was 17 days; the average cost per hospitalization was AUD 12,704; and in 7.3% of admissions (47 out of 641) the patient died. After adjusting for age and sex, hospitalizations with CDI were associated with longer LOS, higher costs, and a greater proportion of in-hospital deaths compared with hospitalizations with similar principal diagnosis but without CDI. CDI places additional burden on the Australian hospital system, with CDI patients having relatively lengthy hospital stays and high costs. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  10. A health economic model for the development and evaluation of innovations in aged care: an application to consumer-directed care-study protocol.

    Science.gov (United States)

    Ratcliffe, Julie; Lancsar, Emily; Luszcz, Mary; Crotty, Maria; Gray, Len; Paterson, Jan; Cameron, Ian D

    2014-06-25

    Consumer-directed care is currently being embraced within Australia and internationally as a means of promoting autonomy and choice in the delivery of health and aged care services. Despite its wide proliferation little research has been conducted to date to assess the views and preferences of older people for consumer-directed care or to assess the costs and benefits of such an approach relative to existing models of service delivery. A comprehensive health economic model will be developed and applied to the evolution, implementation and evaluation of consumer-directed care in an Australian community aged care setting. A mixed methods approach comprising qualitative interviews and a discrete choice experiment will determine the attitudes and preferences of older people and their informal carers for consumer-directed care. The results of the qualitative interviews and the discrete choice experiment will inform the introduction of a new consumer-directed care innovation in service delivery. The cost-effectiveness of consumer-directed care will be evaluated by comparing incremental changes in resource use, costs and health and quality of life outcomes relative to traditional services. The discrete choice experiment will be repeated at the end of the implementation period to determine the extent to which attitudes and preferences change as a consequence of experience of consumer-directed care. The proposed framework will have wide applicability in the future development and economic evaluation of new innovations across the health and aged care sectors. The study is approved by Flinders University Social and Behavioural Research Ethics Committee (Project No. 6114/SBREC). Findings from the qualitative interviews, discrete choice experiments and the economic evaluation will be reported at a workshop of stakeholders to be held in 2015 and will be documented in reports and in peer reviewed journal articles. Published by the BMJ Publishing Group Limited. For permission to

  11. Reference Values and Age Differences in Body Composition of Community-Dwelling Older Japanese Men and Women: A Pooled Analysis of Four Cohort Studies.

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    Satoshi Seino

    Full Text Available To determine age- and sex-specific body composition reference values and investigate age differences in these parameters for community-dwelling older Japanese men and women, using direct segmental multi-frequency bioelectrical impedance analysis.We conducted a pooled analysis of data collected in four cohort studies between 2008 and 2012: Kusatsu Longitudinal Study, Hatoyama Cohort Study, Itabashi Cohort Study, and Kashiwa Cohort Study. The pooled analysis included cross-sectional data from 4478 nondisabled, community-dwelling adults aged 65-94 years (2145 men, 2333 women; mean age: 72.9 years in men and 72.6 years in women. Body weight, fat mass (FM, percentage FM, fat-free mass (FFM, and appendicular lean soft tissue mass were measured using the InBody 720 and 430 (Biospace Co. Ltd, Seoul, Korea. The values were then normalized by height in meters squared to determine body mass index (BMI, FM index (FMI, FFM index (FFMI, and skeletal muscle mass index (SMI.Simple means (standard deviation of BMI, percentage FM, FMI, FFMI, and SMI were 23.4 (2.9 kg/m(2, 24.9 (6.3%, 5.96 (2.09 kg/m(2, 17.4 (1.5 kg/m(2, and 7.29 (0.76 kg/m(2, respectively, in men and 22.7 (3.3 kg/m(2, 31.7 (7.1%, 7.40 (2.61 kg/m(2, 15.3 (1.2 kg/m(2, and 5.86 (0.67 kg/m(2, respectively, in women. We then calculated quartiles and quintiles for these indices after stratifying for sex and 5-year age group. FFMI and SMI decreased significantly with age in both sexes (P < 0.001 for trends, but FFMI remained constant among the women with only a 1% decrease up to age 84 years. Percentage FM increased significantly, with age (P < 0.001 in men and P = 0.045 in women for trends, but FMI was unchanged in both sexes (P = 0.147 in men and P = 0.176 in women for trends.The present data should be useful in the clinical evaluation of body composition of older Japanese and for international comparisons. The small age-related decrease in FFMI may be a noteworthy characteristic of body composition

  12. Health and aging in elderly farmers: the AMI cohort

    Directory of Open Access Journals (Sweden)

    Pérès Karine

    2012-07-01

    Full Text Available Abstract Background The health of the agricultural population has been previously explored, particularly in relation to the farming exposures and among professionally active individuals. However, few studies specifically focused on health and aging among elders retired from agriculture. Yet, this population faces the long-term effects of occupational exposures and multiple difficulties related to living and aging in rural area (limited access to shops, services, and practitioners. However, these difficulties may be counter-balanced by advantages related to healthier lifestyle, richer social support and better living environment. The general aim of the AMI cohort was to study health and aging in elderly farmers living in rural area through a multidisciplinary approach, with a main focus on dementia. Methods/design The study initially included 1 002 participants, randomly selected from the Farmer Health Insurance rolls. Selection criteria were: being 65 years and older; living in rural area in Gironde (South-Western France; being retired from agriculture after at least 20 years of activity and being affiliated to the Health Insurance under own name. The study started in 2007, with two follow-up visits over 5 years. Baseline visits were conducted at home by a neuropsychologist then by a geriatrician for all cases suspected of dementia, Parkinson’s disease and depression (to confirm the diagnosis, and by a nurse for others. A large panel of data were collected through standardised questionnaires: complete neuropsychological assessment, material and social living environment, psychological transition to retirement, lifestyle (smoking, alcohol and diet, medications, disability in daily living, sensory impairments and some clinical measures (blood pressure, depression symptomatology, anxiety, visual test, anthropometry…. A blood sampling was performed with biological measurements and constitution of a biological bank, including DNA. Brain MRI

  13. Functional Activation during the Rapid Visual Information Processing Task in a Middle Aged Cohort: An fMRI Study.

    Science.gov (United States)

    Neale, Chris; Johnston, Patrick; Hughes, Matthew; Scholey, Andrew

    2015-01-01

    The Rapid Visual Information Processing (RVIP) task, a serial discrimination task where task performance believed to reflect sustained attention capabilities, is widely used in behavioural research and increasingly in neuroimaging studies. To date, functional neuroimaging research into the RVIP has been undertaken using block analyses, reflecting the sustained processing involved in the task, but not necessarily the transient processes associated with individual trial performance. Furthermore, this research has been limited to young cohorts. This study assessed the behavioural and functional magnetic resonance imaging (fMRI) outcomes of the RVIP task using both block and event-related analyses in a healthy middle aged cohort (mean age = 53.56 years, n = 16). The results show that the version of the RVIP used here is sensitive to changes in attentional demand processes with participants achieving a 43% accuracy hit rate in the experimental task compared with 96% accuracy in the control task. As shown by previous research, the block analysis revealed an increase in activation in a network of frontal, parietal, occipital and cerebellar regions. The event related analysis showed a similar network of activation, seemingly omitting regions involved in the processing of the task (as shown in the block analysis), such as occipital areas and the thalamus, providing an indication of a network of regions involved in correct trial performance. Frontal (superior and inferior frontal gryi), parietal (precuenus, inferior parietal lobe) and cerebellar regions were shown to be active in both the block and event-related analyses, suggesting their importance in sustained attention/vigilance. These networks and the differences between them are discussed in detail, as well as implications for future research in middle aged cohorts.

  14. Functional Activation during the Rapid Visual Information Processing Task in a Middle Aged Cohort: An fMRI Study.

    Directory of Open Access Journals (Sweden)

    Chris Neale

    Full Text Available The Rapid Visual Information Processing (RVIP task, a serial discrimination task where task performance believed to reflect sustained attention capabilities, is widely used in behavioural research and increasingly in neuroimaging studies. To date, functional neuroimaging research into the RVIP has been undertaken using block analyses, reflecting the sustained processing involved in the task, but not necessarily the transient processes associated with individual trial performance. Furthermore, this research has been limited to young cohorts. This study assessed the behavioural and functional magnetic resonance imaging (fMRI outcomes of the RVIP task using both block and event-related analyses in a healthy middle aged cohort (mean age = 53.56 years, n = 16. The results show that the version of the RVIP used here is sensitive to changes in attentional demand processes with participants achieving a 43% accuracy hit rate in the experimental task compared with 96% accuracy in the control task. As shown by previous research, the block analysis revealed an increase in activation in a network of frontal, parietal, occipital and cerebellar regions. The event related analysis showed a similar network of activation, seemingly omitting regions involved in the processing of the task (as shown in the block analysis, such as occipital areas and the thalamus, providing an indication of a network of regions involved in correct trial performance. Frontal (superior and inferior frontal gryi, parietal (precuenus, inferior parietal lobe and cerebellar regions were shown to be active in both the block and event-related analyses, suggesting their importance in sustained attention/vigilance. These networks and the differences between them are discussed in detail, as well as implications for future research in middle aged cohorts.

  15. Ageing and the economic life cycle: The National Transfer Accounts approach.

    Science.gov (United States)

    Temple, Jeromey B; Rice, James M; McDonald, Peter F

    2017-12-01

    To illustrate the use of National Transfer Accounts (NTA) for understanding ageing and the economic life cycle in Australia. The NTA methodology is applied utilising a range of unit record, demographic and administrative data sets from 1981 to 2010. During early and later life, total consumption (public and private) is greater than labour income. On a time series and cohort basis, we show that each successive generation has improved their level of well-being (as measured by consumption) relative to the previous years or previous cohorts from 1981 to 1982 onwards. We also show a substantial increase in labour income earned by mature age workers over this period. International comparisons show Australia to have consumption and labour income age profiles very similar to those of Canada but dissimilar to many other countries, driven by differences in demographic and policy settings. The NTA approach provides a powerful framework to track differences in the economic life cycle across age groups, across time, across cohorts and across countries. © 2017 AJA Inc.

  16. Impact of early personal-history characteristics on the Pace of Aging: implications for clinical trials of therapies to slow aging and extend healthspan.

    Science.gov (United States)

    Belsky, Daniel W; Caspi, Avshalom; Cohen, Harvey J; Kraus, William E; Ramrakha, Sandhya; Poulton, Richie; Moffitt, Terrie E

    2017-08-01

    Therapies to extend healthspan are poised to move from laboratory animal models to human clinical trials. Translation from mouse to human will entail challenges, among them the multifactorial heterogeneity of human aging. To inform clinical trials about this heterogeneity, we report how humans' pace of biological aging relates to personal-history characteristics. Because geroprotective therapies must be delivered by midlife to prevent age-related disease onset, we studied young-adult members of the Dunedin Study 1972-73 birth cohort (n = 954). Cohort members' Pace of Aging was measured as coordinated decline in the integrity of multiple organ systems, by quantifying rate of decline across repeated measurements of 18 biomarkers assayed when cohort members were ages 26, 32, and 38 years. The childhood personal-history characteristics studied were known predictors of age-related disease and mortality, and were measured prospectively during childhood. Personal-history characteristics of familial longevity, childhood social class, adverse childhood experiences, and childhood health, intelligence, and self-control all predicted differences in cohort members' adulthood Pace of Aging. Accumulation of more personal-history risks predicted faster Pace of Aging. Because trials of anti-aging therapies will need to ascertain personal histories retrospectively, we replicated results using cohort members' retrospective personal-history reports made in adulthood. Because many trials recruit participants from clinical settings, we replicated results in the cohort subset who had recent health system contact according to electronic medical records. Quick, inexpensive measures of trial participants' early personal histories can enable clinical trials to study who volunteers for trials, who adheres to treatment, and who responds to anti-aging therapies. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  17. Does the impact of subsequent incontinence risk factors depend on continence status during the first pregnancy or the postpartum period 12 years before? A cohort study in 232 primiparous women.

    Science.gov (United States)

    Viktrup, Lars; Rortveit, Guri; Lose, Gunnar

    2008-07-01

    Assess the impact of subsequent urinary incontinence risk factors in women with different urinary incontinence history. In a cohort study 232 women answered validated questions about urinary incontinence after the first delivery and 12 years later. Women who were continent during the first pregnancy or postpartum period (group 1) or who became incontinent during these periods (group 2) were identified. Urinary incontinence symptoms 12 years after the first delivery were reported by 32.6% (44/135) in group 1 and 66.0% (64/97) in group 2. Overweight and to a minor extent pelvic organ prolapse symptoms or heavy lifting at work was associated with higher relative risk of urinary incontinence in group 1 compared with group 2. Other risk factors such as age, breastfeeding 6 months or longer after both the first and second deliveries, bowel movements or urinary infections were not associated differentially with urinary incontinence in the 2 groups. Subsequent risk factors had a more significant impact in women without initial urinary incontinence.

  18. Variational Wavefunction for the Periodic Anderson Model with Onsite Correlation Factors

    Science.gov (United States)

    Kubo, Katsunori; Onishi, Hiroaki

    2017-01-01

    We propose a variational wavefunction containing parameters to tune the probabilities of all the possible onsite configurations for the periodic Anderson model. We call it the full onsite-correlation wavefunction (FOWF). This is a simple extension of the Gutzwiller wavefunction (GWF), in which one parameter is included to tune the double occupancy of the f electrons at the same site. We compare the energy of the GWF and the FOWF evaluated by the variational Monte Carlo method and that obtained with the density-matrix renormalization group method. We find that the energy is considerably improved in the FOWF. On the other hand, the physical quantities do not change significantly between these two wavefunctions as long as they describe the same phase, such as the paramagnetic phase. From these results, we not only demonstrate the improvement by the FOWF, but we also gain insights on the applicability and limitation of the GWF to the periodic Anderson model.

  19. Variational wavefunction for the periodic anderson model with onsite correlation factors

    International Nuclear Information System (INIS)

    Kubo, Katsunori; Onishi, Hiroaki

    2017-01-01

    We propose a variational wavefunction containing parameters to tune the probabilities of all the possible onsite configurations for the periodic Anderson model. We call it the full onsite-correlation wavefunction (FOWF). This is a simple extension of the Gutzwiller wavefunction (GWF), in which one parameter is included to tune the double occupancy of the f electrons at the same site. We compare the energy of the GWF and the FOWF evaluated by the variational Monte Carlo method and that obtained with the density-matrix renormalization group method. We find that the energy is considerably improved in the FOWF. On the other hand, the physical quantities do not change significantly between these two wavefunctions as long as they describe the same phase, such as the paramagnetic phase. From these results, we not only demonstrate the improvement by the FOWF, but we also gain insights on the applicability and limitation of the GWF to the periodic Anderson model. (author)

  20. Body Esteem in a Western Australian Cleft Lip and/or Palate Cohort Across 3 Age Groups.

    Science.gov (United States)

    Nicholls, Wendy; Harper, Craig; Selvey, Linda A; Robinson, Suzanne; Hartig, Gerald; Persson, Martin

    2018-04-01

    To determine if patients with cleft lip and/or palate (CL/P) from a Western Australian (WA) cohort were more dissatisfied with their body esteem than a normative non-cleft cohort, and identify demographic variables that may have significant associations with body esteem. Questionnaire study using the Body-Esteem Scale (BES) and Cleft Research Questionnaire (CRQ). Self-selected participants from a Western Australian CL/P population across 3 age groups (n=359). The BES is comprised of 3 factors: BE-Appearance, BE-Weight and BE-Attribution. Study mean BES factor scores were compared to normative non-cleft scores. Regression analysis was used to determine significant associations within each age group between BES factor scores and CRQ variables of: gender, self-reported body weight category, cleft type and importance of facial appearance rating. Study mean BE-Attribution scores were significantly lower than the normative scores and significantly lower than the mean BE-Appearance and BE-Weight factor scores within the same age groups of this study. Having a cleft type of lip and palate, being overweight, and placing a high importance on facial appearance had significant negative associations with BES scores. Maintaining a normal body weight and placing a lower level of importance on facial appearance had significant positive associations. Gender had no significant associations. In this study, the attribution aspect of body esteem had a greater negative impact on patients than their appearance and body weight. This has important implications for clinical treatment and support of patients.