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  1. Risk Factors of Falls in Community-Dwelling Older Adults: Logistic Regression Tree Analysis

    Science.gov (United States)

    Yamashita, Takashi; Noe, Douglas A.; Bailer, A. John

    2012-01-01

    Purpose of the Study: A novel logistic regression tree-based method was applied to identify fall risk factors and possible interaction effects of those risk factors. Design and Methods: A nationally representative sample of American older adults aged 65 years and older (N = 9,592) in the Health and Retirement Study 2004 and 2006 modules was used.…

  2. Global burden of road traffic accidents in older adults: A systematic review and meta-regression analysis.

    Science.gov (United States)

    Ang, Boon Hong; Chen, Won Sun; Lee, Shaun Wen Huey

    2017-09-01

    This study aims to estimate the burden of road traffic accidents and death among older adults. A systematic literature review was conducted on 10 electronic databases for articles describing Road Traffic Accident(RTA) mortality in older adults until September 2016. A random-effects meta-regression analyses was conducted to estimate the pooled rates of road traffic accidents and death. A total 5018 studies were identified and 23 studies were included. Most of the reported older adults were aged between 60 and 74 years, with majority being male gender and sustained minor trauma due to Motor-Vehicle Collision (MVC). The overall pooled mortality rate was 14% (95% Confidence Interval, CI: 11%, 16%), with higher mortality rates in studies conducted in North America (15%, 95% CI: 12%, 18%) and older adults admitted to trauma centers (17%, 95% CI: 14%, 21%). Secondary analysis showed that the very elderly adults (aged >75years) and pedestrians had higher odds of mortality death (Odds Ratio, OR: 2.05, 95% CI: 1.25, 3.38; OR: 2.08, 95% CI: 1.63, 2.66, respectively). A new comprehensive trauma management guidelines tailored to older adults should be established in low and middle-income countries where such guidelines are still lacking. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Regression analysis by example

    CERN Document Server

    Chatterjee, Samprit

    2012-01-01

    Praise for the Fourth Edition: ""This book is . . . an excellent source of examples for regression analysis. It has been and still is readily readable and understandable."" -Journal of the American Statistical Association Regression analysis is a conceptually simple method for investigating relationships among variables. Carrying out a successful application of regression analysis, however, requires a balance of theoretical results, empirical rules, and subjective judgment. Regression Analysis by Example, Fifth Edition has been expanded

  4. Principal component regression analysis with SPSS.

    Science.gov (United States)

    Liu, R X; Kuang, J; Gong, Q; Hou, X L

    2003-06-01

    The paper introduces all indices of multicollinearity diagnoses, the basic principle of principal component regression and determination of 'best' equation method. The paper uses an example to describe how to do principal component regression analysis with SPSS 10.0: including all calculating processes of the principal component regression and all operations of linear regression, factor analysis, descriptives, compute variable and bivariate correlations procedures in SPSS 10.0. The principal component regression analysis can be used to overcome disturbance of the multicollinearity. The simplified, speeded up and accurate statistical effect is reached through the principal component regression analysis with SPSS.

  5. Polynomial regression analysis and significance test of the regression function

    International Nuclear Information System (INIS)

    Gao Zhengming; Zhao Juan; He Shengping

    2012-01-01

    In order to analyze the decay heating power of a certain radioactive isotope per kilogram with polynomial regression method, the paper firstly demonstrated the broad usage of polynomial function and deduced its parameters with ordinary least squares estimate. Then significance test method of polynomial regression function is derived considering the similarity between the polynomial regression model and the multivariable linear regression model. Finally, polynomial regression analysis and significance test of the polynomial function are done to the decay heating power of the iso tope per kilogram in accord with the authors' real work. (authors)

  6. Applied regression analysis a research tool

    CERN Document Server

    Pantula, Sastry; Dickey, David

    1998-01-01

    Least squares estimation, when used appropriately, is a powerful research tool. A deeper understanding of the regression concepts is essential for achieving optimal benefits from a least squares analysis. This book builds on the fundamentals of statistical methods and provides appropriate concepts that will allow a scientist to use least squares as an effective research tool. Applied Regression Analysis is aimed at the scientist who wishes to gain a working knowledge of regression analysis. The basic purpose of this book is to develop an understanding of least squares and related statistical methods without becoming excessively mathematical. It is the outgrowth of more than 30 years of consulting experience with scientists and many years of teaching an applied regression course to graduate students. Applied Regression Analysis serves as an excellent text for a service course on regression for non-statisticians and as a reference for researchers. It also provides a bridge between a two-semester introduction to...

  7. Regression Analysis by Example. 5th Edition

    Science.gov (United States)

    Chatterjee, Samprit; Hadi, Ali S.

    2012-01-01

    Regression analysis is a conceptually simple method for investigating relationships among variables. Carrying out a successful application of regression analysis, however, requires a balance of theoretical results, empirical rules, and subjective judgment. "Regression Analysis by Example, Fifth Edition" has been expanded and thoroughly…

  8. Assessing the Multidimensional Relationship Between Medication Beliefs and Adherence in Older Adults With Hypertension Using Polynomial Regression.

    Science.gov (United States)

    Dillon, Paul; Phillips, L Alison; Gallagher, Paul; Smith, Susan M; Stewart, Derek; Cousins, Gráinne

    2018-02-05

    The Necessity-Concerns Framework (NCF) is a multidimensional theory describing the relationship between patients' positive and negative evaluations of their medication which interplay to influence adherence. Most studies evaluating the NCF have failed to account for the multidimensional nature of the theory, placing the separate dimensions of medication "necessity beliefs" and "concerns" onto a single dimension (e.g., the Beliefs about Medicines Questionnaire-difference score model). To assess the multidimensional effect of patient medication beliefs (concerns and necessity beliefs) on medication adherence using polynomial regression with response surface analysis. Community-dwelling older adults >65 years (n = 1,211) presenting their own prescription for antihypertensive medication to 106 community pharmacies in the Republic of Ireland rated their concerns and necessity beliefs to antihypertensive medications at baseline and their adherence to antihypertensive medication at 12 months via structured telephone interview. Confirmatory polynomial regression found the difference-score model to be inaccurate; subsequent exploratory analysis identified a quadratic model to be the best-fitting polynomial model. Adherence was lowest among those with strong medication concerns and weak necessity beliefs, and adherence was greatest for those with weak concerns and strong necessity beliefs (slope β = -0.77, pnecessity beliefs had lower adherence than those with simultaneously low concerns and necessity beliefs (slope β = -0.36, p = .004; curvature β = -0.25, p = .003). The difference-score model fails to account for the potential nonreciprocal effects. Results extend evidence supporting the use of polynomial regression to assess the multidimensional effect of medication beliefs on adherence.

  9. Regression analysis with categorized regression calibrated exposure: some interesting findings

    Directory of Open Access Journals (Sweden)

    Hjartåker Anette

    2006-07-01

    Full Text Available Abstract Background Regression calibration as a method for handling measurement error is becoming increasingly well-known and used in epidemiologic research. However, the standard version of the method is not appropriate for exposure analyzed on a categorical (e.g. quintile scale, an approach commonly used in epidemiologic studies. A tempting solution could then be to use the predicted continuous exposure obtained through the regression calibration method and treat it as an approximation to the true exposure, that is, include the categorized calibrated exposure in the main regression analysis. Methods We use semi-analytical calculations and simulations to evaluate the performance of the proposed approach compared to the naive approach of not correcting for measurement error, in situations where analyses are performed on quintile scale and when incorporating the original scale into the categorical variables, respectively. We also present analyses of real data, containing measures of folate intake and depression, from the Norwegian Women and Cancer study (NOWAC. Results In cases where extra information is available through replicated measurements and not validation data, regression calibration does not maintain important qualities of the true exposure distribution, thus estimates of variance and percentiles can be severely biased. We show that the outlined approach maintains much, in some cases all, of the misclassification found in the observed exposure. For that reason, regression analysis with the corrected variable included on a categorical scale is still biased. In some cases the corrected estimates are analytically equal to those obtained by the naive approach. Regression calibration is however vastly superior to the naive method when applying the medians of each category in the analysis. Conclusion Regression calibration in its most well-known form is not appropriate for measurement error correction when the exposure is analyzed on a

  10. Gaussian process regression analysis for functional data

    CERN Document Server

    Shi, Jian Qing

    2011-01-01

    Gaussian Process Regression Analysis for Functional Data presents nonparametric statistical methods for functional regression analysis, specifically the methods based on a Gaussian process prior in a functional space. The authors focus on problems involving functional response variables and mixed covariates of functional and scalar variables.Covering the basics of Gaussian process regression, the first several chapters discuss functional data analysis, theoretical aspects based on the asymptotic properties of Gaussian process regression models, and new methodological developments for high dime

  11. Global Prevalence of Elder Abuse: A Meta-analysis and Meta-regression.

    Science.gov (United States)

    Ho, C Sh; Wong, S Y; Chiu, M M; Ho, R Cm

    2017-06-01

    Elder abuse is increasingly recognised as a global public health and social problem. There has been limited inter-study comparison of the prevalence and risk factors for elder abuse. This study aimed to estimate the pooled and subtype prevalence of elder abuse worldwide and identify significant associated risk factors. We conducted a meta-analysis and meta-regression of 34 population-based and 17 non-population-based studies. The pooled prevalences of elder abuse were 10.0% (95% confidence interval, 5.2%-18.6%) and 34.3% (95% confidence interval, 22.9%-47.8%) in population-based studies and third party- or caregiver-reported studies, respectively. Being in a marital relationship was found to be a significant moderator using random-effects model. This meta-analysis revealed that third parties or caregivers were more likely to report abuse than older abused adults. Subgroup analyses showed that females and those resident in non-western countries were more likely to be abused. Emotional abuse was the most prevalent elder abuse subtype and financial abuse was less commonly reported by third parties or caregivers. Heterogeneity in the prevalence was due to the high proportion of married older adults in the sample. Subgroup analysis showed that cultural factors, subtypes of abuse, and gender also contributed to heterogeneity in the pooled prevalence of elder abuse.

  12. Identifying Dietary Patterns Associated with Mild Cognitive Impairment in Older Korean Adults Using Reduced Rank Regression

    Directory of Open Access Journals (Sweden)

    Dayeon Shin

    2018-01-01

    Full Text Available Diet plays a crucial role in cognitive function. Few studies have examined the relationship between dietary patterns and cognitive functions of older adults in the Korean population. This study aimed to identify the effect of dietary patterns on the risk of mild cognitive impairment. A total of 239 participants, including 88 men and 151 women, aged 65 years and older were selected from health centers in the district of Seoul, Gyeonggi province, and Incheon, in Korea. Dietary patterns were determined using Reduced Rank Regression (RRR methods with responses regarding vitamin B6, vitamin C, and iron intakes, based on both a one-day 24-h recall and a food frequency questionnaire. Cognitive function was assessed using the Korean-Mini Mental State Examination (K-MMSE. Multivariable logistic regression models were used to estimate the association between dietary pattern score and the risk of mild cognitive impairment. A total of 20 (8% out of the 239 participants had mild cognitive impairment. Three dietary patterns were identified: seafood and vegetables, high meat, and bread, ham, and alcohol. Among the three dietary patterns, the older adult population who adhered to the seafood and vegetables pattern, characterized by high intake of seafood, vegetables, fruits, bread, snacks, soy products, beans, chicken, pork, ham, egg, and milk had a decreased risk of mild cognitive impairment compared to those who did not (adjusted odds ratios 0.06, 95% confidence interval 0.01–0.72 after controlling for gender, supplementation, education, history of dementia, physical activity, body mass index (BMI, and duration of sleep. The other two dietary patterns were not significantly associated with the risk of mild cognitive impairment. In conclusion, high consumption of fruits, vegetables, seafood, and protein foods was significantly associated with reduced mild cognitive impairment in older Korean adults. These results can contribute to the establishment of

  13. Regression and regression analysis time series prediction modeling on climate data of quetta, pakistan

    International Nuclear Information System (INIS)

    Jafri, Y.Z.; Kamal, L.

    2007-01-01

    Various statistical techniques was used on five-year data from 1998-2002 of average humidity, rainfall, maximum and minimum temperatures, respectively. The relationships to regression analysis time series (RATS) were developed for determining the overall trend of these climate parameters on the basis of which forecast models can be corrected and modified. We computed the coefficient of determination as a measure of goodness of fit, to our polynomial regression analysis time series (PRATS). The correlation to multiple linear regression (MLR) and multiple linear regression analysis time series (MLRATS) were also developed for deciphering the interdependence of weather parameters. Spearman's rand correlation and Goldfeld-Quandt test were used to check the uniformity or non-uniformity of variances in our fit to polynomial regression (PR). The Breusch-Pagan test was applied to MLR and MLRATS, respectively which yielded homoscedasticity. We also employed Bartlett's test for homogeneity of variances on a five-year data of rainfall and humidity, respectively which showed that the variances in rainfall data were not homogenous while in case of humidity, were homogenous. Our results on regression and regression analysis time series show the best fit to prediction modeling on climatic data of Quetta, Pakistan. (author)

  14. Regression Analysis and the Sociological Imagination

    Science.gov (United States)

    De Maio, Fernando

    2014-01-01

    Regression analysis is an important aspect of most introductory statistics courses in sociology but is often presented in contexts divorced from the central concerns that bring students into the discipline. Consequently, we present five lesson ideas that emerge from a regression analysis of income inequality and mortality in the USA and Canada.

  15. Polylinear regression analysis in radiochemistry

    International Nuclear Information System (INIS)

    Kopyrin, A.A.; Terent'eva, T.N.; Khramov, N.N.

    1995-01-01

    A number of radiochemical problems have been formulated in the framework of polylinear regression analysis, which permits the use of conventional mathematical methods for their solution. The authors have considered features of the use of polylinear regression analysis for estimating the contributions of various sources to the atmospheric pollution, for studying irradiated nuclear fuel, for estimating concentrations from spectral data, for measuring neutron fields of a nuclear reactor, for estimating crystal lattice parameters from X-ray diffraction patterns, for interpreting data of X-ray fluorescence analysis, for estimating complex formation constants, and for analyzing results of radiometric measurements. The problem of estimating the target parameters can be incorrect at certain properties of the system under study. The authors showed the possibility of regularization by adding a fictitious set of data open-quotes obtainedclose quotes from the orthogonal design. To estimate only a part of the parameters under consideration, the authors used incomplete rank models. In this case, it is necessary to take into account the possibility of confounding estimates. An algorithm for evaluating the degree of confounding is presented which is realized using standard software or regression analysis

  16. Linear Regression Analysis

    CERN Document Server

    Seber, George A F

    2012-01-01

    Concise, mathematically clear, and comprehensive treatment of the subject.* Expanded coverage of diagnostics and methods of model fitting.* Requires no specialized knowledge beyond a good grasp of matrix algebra and some acquaintance with straight-line regression and simple analysis of variance models.* More than 200 problems throughout the book plus outline solutions for the exercises.* This revision has been extensively class-tested.

  17. Preface to Berk's "Regression Analysis: A Constructive Critique"

    OpenAIRE

    de Leeuw, Jan

    2003-01-01

    It is pleasure to write a preface for the book ”Regression Analysis” of my fellow series editor Dick Berk. And it is a pleasure in particular because the book is about regression analysis, the most popular and the most fundamental technique in applied statistics. And because it is critical of the way regression analysis is used in the sciences, in particular in the social and behavioral sciences. Although the book can be read as an introduction to regression analysis, it can also be read as a...

  18. Multicollinearity and Regression Analysis

    Science.gov (United States)

    Daoud, Jamal I.

    2017-12-01

    In regression analysis it is obvious to have a correlation between the response and predictor(s), but having correlation among predictors is something undesired. The number of predictors included in the regression model depends on many factors among which, historical data, experience, etc. At the end selection of most important predictors is something objective due to the researcher. Multicollinearity is a phenomena when two or more predictors are correlated, if this happens, the standard error of the coefficients will increase [8]. Increased standard errors means that the coefficients for some or all independent variables may be found to be significantly different from In other words, by overinflating the standard errors, multicollinearity makes some variables statistically insignificant when they should be significant. In this paper we focus on the multicollinearity, reasons and consequences on the reliability of the regression model.

  19. Hierarchical regression analysis in structural Equation Modeling

    NARCIS (Netherlands)

    de Jong, P.F.

    1999-01-01

    In a hierarchical or fixed-order regression analysis, the independent variables are entered into the regression equation in a prespecified order. Such an analysis is often performed when the extra amount of variance accounted for in a dependent variable by a specific independent variable is the main

  20. Marital status integration and suicide: A meta-analysis and meta-regression.

    Science.gov (United States)

    Kyung-Sook, Woo; SangSoo, Shin; Sangjin, Shin; Young-Jeon, Shin

    2018-01-01

    Marital status is an index of the phenomenon of social integration within social structures and has long been identified as an important predictor suicide. However, previous meta-analyses have focused only on a particular marital status, or not sufficiently explored moderators. A meta-analysis of observational studies was conducted to explore the relationships between marital status and suicide and to understand the important moderating factors in this association. Electronic databases were searched to identify studies conducted between January 1, 2000 and June 30, 2016. We performed a meta-analysis, subgroup analysis, and meta-regression of 170 suicide risk estimates from 36 publications. Using random effects model with adjustment for covariates, the study found that the suicide risk for non-married versus married was OR = 1.92 (95% CI: 1.75-2.12). The suicide risk was higher for non-married individuals aged analysis by gender, non-married men exhibited a greater risk of suicide than their married counterparts in all sub-analyses, but women aged 65 years or older showed no significant association between marital status and suicide. The suicide risk in divorced individuals was higher than for non-married individuals in both men and women. The meta-regression showed that gender, age, and sample size affected between-study variation. The results of the study indicated that non-married individuals have an aggregate higher suicide risk than married ones. In addition, gender and age were confirmed as important moderating factors in the relationship between marital status and suicide. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Multivariate Regression Analysis and Slaughter Livestock,

    Science.gov (United States)

    AGRICULTURE, *ECONOMICS), (*MEAT, PRODUCTION), MULTIVARIATE ANALYSIS, REGRESSION ANALYSIS , ANIMALS, WEIGHT, COSTS, PREDICTIONS, STABILITY, MATHEMATICAL MODELS, STORAGE, BEEF, PORK, FOOD, STATISTICAL DATA, ACCURACY

  2. Prediction of unwanted pregnancies using logistic regression, probit regression and discriminant analysis.

    Science.gov (United States)

    Ebrahimzadeh, Farzad; Hajizadeh, Ebrahim; Vahabi, Nasim; Almasian, Mohammad; Bakhteyar, Katayoon

    2015-01-01

    Unwanted pregnancy not intended by at least one of the parents has undesirable consequences for the family and the society. In the present study, three classification models were used and compared to predict unwanted pregnancies in an urban population. In this cross-sectional study, 887 pregnant mothers referring to health centers in Khorramabad, Iran, in 2012 were selected by the stratified and cluster sampling; relevant variables were measured and for prediction of unwanted pregnancy, logistic regression, discriminant analysis, and probit regression models and SPSS software version 21 were used. To compare these models, indicators such as sensitivity, specificity, the area under the ROC curve, and the percentage of correct predictions were used. The prevalence of unwanted pregnancies was 25.3%. The logistic and probit regression models indicated that parity and pregnancy spacing, contraceptive methods, household income and number of living male children were related to unwanted pregnancy. The performance of the models based on the area under the ROC curve was 0.735, 0.733, and 0.680 for logistic regression, probit regression, and linear discriminant analysis, respectively. Given the relatively high prevalence of unwanted pregnancies in Khorramabad, it seems necessary to revise family planning programs. Despite the similar accuracy of the models, if the researcher is interested in the interpretability of the results, the use of the logistic regression model is recommended.

  3. Motivation to Learn among Older Adults in Taiwan

    Science.gov (United States)

    Chang, Dian-Fu; Lin, Sung-Po

    2011-01-01

    This study analyzed the survey on adults administered by the Ministry of Education in Taiwan in 2008, and logistic regression analysis showed a close relationship between learning motivations of older adults. The finding revealed that the higher age or the lower education attainment of older adults, the lower their learning motivation. The…

  4. Bayesian logistic regression analysis

    NARCIS (Netherlands)

    Van Erp, H.R.N.; Van Gelder, P.H.A.J.M.

    2012-01-01

    In this paper we present a Bayesian logistic regression analysis. It is found that if one wishes to derive the posterior distribution of the probability of some event, then, together with the traditional Bayes Theorem and the integrating out of nuissance parameters, the Jacobian transformation is an

  5. Regression analysis using dependent Polya trees.

    Science.gov (United States)

    Schörgendorfer, Angela; Branscum, Adam J

    2013-11-30

    Many commonly used models for linear regression analysis force overly simplistic shape and scale constraints on the residual structure of data. We propose a semiparametric Bayesian model for regression analysis that produces data-driven inference by using a new type of dependent Polya tree prior to model arbitrary residual distributions that are allowed to evolve across increasing levels of an ordinal covariate (e.g., time, in repeated measurement studies). By modeling residual distributions at consecutive covariate levels or time points using separate, but dependent Polya tree priors, distributional information is pooled while allowing for broad pliability to accommodate many types of changing residual distributions. We can use the proposed dependent residual structure in a wide range of regression settings, including fixed-effects and mixed-effects linear and nonlinear models for cross-sectional, prospective, and repeated measurement data. A simulation study illustrates the flexibility of our novel semiparametric regression model to accurately capture evolving residual distributions. In an application to immune development data on immunoglobulin G antibodies in children, our new model outperforms several contemporary semiparametric regression models based on a predictive model selection criterion. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Examination of Parameters Affecting the House Prices by Multiple Regression Analysis and its Contributions to Earthquake-Based Urban Transformation

    Science.gov (United States)

    Denli, H. H.; Durmus, B.

    2016-12-01

    The purpose of this study is to examine the factors which may affect the apartment prices with multiple linear regression analysis models and visualize the results by value maps. The study is focused on a county of Istanbul - Turkey. Totally 390 apartments around the county Umraniye are evaluated due to their physical and locational conditions. The identification of factors affecting the price of apartments in the county with a population of approximately 600k is expected to provide a significant contribution to the apartment market.Physical factors are selected as the age, number of rooms, size, floor numbers of the building and the floor that the apartment is positioned in. Positional factors are selected as the distances to the nearest hospital, school, park and police station. Totally ten physical and locational parameters are examined by regression analysis.After the regression analysis has been performed, value maps are composed from the parameters age, price and price per square meters. The most significant of the composed maps is the price per square meters map. Results show that the location of the apartment has the most influence to the square meter price information of the apartment. A different practice is developed from the composed maps by searching the ability of using price per square meters map in urban transformation practices. By marking the buildings older than 15 years in the price per square meters map, a different and new interpretation has been made to determine the buildings, to which should be given priority during an urban transformation in the county.This county is very close to the North Anatolian Fault zone and is under the threat of earthquakes. By marking the apartments older than 15 years on the price per square meters map, both older and expensive square meters apartments list can be gathered. By the help of this list, the priority could be given to the selected higher valued old apartments to support the economy of the country

  7. RAWS II: A MULTIPLE REGRESSION ANALYSIS PROGRAM,

    Science.gov (United States)

    This memorandum gives instructions for the use and operation of a revised version of RAWS, a multiple regression analysis program. The program...of preprocessed data, the directed retention of variable, listing of the matrix of the normal equations and its inverse, and the bypassing of the regression analysis to provide the input variable statistics only. (Author)

  8. Clinical differences between younger and older adults with HIV/AIDS starting antiretroviral therapy in Uganda and Zimbabwe: a secondary analysis of the DART trial.

    Directory of Open Access Journals (Sweden)

    Sujal M Parikh

    Full Text Available Clinical and immunological data about HIV in older adults from low and middle income countries is scarce. We aimed to describe differences between younger and older adults with HIV starting antiretroviral therapy in two low-income African countries.HIV clinics in Uganda and Zimbabwe.Secondary exploratory cross-sectional analysis of the DART randomized controlled trial.Clinical and laboratory characteristics were compared between adults aged 18-49 years (younger and ≥ 50 years (older, using two exploratory multivariable logistic regression models, one with HIV viral load (measured in a subset pre-ART and one without.A total of 3316 eligible participants enrolled in DART were available for analysis; 219 (7% were ≥ 50 years and 1160 (35% were male. Across the two adjusted regression models, older adults had significantly higher systolic blood pressure, lower creatinine clearance and were consistently less likely to be females compared to younger adults with HIV. Paradoxically, the models separately suggested that older adults had statistically significant (but not clinically important higher CD4+ cell counts and higher plasma HIV-1 viral copies at initiation. Crude associations between older age and higher baseline hemoglobin, body mass index, diastolic blood pressure and lower WHO clinical stage were not sustained in the adjusted analysis.Our study found clinical and immunological differences between younger and older adults, in a cohort of Africans starting antiretroviral therapy. Further investigations should explore how these differences could be used to ensure equity in service delivery and affect outcomes of antiretroviral therapy.

  9. Common pitfalls in statistical analysis: Linear regression analysis

    Directory of Open Access Journals (Sweden)

    Rakesh Aggarwal

    2017-01-01

    Full Text Available In a previous article in this series, we explained correlation analysis which describes the strength of relationship between two continuous variables. In this article, we deal with linear regression analysis which predicts the value of one continuous variable from another. We also discuss the assumptions and pitfalls associated with this analysis.

  10. Passive Suicide Ideation Among Older Adults in Europe: A Multilevel Regression Analysis of Individual and Societal Determinants in 12 Countries (SHARE).

    Science.gov (United States)

    Stolz, Erwin; Fux, Beat; Mayerl, Hannes; Rásky, Éva; Freidl, Wolfgang

    2016-09-01

    Passive suicide ideation (PSI) is common among older adults, but prevalences have been reported to vary considerably across European countries. The goal of this study was to assess the role of individual-level risk factors and societal contextual factors associated with PSI in old age. We analyzed longitudinal data from the Survey of Health, Ageing, and Retirement in Europe (SHARE) on 6,791 community-dwelling respondents (75+) from 12 countries. Bayesian logistic multilevel regression models were used to assess variance components, individual-level and country-level risk factors. About 4% of the total variance of PSI was located at the country level, a third of which was attributable to compositional effects of individual-level predictors. Predictors for the development of PSI at the individual level were female gender, depression, older age, poor health, smaller social network size, loneliness, nonreligiosity, and low perceived control (R (2) = 25.8%). At the country level, cultural acceptance of suicide, religiosity, and intergenerational cohabitation were associated with the rates of PSI. Cross-national variation in old-age PSI is mostly attributable to individual-level determinants and compositional differences, but there is also evidence for contextual effects of country-level characteristics. Suicide prevention programs should be intensified in high-risk countries and attitudes toward suicide should be addressed in information campaigns. © 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.

  11. Exercise for depression in older adults: a meta-analysis of randomized controlled trials adjusting for publication bias

    Directory of Open Access Journals (Sweden)

    Felipe B. Schuch

    Full Text Available Objective: To evaluate the antidepressant effects of exercise in older adults, using randomized controlled trial (RCT data. Methods: We conducted a meta-analysis of exercise in older adults, addressing limitations of previous works. RCTs of exercise interventions in older people with depression (≥ 60 years comparing exercise vs. control were eligible. A random-effects meta-analysis calculating the standardized mean difference (SMD (95% confidence interval [95%CI], meta-regressions, and trim, fill, and fail-safe number analyses were conducted. Results: Eight RCTs were included, representing 138 participants in exercise arms and 129 controls. Exercise had a large and significant effect on depression (SMD = -0.90 [95%CI -0.29 to -1.51], with a fail-safe number of 71 studies. Significant effects were found for 1 mixed aerobic and anaerobic interventions, 2 at moderate intensity, 3 that were group-based, 4 that utilized mixed supervised and unsupervised formats, and 5 in people without other clinical comorbidities. Conclusion: Adjusting for publication bias increased the beneficial effects of exercise in three subgroup analysis, suggesting that previous meta-analyses have underestimated the benefits of exercise due to publication bias. We advocate that exercise be considered as a routine component of the management of depression in older adults.

  12. Moderation analysis using a two-level regression model.

    Science.gov (United States)

    Yuan, Ke-Hai; Cheng, Ying; Maxwell, Scott

    2014-10-01

    Moderation analysis is widely used in social and behavioral research. The most commonly used model for moderation analysis is moderated multiple regression (MMR) in which the explanatory variables of the regression model include product terms, and the model is typically estimated by least squares (LS). This paper argues for a two-level regression model in which the regression coefficients of a criterion variable on predictors are further regressed on moderator variables. An algorithm for estimating the parameters of the two-level model by normal-distribution-based maximum likelihood (NML) is developed. Formulas for the standard errors (SEs) of the parameter estimates are provided and studied. Results indicate that, when heteroscedasticity exists, NML with the two-level model gives more efficient and more accurate parameter estimates than the LS analysis of the MMR model. When error variances are homoscedastic, NML with the two-level model leads to essentially the same results as LS with the MMR model. Most importantly, the two-level regression model permits estimating the percentage of variance of each regression coefficient that is due to moderator variables. When applied to data from General Social Surveys 1991, NML with the two-level model identified a significant moderation effect of race on the regression of job prestige on years of education while LS with the MMR model did not. An R package is also developed and documented to facilitate the application of the two-level model.

  13. Predictors of depressive symptoms in older Japanese primiparas at 1 month post-partum: A risk-stratified analysis.

    Science.gov (United States)

    Iwata, Hiroko; Mori, Emi; Tsuchiya, Miyako; Sakajo, Akiko; Maehara, Kunie; Ozawa, Harumi; Morita, Akiko; Maekawa, Tomoko; Aoki, Kyoko; Tamakoshi, Koji

    2016-01-01

    Older maternal age has become more common in Japan. Studies suggest that older maternal age and primiparity are associated with post-partum depression. The present study aimed to identify predictors of post-partum depression in older Japanese primiparas at 1 month post-partum. Participants were 479 primiparas aged 35 years and over, drawn from a prospective cohort study. Data were collected using self-report questionnaires. Depression was measured with the Japanese version of the Edinburgh Postnatal Depression Scale. Stepwise logistic regression analysis was conducted on binary outcome variables of depression at 1 month post-partum, along with a stratified analysis based on the risk status of depression. Five predictors were identified: (i) the depression score during hospital stay; (ii) financial burden; (iii) dissatisfaction with appraisal support; (iv) physical burden in daily life; and (v) concerns about infant caretaking. Stratified analysis identified dissatisfaction with instrumental support in the low-risk group, and the Child-care Value Scale score as unique predictors in the high-risk group. These results highlight the importance of early assessment of depressive symptoms and the provision of continuous care. © 2015 Japan Academy of Nursing Science.

  14. Two Paradoxes in Linear Regression Analysis

    Science.gov (United States)

    FENG, Ge; PENG, Jing; TU, Dongke; ZHENG, Julia Z.; FENG, Changyong

    2016-01-01

    Summary Regression is one of the favorite tools in applied statistics. However, misuse and misinterpretation of results from regression analysis are common in biomedical research. In this paper we use statistical theory and simulation studies to clarify some paradoxes around this popular statistical method. In particular, we show that a widely used model selection procedure employed in many publications in top medical journals is wrong. Formal procedures based on solid statistical theory should be used in model selection. PMID:28638214

  15. Using Dominance Analysis to Determine Predictor Importance in Logistic Regression

    Science.gov (United States)

    Azen, Razia; Traxel, Nicole

    2009-01-01

    This article proposes an extension of dominance analysis that allows researchers to determine the relative importance of predictors in logistic regression models. Criteria for choosing logistic regression R[superscript 2] analogues were determined and measures were selected that can be used to perform dominance analysis in logistic regression. A…

  16. Linear regression and sensitivity analysis in nuclear reactor design

    International Nuclear Information System (INIS)

    Kumar, Akansha; Tsvetkov, Pavel V.; McClarren, Ryan G.

    2015-01-01

    Highlights: • Presented a benchmark for the applicability of linear regression to complex systems. • Applied linear regression to a nuclear reactor power system. • Performed neutronics, thermal–hydraulics, and energy conversion using Brayton’s cycle for the design of a GCFBR. • Performed detailed sensitivity analysis to a set of parameters in a nuclear reactor power system. • Modeled and developed reactor design using MCNP, regression using R, and thermal–hydraulics in Java. - Abstract: The paper presents a general strategy applicable for sensitivity analysis (SA), and uncertainity quantification analysis (UA) of parameters related to a nuclear reactor design. This work also validates the use of linear regression (LR) for predictive analysis in a nuclear reactor design. The analysis helps to determine the parameters on which a LR model can be fit for predictive analysis. For those parameters, a regression surface is created based on trial data and predictions are made using this surface. A general strategy of SA to determine and identify the influential parameters those affect the operation of the reactor is mentioned. Identification of design parameters and validation of linearity assumption for the application of LR of reactor design based on a set of tests is performed. The testing methods used to determine the behavior of the parameters can be used as a general strategy for UA, and SA of nuclear reactor models, and thermal hydraulics calculations. A design of a gas cooled fast breeder reactor (GCFBR), with thermal–hydraulics, and energy transfer has been used for the demonstration of this method. MCNP6 is used to simulate the GCFBR design, and perform the necessary criticality calculations. Java is used to build and run input samples, and to extract data from the output files of MCNP6, and R is used to perform regression analysis and other multivariate variance, and analysis of the collinearity of data

  17. Least Squares Adjustment: Linear and Nonlinear Weighted Regression Analysis

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg

    2007-01-01

    This note primarily describes the mathematics of least squares regression analysis as it is often used in geodesy including land surveying and satellite positioning applications. In these fields regression is often termed adjustment. The note also contains a couple of typical land surveying...... and satellite positioning application examples. In these application areas we are typically interested in the parameters in the model typically 2- or 3-D positions and not in predictive modelling which is often the main concern in other regression analysis applications. Adjustment is often used to obtain...... the clock error) and to obtain estimates of the uncertainty with which the position is determined. Regression analysis is used in many other fields of application both in the natural, the technical and the social sciences. Examples may be curve fitting, calibration, establishing relationships between...

  18. Design and analysis of experiments classical and regression approaches with SAS

    CERN Document Server

    Onyiah, Leonard C

    2008-01-01

    Introductory Statistical Inference and Regression Analysis Elementary Statistical Inference Regression Analysis Experiments, the Completely Randomized Design (CRD)-Classical and Regression Approaches Experiments Experiments to Compare Treatments Some Basic Ideas Requirements of a Good Experiment One-Way Experimental Layout or the CRD: Design and Analysis Analysis of Experimental Data (Fixed Effects Model) Expected Values for the Sums of Squares The Analysis of Variance (ANOVA) Table Follow-Up Analysis to Check fo

  19. Perioperative factors predicting poor outcome in elderly patients following emergency general surgery: a multivariate regression analysis

    Science.gov (United States)

    Lees, Mackenzie C.; Merani, Shaheed; Tauh, Keerit; Khadaroo, Rachel G.

    2015-01-01

    Background Older adults (≥ 65 yr) are the fastest growing population and are presenting in increasing numbers for acute surgical care. Emergency surgery is frequently life threatening for older patients. Our objective was to identify predictors of mortality and poor outcome among elderly patients undergoing emergency general surgery. Methods We conducted a retrospective cohort study of patients aged 65–80 years undergoing emergency general surgery between 2009 and 2010 at a tertiary care centre. Demographics, comorbidities, in-hospital complications, mortality and disposition characteristics of patients were collected. Logistic regression analysis was used to identify covariate-adjusted predictors of in-hospital mortality and discharge of patients home. Results Our analysis included 257 patients with a mean age of 72 years; 52% were men. In-hospital mortality was 12%. Mortality was associated with patients who had higher American Society of Anesthesiologists (ASA) class (odds ratio [OR] 3.85, 95% confidence interval [CI] 1.43–10.33, p = 0.008) and in-hospital complications (OR 1.93, 95% CI 1.32–2.83, p = 0.001). Nearly two-thirds of patients discharged home were younger (OR 0.92, 95% CI 0.85–0.99, p = 0.036), had lower ASA class (OR 0.45, 95% CI 0.27–0.74, p = 0.002) and fewer in-hospital complications (OR 0.69, 95% CI 0.53–0.90, p = 0.007). Conclusion American Society of Anesthesiologists class and in-hospital complications are perioperative predictors of mortality and disposition in the older surgical population. Understanding the predictors of poor outcome and the importance of preventing in-hospital complications in older patients will have important clinical utility in terms of preoperative counselling, improving health care and discharging patients home. PMID:26204143

  20. Age management in Slovenian enterprises: the viewpoint of older employees

    Directory of Open Access Journals (Sweden)

    Jana Žnidaršič

    2010-12-01

    Full Text Available The main aim of this research is to highlight age management within Slovenian enterprises from the viewpoint of older employees by finding out what influences older employees to decide “should I stay or should I go”. The empirical research methodology is based on mixed strategy of approaching organizations (employees, which means that the quantitative (factor analysis, cluster analysis, correlation, regression, descriptive statistics and frequency distributions and qualitative parts (in-depth interviews analysis of research were conducted simultaneously. The results of the research indicate that there are in fact two groups of older employees, which can be referred to as “susceptible” and “insusceptible” in terms of how the employer can affect their decisions. “The unsusceptible” have already decided to retire as soon as possible and they cannot be influenced by any employer measure. On the other hand, “the susceptible” employees are sensitive to employers’ measures aimed at prolonging their working lives. Besides, a regression analysis confirmed a statistically significant correlation between the inclination towards extending one’s employment period and the susceptibility to the employer measures. It can thus be concluded that, through age management measures, an employer has an impact on an extended employment period of older employees. However, employers should be interested primarily in those employees who are inclined towards extending their working lives.

  1. Sparse Regression by Projection and Sparse Discriminant Analysis

    KAUST Repository

    Qi, Xin

    2015-04-03

    © 2015, © American Statistical Association, Institute of Mathematical Statistics, and Interface Foundation of North America. Recent years have seen active developments of various penalized regression methods, such as LASSO and elastic net, to analyze high-dimensional data. In these approaches, the direction and length of the regression coefficients are determined simultaneously. Due to the introduction of penalties, the length of the estimates can be far from being optimal for accurate predictions. We introduce a new framework, regression by projection, and its sparse version to analyze high-dimensional data. The unique nature of this framework is that the directions of the regression coefficients are inferred first, and the lengths and the tuning parameters are determined by a cross-validation procedure to achieve the largest prediction accuracy. We provide a theoretical result for simultaneous model selection consistency and parameter estimation consistency of our method in high dimension. This new framework is then generalized such that it can be applied to principal components analysis, partial least squares, and canonical correlation analysis. We also adapt this framework for discriminant analysis. Compared with the existing methods, where there is relatively little control of the dependency among the sparse components, our method can control the relationships among the components. We present efficient algorithms and related theory for solving the sparse regression by projection problem. Based on extensive simulations and real data analysis, we demonstrate that our method achieves good predictive performance and variable selection in the regression setting, and the ability to control relationships between the sparse components leads to more accurate classification. In supplementary materials available online, the details of the algorithms and theoretical proofs, and R codes for all simulation studies are provided.

  2. The Use of Nonparametric Kernel Regression Methods in Econometric Production Analysis

    DEFF Research Database (Denmark)

    Czekaj, Tomasz Gerard

    and nonparametric estimations of production functions in order to evaluate the optimal firm size. The second paper discusses the use of parametric and nonparametric regression methods to estimate panel data regression models. The third paper analyses production risk, price uncertainty, and farmers' risk preferences...... within a nonparametric panel data regression framework. The fourth paper analyses the technical efficiency of dairy farms with environmental output using nonparametric kernel regression in a semiparametric stochastic frontier analysis. The results provided in this PhD thesis show that nonparametric......This PhD thesis addresses one of the fundamental problems in applied econometric analysis, namely the econometric estimation of regression functions. The conventional approach to regression analysis is the parametric approach, which requires the researcher to specify the form of the regression...

  3. Prevalence of rapid eye movement sleep behavior disorder (RBD) in Parkinson's disease: a meta and meta-regression analysis.

    Science.gov (United States)

    Zhang, Xiaona; Sun, Xiaoxuan; Wang, Junhong; Tang, Liou; Xie, Anmu

    2017-01-01

    Rapid eye movement sleep behavior disorder (RBD) is thought to be one of the most frequent preceding symptoms of Parkinson's disease (PD). However, the prevalence of RBD in PD stated in the published studies is still inconsistent. We conducted a meta and meta-regression analysis in this paper to estimate the pooled prevalence. We searched the electronic databases of PubMed, ScienceDirect, EMBASE and EBSCO up to June 2016 for related articles. STATA 12.0 statistics software was used to calculate the available data from each research. The prevalence of RBD in PD patients in each study was combined to a pooled prevalence with a 95 % confidence interval (CI). Subgroup analysis and meta-regression analysis were performed to search for the causes of the heterogeneity. A total of 28 studies with 6869 PD cases were deemed eligible and included in our meta-analysis based on the inclusion and exclusion criteria. The pooled prevalence of RBD in PD was 42.3 % (95 % CI 37.4-47.1 %). In subgroup analysis and meta-regression analysis, we found that the important causes of heterogeneity were the diagnosis criteria of RBD and age of PD patients (P = 0.016, P = 0.019, respectively). The results indicate that nearly half of the PD patients are suffering from RBD. Older age and longer duration are risk factors for RBD in PD. We can use the minimal diagnosis criteria for RBD according to the International Classification of Sleep Disorders to diagnose RBD patients in our daily work if polysomnography is not necessary.

  4. Self-determination and older people--a concept analysis.

    Science.gov (United States)

    Ekelund, Christina; Dahlin-Ivanoff, Synneve; Eklund, Kajsa

    2014-03-01

    Self-determination has emerged as an important concept within health care, used to emphasize clients' control and independence as they participate in rehabilitation. To strengthen clients' self-determination is a central aim in occupational therapy. However, there is a lack of a clear definition of self-determination concerning community-dwelling older people. The definition should be flexible in different contexts, such as cultural. To define and clarify the concept of self-determination in relation to community-dwelling frail older people. Walker & Avant's analysis procedure was carried out to identify textual attributes to the concept of self-determination, supplemented by a content analysis of 21 articles that were used to define and further justify the textual attributes. Self-determination was used in diverse contexts for community-dwelling older people, concerning: decision-making in everyday life, professionals' views, health, and legal/ethical rights. Different textual attributes were identified, to propose a conceptual definition of self-determination in relation to community-dwelling frail older people: A process in which a person has control and legal/ethical rights, and has the knowledge and ability to make a decision of his/her own free choice. This concept analysis has contributed to clarifying the concept for the convenience of research with community-dwelling frail older people.

  5. Simulation Experiments in Practice: Statistical Design and Regression Analysis

    OpenAIRE

    Kleijnen, J.P.C.

    2007-01-01

    In practice, simulation analysts often change only one factor at a time, and use graphical analysis of the resulting Input/Output (I/O) data. The goal of this article is to change these traditional, naïve methods of design and analysis, because statistical theory proves that more information is obtained when applying Design Of Experiments (DOE) and linear regression analysis. Unfortunately, classic DOE and regression analysis assume a single simulation response that is normally and independen...

  6. How do older adult drivers self-regulate? Characteristics of self-regulation classes defined by latent class analysis.

    Science.gov (United States)

    Bergen, Gwen; West, Bethany A; Luo, Feijun; Bird, Donna C; Freund, Katherine; Fortinsky, Richard H; Staplin, Loren

    2017-06-01

    Motor-vehicle crashes were the second leading cause of injury death for adults aged 65-84years in 2014. Some older drivers choose to self-regulate their driving to maintain mobility while reducing driving risk, yet the process remains poorly understood. Data from 729 older adults (aged ≥60years) who joined an older adult ride service program between April 1, 2010 and November 8, 2013 were analyzed to define and describe classes of driving self-regulation. Latent class analysis was employed to characterize older adult driving self-regulation classes using driving frequency and avoidance of seven driving situations. Logistic regression was used to explore associations between characteristics affecting mobility and self-regulation class. Three classes were identified (low, medium, and high self-regulation). High self-regulating participants reported the highest proportion of always avoiding seven risky driving situations and the lowest driving frequency followed by medium and low self-regulators. Those who were female, aged 80years or older, visually impaired, assistive device users, and those with special health needs were more likely to be high self-regulating compared with low self-regulating. Avoidance of certain driving situations and weekly driving frequency are valid indicators for describing driving self-regulation classes in older adults. Understanding the unique characteristics and mobility limitations of each class can guide optimal transportation strategies for older adults. Published by Elsevier Ltd.

  7. General Nature of Multicollinearity in Multiple Regression Analysis.

    Science.gov (United States)

    Liu, Richard

    1981-01-01

    Discusses multiple regression, a very popular statistical technique in the field of education. One of the basic assumptions in regression analysis requires that independent variables in the equation should not be highly correlated. The problem of multicollinearity and some of the solutions to it are discussed. (Author)

  8. On logistic regression analysis of dichotomized responses.

    Science.gov (United States)

    Lu, Kaifeng

    2017-01-01

    We study the properties of treatment effect estimate in terms of odds ratio at the study end point from logistic regression model adjusting for the baseline value when the underlying continuous repeated measurements follow a multivariate normal distribution. Compared with the analysis that does not adjust for the baseline value, the adjusted analysis produces a larger treatment effect as well as a larger standard error. However, the increase in standard error is more than offset by the increase in treatment effect so that the adjusted analysis is more powerful than the unadjusted analysis for detecting the treatment effect. On the other hand, the true adjusted odds ratio implied by the normal distribution of the underlying continuous variable is a function of the baseline value and hence is unlikely to be able to be adequately represented by a single value of adjusted odds ratio from the logistic regression model. In contrast, the risk difference function derived from the logistic regression model provides a reasonable approximation to the true risk difference function implied by the normal distribution of the underlying continuous variable over the range of the baseline distribution. We show that different metrics of treatment effect have similar statistical power when evaluated at the baseline mean. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. On two flexible methods of 2-dimensional regression analysis

    Czech Academy of Sciences Publication Activity Database

    Volf, Petr

    2012-01-01

    Roč. 18, č. 4 (2012), s. 154-164 ISSN 1803-9782 Grant - others:GA ČR(CZ) GAP209/10/2045 Institutional support: RVO:67985556 Keywords : regression analysis * Gordon surface * prediction error * projection pursuit Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2013/SI/volf-on two flexible methods of 2-dimensional regression analysis.pdf

  10. [Analysis of the characteristics of the older adults with depression using data mining decision tree analysis].

    Science.gov (United States)

    Park, Myonghwa; Choi, Sora; Shin, A Mi; Koo, Chul Hoi

    2013-02-01

    The purpose of this study was to develop a prediction model for the characteristics of older adults with depression using the decision tree method. A large dataset from the 2008 Korean Elderly Survey was used and data of 14,970 elderly people were analyzed. Target variable was depression and 53 input variables were general characteristics, family & social relationship, economic status, health status, health behavior, functional status, leisure & social activity, quality of life, and living environment. Data were analyzed by decision tree analysis, a data mining technique using SPSS Window 19.0 and Clementine 12.0 programs. The decision trees were classified into five different rules to define the characteristics of older adults with depression. Classification & Regression Tree (C&RT) showed the best prediction with an accuracy of 80.81% among data mining models. Factors in the rules were life satisfaction, nutritional status, daily activity difficulty due to pain, functional limitation for basic or instrumental daily activities, number of chronic diseases and daily activity difficulty due to disease. The different rules classified by the decision tree model in this study should contribute as baseline data for discovering informative knowledge and developing interventions tailored to these individual characteristics.

  11. Resting-state functional magnetic resonance imaging: the impact of regression analysis.

    Science.gov (United States)

    Yeh, Chia-Jung; Tseng, Yu-Sheng; Lin, Yi-Ru; Tsai, Shang-Yueh; Huang, Teng-Yi

    2015-01-01

    To investigate the impact of regression methods on resting-state functional magnetic resonance imaging (rsfMRI). During rsfMRI preprocessing, regression analysis is considered effective for reducing the interference of physiological noise on the signal time course. However, it is unclear whether the regression method benefits rsfMRI analysis. Twenty volunteers (10 men and 10 women; aged 23.4 ± 1.5 years) participated in the experiments. We used node analysis and functional connectivity mapping to assess the brain default mode network by using five combinations of regression methods. The results show that regressing the global mean plays a major role in the preprocessing steps. When a global regression method is applied, the values of functional connectivity are significantly lower (P ≤ .01) than those calculated without a global regression. This step increases inter-subject variation and produces anticorrelated brain areas. rsfMRI data processed using regression should be interpreted carefully. The significance of the anticorrelated brain areas produced by global signal removal is unclear. Copyright © 2014 by the American Society of Neuroimaging.

  12. Development of a User Interface for a Regression Analysis Software Tool

    Science.gov (United States)

    Ulbrich, Norbert Manfred; Volden, Thomas R.

    2010-01-01

    An easy-to -use user interface was implemented in a highly automated regression analysis tool. The user interface was developed from the start to run on computers that use the Windows, Macintosh, Linux, or UNIX operating system. Many user interface features were specifically designed such that a novice or inexperienced user can apply the regression analysis tool with confidence. Therefore, the user interface s design minimizes interactive input from the user. In addition, reasonable default combinations are assigned to those analysis settings that influence the outcome of the regression analysis. These default combinations will lead to a successful regression analysis result for most experimental data sets. The user interface comes in two versions. The text user interface version is used for the ongoing development of the regression analysis tool. The official release of the regression analysis tool, on the other hand, has a graphical user interface that is more efficient to use. This graphical user interface displays all input file names, output file names, and analysis settings for a specific software application mode on a single screen which makes it easier to generate reliable analysis results and to perform input parameter studies. An object-oriented approach was used for the development of the graphical user interface. This choice keeps future software maintenance costs to a reasonable limit. Examples of both the text user interface and graphical user interface are discussed in order to illustrate the user interface s overall design approach.

  13. Method for nonlinear exponential regression analysis

    Science.gov (United States)

    Junkin, B. G.

    1972-01-01

    Two computer programs developed according to two general types of exponential models for conducting nonlinear exponential regression analysis are described. Least squares procedure is used in which the nonlinear problem is linearized by expanding in a Taylor series. Program is written in FORTRAN 5 for the Univac 1108 computer.

  14. Regression of uveal malignant melanomas following cobalt-60 plaque. Correlates between acoustic spectrum analysis and tumor regression

    International Nuclear Information System (INIS)

    Coleman, D.J.; Lizzi, F.L.; Silverman, R.H.; Ellsworth, R.M.; Haik, B.G.; Abramson, D.H.; Smith, M.E.; Rondeau, M.J.

    1985-01-01

    Parameters derived from computer analysis of digital radio-frequency (rf) ultrasound scan data of untreated uveal malignant melanomas were examined for correlations with tumor regression following cobalt-60 plaque. Parameters included tumor height, normalized power spectrum and acoustic tissue type (ATT). Acoustic tissue type was based upon discriminant analysis of tumor power spectra, with spectra of tumors of known pathology serving as a model. Results showed ATT to be correlated with tumor regression during the first 18 months following treatment. Tumors with ATT associated with spindle cell malignant melanoma showed over twice the percentage reduction in height as those with ATT associated with mixed/epithelioid melanomas. Pre-treatment height was only weakly correlated with regression. Additionally, significant spectral changes were observed following treatment. Ultrasonic spectrum analysis thus provides a noninvasive tool for classification, prediction and monitoring of tumor response to cobalt-60 plaque

  15. Residential patterns in older homeless adults: Results of a cluster analysis.

    Science.gov (United States)

    Lee, Christopher Thomas; Guzman, David; Ponath, Claudia; Tieu, Lina; Riley, Elise; Kushel, Margot

    2016-03-01

    Adults aged 50 and older make up half of individuals experiencing homelessness and have high rates of morbidity and mortality. They may have different life trajectories and reside in different environments than do younger homeless adults. Although the environmental risks associated with homelessness are substantial, the environments in which older homeless individuals live have not been well characterized. We classified living environments and identified associated factors in a sample of older homeless adults. From July 2013 to June 2014, we recruited a community-based sample of 350 homeless men and women aged fifty and older in Oakland, California. We administered structured interviews including assessments of health, history of homelessness, social support, and life course. Participants used a recall procedure to describe where they stayed in the prior six months. We performed cluster analysis to classify residential venues and used multinomial logistic regression to identify individual factors prior to the onset of homelessness as well as the duration of unstable housing associated with living in them. We generated four residential groups describing those who were unsheltered (n = 162), cohabited unstably with friends and family (n = 57), resided in multiple institutional settings (shelters, jails, transitional housing) (n = 88), or lived primarily in rental housing (recently homeless) (n = 43). Compared to those who were unsheltered, having social support when last stably housed was significantly associated with cohabiting and institution use. Cohabiters and renters were significantly more likely to be women and have experienced a shorter duration of homelessness. Cohabiters were significantly more likely than unsheltered participants to have experienced abuse prior to losing stable housing. Pre-homeless social support appears to protect against street homelessness while low levels of social support may increase the risk for becoming homeless immediately after

  16. Detecting overdispersion in count data: A zero-inflated Poisson regression analysis

    Science.gov (United States)

    Afiqah Muhamad Jamil, Siti; Asrul Affendi Abdullah, M.; Kek, Sie Long; Nor, Maria Elena; Mohamed, Maryati; Ismail, Norradihah

    2017-09-01

    This study focusing on analysing count data of butterflies communities in Jasin, Melaka. In analysing count dependent variable, the Poisson regression model has been known as a benchmark model for regression analysis. Continuing from the previous literature that used Poisson regression analysis, this study comprising the used of zero-inflated Poisson (ZIP) regression analysis to gain acute precision on analysing the count data of butterfly communities in Jasin, Melaka. On the other hands, Poisson regression should be abandoned in the favour of count data models, which are capable of taking into account the extra zeros explicitly. By far, one of the most popular models include ZIP regression model. The data of butterfly communities which had been called as the number of subjects in this study had been taken in Jasin, Melaka and consisted of 131 number of subjects visits Jasin, Melaka. Since the researchers are considering the number of subjects, this data set consists of five families of butterfly and represent the five variables involve in the analysis which are the types of subjects. Besides, the analysis of ZIP used the SAS procedure of overdispersion in analysing zeros value and the main purpose of continuing the previous study is to compare which models would be better than when exists zero values for the observation of the count data. The analysis used AIC, BIC and Voung test of 5% level significance in order to achieve the objectives. The finding indicates that there is a presence of over-dispersion in analysing zero value. The ZIP regression model is better than Poisson regression model when zero values exist.

  17. An Analysis of Bank Service Satisfaction Based on Quantile Regression and Grey Relational Analysis

    Directory of Open Access Journals (Sweden)

    Wen-Tsao Pan

    2016-01-01

    Full Text Available Bank service satisfaction is vital to the success of a bank. In this paper, we propose to use the grey relational analysis to gauge the levels of service satisfaction of the banks. With the grey relational analysis, we compared the effects of different variables on service satisfaction. We gave ranks to the banks according to their levels of service satisfaction. We further used the quantile regression model to find the variables that affected the satisfaction of a customer at a specific quantile of satisfaction level. The result of the quantile regression analysis provided a bank manager with information to formulate policies to further promote satisfaction of the customers at different quantiles of satisfaction level. We also compared the prediction accuracies of the regression models at different quantiles. The experiment result showed that, among the seven quantile regression models, the median regression model has the best performance in terms of RMSE, RTIC, and CE performance measures.

  18. Family Support and Loneliness among Older Persons in Multiethnic Malaysia

    OpenAIRE

    Teh, Jane Kimm Lii; Tey, Nai Peng; Ng, Sor Tho

    2014-01-01

    This study investigates factors affecting older persons' state of loneliness in multiethnic Malaysia using data from the 2004 Malaysian Population and Family Survey, the first nationally representative sample in Malaysia. The study sample was extracted to include Malays, Chinese, Indians and other Indigenous groups aged 60 and above, and who had children (n = 1791). Cross tabulations and ordinal logistic regression methods were used in the analysis. Among the ethnic groups, older Malays were ...

  19. Research and analyze of physical health using multiple regression analysis

    Directory of Open Access Journals (Sweden)

    T. S. Kyi

    2014-01-01

    Full Text Available This paper represents the research which is trying to create a mathematical model of the "healthy people" using the method of regression analysis. The factors are the physical parameters of the person (such as heart rate, lung capacity, blood pressure, breath holding, weight height coefficient, flexibility of the spine, muscles of the shoulder belt, abdominal muscles, squatting, etc.., and the response variable is an indicator of physical working capacity. After performing multiple regression analysis, obtained useful multiple regression models that can predict the physical performance of boys the aged of fourteen to seventeen years. This paper represents the development of regression model for the sixteen year old boys and analyzed results.

  20. An improved multiple linear regression and data analysis computer program package

    Science.gov (United States)

    Sidik, S. M.

    1972-01-01

    NEWRAP, an improved version of a previous multiple linear regression program called RAPIER, CREDUC, and CRSPLT, allows for a complete regression analysis including cross plots of the independent and dependent variables, correlation coefficients, regression coefficients, analysis of variance tables, t-statistics and their probability levels, rejection of independent variables, plots of residuals against the independent and dependent variables, and a canonical reduction of quadratic response functions useful in optimum seeking experimentation. A major improvement over RAPIER is that all regression calculations are done in double precision arithmetic.

  1. An analysis on older driver's driving behavior by GPS tracking data: Road selection, left/right turn, and driving speed

    Directory of Open Access Journals (Sweden)

    Yanning Zhao

    2018-02-01

    Full Text Available With the high older-related accident ratio and increasing population aging problem, understanding older drivers' driving behaviors has become more and more important for building and improving transportation system. This paper examines older driver's driving behavior which includes road selection, left/right turn and driving speed. A two-month experiment of 108 participants was carried out in Aichi Prefecture, Japan. Since apparently contradictory statements were often drawn in survey-based or simulators-based studies, this study collected not only drivers' basic information but also GPS data. Analysis of road selection demonstrates that older drivers are reluctant to drive on expressway not only in short trips but also in long trips. The present study did not find significant difference between older drivers and others while turning at the intersections. To investigate the impact factors on driving speed, a random-effects regression model is constructed with explanatory variables including age, gender, road types and the interaction terms between age and road types. Compared with other variables, it fails to find that age (60 years old or over has significant impact on driving speed. Moreover, the results reflect that older drivers drive even faster than others at particular road types: national road and ordinary municipal road. The results in this study are expected to help improve transportation planning and develop driving assistance systems for older drivers.

  2. Logistic regression analysis of factors associated with avascular necrosis of the femoral head following femoral neck fractures in middle-aged and elderly patients.

    Science.gov (United States)

    Ai, Zi-Sheng; Gao, You-Shui; Sun, Yuan; Liu, Yue; Zhang, Chang-Qing; Jiang, Cheng-Hua

    2013-03-01

    Risk factors for femoral neck fracture-induced avascular necrosis of the femoral head have not been elucidated clearly in middle-aged and elderly patients. Moreover, the high incidence of screw removal in China and its effect on the fate of the involved femoral head require statistical methods to reflect their intrinsic relationship. Ninety-nine patients older than 45 years with femoral neck fracture were treated by internal fixation between May 1999 and April 2004. Descriptive analysis, interaction analysis between associated factors, single factor logistic regression, multivariate logistic regression, and detailed interaction analysis were employed to explore potential relationships among associated factors. Avascular necrosis of the femoral head was found in 15 cases (15.2 %). Age × the status of implants (removal vs. maintenance) and gender × the timing of reduction were interactive according to two-factor interactive analysis. Age, the displacement of fractures, the quality of reduction, and the status of implants were found to be significant factors in single factor logistic regression analysis. Age, age × the status of implants, and the quality of reduction were found to be significant factors in multivariate logistic regression analysis. In fine interaction analysis after multivariate logistic regression analysis, implant removal was the most important risk factor for avascular necrosis in 56-to-85-year-old patients, with a risk ratio of 26.00 (95 % CI = 3.076-219.747). The middle-aged and elderly have less incidence of avascular necrosis of the femoral head following femoral neck fractures treated by cannulated screws. The removal of cannulated screws can induce a significantly high incidence of avascular necrosis of the femoral head in elderly patients, while a high-quality reduction is helpful to reduce avascular necrosis.

  3. Functional data analysis of generalized regression quantiles

    KAUST Repository

    Guo, Mengmeng; Zhou, Lan; Huang, Jianhua Z.; Hä rdle, Wolfgang Karl

    2013-01-01

    Generalized regression quantiles, including the conditional quantiles and expectiles as special cases, are useful alternatives to the conditional means for characterizing a conditional distribution, especially when the interest lies in the tails. We develop a functional data analysis approach to jointly estimate a family of generalized regression quantiles. Our approach assumes that the generalized regression quantiles share some common features that can be summarized by a small number of principal component functions. The principal component functions are modeled as splines and are estimated by minimizing a penalized asymmetric loss measure. An iterative least asymmetrically weighted squares algorithm is developed for computation. While separate estimation of individual generalized regression quantiles usually suffers from large variability due to lack of sufficient data, by borrowing strength across data sets, our joint estimation approach significantly improves the estimation efficiency, which is demonstrated in a simulation study. The proposed method is applied to data from 159 weather stations in China to obtain the generalized quantile curves of the volatility of the temperature at these stations. © 2013 Springer Science+Business Media New York.

  4. Functional data analysis of generalized regression quantiles

    KAUST Repository

    Guo, Mengmeng

    2013-11-05

    Generalized regression quantiles, including the conditional quantiles and expectiles as special cases, are useful alternatives to the conditional means for characterizing a conditional distribution, especially when the interest lies in the tails. We develop a functional data analysis approach to jointly estimate a family of generalized regression quantiles. Our approach assumes that the generalized regression quantiles share some common features that can be summarized by a small number of principal component functions. The principal component functions are modeled as splines and are estimated by minimizing a penalized asymmetric loss measure. An iterative least asymmetrically weighted squares algorithm is developed for computation. While separate estimation of individual generalized regression quantiles usually suffers from large variability due to lack of sufficient data, by borrowing strength across data sets, our joint estimation approach significantly improves the estimation efficiency, which is demonstrated in a simulation study. The proposed method is applied to data from 159 weather stations in China to obtain the generalized quantile curves of the volatility of the temperature at these stations. © 2013 Springer Science+Business Media New York.

  5. Analysis of Relationship Between Personality and Favorite Places with Poisson Regression Analysis

    Directory of Open Access Journals (Sweden)

    Yoon Song Ha

    2018-01-01

    Full Text Available A relationship between human personality and preferred locations have been a long conjecture for human mobility research. In this paper, we analyzed the relationship between personality and visiting place with Poisson Regression. Poisson Regression can analyze correlation between countable dependent variable and independent variable. For this analysis, 33 volunteers provided their personality data and 49 location categories data are used. Raw location data is preprocessed to be normalized into rates of visit and outlier data is prunned. For the regression analysis, independent variables are personality data and dependent variables are preprocessed location data. Several meaningful results are found. For example, persons with high tendency of frequent visiting to university laboratory has personality with high conscientiousness and low openness. As well, other meaningful location categories are presented in this paper.

  6. application of multilinear regression analysis in modeling of soil

    African Journals Online (AJOL)

    Windows User

    Accordingly [1, 3] in their work, they applied linear regression ... (MLRA) is a statistical technique that uses several explanatory ... order to check this, they adopted bivariate correlation analysis .... groups, namely A-1 through A-7, based on their relative expected ..... Multivariate Regression in Gorgan Province North of Iran” ...

  7. A systematic review and meta-regression analysis of mivacurium for tracheal intubation.

    Science.gov (United States)

    Vanlinthout, L E H; Mesfin, S H; Hens, N; Vanacker, B F; Robertson, E N; Booij, L H D J

    2014-12-01

    We systematically reviewed factors associated with intubation conditions in randomised controlled trials of mivacurium, using random-effects meta-regression analysis. We included 29 studies of 1050 healthy participants. Four factors explained 72.9% of the variation in the probability of excellent intubation conditions: mivacurium dose, 24.4%; opioid use, 29.9%; time to intubation and age together, 18.6%. The odds ratio (95% CI) for excellent intubation was 3.14 (1.65-5.73) for doubling the mivacurium dose, 5.99 (2.14-15.18) for adding opioids to the intubation sequence, and 6.55 (6.01-7.74) for increasing the delay between mivacurium injection and airway insertion from 1 to 2 min in subjects aged 25 years and 2.17 (2.01-2.69) for subjects aged 70 years, p < 0.001 for all. We conclude that good conditions for tracheal intubation are more likely by delaying laryngoscopy after injecting a higher dose of mivacurium with an opioid, particularly in older people. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

  8. Multiple regression analysis of Jominy hardenability data for boron treated steels

    International Nuclear Information System (INIS)

    Komenda, J.; Sandstroem, R.; Tukiainen, M.

    1997-01-01

    The relations between chemical composition and their hardenability of boron treated steels have been investigated using a multiple regression analysis method. A linear model of regression was chosen. The free boron content that is effective for the hardenability was calculated using a model proposed by Jansson. The regression analysis for 1261 steel heats provided equations that were statistically significant at the 95% level. All heats met the specification according to the nordic countries producers classification. The variation in chemical composition explained typically 80 to 90% of the variation in the hardenability. In the regression analysis elements which did not significantly contribute to the calculated hardness according to the F test were eliminated. Carbon, silicon, manganese, phosphorus and chromium were of importance at all Jominy distances, nickel, vanadium, boron and nitrogen at distances above 6 mm. After the regression analysis it was demonstrated that very few outliers were present in the data set, i.e. data points outside four times the standard deviation. The model has successfully been used in industrial practice replacing some of the necessary Jominy tests. (orig.)

  9. Understanding logistic regression analysis

    OpenAIRE

    Sperandei, Sandro

    2014-01-01

    Logistic regression is used to obtain odds ratio in the presence of more than one explanatory variable. The procedure is quite similar to multiple linear regression, with the exception that the response variable is binomial. The result is the impact of each variable on the odds ratio of the observed event of interest. The main advantage is to avoid confounding effects by analyzing the association of all variables together. In this article, we explain the logistic regression procedure using ex...

  10. Background stratified Poisson regression analysis of cohort data.

    Science.gov (United States)

    Richardson, David B; Langholz, Bryan

    2012-03-01

    Background stratified Poisson regression is an approach that has been used in the analysis of data derived from a variety of epidemiologically important studies of radiation-exposed populations, including uranium miners, nuclear industry workers, and atomic bomb survivors. We describe a novel approach to fit Poisson regression models that adjust for a set of covariates through background stratification while directly estimating the radiation-disease association of primary interest. The approach makes use of an expression for the Poisson likelihood that treats the coefficients for stratum-specific indicator variables as 'nuisance' variables and avoids the need to explicitly estimate the coefficients for these stratum-specific parameters. Log-linear models, as well as other general relative rate models, are accommodated. This approach is illustrated using data from the Life Span Study of Japanese atomic bomb survivors and data from a study of underground uranium miners. The point estimate and confidence interval obtained from this 'conditional' regression approach are identical to the values obtained using unconditional Poisson regression with model terms for each background stratum. Moreover, it is shown that the proposed approach allows estimation of background stratified Poisson regression models of non-standard form, such as models that parameterize latency effects, as well as regression models in which the number of strata is large, thereby overcoming the limitations of previously available statistical software for fitting background stratified Poisson regression models.

  11. Impact of internet use on loneliness and contact with others among older adults: cross-sectional analysis.

    Science.gov (United States)

    Cotten, Shelia R; Anderson, William A; McCullough, Brandi M

    2013-02-28

    Older adults are at increased risk of experiencing loneliness and depression, particularly as they move into different types of care communities. Information and communication technology (ICT) usage may help older adults to maintain contact with social ties. However, prior research is not consistent about whether ICT use increases or decreases isolation and loneliness among older adults. The purpose of this study was to examine how Internet use affects perceived social isolation and loneliness of older adults in assisted and independent living communities. We also examined the perceptions of how Internet use affects communication and social interaction. One wave of data from an ongoing study of ICT usage among older adults in assisted and independent living communities in Alabama was used. Regression analysis was used to determine the relationship between frequency of going online and isolation and loneliness (n=205) and perceptions of the effects of Internet use on communication and social interaction (n=60). After controlling for the number of friends and family, physical/emotional social limitations, age, and study arm, a 1-point increase in the frequency of going online was associated with a 0.147-point decrease in loneliness scores (P=.005). Going online was not associated with perceived social isolation (P=.14). Among the measures of perception of the social effects of the Internet, each 1-point increase in the frequency of going online was associated with an increase in agreement that using the Internet had: (1) made it easier to reach people (b=0.508, PInternet may be beneficial for decreasing loneliness and increasing social contact among older adults in assisted and independent living communities.

  12. Poisson Regression Analysis of Illness and Injury Surveillance Data

    Energy Technology Data Exchange (ETDEWEB)

    Frome E.L., Watkins J.P., Ellis E.D.

    2012-12-12

    The Department of Energy (DOE) uses illness and injury surveillance to monitor morbidity and assess the overall health of the work force. Data collected from each participating site include health events and a roster file with demographic information. The source data files are maintained in a relational data base, and are used to obtain stratified tables of health event counts and person time at risk that serve as the starting point for Poisson regression analysis. The explanatory variables that define these tables are age, gender, occupational group, and time. Typical response variables of interest are the number of absences due to illness or injury, i.e., the response variable is a count. Poisson regression methods are used to describe the effect of the explanatory variables on the health event rates using a log-linear main effects model. Results of fitting the main effects model are summarized in a tabular and graphical form and interpretation of model parameters is provided. An analysis of deviance table is used to evaluate the importance of each of the explanatory variables on the event rate of interest and to determine if interaction terms should be considered in the analysis. Although Poisson regression methods are widely used in the analysis of count data, there are situations in which over-dispersion occurs. This could be due to lack-of-fit of the regression model, extra-Poisson variation, or both. A score test statistic and regression diagnostics are used to identify over-dispersion. A quasi-likelihood method of moments procedure is used to evaluate and adjust for extra-Poisson variation when necessary. Two examples are presented using respiratory disease absence rates at two DOE sites to illustrate the methods and interpretation of the results. In the first example the Poisson main effects model is adequate. In the second example the score test indicates considerable over-dispersion and a more detailed analysis attributes the over-dispersion to extra

  13. The impact of foreign caregiving on depression among older people in Taiwan: model testing.

    Science.gov (United States)

    Chiao, Chia-Yi; Schepp, Karen G

    2012-05-01

      This article is a report of a study of predicting the factors that influence depression in the older people in Taiwan. Background.  In 1991, Taiwan opened the labour market to foreign caregivers for the older people who needed long-term care. With the differences in language, culture and lifestyle between foreign caregivers and older people in Taiwan, it was hypothesized that the older people would not be able to relate to them, and therefore become depressed.   The data were collected from 116 Taiwanese older people from July to September, 2005. Path analysis using multiple regression analyses was conducted to estimate the direct and indirect effects of caregiving communication, activities of daily living, income and social support on depression among older people in Taiwan. To evaluate the hypotheses for this research, bi-variate linear regression and multiple regression analyses were used.   The results indicated that the level of activities of daily living (β = -0·201, P = 0·010), care-giving communication (β = -0·272, P = 0·002) income (β = -0·305, P = 0·000) and social support (β = -0·276, P = 0·002) were the predictors of depression in older people in Taiwan. Social support was a mediating factor for caregiving communication and depression. Furthermore, foreign caregiver care was not correlated with depression among older people in Taiwan.   The findings influence the public awareness of depression in older people, and provide the foundational information to influence the policy makers of Taiwan to evaluate the foreign caregiver policy. © 2011 The Authors. Journal of Advanced Nursing © 2011 Blackwell Publishing Ltd.

  14. A Quality Assessment Tool for Non-Specialist Users of Regression Analysis

    Science.gov (United States)

    Argyrous, George

    2015-01-01

    This paper illustrates the use of a quality assessment tool for regression analysis. It is designed for non-specialist "consumers" of evidence, such as policy makers. The tool provides a series of questions such consumers of evidence can ask to interrogate regression analysis, and is illustrated with reference to a recent study published…

  15. Assessing the Prayer Lives of Older Whites, Older Blacks and Older Mexican Americans: A Descriptive Analysis

    Science.gov (United States)

    Krause, Neal

    2011-01-01

    The purpose of this study was to see whether differences emerge between older whites, older blacks, and older Mexican Americans in 12 measures of prayer. These measures assess four dimensions of prayer: The social context of prayer, interpersonal aspects of prayer, beliefs about how prayer operates, and the content or focus of prayers. Data from two nationwide surveys of older adults suggest that with respect to all four dimensions, the prayer lives of older whites appear be less developed than the prayer lives of older blacks and older Mexican Americans. In contrast, relatively few differences were found in the prayer lives of older African Americans and older Mexican Americans. The theoretical implications of these findings are discussed. PMID:22523464

  16. Understanding Older Adults' Perceptions of Internet Use: An Exploratory Factor Analysis

    Science.gov (United States)

    Zheng, Robert; Spears, Jeffrey; Luptak, Marilyn; Wilby, Frances

    2015-01-01

    The current study examined factors related to older adults' perceptions of Internet use. Three hundred ninety five older adults participated in the study. The factor analysis revealed four factors perceived by older adults as critical to their Internet use: social connection, self-efficacy, the need to seek financial information, and the need to…

  17. Which Frail Older People Are Dehydrated? The UK DRIE Study.

    Science.gov (United States)

    Hooper, Lee; Bunn, Diane K; Downing, Alice; Jimoh, Florence O; Groves, Joyce; Free, Carol; Cowap, Vicky; Potter, John F; Hunter, Paul R; Shepstone, Lee

    2016-10-01

    Water-loss dehydration in older people is associated with increased mortality and disability. We aimed to assess the prevalence of dehydration in older people living in UK long-term care and associated cognitive, functional, and health characteristics. The Dehydration Recognition In our Elders (DRIE) cohort study included people aged 65 or older living in long-term care without heart or renal failure. In a cross-sectional baseline analysis, we assessed serum osmolality, previously suggested dehydration risk factors, general health, markers of continence, cognitive and functional health, nutrition status, and medications. Univariate linear regression was used to assess relationships between participant characteristics and serum osmolality, then associated characteristics entered into stepwise backwards multivariate linear regression. DRIE included 188 residents (mean age 86 years, 66% women) of whom 20% were dehydrated (serum osmolality >300 mOsm/kg). Linear and logistic regression suggested that renal, cognitive, and diabetic status were consistently associated with serum osmolality and odds of dehydration, while potassium-sparing diuretics, sex, number of recent health contacts, and bladder incontinence were sometimes associated. Thirst was not associated with hydration status. DRIE found high prevalence of dehydration in older people living in UK long-term care, reinforcing the proposed association between cognitive and renal function and hydration. Dehydration is associated with increased mortality and disability in older people, but trials to assess effects of interventions to support healthy fluid intakes in older people living in residential care are needed to enable us to formally assess causal direction and any health benefits of increasing fluid intakes. © The Author 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.

  18. Background stratified Poisson regression analysis of cohort data

    International Nuclear Information System (INIS)

    Richardson, David B.; Langholz, Bryan

    2012-01-01

    Background stratified Poisson regression is an approach that has been used in the analysis of data derived from a variety of epidemiologically important studies of radiation-exposed populations, including uranium miners, nuclear industry workers, and atomic bomb survivors. We describe a novel approach to fit Poisson regression models that adjust for a set of covariates through background stratification while directly estimating the radiation-disease association of primary interest. The approach makes use of an expression for the Poisson likelihood that treats the coefficients for stratum-specific indicator variables as 'nuisance' variables and avoids the need to explicitly estimate the coefficients for these stratum-specific parameters. Log-linear models, as well as other general relative rate models, are accommodated. This approach is illustrated using data from the Life Span Study of Japanese atomic bomb survivors and data from a study of underground uranium miners. The point estimate and confidence interval obtained from this 'conditional' regression approach are identical to the values obtained using unconditional Poisson regression with model terms for each background stratum. Moreover, it is shown that the proposed approach allows estimation of background stratified Poisson regression models of non-standard form, such as models that parameterize latency effects, as well as regression models in which the number of strata is large, thereby overcoming the limitations of previously available statistical software for fitting background stratified Poisson regression models. (orig.)

  19. Understanding logistic regression analysis.

    Science.gov (United States)

    Sperandei, Sandro

    2014-01-01

    Logistic regression is used to obtain odds ratio in the presence of more than one explanatory variable. The procedure is quite similar to multiple linear regression, with the exception that the response variable is binomial. The result is the impact of each variable on the odds ratio of the observed event of interest. The main advantage is to avoid confounding effects by analyzing the association of all variables together. In this article, we explain the logistic regression procedure using examples to make it as simple as possible. After definition of the technique, the basic interpretation of the results is highlighted and then some special issues are discussed.

  20. A concept analysis of dignity for older adults.

    Science.gov (United States)

    Jacelon, Cynthia S; Connelly, Thomas W; Brown, Rana; Proulx, Kathy; Vo, Thuy

    2004-10-01

    Human dignity is an essential value of professional nursing education as well as a component of the American Nurses Association Code of Ethics. Nurses are exhorted to treat patients with dignity, and older adults want to be treated with dignity and die with dignity. Although dignity, particularly the dignity of older adults, is often discussed in the health care literature, its meaning is not always clear. The aim of this paper is to describe a concept analysis to develop a definition of dignity in older adults. Data were collected using a literature review and five focus groups composed of older adults. The literature provided data about professionals' ideas of dignity and the focus groups provided qualitative data about the nature of dignity in older people. The literature review and focus groups were carried out concurrently, followed by synthesis of the findings. Dignity is an inherent characteristic of being human, it can be subjectively felt as an attribute of the self, and is made manifest through behaviour that demonstrates respect for self and others. Dignity must be learned, and an individual's dignity is affected by the treatment received from others. A behavioural definition of dignity was constructed and this could provide the theoretical basis for nurses to develop interventions that foster dignity for older people.

  1. Daily Living Functioning, Social Engagement and Wellness of Older Adults

    Directory of Open Access Journals (Sweden)

    Noor Zainab

    2017-08-01

    Full Text Available AimThe present study aim to investigate the contributing role of daily living functioning and social engagement in enhancing wellness and various dimensions of wellness in older adults.MethodA correlational research was designed. Socio-demographic data was collected. Lawton Instrumental Activities of Daily Living, Lubben Social Network Scale, and Perceived Wellness Survey were administered on a sample of 112 participants, including 56 men and 56 women.ResultsA correlation analysis found positive correlations between daily living functioning, social engagement and wellness of older adults. The results of regression analysis concluded that both the daily living functioning and social engagement predicted wellness and domains of wellness as well.ConclusionThe obtained results indicate that older adults who are self-reliant lead a more satisfied life in old age and demonstrate to be more adjusted to the effects of aging.

  2. Retro-regression--another important multivariate regression improvement.

    Science.gov (United States)

    Randić, M

    2001-01-01

    We review the serious problem associated with instabilities of the coefficients of regression equations, referred to as the MRA (multivariate regression analysis) "nightmare of the first kind". This is manifested when in a stepwise regression a descriptor is included or excluded from a regression. The consequence is an unpredictable change of the coefficients of the descriptors that remain in the regression equation. We follow with consideration of an even more serious problem, referred to as the MRA "nightmare of the second kind", arising when optimal descriptors are selected from a large pool of descriptors. This process typically causes at different steps of the stepwise regression a replacement of several previously used descriptors by new ones. We describe a procedure that resolves these difficulties. The approach is illustrated on boiling points of nonanes which are considered (1) by using an ordered connectivity basis; (2) by using an ordering resulting from application of greedy algorithm; and (3) by using an ordering derived from an exhaustive search for optimal descriptors. A novel variant of multiple regression analysis, called retro-regression (RR), is outlined showing how it resolves the ambiguities associated with both "nightmares" of the first and the second kind of MRA.

  3. Linear regression analysis: part 14 of a series on evaluation of scientific publications.

    Science.gov (United States)

    Schneider, Astrid; Hommel, Gerhard; Blettner, Maria

    2010-11-01

    Regression analysis is an important statistical method for the analysis of medical data. It enables the identification and characterization of relationships among multiple factors. It also enables the identification of prognostically relevant risk factors and the calculation of risk scores for individual prognostication. This article is based on selected textbooks of statistics, a selective review of the literature, and our own experience. After a brief introduction of the uni- and multivariable regression models, illustrative examples are given to explain what the important considerations are before a regression analysis is performed, and how the results should be interpreted. The reader should then be able to judge whether the method has been used correctly and interpret the results appropriately. The performance and interpretation of linear regression analysis are subject to a variety of pitfalls, which are discussed here in detail. The reader is made aware of common errors of interpretation through practical examples. Both the opportunities for applying linear regression analysis and its limitations are presented.

  4. Management of Industrial Performance Indicators: Regression Analysis and Simulation

    Directory of Open Access Journals (Sweden)

    Walter Roberto Hernandez Vergara

    2017-11-01

    Full Text Available Stochastic methods can be used in problem solving and explanation of natural phenomena through the application of statistical procedures. The article aims to associate the regression analysis and systems simulation, in order to facilitate the practical understanding of data analysis. The algorithms were developed in Microsoft Office Excel software, using statistical techniques such as regression theory, ANOVA and Cholesky Factorization, which made it possible to create models of single and multiple systems with up to five independent variables. For the analysis of these models, the Monte Carlo simulation and analysis of industrial performance indicators were used, resulting in numerical indices that aim to improve the goals’ management for compliance indicators, by identifying systems’ instability, correlation and anomalies. The analytical models presented in the survey indicated satisfactory results with numerous possibilities for industrial and academic applications, as well as the potential for deployment in new analytical techniques.

  5. Least-Squares Linear Regression and Schrodinger's Cat: Perspectives on the Analysis of Regression Residuals.

    Science.gov (United States)

    Hecht, Jeffrey B.

    The analysis of regression residuals and detection of outliers are discussed, with emphasis on determining how deviant an individual data point must be to be considered an outlier and the impact that multiple suspected outlier data points have on the process of outlier determination and treatment. Only bivariate (one dependent and one independent)…

  6. Predicting Dropouts of University Freshmen: A Logit Regression Analysis.

    Science.gov (United States)

    Lam, Y. L. Jack

    1984-01-01

    Stepwise discriminant analysis coupled with logit regression analysis of freshmen data from Brandon University (Manitoba) indicated that six tested variables drawn from research on university dropouts were useful in predicting attrition: student status, residence, financial sources, distance from home town, goal fulfillment, and satisfaction with…

  7. Simulation Experiments in Practice : Statistical Design and Regression Analysis

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2007-01-01

    In practice, simulation analysts often change only one factor at a time, and use graphical analysis of the resulting Input/Output (I/O) data. Statistical theory proves that more information is obtained when applying Design Of Experiments (DOE) and linear regression analysis. Unfortunately, classic

  8. Association of Healthy Habits Beliefs and Mortality in Older Adults: A Longitudinal Analysis of the Mexican Health and Aging Study.

    Science.gov (United States)

    Fernandez-Villa, Julio M; Marquez, David X; Sanchez-Garrido, Natalia; Perez-Zepeda, Mario U; Gonzalez-Lara, Mariana

    2017-06-01

    The aim of this article is to establish the association between beliefs about healthy habits and mortality in a group of Mexican older adults. This is an 11-year follow-up secondary analysis of the Mexican Health and Aging Study. There was a significant difference ( p healthy habits have the potential to improve health compared with those who did not. After adjustment for confounders, Cox regression models showed a hazard ratio (HR) of 0.17 (95% confidence interval [CI] [0.07, 0.38], p healthy habits. Although the mechanism is not completely clear, according to our results, believing that healthy habits can improve health was associated with lower rates of mortality. Further research should elucidate potential strategies for changing beliefs in older adults with the goal of improving their overall health.

  9. Quality of life in breast cancer patients--a quantile regression analysis.

    Science.gov (United States)

    Pourhoseingholi, Mohamad Amin; Safaee, Azadeh; Moghimi-Dehkordi, Bijan; Zeighami, Bahram; Faghihzadeh, Soghrat; Tabatabaee, Hamid Reza; Pourhoseingholi, Asma

    2008-01-01

    Quality of life study has an important role in health care especially in chronic diseases, in clinical judgment and in medical resources supplying. Statistical tools like linear regression are widely used to assess the predictors of quality of life. But when the response is not normal the results are misleading. The aim of this study is to determine the predictors of quality of life in breast cancer patients, using quantile regression model and compare to linear regression. A cross-sectional study conducted on 119 breast cancer patients that admitted and treated in chemotherapy ward of Namazi hospital in Shiraz. We used QLQ-C30 questionnaire to assessment quality of life in these patients. A quantile regression was employed to assess the assocciated factors and the results were compared to linear regression. All analysis carried out using SAS. The mean score for the global health status for breast cancer patients was 64.92+/-11.42. Linear regression showed that only grade of tumor, occupational status, menopausal status, financial difficulties and dyspnea were statistically significant. In spite of linear regression, financial difficulties were not significant in quantile regression analysis and dyspnea was only significant for first quartile. Also emotion functioning and duration of disease statistically predicted the QOL score in the third quartile. The results have demonstrated that using quantile regression leads to better interpretation and richer inference about predictors of the breast cancer patient quality of life.

  10. The Digital Divide and urban older adults.

    Science.gov (United States)

    Cresci, M Kay; Yarandi, Hossein N; Morrell, Roger W

    2010-01-01

    Computers and the Internet offer older adults opportunities and resources for independent living. However, many urban older adults do not use computers. This study examined the demographic, health, and social activities of urban older adults to determine variables that might predict the use and nonuse of computers in this population. A secondary data analysis was performed using the 2001 Detroit City-Wide Needs Assessment of Older Adults (n = 1410) data set. Logistic regression was used to explore potential differences in predictor variables between computer users and nonusers. Overall, computer users were younger (27%), had a higher level of education, were more likely to be employed, had an annual income greater than $20,000, and were healthier and more active than nonusers. They also were more likely to have memberships in community organizations and do volunteer work. Preferred computer activities included conducting Internet searches, playing games, writing, and communicating with family members and friends. The results suggest significant differences in demographic and health-related characteristics between computer users and nonusers among urban older adults. Although about a quarter of participants in this study used computers, the Digital Divide continues to exist in urban settings for scores of others.

  11. Chronic Diseases among Older Cancer Survivors

    Directory of Open Access Journals (Sweden)

    Laura Deckx

    2012-01-01

    Full Text Available Objective. To compare the occurrence of pre-existing and subsequent comorbidity among older cancer patients (≥60 years with older non-cancer patients. Material and Methods. Each cancer patient (n=3835, mean age 72 was matched with four non-cancer patients in terms of age, sex, and practice. The occurrence of chronic diseases was assessed cross-sectionally (lifetime prevalence at time of diagnosis and longitudinally (incidence after diagnosis for all cancer patients and for breast, prostate, and colorectal cancer patients separately. Cancer and non-cancer patients were compared using logistic and Cox regression analysis. Results. The occurrence of the most common pre-existing and incident chronic diseases was largely similar in cancer and non-cancer patients, except for pre-existing COPD (OR 1.21, 95% CI 1.06–1.37 and subsequent venous thrombosis in the first two years after cancer diagnosis (HR 4.20, 95% CI 2.74–6.44, which were significantly more frequent (P<0.01 among older cancer compared to non-cancer patients. Conclusion. The frequency of multimorbidity in older cancer patients is high. However, apart from COPD and venous thrombosis, the incidence of chronic diseases in older cancer patients is similar compared to non-cancer patients of the same age, sex, and practice.

  12. Gender Differences in Performance of Script Analysis by Older Adults

    Science.gov (United States)

    Helmes, E.; Bush, J. D.; Pike, D. L.; Drake, D. G.

    2006-01-01

    Script analysis as a test of executive functions is presumed sensitive to cognitive changes seen with increasing age. Two studies evaluated if gender differences exist in performance on scripts for familiar and unfamiliar tasks in groups of cognitively intact older adults. In Study 1, 26 older adults completed male and female stereotypical…

  13. Does cognitive decline decrease health utility value in older adult patients with cancer?

    Science.gov (United States)

    Akechi, Tatsuo; Aiki, Sayo; Sugano, Koji; Uchida, Megumi; Yamada, Atsuro; Komatsu, Hirokazu; Ishida, Takashi; Kusumoto, Shigeru; Iida, Shinsuke; Okuyama, Toru

    2017-05-01

    Cognitive decline is common among older adults with cancer. The present study aimed to investigate the impact of cognitive decline on health utility value in older adults suffering from cancer. Consecutive patients aged 65 years or older with a primary diagnosis of malignant lymphoma or multiple myeloma were recruited. Patients were asked to complete the EuroQoL-5 (EQ-5D) scale to measure health utility and the Mini-Mental State Examination to assess cognitive decline. The potential impact of cognitive decline was investigated with univariate analysis. A multivariate regression analysis was conducted to control for potential confounding factors. Complete data were obtained from 87 patients, 29% of whom had cognitive decline. The mean ± SE EQ-5D score for patients with cognitive decline was significantly lower than that for those without cognitive decline (0.67 ± 0.04 vs 0.79 ± 0.03, t = 2.38, P = 0.02). However, multiple regression analysis showed that cognitive decline was not significantly associated with EQ-5D scores. Female sex and lower performance scores (worse physical condition) were significantly associated with EQ-5D scores. Cognitive decline may be involved in decreased health utility value in older adult patients with cancer. However, this effect does not seem to be independent, and the patient's physical condition may be a relevant confounding factor. © 2016 The Authors. Psychogeriatrics © 2016 Japanese Psychogeriatric Society.

  14. Visual grading characteristics and ordinal regression analysis during optimisation of CT head examinations.

    Science.gov (United States)

    Zarb, Francis; McEntee, Mark F; Rainford, Louise

    2015-06-01

    To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation. Patient images (n = 66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n = 6) performed VGA followed by VGC and ordinal regression analysis. VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examinations (including trauma) in one centre, achieving radiation dose reductions ranging from 24 % to 36 %. In the second centre a 29 % reduction in radiation dose was achieved for follow-up cases. The combined use of VGC and ordinal logistic regression analysis led to clinical decisions being taken on the implementation of the optimised protocols. This improved method of image quality analysis provided the evidence to support imaging protocol optimisation, resulting in significant radiation dose savings. • There is need for scientifically based image quality evaluation during CT optimisation. • VGC and ordinal regression analysis in combination led to better informed clinical decisions. • VGC and ordinal regression analysis led to dose reductions without compromising diagnostic efficacy.

  15. Regression analysis of radiological parameters in nuclear power plants

    International Nuclear Information System (INIS)

    Bhargava, Pradeep; Verma, R.K.; Joshi, M.L.

    2003-01-01

    Indian Pressurized Heavy Water Reactors (PHWRs) have now attained maturity in their operations. Indian PHWR operation started in the year 1972. At present there are 12 operating PHWRs collectively producing nearly 2400 MWe. Sufficient radiological data are available for analysis to draw inferences which may be utilised for better understanding of radiological parameters influencing the collective internal dose. Tritium is the main contributor to the occupational internal dose originating in PHWRs. An attempt has been made to establish the relationship between radiological parameters, which may be useful to draw inferences about the internal dose. Regression analysis have been done to find out the relationship, if it exist, among the following variables: A. Specific tritium activity of heavy water (Moderator and PHT) and tritium concentration in air at various work locations. B. Internal collective occupational dose and tritium release to environment through air route. C. Specific tritium activity of heavy water (Moderator and PHT) and collective internal occupational dose. For this purpose multivariate regression analysis has been carried out. D. Tritium concentration in air at various work location and tritium release to environment through air route. For this purpose multivariate regression analysis has been carried out. This analysis reveals that collective internal dose has got very good correlation with the tritium activity release to the environment through air route. Whereas no correlation has been found between specific tritium activity in the heavy water systems and collective internal occupational dose. The good correlation has been found in case D and F test reveals that it is not by chance. (author)

  16. Comparison of cranial sex determination by discriminant analysis and logistic regression.

    Science.gov (United States)

    Amores-Ampuero, Anabel; Alemán, Inmaculada

    2016-04-05

    Various methods have been proposed for estimating dimorphism. The objective of this study was to compare sex determination results from cranial measurements using discriminant analysis or logistic regression. The study sample comprised 130 individuals (70 males) of known sex, age, and cause of death from San José cemetery in Granada (Spain). Measurements of 19 neurocranial dimensions and 11 splanchnocranial dimensions were subjected to discriminant analysis and logistic regression, and the percentages of correct classification were compared between the sex functions obtained with each method. The discriminant capacity of the selected variables was evaluated with a cross-validation procedure. The percentage accuracy with discriminant analysis was 78.2% for the neurocranium (82.4% in females and 74.6% in males) and 73.7% for the splanchnocranium (79.6% in females and 68.8% in males). These percentages were higher with logistic regression analysis: 85.7% for the neurocranium (in both sexes) and 94.1% for the splanchnocranium (100% in females and 91.7% in males).

  17. Regression Analysis: Instructional Resource for Cost/Managerial Accounting

    Science.gov (United States)

    Stout, David E.

    2015-01-01

    This paper describes a classroom-tested instructional resource, grounded in principles of active learning and a constructivism, that embraces two primary objectives: "demystify" for accounting students technical material from statistics regarding ordinary least-squares (OLS) regression analysis--material that students may find obscure or…

  18. Physical activity during hospitalization: Activities and preferences of adults versus older adults.

    Science.gov (United States)

    Meesters, Jorit; Conijn, D; Vermeulen, H M; Vliet Vlieland, Tpm

    2018-04-16

    Inactivity during hospitalization leads to a functional decline and an increased risk of complications. To date, studies focused on older adults. This study aims to compare the physical activities performed by older adult and adult hospitalized patients. Patients hospitalized for >3 days at a university hospital completed a questionnaire regarding their physical activities (% of days on which an activity was performed divided by the length of stay) and physical activity needs during hospitalization. Crude and adjusted comparisons of older adult (>60 years) and adult (≤60 years) patients were performed using parametric testing and regression analyses. Of 524 patients, 336 (64%) completed the questionnaire, including 166 (49%) older adult patients. On average, the patients were physically active on 35% or less of the days during their hospitalization. Linear regression analysis showed no significant associations between being an older adult and performing physical activities after adjusting for gender, length of stay, surgical intervention, and meeting physical activity recommendations prior to hospitalization. Most patients were well informed regarding physical activity during hospitalization; however, the older adult patients reported a need for information regarding physical activities after hospitalization more frequently (odds ratios, 2.47) after adjusting for educational level, gender, and physical therapy during hospitalization. Both older adult and adult patients are physically inactive during hospitalization, and older adult patients express a greater need for additional information regarding physical activity after hospitalization than adult patients. Therefore, personalized strategies that inform and motivate patients to resume physical activities during hospitalization are needed regardless of age.

  19. Robust Mediation Analysis Based on Median Regression

    Science.gov (United States)

    Yuan, Ying; MacKinnon, David P.

    2014-01-01

    Mediation analysis has many applications in psychology and the social sciences. The most prevalent methods typically assume that the error distribution is normal and homoscedastic. However, this assumption may rarely be met in practice, which can affect the validity of the mediation analysis. To address this problem, we propose robust mediation analysis based on median regression. Our approach is robust to various departures from the assumption of homoscedasticity and normality, including heavy-tailed, skewed, contaminated, and heteroscedastic distributions. Simulation studies show that under these circumstances, the proposed method is more efficient and powerful than standard mediation analysis. We further extend the proposed robust method to multilevel mediation analysis, and demonstrate through simulation studies that the new approach outperforms the standard multilevel mediation analysis. We illustrate the proposed method using data from a program designed to increase reemployment and enhance mental health of job seekers. PMID:24079925

  20. Multiplication factor versus regression analysis in stature estimation from hand and foot dimensions.

    Science.gov (United States)

    Krishan, Kewal; Kanchan, Tanuj; Sharma, Abhilasha

    2012-05-01

    Estimation of stature is an important parameter in identification of human remains in forensic examinations. The present study is aimed to compare the reliability and accuracy of stature estimation and to demonstrate the variability in estimated stature and actual stature using multiplication factor and regression analysis methods. The study is based on a sample of 246 subjects (123 males and 123 females) from North India aged between 17 and 20 years. Four anthropometric measurements; hand length, hand breadth, foot length and foot breadth taken on the left side in each subject were included in the study. Stature was measured using standard anthropometric techniques. Multiplication factors were calculated and linear regression models were derived for estimation of stature from hand and foot dimensions. Derived multiplication factors and regression formula were applied to the hand and foot measurements in the study sample. The estimated stature from the multiplication factors and regression analysis was compared with the actual stature to find the error in estimated stature. The results indicate that the range of error in estimation of stature from regression analysis method is less than that of multiplication factor method thus, confirming that the regression analysis method is better than multiplication factor analysis in stature estimation. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  1. A comparative study of multiple regression analysis and back ...

    Indian Academy of Sciences (India)

    Abhijit Sarkar

    artificial neural network (ANN) models to predict weld bead geometry and HAZ width in submerged arc welding ... Keywords. Submerged arc welding (SAW); multi-regression analysis (MRA); artificial neural network ..... Degree of freedom.

  2. A latent class analysis of social activities and health among community-dwelling older adults in Korea.

    Science.gov (United States)

    Park, Mi Jin; Park, Nan Sook; Chiriboga, David A

    2018-05-01

    This study presents an empirical typology of social activity and its association with the depressive symptoms and self-rated health of community-dwelling older adults (n = 464) in South Korea. Latent class analysis (LCA) was used to classify the types of social activities. Data analyses were conducted using Mplus 7.2 program for LCA and SPSS 22.0 for multiple regression analyses. LCA identified people who fell into one of the four activity groups: Diverse, Community Center/Disengaged, Religion Plus, and Friendship/Leisure. Membership in these four groups predicted differences in depressive symptoms and self-rated health. Results indicate that typologies of social activity could enhance practitioners' understanding of activity patterns and their associations with health and well-being.

  3. Multilayer perceptron for robust nonlinear interval regression analysis using genetic algorithms.

    Science.gov (United States)

    Hu, Yi-Chung

    2014-01-01

    On the basis of fuzzy regression, computational models in intelligence such as neural networks have the capability to be applied to nonlinear interval regression analysis for dealing with uncertain and imprecise data. When training data are not contaminated by outliers, computational models perform well by including almost all given training data in the data interval. Nevertheless, since training data are often corrupted by outliers, robust learning algorithms employed to resist outliers for interval regression analysis have been an interesting area of research. Several approaches involving computational intelligence are effective for resisting outliers, but the required parameters for these approaches are related to whether the collected data contain outliers or not. Since it seems difficult to prespecify the degree of contamination beforehand, this paper uses multilayer perceptron to construct the robust nonlinear interval regression model using the genetic algorithm. Outliers beyond or beneath the data interval will impose slight effect on the determination of data interval. Simulation results demonstrate that the proposed method performs well for contaminated datasets.

  4. Exploratory regression analysis: a tool for selecting models and determining predictor importance.

    Science.gov (United States)

    Braun, Michael T; Oswald, Frederick L

    2011-06-01

    Linear regression analysis is one of the most important tools in a researcher's toolbox for creating and testing predictive models. Although linear regression analysis indicates how strongly a set of predictor variables, taken together, will predict a relevant criterion (i.e., the multiple R), the analysis cannot indicate which predictors are the most important. Although there is no definitive or unambiguous method for establishing predictor variable importance, there are several accepted methods. This article reviews those methods for establishing predictor importance and provides a program (in Excel) for implementing them (available for direct download at http://dl.dropbox.com/u/2480715/ERA.xlsm?dl=1) . The program investigates all 2(p) - 1 submodels and produces several indices of predictor importance. This exploratory approach to linear regression, similar to other exploratory data analysis techniques, has the potential to yield both theoretical and practical benefits.

  5. Impact of Living Alone on Depressive Symptoms in Older Korean Widows

    Directory of Open Access Journals (Sweden)

    Gyeong-Suk Jeon

    2017-10-01

    Full Text Available We examined the relationship between living alone and the prevalence of depressive symptoms in older Korean widows and assessed the individual contributions of health, social ties, and socioeconomic factors to the development of depressive symptoms. The study was a secondary analysis using data from widows, 65 years of age and older, who participated in the Living Profiles of Older People Survey (LPOPS. A logistic regression analysis was used to evaluate the contributions of health, social ties, and socioeconomic factors to the development of depressive symptoms. Working status and equivalent household income were significantly associated with depressive symptoms in both those living with others and those living alone. Adjustment for health status and social ties did not change the impact of living alone on the prevalence of depressive symptoms. However, adjustment for equivalent household income eliminated the negative association between living alone and depressive symptoms. Our findings indicate that economic resources are more important than health and social ties for alleviating the negative impact of living alone on the development of depressive symptoms in older widows.

  6. Regression analysis for LED color detection of visual-MIMO system

    Science.gov (United States)

    Banik, Partha Pratim; Saha, Rappy; Kim, Ki-Doo

    2018-04-01

    Color detection from a light emitting diode (LED) array using a smartphone camera is very difficult in a visual multiple-input multiple-output (visual-MIMO) system. In this paper, we propose a method to determine the LED color using a smartphone camera by applying regression analysis. We employ a multivariate regression model to identify the LED color. After taking a picture of an LED array, we select the LED array region, and detect the LED using an image processing algorithm. We then apply the k-means clustering algorithm to determine the number of potential colors for feature extraction of each LED. Finally, we apply the multivariate regression model to predict the color of the transmitted LEDs. In this paper, we show our results for three types of environmental light condition: room environmental light, low environmental light (560 lux), and strong environmental light (2450 lux). We compare the results of our proposed algorithm from the analysis of training and test R-Square (%) values, percentage of closeness of transmitted and predicted colors, and we also mention about the number of distorted test data points from the analysis of distortion bar graph in CIE1931 color space.

  7. Impact of Social Integration and Living Arrangements on Korean Older Adults' Depression: A Moderation Model.

    Science.gov (United States)

    Lee, Youjung; Jang, Kyeonghee; Lockhart, Naorah C

    2018-04-01

    Depression among older adults is a challenging public health concern in Korea. Using panel data from the Korea Institute for Health and Social Affairs on Korean older adults and their family caregivers, this study explores significant predictors of depression among Korean older adults as well as the moderating effect of living arrangements on the association between social integration and depression. A multivariate logistic regression analysis showed that preexisting depression was the most significant predictor of Korean older adults' current depression, followed by health status and family support. In addition, social integration significantly decreased Korean older adults' depression. Importantly, a significant moderation effect of living arrangements between Korean older adults' social integration and depression was observed. This study implies the development of individually tailored and culturally responsive programs to engage marginalized Korean older adults living alone, helping foster their well-being and optimal aging.

  8. Evaluation of syngas production unit cost of bio-gasification facility using regression analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yangyang; Parajuli, Prem B.

    2011-08-10

    Evaluation of economic feasibility of a bio-gasification facility needs understanding of its unit cost under different production capacities. The objective of this study was to evaluate the unit cost of syngas production at capacities from 60 through 1800Nm 3/h using an economic model with three regression analysis techniques (simple regression, reciprocal regression, and log-log regression). The preliminary result of this study showed that reciprocal regression analysis technique had the best fit curve between per unit cost and production capacity, with sum of error squares (SES) lower than 0.001 and coefficient of determination of (R 2) 0.996. The regression analysis techniques determined the minimum unit cost of syngas production for micro-scale bio-gasification facilities of $0.052/Nm 3, under the capacity of 2,880 Nm 3/h. The results of this study suggest that to reduce cost, facilities should run at a high production capacity. In addition, the contribution of this technique could be the new categorical criterion to evaluate micro-scale bio-gasification facility from the perspective of economic analysis.

  9. A primer for biomedical scientists on how to execute model II linear regression analysis.

    Science.gov (United States)

    Ludbrook, John

    2012-04-01

    1. There are two very different ways of executing linear regression analysis. One is Model I, when the x-values are fixed by the experimenter. The other is Model II, in which the x-values are free to vary and are subject to error. 2. I have received numerous complaints from biomedical scientists that they have great difficulty in executing Model II linear regression analysis. This may explain the results of a Google Scholar search, which showed that the authors of articles in journals of physiology, pharmacology and biochemistry rarely use Model II regression analysis. 3. I repeat my previous arguments in favour of using least products linear regression analysis for Model II regressions. I review three methods for executing ordinary least products (OLP) and weighted least products (WLP) regression analysis: (i) scientific calculator and/or computer spreadsheet; (ii) specific purpose computer programs; and (iii) general purpose computer programs. 4. Using a scientific calculator and/or computer spreadsheet, it is easy to obtain correct values for OLP slope and intercept, but the corresponding 95% confidence intervals (CI) are inaccurate. 5. Using specific purpose computer programs, the freeware computer program smatr gives the correct OLP regression coefficients and obtains 95% CI by bootstrapping. In addition, smatr can be used to compare the slopes of OLP lines. 6. When using general purpose computer programs, I recommend the commercial programs systat and Statistica for those who regularly undertake linear regression analysis and I give step-by-step instructions in the Supplementary Information as to how to use loss functions. © 2011 The Author. Clinical and Experimental Pharmacology and Physiology. © 2011 Blackwell Publishing Asia Pty Ltd.

  10. External Tank Liquid Hydrogen (LH2) Prepress Regression Analysis Independent Review Technical Consultation Report

    Science.gov (United States)

    Parsons, Vickie s.

    2009-01-01

    The request to conduct an independent review of regression models, developed for determining the expected Launch Commit Criteria (LCC) External Tank (ET)-04 cycle count for the Space Shuttle ET tanking process, was submitted to the NASA Engineering and Safety Center NESC on September 20, 2005. The NESC team performed an independent review of regression models documented in Prepress Regression Analysis, Tom Clark and Angela Krenn, 10/27/05. This consultation consisted of a peer review by statistical experts of the proposed regression models provided in the Prepress Regression Analysis. This document is the consultation's final report.

  11. Tutorial on Biostatistics: Linear Regression Analysis of Continuous Correlated Eye Data.

    Science.gov (United States)

    Ying, Gui-Shuang; Maguire, Maureen G; Glynn, Robert; Rosner, Bernard

    2017-04-01

    To describe and demonstrate appropriate linear regression methods for analyzing correlated continuous eye data. We describe several approaches to regression analysis involving both eyes, including mixed effects and marginal models under various covariance structures to account for inter-eye correlation. We demonstrate, with SAS statistical software, applications in a study comparing baseline refractive error between one eye with choroidal neovascularization (CNV) and the unaffected fellow eye, and in a study determining factors associated with visual field in the elderly. When refractive error from both eyes were analyzed with standard linear regression without accounting for inter-eye correlation (adjusting for demographic and ocular covariates), the difference between eyes with CNV and fellow eyes was 0.15 diopters (D; 95% confidence interval, CI -0.03 to 0.32D, p = 0.10). Using a mixed effects model or a marginal model, the estimated difference was the same but with narrower 95% CI (0.01 to 0.28D, p = 0.03). Standard regression for visual field data from both eyes provided biased estimates of standard error (generally underestimated) and smaller p-values, while analysis of the worse eye provided larger p-values than mixed effects models and marginal models. In research involving both eyes, ignoring inter-eye correlation can lead to invalid inferences. Analysis using only right or left eyes is valid, but decreases power. Worse-eye analysis can provide less power and biased estimates of effect. Mixed effects or marginal models using the eye as the unit of analysis should be used to appropriately account for inter-eye correlation and maximize power and precision.

  12. Exercise to prevent falls in older adults: an updated systematic review and meta-analysis.

    Science.gov (United States)

    Sherrington, Catherine; Michaleff, Zoe A; Fairhall, Nicola; Paul, Serene S; Tiedemann, Anne; Whitney, Julie; Cumming, Robert G; Herbert, Robert D; Close, Jacqueline C T; Lord, Stephen R

    2017-12-01

    Previous meta-analyses have found that exercise prevents falls in older people. This study aimed to test whether this effect is still present when new trials are added, and it explores whether characteristics of the trial design, sample or intervention are associated with greater fall prevention effects. Update of a systematic review with random effects meta-analysis and meta-regression. Cochrane Library, CINAHL, MEDLINE, EMBASE, PubMed, PEDro and SafetyLit were searched from January 2010 to January 2016. We included randomised controlled trials that compared fall rates in older people randomised to receive exercise as a single intervention with fall rates in those randomised to a control group. 99 comparisons from 88 trials with 19 478 participants were available for meta-analysis. Overall, exercise reduced the rate of falls in community-dwelling older people by 21% (pooled rate ratio 0.79, 95% CI 0.73 to 0.85, pexercise programmes that challenged balance and involved more than 3 hours/week of exercise. These variables explained 76% of the between-trial heterogeneity and in combination led to a 39% reduction in falls (incident rate ratio 0.61, 95% CI 0.53 to 0.72, pExercise also had a fall prevention effect in community-dwelling people with Parkinson's disease (pooled rate ratio 0.47, 95% CI 0.30 to 0.73, p=0.001, I 2 65%, 6 comparisons) or cognitive impairment (pooled rate ratio 0.55, 95% CI 0.37 to 0.83, p=0.004, I 2 21%, 3 comparisons). There was no evidence of a fall prevention effect of exercise in residential care settings or among stroke survivors or people recently discharged from hospital. Exercise as a single intervention can prevent falls in community-dwelling older people. Exercise programmes that challenge balance and are of a higher dose have larger effects. The impact of exercise as a single intervention in clinical groups and aged care facility residents requires further investigation, but promising results are evident for people with Parkinson

  13. Non-stationary hydrologic frequency analysis using B-spline quantile regression

    Science.gov (United States)

    Nasri, B.; Bouezmarni, T.; St-Hilaire, A.; Ouarda, T. B. M. J.

    2017-11-01

    Hydrologic frequency analysis is commonly used by engineers and hydrologists to provide the basic information on planning, design and management of hydraulic and water resources systems under the assumption of stationarity. However, with increasing evidence of climate change, it is possible that the assumption of stationarity, which is prerequisite for traditional frequency analysis and hence, the results of conventional analysis would become questionable. In this study, we consider a framework for frequency analysis of extremes based on B-Spline quantile regression which allows to model data in the presence of non-stationarity and/or dependence on covariates with linear and non-linear dependence. A Markov Chain Monte Carlo (MCMC) algorithm was used to estimate quantiles and their posterior distributions. A coefficient of determination and Bayesian information criterion (BIC) for quantile regression are used in order to select the best model, i.e. for each quantile, we choose the degree and number of knots of the adequate B-spline quantile regression model. The method is applied to annual maximum and minimum streamflow records in Ontario, Canada. Climate indices are considered to describe the non-stationarity in the variable of interest and to estimate the quantiles in this case. The results show large differences between the non-stationary quantiles and their stationary equivalents for an annual maximum and minimum discharge with high annual non-exceedance probabilities.

  14. Alternative Methods of Regression

    CERN Document Server

    Birkes, David

    2011-01-01

    Of related interest. Nonlinear Regression Analysis and its Applications Douglas M. Bates and Donald G. Watts ".an extraordinary presentation of concepts and methods concerning the use and analysis of nonlinear regression models.highly recommend[ed].for anyone needing to use and/or understand issues concerning the analysis of nonlinear regression models." --Technometrics This book provides a balance between theory and practice supported by extensive displays of instructive geometrical constructs. Numerous in-depth case studies illustrate the use of nonlinear regression analysis--with all data s

  15. Urban and rural factors associated with life satisfaction among older Chinese adults.

    Science.gov (United States)

    Li, Chengbo; Chi, Iris; Zhang, Xu; Cheng, Zhaowen; Zhang, Lei; Chen, Gong

    2015-01-01

    This study compared urban and rural factors associated with life satisfaction among older adults in mainland China. Study data were extracted at random from 10% of the Sample Survey on Aged Population in urban/rural China in 2006 for 1980 participants aged 60 and older, including 997 from urban cities and 983 from rural villages. In this study, 54.6% of urban older adults and 44.1% of rural older adults reported satisfaction with their lives. Binary logistic regression analysis showed that financial strain, depressive symptoms, filial piety, and accessibility of health services were significantly associated with life satisfaction for both urban and rural participants, but age and financial exchange with children were only associated with life satisfaction among urban older adults. Findings are consistent with some previous studies that indicated the importance of financial strain, depressive symptoms, filial piety, and accessibility of health services to life satisfaction among the older adults in both urban and rural areas. This study also demonstrated the importance of age and family financial exchange to the life satisfaction of urban older adults.

  16. Perceived age discrimination in older adults.

    Science.gov (United States)

    Rippon, Isla; Kneale, Dylan; de Oliveira, Cesar; Demakakos, Panayotes; Steptoe, Andrew

    2014-05-01

    to examine perceived age discrimination in a large representative sample of older adults in England. this cross-sectional study of over 7,500 individuals used data from the fifth wave of the English Longitudinal Study of Ageing (ELSA), a longitudinal cohort study of men and women aged 52 years and older in England. Wave 5 asked respondents about the frequency of five everyday discriminatory situations. Participants who attributed any experiences of discrimination to their age were treated as cases of perceived age discrimination. Multivariable logistic regression analysis was used to estimate the odds ratios of experiencing perceived age discrimination in relation to selected sociodemographic factors. approximately a third (33.3%) of all respondents experienced age discrimination, rising to 36.8% in those aged 65 and over. Perceived age discrimination was associated with older age, higher education, lower levels of household wealth and being retired or not in employment. The correlates of age discrimination across the five discriminatory situations were similar. understanding age discrimination is vital if we are to develop appropriate policies and to target future interventions effectively. These findings highlight the scale of the challenge of age discrimination for older adults in England and illustrate that those groups are particularly vulnerable to this form of discrimination.

  17. Is leisure beneficial for older Korean immigrants? An interpretative phenomenological analysis

    Science.gov (United States)

    Kim, Junhyoung; Moon, Sangjeong; Song, Jungsun

    2016-01-01

    Leisure is an important quality of life factor for older Korean immigrants. The purpose of this study was to explore leisure benefits associated with health among older Korean immigrants. A total of 18 individuals participated in the study. Using interpretative phenomenological analysis (IPA), three themes emerged from participants’ personal statements and experiences: (a) experiencing psychological benefits, (b) strengthening social connections, and (c) coping with acculturative stress. The findings indicate that leisure provided a context in which older Korean immigrants created an emotional and social support system that helped them to experience psychological and social benefits. This research suggested that older Korean immigrants used leisure as a coping mechanism that results in health and well-being. PMID:27914195

  18. Is leisure beneficial for older Korean immigrants? An interpretative phenomenological analysis

    Directory of Open Access Journals (Sweden)

    Junhyoung Kim

    2016-11-01

    Full Text Available Leisure is an important quality of life factor for older Korean immigrants. The purpose of this study was to explore leisure benefits associated with health among older Korean immigrants. A total of 18 individuals participated in the study. Using interpretative phenomenological analysis (IPA, three themes emerged from participants’ personal statements and experiences: (a experiencing psychological benefits, (b strengthening social connections, and (c coping with acculturative stress. The findings indicate that leisure provided a context in which older Korean immigrants created an emotional and social support system that helped them to experience psychological and social benefits. This research suggested that older Korean immigrants used leisure as a coping mechanism that results in health and well-being.

  19. Is leisure beneficial for older Korean immigrants? An interpretative phenomenological analysis.

    Science.gov (United States)

    Kim, Junhyoung; Moon, Sangjeong; Song, Jungsun

    2016-01-01

    Leisure is an important quality of life factor for older Korean immigrants. The purpose of this study was to explore leisure benefits associated with health among older Korean immigrants. A total of 18 individuals participated in the study. Using interpretative phenomenological analysis (IPA), three themes emerged from participants' personal statements and experiences: (a) experiencing psychological benefits, (b) strengthening social connections, and (c) coping with acculturative stress. The findings indicate that leisure provided a context in which older Korean immigrants created an emotional and social support system that helped them to experience psychological and social benefits. This research suggested that older Korean immigrants used leisure as a coping mechanism that results in health and well-being.

  20. Friends, Depressive Symptoms, and Life Satisfaction Among Older Korean Americans.

    Science.gov (United States)

    Roh, Soonhee; Lee, Yeon-Shim; Lee, Kyoung Hag; Shibusawa, Tazuko; Yoo, Grace J

    2015-08-01

    This study examined the interactive effects of social network support and depressive symptoms on life satisfaction among older Korean Americans (KAs). Using data from a sample of 200 elders in a large metropolitan area (M age = 72.50, SD = 5.15), hierarchical regression analysis was used to examine the interaction between social network support and depressive symptoms on life satisfaction among older KAs. After controlling for demographic variables, both social network support and depressive symptoms were identified as predictors for life satisfaction. Interaction effects indicated strong associations between higher social network support specifically from friends and lower depressive symptoms with higher levels of life satisfaction. Findings highlight the important role that friends play in terms of social network support for the mental health of older KAs, and the need for geriatric practitioners to monitor and assess the quality of social network support-including friendships-when working with older KAs.

  1. On macroeconomic values investigation using fuzzy linear regression analysis

    Directory of Open Access Journals (Sweden)

    Richard Pospíšil

    2017-06-01

    Full Text Available The theoretical background for abstract formalization of the vague phenomenon of complex systems is the fuzzy set theory. In the paper, vague data is defined as specialized fuzzy sets - fuzzy numbers and there is described a fuzzy linear regression model as a fuzzy function with fuzzy numbers as vague parameters. To identify the fuzzy coefficients of the model, the genetic algorithm is used. The linear approximation of the vague function together with its possibility area is analytically and graphically expressed. A suitable application is performed in the tasks of the time series fuzzy regression analysis. The time-trend and seasonal cycles including their possibility areas are calculated and expressed. The examples are presented from the economy field, namely the time-development of unemployment, agricultural production and construction respectively between 2009 and 2011 in the Czech Republic. The results are shown in the form of the fuzzy regression models of variables of time series. For the period 2009-2011, the analysis assumptions about seasonal behaviour of variables and the relationship between them were confirmed; in 2010, the system behaved fuzzier and the relationships between the variables were vaguer, that has a lot of causes, from the different elasticity of demand, through state interventions to globalization and transnational impacts.

  2. Healthcare professionals' perceptions of neglect of older people in Mexico: A qualitative secondary analysis.

    Science.gov (United States)

    Caceres, Billy A; Bub, Linda; Negrete, Maria Isabel; Giraldo Rodríguez, Liliana; Squires, Allison P

    2018-03-01

    To describe healthcare professionals' perceptions of neglect of older people in Mexico. Mistreatment of older people, particularly neglect, has emerged as a significant public health concern worldwide. However, few studies have been conducted to examine neglect of older people in low- and middle-income countries. Most research has focused on estimating the prevalence of neglect in older populations with little emphasis on the perceptions of healthcare professionals and their role in addressing neglect of older people. Qualitative secondary analysis. The parent study consisted of nine focus groups conducted with healthcare professionals at five public hospitals in Mexico. The purpose of the parent study was to perform a needs assessment to determine the feasibility of adapting the Nurses Improving Care for Healthsystem Elders programme to Mexico. A qualitative secondary analysis with directed content analysis approach was used to extract data related to neglect of older people. A total of 89 participants representing healthcare professionals from several disciplines were interviewed. Three themes emerged: (i) The main point is not here; (ii) We feel hopeless; and (iii) We need preparation. Participants reported distress and hopelessness related to neglect of older people. Lack of community-based resources was noted as contributing to neglect. Increased education regarding care of older people for both caregivers and healthcare professionals and greater interdisciplinary collaboration were identified as potential solutions to combat neglect. Community-based services and resource allocation need to be re-evaluated to improve the care of older Mexicans. Interdisciplinary models of care should be developed to address concerns related to neglect of older people. Neglect negatively impacts healthcare professionals' ability to adequately care for older patients. There is a need to invest in community-based services and models of care to address these concerns. © 2017

  3. REGRESSION ANALYSIS OF SEA-SURFACE-TEMPERATURE PATTERNS FOR THE NORTH PACIFIC OCEAN.

    Science.gov (United States)

    SEA WATER, *SURFACE TEMPERATURE, *OCEANOGRAPHIC DATA, PACIFIC OCEAN, REGRESSION ANALYSIS , STATISTICAL ANALYSIS, UNDERWATER EQUIPMENT, DETECTION, UNDERWATER COMMUNICATIONS, DISTRIBUTION, THERMAL PROPERTIES, COMPUTERS.

  4. Regression analysis understanding and building business and economic models using Excel

    CERN Document Server

    Wilson, J Holton

    2012-01-01

    The technique of regression analysis is used so often in business and economics today that an understanding of its use is necessary for almost everyone engaged in the field. This book will teach you the essential elements of building and understanding regression models in a business/economic context in an intuitive manner. The authors take a non-theoretical treatment that is accessible even if you have a limited statistical background. It is specifically designed to teach the correct use of regression, while advising you of its limitations and teaching about common pitfalls. This book describe

  5. Nonlinear regression analysis for evaluating tracer binding parameters using the programmable K1003 desk computer

    International Nuclear Information System (INIS)

    Sarrach, D.; Strohner, P.

    1986-01-01

    The Gauss-Newton algorithm has been used to evaluate tracer binding parameters of RIA by nonlinear regression analysis. The calculations were carried out on the K1003 desk computer. Equations for simple binding models and its derivatives are presented. The advantages of nonlinear regression analysis over linear regression are demonstrated

  6. Modern Attitudes Toward Older Adults in the Aging World: A Cross-Cultural Meta-Analysis.

    Science.gov (United States)

    North, Michael S; Fiske, Susan T

    2015-09-01

    Prevailing beliefs suggest that Eastern cultures hold older adults in higher esteem than Western cultures do, due to stronger collectivist traditions of filial piety. However, in modern, industrialized societies, the strain presented by dramatic rises in population aging potentially threatens traditional cultural expectations. Addressing these competing hypotheses, a literature search located 37 eligible papers, comprising samples from 23 countries and 21,093 total participants, directly comparing Easterners and Westerners (as classified per U.N. conventions) in their attitudes toward aging and the aged. Contradicting conventional wisdom, a random-effects meta-analysis on these articles found such evaluations to be more negative in the East overall (standardized mean difference = -0.31). High heterogeneity in study comparisons suggested the presence of moderators; indeed, geographical region emerged as a significant moderating factor, with the strongest levels of senior derogation emerging in East Asia (compared with South and Southeast Asia) and non-Anglophone Europe (compared with North American and Anglophone Western regions). At the country level, multiple-moderator meta-regression analysis confirmed recent rises in population aging to significantly predict negative elder attitudes, controlling for industrialization per se over the same time period. Unexpectedly, these analyses also found that cultural individualism significantly predicted relative positivity-suggesting that, for generating elder respect within rapidly aging societies, collectivist traditions may backfire. The findings suggest the importance of demographic challenges in shaping modern attitudes toward elders-presenting considerations for future research in ageism, cross-cultural psychology, and even economic development, as societies across the globe accommodate unprecedented numbers of older citizens. (c) 2015 APA, all rights reserved).

  7. Regression analysis for the social sciences

    CERN Document Server

    Gordon, Rachel A

    2010-01-01

    The book provides graduate students in the social sciences with the basic skills that they need to estimate, interpret, present, and publish basic regression models using contemporary standards. Key features of the book include: interweaving the teaching of statistical concepts with examples developed for the course from publicly-available social science data or drawn from the literature. thorough integration of teaching statistical theory with teaching data processing and analysis. teaching of both SAS and Stata "side-by-side" and use of chapter exercises in which students practice programming and interpretation on the same data set and course exercises in which students can choose their own research questions and data set.

  8. Job characteristics and mental health for older workers.

    Science.gov (United States)

    Mc Carthy, V J C; Cronly, J; Perry, I J

    2017-07-01

    Adverse job characteristics have been linked with increased incidence of depression and anxiety in working populations. However, the association between job characteristics and mental health, in an older working population while controlling for personality traits, is less well known. To examine the association between job characteristics (job demands and job control) and mental health (depression and anxiety) for older workers while controlling for personality traits. A sample of workers aged 50-69 years were recruited from a primary health care clinic in Southern Ireland. Job characteristics were measured using the Copenhagen Psychosocial Questionnaire; demands (quantitative and cognitive) and control (influence at work and possibilities for development). Personality traits were measured using the Ten-Item Personality Inventory, depression was measured using the Center for Epidemiological Studies-Depression Scale and anxiety was measured using the Hospital Anxiety and Depression Scale. Descriptive analysis, simple and multiple linear regression analyses were conducted. The final sample size was 1025 with an initial 67% response rate. Multiple linear regression analysis showed job characteristics (in particular, job demands) to be significant positive predictors of symptoms of depression and anxiety. The inverse was true for job control variables and symptoms of depression. Neither possibilities for development nor influence at work were associated with symptoms of anxiety. Our findings indicate that despite potential confounders, higher demands at work can impact the worker's mental health negatively. Reducing job demands and encouraging role development may benefit the mental health of older workers. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  9. Multivariate Linear Regression and CART Regression Analysis of TBM Performance at Abu Hamour Phase-I Tunnel

    Science.gov (United States)

    Jakubowski, J.; Stypulkowski, J. B.; Bernardeau, F. G.

    2017-12-01

    The first phase of the Abu Hamour drainage and storm tunnel was completed in early 2017. The 9.5 km long, 3.7 m diameter tunnel was excavated with two Earth Pressure Balance (EPB) Tunnel Boring Machines from Herrenknecht. TBM operation processes were monitored and recorded by Data Acquisition and Evaluation System. The authors coupled collected TBM drive data with available information on rock mass properties, cleansed, completed with secondary variables and aggregated by weeks and shifts. Correlations and descriptive statistics charts were examined. Multivariate Linear Regression and CART regression tree models linking TBM penetration rate (PR), penetration per revolution (PPR) and field penetration index (FPI) with TBM operational and geotechnical characteristics were performed for the conditions of the weak/soft rock of Doha. Both regression methods are interpretable and the data were screened with different computational approaches allowing enriched insight. The primary goal of the analysis was to investigate empirical relations between multiple explanatory and responding variables, to search for best subsets of explanatory variables and to evaluate the strength of linear and non-linear relations. For each of the penetration indices, a predictive model coupling both regression methods was built and validated. The resultant models appeared to be stronger than constituent ones and indicated an opportunity for more accurate and robust TBM performance predictions.

  10. [Psychoneuroimmunological predictors for burden in older caregivers of patients with Alzheimer's disease].

    Science.gov (United States)

    Corazza, Danilla I; Pedroso, Renata V; Andreatto, Carla A A; Scarpari, Lais; Garuffi, Marcelo; Costa, José L R; Santos-Galduróz, Ruth F

    2014-01-01

    The responsibility of giving care to patients with Alzheimer's disease (AD) may result in health changes in the older caregiver. It is important to explore the factors which influence the presence of care burden and to create strategies to face this condition. In this context, the aims of present study were to investigate the relationships between psychoneuroimmunological parameters and determine the predictors to burden in older caregivers of patients with AD. A total of 30 AD older caregivers participating in the «Cognitive and Functional Kinesiotherapy Program in Elderly with Alzheimer's disease«(PRO-CDA)», de Rio Claro, SP-Brazil, were submitted to an assessment protocol to evaluate the psychoneuroimmunological parameters. A descriptive statistical analysis, Pearson correlation and multiple linear regressions were performed. The mean age of caregivers was 71.3 (±9.3), and predominantly are first-grade relatives. The caregiver burden was associated with depressive symptoms (r=0.60, P<.001), caregiver distress (r=0.68, P<.001), and neuropsychiatric disorders of AD patients (r=0.53, P<.001). The multiple regression analysis confirmed depressive symptoms and neuropsychiatric disturbances as predictors of caregiver burden. Caregiver burden is associated with, and influenced by parameters related to the caregiver psychological suffering and to characteristics inherent to AD. Thus, it is important to find strategies and implement non-pharmacological programs to provide support to older caregivers, and to assist in the treatment of patients with AD, in order to improve the integral health of this population. Copyright © 2013 SEGG. Published by Elsevier Espana. All rights reserved.

  11. Composite marginal quantile regression analysis for longitudinal adolescent body mass index data.

    Science.gov (United States)

    Yang, Chi-Chuan; Chen, Yi-Hau; Chang, Hsing-Yi

    2017-09-20

    Childhood and adolescenthood overweight or obesity, which may be quantified through the body mass index (BMI), is strongly associated with adult obesity and other health problems. Motivated by the child and adolescent behaviors in long-term evolution (CABLE) study, we are interested in individual, family, and school factors associated with marginal quantiles of longitudinal adolescent BMI values. We propose a new method for composite marginal quantile regression analysis for longitudinal outcome data, which performs marginal quantile regressions at multiple quantile levels simultaneously. The proposed method extends the quantile regression coefficient modeling method introduced by Frumento and Bottai (Biometrics 2016; 72:74-84) to longitudinal data accounting suitably for the correlation structure in longitudinal observations. A goodness-of-fit test for the proposed modeling is also developed. Simulation results show that the proposed method can be much more efficient than the analysis without taking correlation into account and the analysis performing separate quantile regressions at different quantile levels. The application to the longitudinal adolescent BMI data from the CABLE study demonstrates the practical utility of our proposal. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Treating experimental data of inverse kinetic method by unitary linear regression analysis

    International Nuclear Information System (INIS)

    Zhao Yusen; Chen Xiaoliang

    2009-01-01

    The theory of treating experimental data of inverse kinetic method by unitary linear regression analysis was described. Not only the reactivity, but also the effective neutron source intensity could be calculated by this method. Computer code was compiled base on the inverse kinetic method and unitary linear regression analysis. The data of zero power facility BFS-1 in Russia were processed and the results were compared. The results show that the reactivity and the effective neutron source intensity can be obtained correctly by treating experimental data of inverse kinetic method using unitary linear regression analysis and the precision of reactivity measurement is improved. The central element efficiency can be calculated by using the reactivity. The result also shows that the effect to reactivity measurement caused by external neutron source should be considered when the reactor power is low and the intensity of external neutron source is strong. (authors)

  13. Regression analysis of informative current status data with the additive hazards model.

    Science.gov (United States)

    Zhao, Shishun; Hu, Tao; Ma, Ling; Wang, Peijie; Sun, Jianguo

    2015-04-01

    This paper discusses regression analysis of current status failure time data arising from the additive hazards model in the presence of informative censoring. Many methods have been developed for regression analysis of current status data under various regression models if the censoring is noninformative, and also there exists a large literature on parametric analysis of informative current status data in the context of tumorgenicity experiments. In this paper, a semiparametric maximum likelihood estimation procedure is presented and in the method, the copula model is employed to describe the relationship between the failure time of interest and the censoring time. Furthermore, I-splines are used to approximate the nonparametric functions involved and the asymptotic consistency and normality of the proposed estimators are established. A simulation study is conducted and indicates that the proposed approach works well for practical situations. An illustrative example is also provided.

  14. Credit Scoring Problem Based on Regression Analysis

    OpenAIRE

    Khassawneh, Bashar Suhil Jad Allah

    2014-01-01

    ABSTRACT: This thesis provides an explanatory introduction to the regression models of data mining and contains basic definitions of key terms in the linear, multiple and logistic regression models. Meanwhile, the aim of this study is to illustrate fitting models for the credit scoring problem using simple linear, multiple linear and logistic regression models and also to analyze the found model functions by statistical tools. Keywords: Data mining, linear regression, logistic regression....

  15. National stereotypes of older people's competence are related to older adults' participation in paid and volunteer work.

    Science.gov (United States)

    Bowen, Catherine E; Skirbekk, Vegard

    2013-11-01

    Why are older people perceived as more competent in some countries relative to others? In the current study, we investigate the extent to which national variation in perceptions of older people's competence is systematically related to national variation in the extent to which older people participate in paid and volunteer work. We used multilevel regression to analyze data from the European Social Survey and test the relationship between perceptions of older people's competence and older people's participation in paid and volunteer work across 28 countries. We controlled for a number of potentially confounding variables, including life expectancy as well as the gender ratio and average education of the older population in each country. We controlled for the average objective cognitive abilities of the older population in a subsample of 11 countries. Older people were perceived as more competent in countries in which more older people participated in paid or volunteer work, independent of life expectancy and the average education, gender makeup, and average cognitive abilities of the older population. The results suggest that older people's participation in paid and volunteer work is related to perceptions of older people's competence independent of older people's actual competence.

  16. MULGRES: a computer program for stepwise multiple regression analysis

    Science.gov (United States)

    A. Jeff Martin

    1971-01-01

    MULGRES is a computer program source deck that is designed for multiple regression analysis employing the technique of stepwise deletion in the search for most significant variables. The features of the program, along with inputs and outputs, are briefly described, with a note on machine compatibility.

  17. Real-time regression analysis with deep convolutional neural networks

    OpenAIRE

    Huerta, E. A.; George, Daniel; Zhao, Zhizhen; Allen, Gabrielle

    2018-01-01

    We discuss the development of novel deep learning algorithms to enable real-time regression analysis for time series data. We showcase the application of this new method with a timely case study, and then discuss the applicability of this approach to tackle similar challenges across science domains.

  18. [Comparison of application of Cochran-Armitage trend test and linear regression analysis for rate trend analysis in epidemiology study].

    Science.gov (United States)

    Wang, D Z; Wang, C; Shen, C F; Zhang, Y; Zhang, H; Song, G D; Xue, X D; Xu, Z L; Zhang, S; Jiang, G H

    2017-05-10

    We described the time trend of acute myocardial infarction (AMI) from 1999 to 2013 in Tianjin incidence rate with Cochran-Armitage trend (CAT) test and linear regression analysis, and the results were compared. Based on actual population, CAT test had much stronger statistical power than linear regression analysis for both overall incidence trend and age specific incidence trend (Cochran-Armitage trend P valuelinear regression P value). The statistical power of CAT test decreased, while the result of linear regression analysis remained the same when population size was reduced by 100 times and AMI incidence rate remained unchanged. The two statistical methods have their advantages and disadvantages. It is necessary to choose statistical method according the fitting degree of data, or comprehensively analyze the results of two methods.

  19. Independence through social networks: bridging potential among older women and men.

    Science.gov (United States)

    Cornwell, Benjamin

    2011-11-01

    Most studies of older adults' social networks focus on their access to dense networks that yield access to social support. This paper documents gender differences in the extent to which older adults maintain a related, but distinct, form of social capital-bridging potential, which involves serving as a tie between two unconnected parties and thus boosts independence and control of everyday social life. I use egocentric social network data from a national sample of 3,005 older adults--collected in 2005-2006 by the National Social Life, Health, and Aging Project--to compare older men's and women's network bridging potential using multivariate regression analysis. Older women are more likely than older men to have bridging potential in their networks-between both kin and non-kin contacts. These gender differences increase with age. Older women are also more likely to have network members who are not connected to or monopolized by their spouse or partner. Some, but not all, of these gender differences are due to the fact that older women have larger social networks and maintain more ties to people outside of the household. These findings raise important questions about the relational advantages older women have over older men, including greater autonomy, and contradict stereotypes about women having more closely knit, kin-centered networks than men.

  20. The evolution of GDP in USA using cyclic regression analysis

    OpenAIRE

    Catalin Angelo IOAN; Gina IOAN

    2013-01-01

    Based on the four major types of economic cycles (Kondratieff, Juglar, Kitchin, Kuznet), the paper aims to determine their actual length (for the U.S. economy) using cyclic regressions based on Fourier analysis.

  1. Quantile regression for the statistical analysis of immunological data with many non-detects.

    Science.gov (United States)

    Eilers, Paul H C; Röder, Esther; Savelkoul, Huub F J; van Wijk, Roy Gerth

    2012-07-07

    Immunological parameters are hard to measure. A well-known problem is the occurrence of values below the detection limit, the non-detects. Non-detects are a nuisance, because classical statistical analyses, like ANOVA and regression, cannot be applied. The more advanced statistical techniques currently available for the analysis of datasets with non-detects can only be used if a small percentage of the data are non-detects. Quantile regression, a generalization of percentiles to regression models, models the median or higher percentiles and tolerates very high numbers of non-detects. We present a non-technical introduction and illustrate it with an implementation to real data from a clinical trial. We show that by using quantile regression, groups can be compared and that meaningful linear trends can be computed, even if more than half of the data consists of non-detects. Quantile regression is a valuable addition to the statistical methods that can be used for the analysis of immunological datasets with non-detects.

  2. Optimal choice of basis functions in the linear regression analysis

    International Nuclear Information System (INIS)

    Khotinskij, A.M.

    1988-01-01

    Problem of optimal choice of basis functions in the linear regression analysis is investigated. Step algorithm with estimation of its efficiency, which holds true at finite number of measurements, is suggested. Conditions, providing the probability of correct choice close to 1 are formulated. Application of the step algorithm to analysis of decay curves is substantiated. 8 refs

  3. Obesity as a risk factor for developing functional limitation among older adults: A conditional inference tree analysis.

    Science.gov (United States)

    Cheng, Feon W; Gao, Xiang; Bao, Le; Mitchell, Diane C; Wood, Craig; Sliwinski, Martin J; Smiciklas-Wright, Helen; Still, Christopher D; Rolston, David D K; Jensen, Gordon L

    2017-07-01

    To examine the risk factors of developing functional decline and make probabilistic predictions by using a tree-based method that allows higher order polynomials and interactions of the risk factors. The conditional inference tree analysis, a data mining approach, was used to construct a risk stratification algorithm for developing functional limitation based on BMI and other potential risk factors for disability in 1,951 older adults without functional limitations at baseline (baseline age 73.1 ± 4.2 y). We also analyzed the data with multivariate stepwise logistic regression and compared the two approaches (e.g., cross-validation). Over a mean of 9.2 ± 1.7 years of follow-up, 221 individuals developed functional limitation. Higher BMI, age, and comorbidity were consistently identified as significant risk factors for functional decline using both methods. Based on these factors, individuals were stratified into four risk groups via the conditional inference tree analysis. Compared to the low-risk group, all other groups had a significantly higher risk of developing functional limitation. The odds ratio comparing two extreme categories was 9.09 (95% confidence interval: 4.68, 17.6). Higher BMI, age, and comorbid disease were consistently identified as significant risk factors for functional decline among older individuals across all approaches and analyses. © 2017 The Obesity Society.

  4. Gender differences in performance of script analysis by older adults.

    Science.gov (United States)

    Helmes, E; Bush, J D; Pike, D L; Drake, D G

    2006-12-01

    Script analysis as a test of executive functions is presumed sensitive to cognitive changes seen with increasing age. Two studies evaluated if gender differences exist in performance on scripts for familiar and unfamiliar tasks in groups of cognitively intact older adults. In Study 1, 26 older adults completed male and female stereotypical scripts. Results were not significant but a tendency was present, with genders making fewer impossible errors on the gender-typical script. Such an interaction was also noted in Study 2, which contrasted 50 older with 50 younger adults on three scripts, including a script with neutral familiarity. The pattern of significant interactions for errors suggested the need to use scripts that are based upon tasks that are equally familiar to both genders.

  5. Regression analysis for the social sciences

    CERN Document Server

    Gordon, Rachel A

    2015-01-01

    Provides graduate students in the social sciences with the basic skills they need to estimate, interpret, present, and publish basic regression models using contemporary standards. Key features of the book include: interweaving the teaching of statistical concepts with examples developed for the course from publicly-available social science data or drawn from the literature. thorough integration of teaching statistical theory with teaching data processing and analysis. teaching of Stata and use of chapter exercises in which students practice programming and interpretation on the same data set. A separate set of exercises allows students to select a data set to apply the concepts learned in each chapter to a research question of interest to them, all updated for this edition.

  6. Predictors of suicidal ideation in older people: a decision tree analysis.

    Science.gov (United States)

    Handley, Tonelle E; Hiles, Sarah A; Inder, Kerry J; Kay-Lambkin, Frances J; Kelly, Brian J; Lewin, Terry J; McEvoy, Mark; Peel, Roseanne; Attia, John R

    2014-11-01

    Suicide among older adults is a major public health issue worldwide. Although studies have identified psychological, physical, and social contributors to suicidal thoughts in older adults, few have explored the specific interactions between these factors. This article used a novel statistical approach to explore predictors of suicidal ideation in a community-based sample of older adults. Prospective cohort study. Participants aged 55-85 years were randomly selected from the Hunter Region, a large regional center in New South Wales, Australia. Baseline psychological, physical, and social factors, including psychological distress, physical functioning, and social support, were used to predict suicidal ideation at the 5-year follow-up. Classification and regression tree modeling was used to determine specific risk profiles for participants depending on their individual well-being in each of these key areas. Psychological distress was the strongest predictor, with 25% of people with high distress reporting suicidal ideation. Within high psychological distress, lower physical functioning significantly increased the likelihood of suicidal ideation, with high distress and low functioning being associated with ideation in 50% of cases. A substantial subgroup reported suicidal ideation in the absence of psychological distress; dissatisfaction with social support was the most important predictor among this group. The performance of the model was high (area under the curve: 0.81). Decision tree modeling enabled individualized "risk" profiles for suicidal ideation to be determined. Although psychological factors are important for predicting suicidal ideation, both physical and social factors significantly improved the predictive ability of the model. Assessing these factors may enhance identification of older people at risk of suicidal ideation. Copyright © 2014. Published by Elsevier Inc.

  7. A method for nonlinear exponential regression analysis

    Science.gov (United States)

    Junkin, B. G.

    1971-01-01

    A computer-oriented technique is presented for performing a nonlinear exponential regression analysis on decay-type experimental data. The technique involves the least squares procedure wherein the nonlinear problem is linearized by expansion in a Taylor series. A linear curve fitting procedure for determining the initial nominal estimates for the unknown exponential model parameters is included as an integral part of the technique. A correction matrix was derived and then applied to the nominal estimate to produce an improved set of model parameters. The solution cycle is repeated until some predetermined criterion is satisfied.

  8. Analysis of Functional Data with Focus on Multinomial Regression and Multilevel Data

    DEFF Research Database (Denmark)

    Mousavi, Seyed Nourollah

    Functional data analysis (FDA) is a fast growing area in statistical research with increasingly diverse range of application from economics, medicine, agriculture, chemometrics, etc. Functional regression is an area of FDA which has received the most attention both in aspects of application...... and methodological development. Our main Functional data analysis (FDA) is a fast growing area in statistical research with increasingly diverse range of application from economics, medicine, agriculture, chemometrics, etc. Functional regression is an area of FDA which has received the most attention both in aspects...

  9. Perception of Spiritual Health: A Qualitative Content Analysis in Iranian Older Adults

    Science.gov (United States)

    Zibad, Hosein Ajam; Foroughan, Mahshid; Shahboulaghi, Farahnaz Mohammadi; Rafiey, Hassan; Rassouli, Maryam

    2017-01-01

    The present study was performed with the aim to explain older people's perceptions of spiritual health. It was conducted using the conventional content analysis method. Twelve individuals aged 60 years or older with normal cognition participated in the study using purposive sampling. Data were collected by in-depth interviews. Data analysis…

  10. Life satisfaction of older Turks living in Australia.

    Science.gov (United States)

    Öztop, Hülya; Kınacı, Bahar

    2017-03-01

    This study examined the influence of socio-economic and demographic variables, the frequency of travel to Turkey and years of living in Sydney on the life satisfaction of older Turkish people. This study was conducted with 110 participants of 60 years of age or older, at the New South Wales Turkish Welfare Association in Sydney, Australia. The surveys were administered face-to-face at a date and time these participants went to the Association. The dependent variable of the study was the Life Satisfaction Scale. The study data were analysed using hierarchical regression analysis, and the three sets of regression models were run for each sex. The research found that in addition to sociodemographic factors, frequency of travel to Turkey, particularly for older women, and their years of living in Sydney had negative effects on life satisfaction. The study results indicate that the frequency of both the male and female participants' visits to Turkey had a strong negative influence on their life satisfaction. Life satisfaction decreased as the frequency of the participants' visits to Turkey and years of living in Sydney increased. These findings support the current literature that shows the effects of the frequency of travel to Turkey and years of living in Sydney, which were considered to influence relationships with social networks, on life satisfaction, and indicates the necessity for a more detailed examination of social network relationships. © 2017 AJA Inc.

  11. Prevalence and Clinical Correlates of Sarcopenia in Community-Dwelling Older People: Application of the EWGSOP Definition and Diagnostic Algorithm

    Science.gov (United States)

    2014-01-01

    Background. Muscle impairment is a common condition in older people and a powerful risk factor for disability and mortality. The aim of this study was to apply the European Working Group on Sarcopenia in Older People criteria to estimate the prevalence and investigate the clinical correlates of sarcopenia, in a sample of Italian community-dwelling older people. Methods. Cross-sectional analysis of 730 participants (74% aged 65 years and older) enrolled in the InCHIANTI study. Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People criteria using bioimpedance analysis for muscle mass assessment. Logistic regression analysis was used to identify the factors independently associated with sarcopenia. Results. Sarcopenia defined by the European Working Group on Sarcopenia in Older People criteria increased steeply with age (p Nutritional intake, physical activity, and level of comorbidity were not associated with sarcopenia. Conclusions. Sarcopenia identified by the European Working Group on Sarcopenia in Older People criteria is a relatively common condition in Italian octogenarians, and its prevalence increases with aging. Correlates of sarcopenia identified in this study might suggest new approaches for prevention and treatment of sarcopenia. PMID:24085400

  12. Regression analysis of a chemical reaction fouling model

    International Nuclear Information System (INIS)

    Vasak, F.; Epstein, N.

    1996-01-01

    A previously reported mathematical model for the initial chemical reaction fouling of a heated tube is critically examined in the light of the experimental data for which it was developed. A regression analysis of the model with respect to that data shows that the reference point upon which the two adjustable parameters of the model were originally based was well chosen, albeit fortuitously. (author). 3 refs., 2 tabs., 2 figs

  13. Advertising Representations of Older People in the United Kingdom and Taiwan: A Comparative Analysis.

    Science.gov (United States)

    Chen, Chin-Hui

    2015-01-01

    Cross-cultural studies of advertising representations of older people are relatively scarce. This article aims to fill in this gap via a comparison between Taiwan and the United Kingdom, employing a combination of quantitative content analysis and the qualitative grounded theory method. The content-analysis phase reveals underrepresentation of older people in both countries' advertising contexts, as well as representational differences between Taiwan and the United Kingdom in terms of older characters' role salience, the products, physical settings, and social networks they are associated with. The grounded-theory phase yields nine prototypes of older people along with subcategories to conceptualize the qualities of older people as they appear in TV ads in these countries. The findings are discussed in relation to the stereotyping of older people and transformed into hypothetical statements to be modified in future research. In conclusion, the Confucian tradition of filial piety is still found to be important in explaining the observed cross-cultural differences, but the emergence of new norms about aging in Taiwanese advertising also suggests that this tradition may be in decline. © The Author(s) 2015.

  14. [A SAS marco program for batch processing of univariate Cox regression analysis for great database].

    Science.gov (United States)

    Yang, Rendong; Xiong, Jie; Peng, Yangqin; Peng, Xiaoning; Zeng, Xiaomin

    2015-02-01

    To realize batch processing of univariate Cox regression analysis for great database by SAS marco program. We wrote a SAS macro program, which can filter, integrate, and export P values to Excel by SAS9.2. The program was used for screening survival correlated RNA molecules of ovarian cancer. A SAS marco program could finish the batch processing of univariate Cox regression analysis, the selection and export of the results. The SAS macro program has potential applications in reducing the workload of statistical analysis and providing a basis for batch processing of univariate Cox regression analysis.

  15. Sensitivity analysis and optimization of system dynamics models : Regression analysis and statistical design of experiments

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    1995-01-01

    This tutorial discusses what-if analysis and optimization of System Dynamics models. These problems are solved, using the statistical techniques of regression analysis and design of experiments (DOE). These issues are illustrated by applying the statistical techniques to a System Dynamics model for

  16. The impact of patient autonomy on older adults with asthma.

    Science.gov (United States)

    Karamched, Keerthi R; Hao, Wei; Song, Peter X; Carpenter, Laurie; Steinberg, Joel; Baptist, Alan P

    2018-05-03

    Understanding patient preferences and desire for involvement in making medical decisions is important when managing chronic conditions. Previous studies have utilized the Autonomy Preference Index (API) in younger asthmatic patients to evaluate these preferences. To identify factors associated with autonomy, and to determine if autonomy is related to asthma outcomes among older adults. 189 older adults (>55 yr) with persistent asthma were included. Preferences for autonomy were assessed using the API, with a higher score indicating higher desire for autonomy. Scores were separated into two domains of 'information seeking' and 'decision making' preferences. The separated scores were correlated with asthma outcomes and demographic variables. To control for confounding factors, a linear regression analysis was performed. Higher 'decision making' preference scores correlated with female gender (p=0.007), higher education level (p=0.01), and lower depression scores (p=0.04). Regarding outcomes, 'decision making' scores positively correlated with asthma quality of life questionnaire (AQLQ) scores (p=0.01). On linear regression analysis, the AQLQ score remained significantly associated with 'decision making' preference scores (p=0.03). There was no association with asthma control test scores, spirometry values, and healthcare utilization. 'Information seeking' preference scores correlated with education level (p=0.03), but there was no correlation with asthma outcomes. Older asthmatic adults with a greater desire for involvement in decision making have a higher asthma related quality of life. Future studies with the intention to increase patient autonomy may help establish a causal relationship. Copyright © 2018. Published by Elsevier Inc.

  17. Comparison of Well-being of Older Adult Choir Singers and the General Population in Finland: A Case-Control Study.

    Science.gov (United States)

    Johnson, Julene K; Louhivuori, Jukka; Siljander, Eero

    2017-06-01

    Previous research suggests that singing in a choir as an older adult is associated with better quality of life (QOL). However, the degree to which sociodemographic variables and level of engagement in hobbies contribute to this relationship is largely unknown. The aim of the study was to compare quality of life (QOL) of older adult choir singers with a matched sample of older adults from the general population in Finland, taking into consideration sociodemographic, satisfaction with health, and level of engagement in hobbies (active, inactive). Case-control methods were used to match a sample of 109 older adult singers with a sample of 307 older adults from the general population. Tobit regression analysis with sociodemographic covariates was used to explore observed group differences in QOL as measured by two WHOQOL-Bref domains (psychological and physical). Probit regression analysis was used to examine the effect of sociodemographic variables and engagement in hobbies and on overall QOL and satisfaction with health. As expected, sociodemographic variables were strongly associated with physical and psychological QOL. After controlling for sociodemographic variables, the older choir singers reported significantly higher ratings on physical QOL, but not psychological QOL, compared to matched controls. Additional adjustment for satisfaction for health attenuated the results. When considering level of engagement in hobbies, older adult choir singers reported significantly higher overall QOL and satisfaction with health when compared to either controls who were either actively engaged in hobbies or not active in hobbies. These results suggest that singing in a choir as an older adult may promote well-being, even after accounting for sociodemographic and level of engagement in hobbies.

  18. Family Support and Loneliness among Older Persons in Multiethnic Malaysia

    Science.gov (United States)

    Teh, Jane Kimm Lii; Tey, Nai Peng; Ng, Sor Tho

    2014-01-01

    This study investigates factors affecting older persons' state of loneliness in multiethnic Malaysia using data from the 2004 Malaysian Population and Family Survey, the first nationally representative sample in Malaysia. The study sample was extracted to include Malays, Chinese, Indians and other Indigenous groups aged 60 and above, and who had children (n = 1791). Cross tabulations and ordinal logistic regression methods were used in the analysis. Among the ethnic groups, older Malays were more likely than their Chinese and Indian counterparts to experience loneliness. Loneliness was found to be associated with age, marital status, education level, sources of income, health status, and physical limitations. Among older people, feelings of loneliness were inversely related with coresidence with adult children and participation in religious activities. Sociodemographic changes have eroded the traditional family support system for the elderly, while social security remains inadequate. This study shows the important role of family in alleviating loneliness among older people. Hence the need to promote and facilitate coresidence, as well as participation in religious activities, and a healthy lifestyle as a priority strategy is in line with the objectives of the National Policy for the Older People. PMID:25383374

  19. Family Support and Loneliness among Older Persons in Multiethnic Malaysia

    Directory of Open Access Journals (Sweden)

    Jane Kimm Lii Teh

    2014-01-01

    Full Text Available This study investigates factors affecting older persons’ state of loneliness in multiethnic Malaysia using data from the 2004 Malaysian Population and Family Survey, the first nationally representative sample in Malaysia. The study sample was extracted to include Malays, Chinese, Indians and other Indigenous groups aged 60 and above, and who had children (n = 1791. Cross tabulations and ordinal logistic regression methods were used in the analysis. Among the ethnic groups, older Malays were more likely than their Chinese and Indian counterparts to experience loneliness. Loneliness was found to be associated with age, marital status, education level, sources of income, health status, and physical limitations. Among older people, feelings of loneliness were inversely related with coresidence with adult children and participation in religious activities. Sociodemographic changes have eroded the traditional family support system for the elderly, while social security remains inadequate. This study shows the important role of family in alleviating loneliness among older people. Hence the need to promote and facilitate coresidence, as well as participation in religious activities, and a healthy lifestyle as a priority strategy is in line with the objectives of the National Policy for the Older People.

  20. Family support and loneliness among older persons in multiethnic Malaysia.

    Science.gov (United States)

    Teh, Jane Kimm Lii; Tey, Nai Peng; Ng, Sor Tho

    2014-01-01

    This study investigates factors affecting older persons' state of loneliness in multiethnic Malaysia using data from the 2004 Malaysian Population and Family Survey, the first nationally representative sample in Malaysia. The study sample was extracted to include Malays, Chinese, Indians and other Indigenous groups aged 60 and above, and who had children (n = 1791). Cross tabulations and ordinal logistic regression methods were used in the analysis. Among the ethnic groups, older Malays were more likely than their Chinese and Indian counterparts to experience loneliness. Loneliness was found to be associated with age, marital status, education level, sources of income, health status, and physical limitations. Among older people, feelings of loneliness were inversely related with coresidence with adult children and participation in religious activities. Sociodemographic changes have eroded the traditional family support system for the elderly, while social security remains inadequate. This study shows the important role of family in alleviating loneliness among older people. Hence the need to promote and facilitate coresidence, as well as participation in religious activities, and a healthy lifestyle as a priority strategy is in line with the objectives of the National Policy for the Older People.

  1. Application of multilinear regression analysis in modeling of soil ...

    African Journals Online (AJOL)

    The application of Multi-Linear Regression Analysis (MLRA) model for predicting soil properties in Calabar South offers a technical guide and solution in foundation designs problems in the area. Forty-five soil samples were collected from fifteen different boreholes at a different depth and 270 tests were carried out for CBR, ...

  2. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  3. Bias due to two-stage residual-outcome regression analysis in genetic association studies.

    Science.gov (United States)

    Demissie, Serkalem; Cupples, L Adrienne

    2011-11-01

    Association studies of risk factors and complex diseases require careful assessment of potential confounding factors. Two-stage regression analysis, sometimes referred to as residual- or adjusted-outcome analysis, has been increasingly used in association studies of single nucleotide polymorphisms (SNPs) and quantitative traits. In this analysis, first, a residual-outcome is calculated from a regression of the outcome variable on covariates and then the relationship between the adjusted-outcome and the SNP is evaluated by a simple linear regression of the adjusted-outcome on the SNP. In this article, we examine the performance of this two-stage analysis as compared with multiple linear regression (MLR) analysis. Our findings show that when a SNP and a covariate are correlated, the two-stage approach results in biased genotypic effect and loss of power. Bias is always toward the null and increases with the squared-correlation between the SNP and the covariate (). For example, for , 0.1, and 0.5, two-stage analysis results in, respectively, 0, 10, and 50% attenuation in the SNP effect. As expected, MLR was always unbiased. Since individual SNPs often show little or no correlation with covariates, a two-stage analysis is expected to perform as well as MLR in many genetic studies; however, it produces considerably different results from MLR and may lead to incorrect conclusions when independent variables are highly correlated. While a useful alternative to MLR under , the two -stage approach has serious limitations. Its use as a simple substitute for MLR should be avoided. © 2011 Wiley Periodicals, Inc.

  4. Ethnic differences in attitudes and bias toward older people comparing White and Asian nursing students.

    Science.gov (United States)

    Lee, Young-Shin

    2015-03-01

    To identify attitudes and bias toward aging between Asian and White students and identify factors affecting attitudes toward aging. A cross-sectional sample of 308 students in a nursing program completed the measure of Attitudes Toward Older People and Aging Quiz electronically. There were no differences in positive attitudes and pro-aged bias between Asian and White groups, but Asian students had significantly more negative attitudes and anti-aged bias toward older people than White students. Multiple regression analysis showed ethnicity/race was the strongest variable to explain negative attitudes toward older people. Feeling uneasy about talking to older adults was the most significant factor to explain all attitudinal concepts. Asian students were uneasy about talking with older people and had negative attitudes toward older adults. To become competent in cross-cultural care and communication in nursing, educational strategies to reduce negative attitudes on aging are necessary. © The Author(s) 2014.

  5. An Original Stepwise Multilevel Logistic Regression Analysis of Discriminatory Accuracy

    DEFF Research Database (Denmark)

    Merlo, Juan; Wagner, Philippe; Ghith, Nermin

    2016-01-01

    BACKGROUND AND AIM: Many multilevel logistic regression analyses of "neighbourhood and health" focus on interpreting measures of associations (e.g., odds ratio, OR). In contrast, multilevel analysis of variance is rarely considered. We propose an original stepwise analytical approach that disting...

  6. Advanced statistics: linear regression, part I: simple linear regression.

    Science.gov (United States)

    Marill, Keith A

    2004-01-01

    Simple linear regression is a mathematical technique used to model the relationship between a single independent predictor variable and a single dependent outcome variable. In this, the first of a two-part series exploring concepts in linear regression analysis, the four fundamental assumptions and the mechanics of simple linear regression are reviewed. The most common technique used to derive the regression line, the method of least squares, is described. The reader will be acquainted with other important concepts in simple linear regression, including: variable transformations, dummy variables, relationship to inference testing, and leverage. Simplified clinical examples with small datasets and graphic models are used to illustrate the points. This will provide a foundation for the second article in this series: a discussion of multiple linear regression, in which there are multiple predictor variables.

  7. Ordinary least square regression, orthogonal regression, geometric mean regression and their applications in aerosol science

    International Nuclear Information System (INIS)

    Leng Ling; Zhang Tianyi; Kleinman, Lawrence; Zhu Wei

    2007-01-01

    Regression analysis, especially the ordinary least squares method which assumes that errors are confined to the dependent variable, has seen a fair share of its applications in aerosol science. The ordinary least squares approach, however, could be problematic due to the fact that atmospheric data often does not lend itself to calling one variable independent and the other dependent. Errors often exist for both measurements. In this work, we examine two regression approaches available to accommodate this situation. They are orthogonal regression and geometric mean regression. Comparisons are made theoretically as well as numerically through an aerosol study examining whether the ratio of organic aerosol to CO would change with age

  8. Linear Regression with a Randomly Censored Covariate: Application to an Alzheimer's Study.

    Science.gov (United States)

    Atem, Folefac D; Qian, Jing; Maye, Jacqueline E; Johnson, Keith A; Betensky, Rebecca A

    2017-01-01

    The association between maternal age of onset of dementia and amyloid deposition (measured by in vivo positron emission tomography (PET) imaging) in cognitively normal older offspring is of interest. In a regression model for amyloid, special methods are required due to the random right censoring of the covariate of maternal age of onset of dementia. Prior literature has proposed methods to address the problem of censoring due to assay limit of detection, but not random censoring. We propose imputation methods and a survival regression method that do not require parametric assumptions about the distribution of the censored covariate. Existing imputation methods address missing covariates, but not right censored covariates. In simulation studies, we compare these methods to the simple, but inefficient complete case analysis, and to thresholding approaches. We apply the methods to the Alzheimer's study.

  9. Relationship between health service use and health information technology use among older adults: analysis of the US National Health Interview Survey.

    Science.gov (United States)

    Choi, Namkee

    2011-04-20

    Older adults are the most frequent and heaviest users of health services in the United States; however, previous research on older adults' use of health information technology (HIT) has not examined the possible association of HIT use among older adults with their use of health services. This study examined the relationship between US older adults' use of health services and their use of the Internet for health-related activities, controlling for socioeconomic characteristics and aging-related limitations in sensory and cognitive function. It also examined gender differences in the pattern of association between the types of health services used and HIT use. The data for this study were drawn from the 2009 US National Health Interview Survey (NHIS), which was the first nationally representative household survey to collect data on HIT (Internet) use. First, the rates of lifetime and 12-month HIT use among sample adults (n = 27,731) by age group (18-29 to 85 and over) were analyzed. Second, bivariate analysis of sociodemographic characteristics, health status, and health service use by HIT use status among those aged 65 or older (n = 5294) was conducted. Finally, multivariate binary logistic regression analysis was used to test the study hypotheses with 12-month HIT use as the dependent variable and 12-month health service uses among the age group 65 or older as possible correlates. The rates of HIT use were significantly lower among the age groups 65 or older compared with the younger age groups, although the age group 55 to 64 was not different from those younger. The rates of HIT use decreased from 32.2% in the age group 65 to 74 to 14.5% in the age group 75 to 84 and 4.9% in the 85 and older age group. For both genders, having seen or talked to a general practitioner increased the odds of HIT use. However, having seen or talked to a medical specialist, eye doctor, or physical therapist/occupational therapist (PT/OT) were significantly associated with HIT use only

  10. The Relationship of Frailty and Hospitalization Among Older People: Evidence From a Meta-Analysis.

    Science.gov (United States)

    Chang, Shu-Fang; Lin, Hsiang-Chun; Cheng, Chih-Ling

    2018-06-06

    This research explored the relationship between the stages of frailty and risk for hospitalization in older adults and evaluated the risk for hospitalization among the elderly in relation to various frailty assessment indexes. A systematic literature review and meta-analysis were carried out. A total of 32,998 older people, 8,666 of whom were hospitalized, were included in this study. Two of the researchers independently collected and reviewed the literature. The key search terms used were "frailty" or "frail," "hospitalization," and "older people" or "older" or "geriatric" or "senior." Data were recorded from January 2001 to July 2016. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adopted for quality assessment. A systematic search was carried out using Embase and Scopus to analyze the collected literature. A meta-analysis was conducted on eight studies that discussed the relationship between frailty and hospitalization risk in older adults 65 years of age or older. The results showed that frail older people exhibited the highest risk for hospitalization, following by prefrail and robust older people. Next, different frailty assessment indicators were used to predict the risk for hospitalization among older people. All of these indexes also showed that older persons with frailty had the highest risk for hospitalization, followed by prefrail older people. Frailty is a vital issue in geriatric care and is a crucial factor in the hospitalization of older people. Frail older people were at the highest risk for hospitalization, following by prefrail and robust older people. Assessing frailty as early as possible can reduce the hospitalization risk among older people. Professional nursing staff should use frailty indicators in a timely fashion to assess the status of frailty in older people and should effectively develop frailty prevention strategies to decrease the risk for hospitalization and to enhance quality of life

  11. Forecasting urban water demand: A meta-regression analysis.

    Science.gov (United States)

    Sebri, Maamar

    2016-12-01

    Water managers and planners require accurate water demand forecasts over the short-, medium- and long-term for many purposes. These range from assessing water supply needs over spatial and temporal patterns to optimizing future investments and planning future allocations across competing sectors. This study surveys the empirical literature on the urban water demand forecasting using the meta-analytical approach. Specifically, using more than 600 estimates, a meta-regression analysis is conducted to identify explanations of cross-studies variation in accuracy of urban water demand forecasting. Our study finds that accuracy depends significantly on study characteristics, including demand periodicity, modeling method, forecasting horizon, model specification and sample size. The meta-regression results remain robust to different estimators employed as well as to a series of sensitivity checks performed. The importance of these findings lies in the conclusions and implications drawn out for regulators and policymakers and for academics alike. Copyright © 2016. Published by Elsevier Ltd.

  12. A simple linear regression method for quantitative trait loci linkage analysis with censored observations.

    Science.gov (United States)

    Anderson, Carl A; McRae, Allan F; Visscher, Peter M

    2006-07-01

    Standard quantitative trait loci (QTL) mapping techniques commonly assume that the trait is both fully observed and normally distributed. When considering survival or age-at-onset traits these assumptions are often incorrect. Methods have been developed to map QTL for survival traits; however, they are both computationally intensive and not available in standard genome analysis software packages. We propose a grouped linear regression method for the analysis of continuous survival data. Using simulation we compare this method to both the Cox and Weibull proportional hazards models and a standard linear regression method that ignores censoring. The grouped linear regression method is of equivalent power to both the Cox and Weibull proportional hazards methods and is significantly better than the standard linear regression method when censored observations are present. The method is also robust to the proportion of censored individuals and the underlying distribution of the trait. On the basis of linear regression methodology, the grouped linear regression model is computationally simple and fast and can be implemented readily in freely available statistical software.

  13. The use of cognitive ability measures as explanatory variables in regression analysis.

    Science.gov (United States)

    Junker, Brian; Schofield, Lynne Steuerle; Taylor, Lowell J

    2012-12-01

    Cognitive ability measures are often taken as explanatory variables in regression analysis, e.g., as a factor affecting a market outcome such as an individual's wage, or a decision such as an individual's education acquisition. Cognitive ability is a latent construct; its true value is unobserved. Nonetheless, researchers often assume that a test score , constructed via standard psychometric practice from individuals' responses to test items, can be safely used in regression analysis. We examine problems that can arise, and suggest that an alternative approach, a "mixed effects structural equations" (MESE) model, may be more appropriate in many circumstances.

  14. Multiple Imputation of a Randomly Censored Covariate Improves Logistic Regression Analysis.

    Science.gov (United States)

    Atem, Folefac D; Qian, Jing; Maye, Jacqueline E; Johnson, Keith A; Betensky, Rebecca A

    2016-01-01

    Randomly censored covariates arise frequently in epidemiologic studies. The most commonly used methods, including complete case and single imputation or substitution, suffer from inefficiency and bias. They make strong parametric assumptions or they consider limit of detection censoring only. We employ multiple imputation, in conjunction with semi-parametric modeling of the censored covariate, to overcome these shortcomings and to facilitate robust estimation. We develop a multiple imputation approach for randomly censored covariates within the framework of a logistic regression model. We use the non-parametric estimate of the covariate distribution or the semiparametric Cox model estimate in the presence of additional covariates in the model. We evaluate this procedure in simulations, and compare its operating characteristics to those from the complete case analysis and a survival regression approach. We apply the procedures to an Alzheimer's study of the association between amyloid positivity and maternal age of onset of dementia. Multiple imputation achieves lower standard errors and higher power than the complete case approach under heavy and moderate censoring and is comparable under light censoring. The survival regression approach achieves the highest power among all procedures, but does not produce interpretable estimates of association. Multiple imputation offers a favorable alternative to complete case analysis and ad hoc substitution methods in the presence of randomly censored covariates within the framework of logistic regression.

  15. Exploring the Knowledge Structure of Nursing Care for Older Patients With Delirium: Keyword Network Analysis.

    Science.gov (United States)

    Choi, Jung Eun; Kim, Mi So

    2018-05-01

    Prevention of delirium is considered a critical part of the agenda for patient safety and an indicator of healthcare quality for older patients. As the incidence rate of delirium for older patients has increased in recent years, there has been a significant expansion in knowledge relevant to nursing care. The purposes of this study were to analyze the knowledge structure and trends in nursing care for older adults with delirium based on a keyword network analysis, and to provide a foundation for future research. Data analysis showed that knowledge structure in this area consists of three themes of research: postoperative acute care for older patients with delirium, prevention of delirium for older patients in intensive care units, and safety management for the improvement of outcomes for patients with delirium. Through research trend analysis, we found that research on care for patients with delirium has achieved both quantitative and qualitative improvements over the last decades. Concerning future research, we propose the expansion of patient- and family-centered care, community care, specific nursing interventions, and the integration of new technology into care for patients with delirium. These results provide a reference framework for understanding and developing nursing care for older adults with delirium.

  16. Temporal trends in sperm count: a systematic review and meta-regression analysis.

    Science.gov (United States)

    Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson; Mendiola, Jaime; Weksler-Derri, Dan; Mindlis, Irina; Pinotti, Rachel; Swan, Shanna H

    2017-11-01

    Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality. To provide a systematic review and meta-regression analysis of recent trends in sperm counts as measured by sperm concentration (SC) and total sperm count (TSC), and their modification by fertility and geographic group. PubMed/MEDLINE and EMBASE were searched for English language studies of human SC published in 1981-2013. Following a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years of sample collection and covariates [fertility group ('Unselected by fertility' versus 'Fertile'), geographic group ('Western', including North America, Europe Australia and New Zealand versus 'Other', including South America, Asia and Africa), age, ejaculation abstinence time, semen collection method, method of measuring SC and semen volume, exclusion criteria and indicators of completeness of covariate data]. The slopes of SC and TSC were estimated as functions of sample collection year using both simple linear regression and weighted meta-regression models and the latter were adjusted for pre-determined covariates and modification by fertility and geographic group. Assumptions were examined using multiple sensitivity analyses and nonlinear models. SC declined significantly between 1973 and 2011 (slope in unadjusted simple regression models -0.70 million/ml/year; 95% CI: -0.72 to -0.69; P regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because

  17. Neighborhood social capital and crime victimization: comparison of spatial regression analysis and hierarchical regression analysis.

    Science.gov (United States)

    Takagi, Daisuke; Ikeda, Ken'ichi; Kawachi, Ichiro

    2012-11-01

    Crime is an important determinant of public health outcomes, including quality of life, mental well-being, and health behavior. A body of research has documented the association between community social capital and crime victimization. The association between social capital and crime victimization has been examined at multiple levels of spatial aggregation, ranging from entire countries, to states, metropolitan areas, counties, and neighborhoods. In multilevel analysis, the spatial boundaries at level 2 are most often drawn from administrative boundaries (e.g., Census tracts in the U.S.). One problem with adopting administrative definitions of neighborhoods is that it ignores spatial spillover. We conducted a study of social capital and crime victimization in one ward of Tokyo city, using a spatial Durbin model with an inverse-distance weighting matrix that assigned each respondent a unique level of "exposure" to social capital based on all other residents' perceptions. The study is based on a postal questionnaire sent to 20-69 years old residents of Arakawa Ward, Tokyo. The response rate was 43.7%. We examined the contextual influence of generalized trust, perceptions of reciprocity, two types of social network variables, as well as two principal components of social capital (constructed from the above four variables). Our outcome measure was self-reported crime victimization in the last five years. In the spatial Durbin model, we found that neighborhood generalized trust, reciprocity, supportive networks and two principal components of social capital were each inversely associated with crime victimization. By contrast, a multilevel regression performed with the same data (using administrative neighborhood boundaries) found generally null associations between neighborhood social capital and crime. Spatial regression methods may be more appropriate for investigating the contextual influence of social capital in homogeneous cultural settings such as Japan. Copyright

  18. Optimism and Planning for Future Care Needs among Older Adults

    Science.gov (United States)

    Sörensen, Silvia; Hirsch, Jameson K.; Lyness, Jeffrey M.

    2015-01-01

    Aging is associated with an increase in need for assistance. Preparation for future care (PFC) is related to improved coping ability as well as better mental and physical health outcomes among older adults. We examined the association of optimism with components of PFC among older adults. We also explored race differences in the relationship between optimism and PFC. In Study 1, multiple regression showed that optimism was positively related to concrete planning. In Study 2, optimism was related to gathering information. An exploratory analysis combining the samples yielded a race interaction: For Whites higher optimism, but for Blacks lower optimism was associated with more planning. High optimism may be a barrier to future planning in certain social and cultural contexts. PMID:26045699

  19. Introduction to regression graphics

    CERN Document Server

    Cook, R Dennis

    2009-01-01

    Covers the use of dynamic and interactive computer graphics in linear regression analysis, focusing on analytical graphics. Features new techniques like plot rotation. The authors have composed their own regression code, using Xlisp-Stat language called R-code, which is a nearly complete system for linear regression analysis and can be utilized as the main computer program in a linear regression course. The accompanying disks, for both Macintosh and Windows computers, contain the R-code and Xlisp-Stat. An Instructor's Manual presenting detailed solutions to all the problems in the book is ava

  20. Analysis of γ spectra in airborne radioactivity measurements using multiple linear regressions

    International Nuclear Information System (INIS)

    Bao Min; Shi Quanlin; Zhang Jiamei

    2004-01-01

    This paper describes the net peak counts calculating of nuclide 137 Cs at 662 keV of γ spectra in airborne radioactivity measurements using multiple linear regressions. Mathematic model is founded by analyzing every factor that has contribution to Cs peak counts in spectra, and multiple linear regression function is established. Calculating process adopts stepwise regression, and the indistinctive factors are eliminated by F check. The regression results and its uncertainty are calculated using Least Square Estimation, then the Cs peak net counts and its uncertainty can be gotten. The analysis results for experimental spectrum are displayed. The influence of energy shift and energy resolution on the analyzing result is discussed. In comparison with the stripping spectra method, multiple linear regression method needn't stripping radios, and the calculating result has relation with the counts in Cs peak only, and the calculating uncertainty is reduced. (authors)

  1. Regression Analysis and Calibration Recommendations for the Characterization of Balance Temperature Effects

    Science.gov (United States)

    Ulbrich, N.; Volden, T.

    2018-01-01

    Analysis and use of temperature-dependent wind tunnel strain-gage balance calibration data are discussed in the paper. First, three different methods are presented and compared that may be used to process temperature-dependent strain-gage balance data. The first method uses an extended set of independent variables in order to process the data and predict balance loads. The second method applies an extended load iteration equation during the analysis of balance calibration data. The third method uses temperature-dependent sensitivities for the data analysis. Physical interpretations of the most important temperature-dependent regression model terms are provided that relate temperature compensation imperfections and the temperature-dependent nature of the gage factor to sets of regression model terms. Finally, balance calibration recommendations are listed so that temperature-dependent calibration data can be obtained and successfully processed using the reviewed analysis methods.

  2. Social support and the self-rated health of older people

    Science.gov (United States)

    Dai, Yue; Zhang, Chen-Yun; Zhang, Bao-Quan; Li, Zhanzhan; Jiang, Caixiao; Huang, Hui-Ling

    2016-01-01

    Abstract The lack of social support in elderly populations incurs real societal costs and can lead to their poor health. The aim of this study is to investigate the self-rated health (SRH) and social support among older people as well as its associated factors. We conducted a cross-sectional study among 312 urban community-dwelling elderly aged 65 to 90 years in Tainan Taiwan and Fuzhou Fujian Province from March 2012 to October 2012. A Spearson correlation test, independent t test, a Pearson χ2 test, a linear regression analysis, and a multiple-level model were performed to analyze the results. The participants identified children as the most important source of objective and subjective support, followed by spouse and relatives. Tainan's elderly received more daily life assistance and emotional support, showed stronger awareness of the need to seek help, and maintained a higher frequency of social interactions compared with the elderly in Fuzhou. The mean objective support, subjective support, and support utilization scores as well as the overall social support among Tainan's elderly were significantly high compared with the scores among Fuzhou's elderly. Further, Tainan's elderly rated better SRH than Fuzhou's elderly. Correlation analysis showed that social support was significantly correlated with city, age, living conditions, marital status, and SRH. Multiple linear regression analysis, with social support as a dependent variable, retained the following independent predictors in the final regression model: city (4.792, 95% confidence interval [CI]: 3.068–6.516, P = 0.000), age (−0.805, 95% CI: −1.394 to −0.135, P = 0.013), marital status (−1.260, 95% CI: −1.891 to −0.629, P = 0.000), living conditions (4.069, 95% CI: 3.022–5.116, P = 0.000), and SRH −1.941, 95% CI: −3.194 to −0.688, P = 0.003). The multiple-level model showed that city would impact older people's social support (χ2 = 5.103, P older people. This study presents some

  3. Clinical evaluation of a novel population-based regression analysis for detecting glaucomatous visual field progression.

    Science.gov (United States)

    Kovalska, M P; Bürki, E; Schoetzau, A; Orguel, S F; Orguel, S; Grieshaber, M C

    2011-04-01

    The distinction of real progression from test variability in visual field (VF) series may be based on clinical judgment, on trend analysis based on follow-up of test parameters over time, or on identification of a significant change related to the mean of baseline exams (event analysis). The aim of this study was to compare a new population-based method (Octopus field analysis, OFA) with classic regression analyses and clinical judgment for detecting glaucomatous VF changes. 240 VF series of 240 patients with at least 9 consecutive examinations available were included into this study. They were independently classified by two experienced investigators. The results of such a classification served as a reference for comparison for the following statistical tests: (a) t-test global, (b) r-test global, (c) regression analysis of 10 VF clusters and (d) point-wise linear regression analysis. 32.5 % of the VF series were classified as progressive by the investigators. The sensitivity and specificity were 89.7 % and 92.0 % for r-test, and 73.1 % and 93.8 % for the t-test, respectively. In the point-wise linear regression analysis, the specificity was comparable (89.5 % versus 92 %), but the sensitivity was clearly lower than in the r-test (22.4 % versus 89.7 %) at a significance level of p = 0.01. A regression analysis for the 10 VF clusters showed a markedly higher sensitivity for the r-test (37.7 %) than the t-test (14.1 %) at a similar specificity (88.3 % versus 93.8 %) for a significant trend (p = 0.005). In regard to the cluster distribution, the paracentral clusters and the superior nasal hemifield progressed most frequently. The population-based regression analysis seems to be superior to the trend analysis in detecting VF progression in glaucoma, and may eliminate the drawbacks of the event analysis. Further, it may assist the clinician in the evaluation of VF series and may allow better visualization of the correlation between function and structure owing to VF

  4. Selective principal component regression analysis of fluorescence hyperspectral image to assess aflatoxin contamination in corn

    Science.gov (United States)

    Selective principal component regression analysis (SPCR) uses a subset of the original image bands for principal component transformation and regression. For optimal band selection before the transformation, this paper used genetic algorithms (GA). In this case, the GA process used the regression co...

  5. Determining Balıkesir’s Energy Potential Using a Regression Analysis Computer Program

    Directory of Open Access Journals (Sweden)

    Bedri Yüksel

    2014-01-01

    Full Text Available Solar power and wind energy are used concurrently during specific periods, while at other times only the more efficient is used, and hybrid systems make this possible. When establishing a hybrid system, the extent to which these two energy sources support each other needs to be taken into account. This paper is a study of the effects of wind speed, insolation levels, and the meteorological parameters of temperature and humidity on the energy potential in Balıkesir, in the Marmara region of Turkey. The relationship between the parameters was studied using a multiple linear regression method. Using a designed-for-purpose computer program, two different regression equations were derived, with wind speed being the dependent variable in the first and insolation levels in the second. The regression equations yielded accurate results. The computer program allowed for the rapid calculation of different acceptance rates. The results of the statistical analysis proved the reliability of the equations. An estimate of identified meteorological parameters and unknown parameters could be produced with a specified precision by using the regression analysis method. The regression equations also worked for the evaluation of energy potential.

  6. Covariate Imbalance and Adjustment for Logistic Regression Analysis of Clinical Trial Data

    Science.gov (United States)

    Ciolino, Jody D.; Martin, Reneé H.; Zhao, Wenle; Jauch, Edward C.; Hill, Michael D.; Palesch, Yuko Y.

    2014-01-01

    In logistic regression analysis for binary clinical trial data, adjusted treatment effect estimates are often not equivalent to unadjusted estimates in the presence of influential covariates. This paper uses simulation to quantify the benefit of covariate adjustment in logistic regression. However, International Conference on Harmonization guidelines suggest that covariate adjustment be pre-specified. Unplanned adjusted analyses should be considered secondary. Results suggest that that if adjustment is not possible or unplanned in a logistic setting, balance in continuous covariates can alleviate some (but never all) of the shortcomings of unadjusted analyses. The case of log binomial regression is also explored. PMID:24138438

  7. Racial and socioeconomic disparities in sexual activity among older married Malaysians.

    Science.gov (United States)

    Momtaz, Yadollah Abolfathi; Hamid, Tengku Aizan; Ibrahim, Rahimah; Akahbar, Siti Aisyah Nor

    2014-01-01

    Sexuality as an important part of life has not been well studied in Malaysia, particularly among older adults. The main aim of this study was to investigate the racial and socioeconomic differences in sexual activity among older married Malaysians. Data for this study consisting of 1036 older married adults aged 60 years and older were obtained from the nationwide community-based cross-sectional survey entitled "Determinants of Wellness among Older Malaysian: A Health Promotion Perspective", conducted in 2010. Data were analyzed using SPSS version 21 for Windows. The results showed that 57.3% (95% CI: 54.3-60.3) of the respondents (61.6% of men and 50.6% of women) had engaged in sexual intercourse during the last 12 months. The adjusted multivariate logistic regression analysis revealed that ethnicity and educational attainment were independently and significantly associated with sexual activity, after controlling for the possible confounding effects of chronic medical conditions and demographic characteristics. The findings from this study do support the notion that sexuality is a lifelong need and cultural teachings and formal education may have important role in maintaining the quality of sexuality in later life. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Is total lymphocyte count related to nutritional markers in hospitalized older adults?

    Directory of Open Access Journals (Sweden)

    Vânia Aparecida LEANDRO-MERHI

    Full Text Available ABSTRACT BACKGROUND Older patients are commonly malnourished during hospital stay, and a high prevalence of malnutrition is found in hospitalized patients aged more than 65 years. OBJECTIVE To investigate whether total lymphocyte count is related to other nutritional markers in hospitalized older adults. METHODS Hospitalized older adults (N=131 were recruited for a cross-sectional study. Their nutritional status was assessed by the Nutritional Risk Screening (NRS, anthropometry, and total lymphocyte count. The statistical analyses included the chi-square test, Fisher's exact test, and Mann-Whitney test. Spearman's linear correlation coefficient determined whether total lymphocyte count was correlated with the nutritional markers. Multiple linear regression determined the parameters associated with lymphocyte count. The significance level was set at 5%. RESULTS According to the NRS, 41.2% of the patients were at nutritional risk, and 36% had mild or moderate depletion according to total lymphocyte count. Total lymphocyte count was weakly correlated with mid-upper arm circumference (r=0.20507; triceps skinfold thickness (r=0.29036, and length of hospital stay (r= -0.21518. Total lymphocyte count in different NRS categories differed significantly: older adults who were not at nutritional risk had higher mean and median total lymphocyte count ( P =0.0245. Multiple regression analysis showed that higher lymphocyte counts were associated with higher triceps skinfold thicknesses and no nutritional risk according to the NRS. CONCLUSION Total lymphocyte count was correlated with mid-upper arm circumference, triceps skinfold thickness, and nutritional risk according to the NRS. In multiple regression the combined factors that remained associated with lymphocyte count were NRS and triceps skinfold thickness. Therefore, total lymphocyte count may be considered a nutritional marker. Other studies should confirm these findings.

  9. Declining Bias and Gender Wage Discrimination? A Meta-Regression Analysis

    Science.gov (United States)

    Jarrell, Stephen B.; Stanley, T. D.

    2004-01-01

    The meta-regression analysis reveals that there is a strong tendency for discrimination estimates to fall and wage discrimination exist against the woman. The biasing effect of researchers' gender of not correcting for selection bias has weakened and changes in labor market have made it less important.

  10. Statistical methods in regression and calibration analysis of chromosome aberration data

    International Nuclear Information System (INIS)

    Merkle, W.

    1983-01-01

    The method of iteratively reweighted least squares for the regression analysis of Poisson distributed chromosome aberration data is reviewed in the context of other fit procedures used in the cytogenetic literature. As an application of the resulting regression curves methods for calculating confidence intervals on dose from aberration yield are described and compared, and, for the linear quadratic model a confidence interval is given. Emphasis is placed on the rational interpretation and the limitations of various methods from a statistical point of view. (orig./MG)

  11. Length bias correction in gene ontology enrichment analysis using logistic regression.

    Science.gov (United States)

    Mi, Gu; Di, Yanming; Emerson, Sarah; Cumbie, Jason S; Chang, Jeff H

    2012-01-01

    When assessing differential gene expression from RNA sequencing data, commonly used statistical tests tend to have greater power to detect differential expression of genes encoding longer transcripts. This phenomenon, called "length bias", will influence subsequent analyses such as Gene Ontology enrichment analysis. In the presence of length bias, Gene Ontology categories that include longer genes are more likely to be identified as enriched. These categories, however, are not necessarily biologically more relevant. We show that one can effectively adjust for length bias in Gene Ontology analysis by including transcript length as a covariate in a logistic regression model. The logistic regression model makes the statistical issue underlying length bias more transparent: transcript length becomes a confounding factor when it correlates with both the Gene Ontology membership and the significance of the differential expression test. The inclusion of the transcript length as a covariate allows one to investigate the direct correlation between the Gene Ontology membership and the significance of testing differential expression, conditional on the transcript length. We present both real and simulated data examples to show that the logistic regression approach is simple, effective, and flexible.

  12. Physical activity and depression in older adults with and without cognitive impairment.

    Science.gov (United States)

    Yuenyongchaiwat, Kornanong; Pongpanit, Khajonsak; Hanmanop, Somrudee

    2018-01-01

    Low physical activity and depression may be related to cognitive impairment in the elderly. To determine depression and physical activity (PA) among older adults with and without cognitive impairment. 156 older adults, both males and females, aged ≥60 years, were asked to complete the Thai Mini-Mental State Examination (Thai-MMSE), a global cognitive impairment screening tool. Seventy-eight older adults with cognitive impairment and 78 older adults without cognitive impairment were then separately administered two questionnaires (i.e., the Thai Geriatric Depression Scale; TGDS and Global Physical Activity Questionnaire; GPAQ). Logistic regression analysis was used to determine the risk of developing cognitive impairment in the groups of older individuals with and without cognitive impairment. A cross-sectional study of elderly with a mean age of 74.47 ± 8.14 years was conducted. There were significant differences on the depression scale and in PA between older adults with and without cognitive impairment. Further, participants with low PA and high level of depressive symptoms had an increased risk of cognitive impairment (Odds ratio = 4.808 and 3.298, respectively). Significant differences were noted in PA and on depression scales between older adults with and without cognitive impairment. Therefore, increased PA and decreased depressive symptoms (i.e., having psychological support) are suggested to reduce the risks of cognitive impairment in older adults.

  13. Analysis of designed experiments by stabilised PLS Regression and jack-knifing

    DEFF Research Database (Denmark)

    Martens, Harald; Høy, M.; Westad, F.

    2001-01-01

    Pragmatical, visually oriented methods for assessing and optimising bi-linear regression models are described, and applied to PLS Regression (PLSR) analysis of multi-response data from controlled experiments. The paper outlines some ways to stabilise the PLSR method to extend its range...... the reliability of the linear and bi-linear model parameter estimates. The paper illustrates how the obtained PLSR "significance" probabilities are similar to those from conventional factorial ANOVA, but the PLSR is shown to give important additional overview plots of the main relevant structures in the multi....... An Introduction, Wiley, Chichester, UK, 2001]....

  14. Muscle Functions and Functional Performance among Older Persons with and without Low Back Pain

    Directory of Open Access Journals (Sweden)

    Nor Azizah Ishak

    2016-01-01

    Full Text Available This study aims to compare muscle functions and functional performances between older persons with and without low back pain (LBP and to determine the association between muscle functions and functional performances. This is a cross-sectional study, involving 95 older persons (age = 70.27±7.26 years. Anthropometric characteristics, muscle functions, and functional performances were measured. Data were analyzed using ANOVA, Pearson’s correlation, and multiple linear regression. The functional performances showed no significant differences (females LBP versus non-LBP, males LBP versus non-LBP (p<0.05. For muscle functions, significant differences were found (females LBP versus non-LBP for abdominal muscle strength (p=0.006 and back muscle strength (p=0.07. In the LBP group, significant correlations were found between back and abdominal muscle strength and hand grip strength (r=0.377 and r=0.396, resp., multifidus control and lower limb function (r=0.363 in females, and back muscle strength and lower limb function (r=0.393 in males (all p<0.05. Regression analysis showed that abdominal and back muscle strengths were significant predictors of hand grip strength (p=0.041 and p=0.049, resp., and multifidus control was a significant predictor of lower limb function in females (p=0.047. This study demonstrates that older women with LBP exhibit poorer muscle functions compared to older women without LBP.

  15. Replica analysis of overfitting in regression models for time-to-event data

    Science.gov (United States)

    Coolen, A. C. C.; Barrett, J. E.; Paga, P.; Perez-Vicente, C. J.

    2017-09-01

    Overfitting, which happens when the number of parameters in a model is too large compared to the number of data points available for determining these parameters, is a serious and growing problem in survival analysis. While modern medicine presents us with data of unprecedented dimensionality, these data cannot yet be used effectively for clinical outcome prediction. Standard error measures in maximum likelihood regression, such as p-values and z-scores, are blind to overfitting, and even for Cox’s proportional hazards model (the main tool of medical statisticians), one finds in literature only rules of thumb on the number of samples required to avoid overfitting. In this paper we present a mathematical theory of overfitting in regression models for time-to-event data, which aims to increase our quantitative understanding of the problem and provide practical tools with which to correct regression outcomes for the impact of overfitting. It is based on the replica method, a statistical mechanical technique for the analysis of heterogeneous many-variable systems that has been used successfully for several decades in physics, biology, and computer science, but not yet in medical statistics. We develop the theory initially for arbitrary regression models for time-to-event data, and verify its predictions in detail for the popular Cox model.

  16. Predictors of postoperative outcomes of cubital tunnel syndrome treatments using multiple logistic regression analysis.

    Science.gov (United States)

    Suzuki, Taku; Iwamoto, Takuji; Shizu, Kanae; Suzuki, Katsuji; Yamada, Harumoto; Sato, Kazuki

    2017-05-01

    This retrospective study was designed to investigate prognostic factors for postoperative outcomes for cubital tunnel syndrome (CubTS) using multiple logistic regression analysis with a large number of patients. Eighty-three patients with CubTS who underwent surgeries were enrolled. The following potential prognostic factors for disease severity were selected according to previous reports: sex, age, type of surgery, disease duration, body mass index, cervical lesion, presence of diabetes mellitus, Workers' Compensation status, preoperative severity, and preoperative electrodiagnostic testing. Postoperative severity of disease was assessed 2 years after surgery by Messina's criteria which is an outcome measure specifically for CubTS. Bivariate analysis was performed to select candidate prognostic factors for multiple linear regression analyses. Multiple logistic regression analysis was conducted to identify the association between postoperative severity and selected prognostic factors. Both bivariate and multiple linear regression analysis revealed only preoperative severity as an independent risk factor for poor prognosis, while other factors did not show any significant association. Although conflicting results exist regarding prognosis of CubTS, this study supports evidence from previous studies and concludes early surgical intervention portends the most favorable prognosis. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  17. Perceived health status and daily activity participation of older Malaysians.

    Science.gov (United States)

    Ng, Sor Tho; Tengku-Aizan, Hamid; Tey, Nai Peng

    2011-07-01

    This article investigates the influence of perceived health status on the daily activity participation of older Malaysians. Data from the Survey on Perceptions of Needs and Problems of the Elderly, which was conducted in 1999, were used. The negative binomial regression results show that older persons with good perceived health status reported more varieties of daily activity participation, especially among the uneducated and those with below-average self-esteem. The multinomial logistic regression model suggests that older persons with good perceived health status tended to engage daily in paid work only or with leisure activities, whereas those perceived to have poor health were more likely to engage in leisure activities only or leisure and family role activities. Promotion of a healthy lifestyle at a younger age encourages every person to monitor and take responsibility for their own health, which is a necessary strategy to ensure active participation at an older age, and thus improve their well-being.

  18. Multiple linear regression analysis

    Science.gov (United States)

    Edwards, T. R.

    1980-01-01

    Program rapidly selects best-suited set of coefficients. User supplies only vectors of independent and dependent data and specifies confidence level required. Program uses stepwise statistical procedure for relating minimal set of variables to set of observations; final regression contains only most statistically significant coefficients. Program is written in FORTRAN IV for batch execution and has been implemented on NOVA 1200.

  19. Healthcare-Associated Meningitis or Ventriculitis in Older Adults.

    Science.gov (United States)

    Srihawan, Chanunya; Habib, Onaizah; Salazar, Lucrecia; Hasbun, Rodrigo

    2017-12-01

    Healthcare-associated meningitis or ventriculitis (HCAMV) is a serious and life-threatening complication of invasive neurosurgical procedures or penetrating head trauma. Older adults are at higher risk of adverse outcomes in community-acquired meningitis but studies of HCAMV are lacking. Therefore, we perform the study to define the differences in clinical outcomes between older and younger adults with HCAMV. Retrospective study. A large tertiary care hospital in Houston, Texas, from July 2003 to November 2014. Adults with a diagnosis of HCAMV (N = 160) aged ≥65 (n = 35), aged 18-64 (n = 125). Demographic characteristics, clinical presentation, laboratory results, treatments, and outcomes (Glasgow Outcome Scale). Older adults had more comorbidities and CSF abnormalities [pleocytosis, high cerebrospinal fluid (CSF) protein, low CSF glucose) and were more likely to have altered mental status than younger adults (P older (97%) and younger (86%) adults (P = .13). On logistic regression analysis, abnormal neurological examination (adjusted odds ratio (aOR) = 7.13, 95% confidence interval (CI) = 2.15-23.63, P = .001) and mechanical ventilation (aOR = 11.03, 95% CI = 1.35-90.51, P = .02) were associated with adverse clinical outcomes. Older adults with HCAMV have more comorbidities and CSF abnormalities and are more likely to have altered mental status than younger adults but have similar high rates of adverse clinical outcomes. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  20. Exploring factors associated with traumatic dental injuries in preschool children: a Poisson regression analysis.

    Science.gov (United States)

    Feldens, Carlos Alberto; Kramer, Paulo Floriani; Ferreira, Simone Helena; Spiguel, Mônica Hermann; Marquezan, Marcela

    2010-04-01

    This cross-sectional study aimed to investigate the factors associated with dental trauma in preschool children using Poisson regression analysis with robust variance. The study population comprised 888 children aged 3- to 5-year-old attending public nurseries in Canoas, southern Brazil. Questionnaires assessing information related to the independent variables (age, gender, race, mother's educational level and family income) were completed by the parents. Clinical examinations were carried out by five trained examiners in order to assess traumatic dental injuries (TDI) according to Andreasen's classification. One of the five examiners was calibrated to assess orthodontic characteristics (open bite and overjet). Multivariable Poisson regression analysis with robust variance was used to determine the factors associated with dental trauma as well as the strengths of association. Traditional logistic regression was also performed in order to compare the estimates obtained by both methods of statistical analysis. 36.4% (323/888) of the children suffered dental trauma and there was no difference in prevalence rates from 3 to 5 years of age. Poisson regression analysis showed that the probability of the outcome was almost 30% higher for children whose mothers had more than 8 years of education (Prevalence Ratio = 1.28; 95% CI = 1.03-1.60) and 63% higher for children with an overjet greater than 2 mm (Prevalence Ratio = 1.63; 95% CI = 1.31-2.03). Odds ratios clearly overestimated the size of the effect when compared with prevalence ratios. These findings indicate the need for preventive orientation regarding TDI, in order to educate parents and caregivers about supervising infants, particularly those with increased overjet and whose mothers have a higher level of education. Poisson regression with robust variance represents a better alternative than logistic regression to estimate the risk of dental trauma in preschool children.

  1. Regressão e crescimento do primogênito no processo de tornar-se irmão Firstborn's regression and growth in the process of becoming a sibling

    Directory of Open Access Journals (Sweden)

    Débora Silva Oliveira

    2013-03-01

    Full Text Available Investigaram-se indicadores de regressão e crescimento do primogênito no processo de tornar-se irmão. Participaram três primogênitos pré-escolares no terceiro trimestre de gestação, aos 12 e 24 meses do irmão. Foi aplicado o Teste das Fábulas e realizada análise qualitativa de conteúdo. Os resultados revelaram regressão do primogênito na gestação materna e crescimento, aos 12 e aos 24 meses de idade do irmão. A regressão foi uma forma de enfrentar a chegada do irmão, enquanto que o crescimento revelou capacidade para conquistas ou custos de ser mais velho. Tanto a regressão quanto o crescimento oportunizaram um ir e vir saudável, fundamental para o desenvolvimento rumo à independência. Esses achados têm implicações para a pesquisa e para a clínica.Regression and growth indicators in the process of becoming a sibling were investigated. Three firstborns took part in the study during the first sibling's third trimester of pregnancy, and when the sibling was 12 and 24 months old, respectively. The Fables Test was used and a qualitative content analysis was carried out. Results revealed regression indicators during pregnancy. At 12 and 24 months there were growth indicators together with regression indicators. Regression was used by the firstborn for coping with the sibling's arrival while growth revealed the capacity for acquisitions or the costs of being an older sibling. Both regressive and growth manifestations enabled a healthy to and fro, which is fundamental for development towards independence. These findings have both research and clinical implications.

  2. Demographic and psychosocial correlates of sexual activity in older Chinese people.

    Science.gov (United States)

    Yang, Shuyan; Yan, Elsie

    2016-03-01

    This study examines sexual activity and associated psychosocial factors in older Chinese people. Sexuality continues to play a pivotal role in our lives even as we grow old. There is, however, very limited research on the topic in older populations. Cross-sectional survey. A representative sample of 688 older Chinese people (>60 years old) were individually interviewed on their demographic characteristics; their interest in, knowledge of and perceived control over sexual activities; and their engagement in sexual activity. The results show that 51·32% of men and 41·26% of women reported engaging in some form of sexual activity. Sexual intercourse and caressing were commonly reported. A multiple regression analysis also showed that a higher level of sexual activity was associated with being younger, living with a spouse, having a strong interest in sex, having sufficient knowledge of elder sexuality and a high perceived control over sex. Distinct predictive factors in each gender were observed. A high level of perceived control was associated with a higher level of sexual activity in males but not females. A series of binary logistic regression analyses were conducted to determine the demographic and psychosocial correlates of sexual activity. With the exception of the use of objects (sex toys), sexual activities were consistently associated with being younger; living with a spouse; and having high levels of interest, knowledge and perceived control. A sizable amount of older Chinese people engage in varying degrees of sexual activity, and most are still interested in sex. Frontline health professionals need to be aware of the growing needs for sex education in older persons, particular attention should be paid to discuss the limitations brought about by various chronic conditions associated with ageing and their relevance to elder sexuality. © 2015 John Wiley & Sons Ltd.

  3. Frailty as a Predictor of Alzheimer Disease, Vascular Dementia, and All Dementia Among Community-Dwelling Older People: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Kojima, Gotaro; Taniguchi, Yu; Iliffe, Steve; Walters, Kate

    2016-10-01

    To perform a systematic search of the literature for currently available evidence on frailty as a predictor of dementia and to conduct a meta-analysis to synthesize the pooled risk estimates among community-dwelling older people. A systematic review and meta-analysis. Embase, MEDLINE, CINAHL Plus, PsycINFO, and the Cochrane Library from 2000 to January 2016, and reference lists of relevant articles. Any studies that prospectively examined the incident risks of dementia with frailty among community-dwelling older people without language restriction. Of 2565 studies identified through the systematic review, 7 studies were included in this review. Of these, 4 studies reported hazard ratios (HR) of incident dementia for physical frailty defined by Cardiovascular Health Study criteria and were included in a meta-analysis. Frailty was a significant predictor of incident Alzheimer disease (4 studies: pooled HR = 1.28, 95% confidence interval (95% CI) = 1.00-1.63, P = .05), vascular dementia (2 studies: pooled HR 2.70, 95% CI 1.40-5.23, P = .003), and all dementia (3 studies: pooled HR 1.33, 95% CI 1.07-1.67, P = .01). Heterogeneity across the studies was low to modest (I(2) = 0%-51%). A random-effects meta-regression analysis showed that the female proportion of the cohort primarily mediated the association of frailty with Alzheimer disease (female proportion coefficient = 0.04, 95%CI = 0.01-0.08, P = .01). This systematic review and meta-analysis suggests that frailty was a significant predictor of Alzheimer disease, vascular dementia, and all dementia among community-dwelling older people. Frail women may have a higher risk of incident Alzheimer disease than frail men. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  4. Depressive symptoms in institutionalized older adults

    Directory of Open Access Journals (Sweden)

    Lívia Maria Santiago

    2014-04-01

    Full Text Available OBJECTIVE To estimate the prevalence of depressive symptoms among institutionalized elderly individuals and to analyze factors associated with this condition. METHODS This was a cross-sectional study involving 462 individuals aged 60 or older, residents in long stay institutions in four Brazilian municipalities. The dependent variable was assessed using the 15-item Geriatric Depression Scale. Poisson’s regression was used to evaluate associations with co-variables. We investigated which variables were most relevant in terms of presence of depressive symptoms within the studied context through factor analysis. RESULTS Prevalence of depressive symptoms was 48.7%. The variables associated with depressive symptoms were: regular/bad/very bad self-rated health; comorbidities; hospitalizations; and lack of friends in the institution. Five components accounted for 49.2% of total variance of the sample: functioning, social support, sensory deficiency, institutionalization and health conditions. In the factor analysis, functionality and social support were the components which explained a large part of observed variance. CONCLUSIONS A high prevalence of depressive symptoms, with significant variation in distribution, was observed. Such results emphasize the importance of health conditions and functioning for institutionalized older individuals developing depression. They also point to the importance of providing opportunities for interaction among institutionalized individuals.

  5. Impact of cognitive function on oral perception in independently living older people.

    Science.gov (United States)

    Fukutake, Motoyoshi; Ogawa, Taiji; Ikebe, Kazunori; Mihara, Yusuke; Inomata, Chisato; Takeshita, Hajime; Matsuda, Kenichi; Hatta, Kodai; Gondo, Yasuyuki; Masui, Yukie; Inagaki, Hiroki; Arai, Yasumichi; Kamide, Kei; Ishizaki, Tatsuro; Maeda, Yoshinobu

    2018-04-10

    Oral tactile perception is important for better mastication, appetite, and enjoyment of food. However, previous investigations have not utilized comprehensible variables thought to have negative effect on oral perception, including aging, denture wearing, and cognitive function. The aim of this study was to elucidate the impact of cognitive function on oral perception in independently living older individuals. The study sample was comprised of 987 participants (466 males, 521 females; age 69-71 years). Oral examinations, assessments of cognitive function in preclinical level by Montreal Cognitive Assessment (MoCA)-J, and determination of oral stereognostic ability as an indicator of oral perception were performed. Related variables were selected by univariate analyses; then, multivariate logistic regression model analysis was conducted. Univariate analyses revealed that number of teeth, removable dentures usage, and cognitive function respectively had a significant relationship with stereognostic score. Next, the subjects were classified into good and poor perception groups (lowest 17.4%) according to oral stereognostic ability. Logistic regression analysis revealed that lower cognitive function was significantly associated with poor oral perception (OR = 0.934, p = 0.017) after controlling for other variables. Cognitive decline even in preclinical stage was associated with reduced oral perception after controlling for gender, tooth number and denture use in independent living older people. This study suggested that preclinical level of change in cognitive function affected oral perception. Dental practitioners and caregivers may need to pay attention to reduced oral perception among older people even if they do not have trouble in daily life.

  6. Application of range-test in multiple linear regression analysis in ...

    African Journals Online (AJOL)

    Application of range-test in multiple linear regression analysis in the presence of outliers is studied in this paper. First, the plot of the explanatory variables (i.e. Administration, Social/Commercial, Economic services and Transfer) on the dependent variable (i.e. GDP) was done to identify the statistical trend over the years.

  7. Multiple regression analysis of anthropometric measurements influencing the cephalic index of male Japanese university students.

    Science.gov (United States)

    Hossain, Md Golam; Saw, Aik; Alam, Rashidul; Ohtsuki, Fumio; Kamarul, Tunku

    2013-09-01

    Cephalic index (CI), the ratio of head breadth to head length, is widely used to categorise human populations. The aim of this study was to access the impact of anthropometric measurements on the CI of male Japanese university students. This study included 1,215 male university students from Tokyo and Kyoto, selected using convenient sampling. Multiple regression analysis was used to determine the effect of anthropometric measurements on CI. The variance inflation factor (VIF) showed no evidence of a multicollinearity problem among independent variables. The coefficients of the regression line demonstrated a significant positive relationship between CI and minimum frontal breadth (p regression analysis showed a greater likelihood for minimum frontal breadth (p regression analysis revealed bizygomatic breadth, head circumference, minimum frontal breadth, head height and morphological facial height to be the best predictor craniofacial measurements with respect to CI. The results suggest that most of the variables considered in this study appear to influence the CI of adult male Japanese students.

  8. Understanding poisson regression.

    Science.gov (United States)

    Hayat, Matthew J; Higgins, Melinda

    2014-04-01

    Nurse investigators often collect study data in the form of counts. Traditional methods of data analysis have historically approached analysis of count data either as if the count data were continuous and normally distributed or with dichotomization of the counts into the categories of occurred or did not occur. These outdated methods for analyzing count data have been replaced with more appropriate statistical methods that make use of the Poisson probability distribution, which is useful for analyzing count data. The purpose of this article is to provide an overview of the Poisson distribution and its use in Poisson regression. Assumption violations for the standard Poisson regression model are addressed with alternative approaches, including addition of an overdispersion parameter or negative binomial regression. An illustrative example is presented with an application from the ENSPIRE study, and regression modeling of comorbidity data is included for illustrative purposes. Copyright 2014, SLACK Incorporated.

  9. Analysis of the influence of quantile regression model on mainland tourists' service satisfaction performance.

    Science.gov (United States)

    Wang, Wen-Cheng; Cho, Wen-Chien; Chen, Yin-Jen

    2014-01-01

    It is estimated that mainland Chinese tourists travelling to Taiwan can bring annual revenues of 400 billion NTD to the Taiwan economy. Thus, how the Taiwanese Government formulates relevant measures to satisfy both sides is the focus of most concern. Taiwan must improve the facilities and service quality of its tourism industry so as to attract more mainland tourists. This paper conducted a questionnaire survey of mainland tourists and used grey relational analysis in grey mathematics to analyze the satisfaction performance of all satisfaction question items. The first eight satisfaction items were used as independent variables, and the overall satisfaction performance was used as a dependent variable for quantile regression model analysis to discuss the relationship between the dependent variable under different quantiles and independent variables. Finally, this study further discussed the predictive accuracy of the least mean regression model and each quantile regression model, as a reference for research personnel. The analysis results showed that other variables could also affect the overall satisfaction performance of mainland tourists, in addition to occupation and age. The overall predictive accuracy of quantile regression model Q0.25 was higher than that of the other three models.

  10. Analysis of the Influence of Quantile Regression Model on Mainland Tourists' Service Satisfaction Performance

    Science.gov (United States)

    Wang, Wen-Cheng; Cho, Wen-Chien; Chen, Yin-Jen

    2014-01-01

    It is estimated that mainland Chinese tourists travelling to Taiwan can bring annual revenues of 400 billion NTD to the Taiwan economy. Thus, how the Taiwanese Government formulates relevant measures to satisfy both sides is the focus of most concern. Taiwan must improve the facilities and service quality of its tourism industry so as to attract more mainland tourists. This paper conducted a questionnaire survey of mainland tourists and used grey relational analysis in grey mathematics to analyze the satisfaction performance of all satisfaction question items. The first eight satisfaction items were used as independent variables, and the overall satisfaction performance was used as a dependent variable for quantile regression model analysis to discuss the relationship between the dependent variable under different quantiles and independent variables. Finally, this study further discussed the predictive accuracy of the least mean regression model and each quantile regression model, as a reference for research personnel. The analysis results showed that other variables could also affect the overall satisfaction performance of mainland tourists, in addition to occupation and age. The overall predictive accuracy of quantile regression model Q0.25 was higher than that of the other three models. PMID:24574916

  11. Analysis of the Influence of Quantile Regression Model on Mainland Tourists’ Service Satisfaction Performance

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Wang

    2014-01-01

    Full Text Available It is estimated that mainland Chinese tourists travelling to Taiwan can bring annual revenues of 400 billion NTD to the Taiwan economy. Thus, how the Taiwanese Government formulates relevant measures to satisfy both sides is the focus of most concern. Taiwan must improve the facilities and service quality of its tourism industry so as to attract more mainland tourists. This paper conducted a questionnaire survey of mainland tourists and used grey relational analysis in grey mathematics to analyze the satisfaction performance of all satisfaction question items. The first eight satisfaction items were used as independent variables, and the overall satisfaction performance was used as a dependent variable for quantile regression model analysis to discuss the relationship between the dependent variable under different quantiles and independent variables. Finally, this study further discussed the predictive accuracy of the least mean regression model and each quantile regression model, as a reference for research personnel. The analysis results showed that other variables could also affect the overall satisfaction performance of mainland tourists, in addition to occupation and age. The overall predictive accuracy of quantile regression model Q0.25 was higher than that of the other three models.

  12. Predictors of Enteral Tube Feeding in Hospitalized Older Adults.

    Science.gov (United States)

    Crenitte, Milton Roberto Furst; Avelino-Silva, Thiago Junqueira; Apolinario, Daniel; Curiati, Jose Antonio Esper; Campora, Flavia; Jacob-Filho, Wilson

    2017-11-01

    Despite general recognition that enteral tube feeding (ETF) is frequently employed in long-term care facilities and patients with dementia, remarkably little research has determined which factors are associated with its use in acutely ill older adults. In this study, we aimed to investigate determinants of ETF introduction in hospitalized older adults. We examined a retrospective cohort of acutely ill patients, aged 60 years and older, admitted to a university hospital's geriatric ward from 2014-2015, in São Paulo, Brazil. The main outcome was the introduction of ETF during hospitalization. Predictors of interest included age, sex, referring unit, comorbidity burden, functional status, malnutrition, depression, dementia severity, and delirium. Multivariate analysis was performed using backward stepwise logistic regression. A total of 214 cases were included. Mean age was 81 years, and 63% were women. Malnutrition was detected in 47% of the cases, dementia in 46%, and delirium in 36%. ETF was initiated in 44 (21%) admissions. Independent predictors of ETF were delirium (odds ratio [OR], 4.83; 95% CI, 2.12-11.01; P ETF. One in five acutely ill older adults used ETF while hospitalized. Delirium and functional dependency were independent predictors of its introduction. Risks and benefits of enteral nutrition in this particular context need to be further explored.

  13. Econometric analysis of realised covariation: high frequency covariance, regression and correlation in financial economics

    OpenAIRE

    Ole E. Barndorff-Nielsen; Neil Shephard

    2002-01-01

    This paper analyses multivariate high frequency financial data using realised covariation. We provide a new asymptotic distribution theory for standard methods such as regression, correlation analysis and covariance. It will be based on a fixed interval of time (e.g. a day or week), allowing the number of high frequency returns during this period to go to infinity. Our analysis allows us to study how high frequency correlations, regressions and covariances change through time. In particular w...

  14. Prediction of radiation levels in residences: A methodological comparison of CART [Classification and Regression Tree Analysis] and conventional regression

    International Nuclear Information System (INIS)

    Janssen, I.; Stebbings, J.H.

    1990-01-01

    In environmental epidemiology, trace and toxic substance concentrations frequently have very highly skewed distributions ranging over one or more orders of magnitude, and prediction by conventional regression is often poor. Classification and Regression Tree Analysis (CART) is an alternative in such contexts. To compare the techniques, two Pennsylvania data sets and three independent variables are used: house radon progeny (RnD) and gamma levels as predicted by construction characteristics in 1330 houses; and ∼200 house radon (Rn) measurements as predicted by topographic parameters. CART may identify structural variables of interest not identified by conventional regression, and vice versa, but in general the regression models are similar. CART has major advantages in dealing with other common characteristics of environmental data sets, such as missing values, continuous variables requiring transformations, and large sets of potential independent variables. CART is most useful in the identification and screening of independent variables, greatly reducing the need for cross-tabulations and nested breakdown analyses. There is no need to discard cases with missing values for the independent variables because surrogate variables are intrinsic to CART. The tree-structured approach is also independent of the scale on which the independent variables are measured, so that transformations are unnecessary. CART identifies important interactions as well as main effects. The major advantages of CART appear to be in exploring data. Once the important variables are identified, conventional regressions seem to lead to results similar but more interpretable by most audiences. 12 refs., 8 figs., 10 tabs

  15. A rotor optimization using regression analysis

    Science.gov (United States)

    Giansante, N.

    1984-01-01

    The design and development of helicopter rotors is subject to the many design variables and their interactions that effect rotor operation. Until recently, selection of rotor design variables to achieve specified rotor operational qualities has been a costly, time consuming, repetitive task. For the past several years, Kaman Aerospace Corporation has successfully applied multiple linear regression analysis, coupled with optimization and sensitivity procedures, in the analytical design of rotor systems. It is concluded that approximating equations can be developed rapidly for a multiplicity of objective and constraint functions and optimizations can be performed in a rapid and cost effective manner; the number and/or range of design variables can be increased by expanding the data base and developing approximating functions to reflect the expanded design space; the order of the approximating equations can be expanded easily to improve correlation between analyzer results and the approximating equations; gradients of the approximating equations can be calculated easily and these gradients are smooth functions reducing the risk of numerical problems in the optimization; the use of approximating functions allows the problem to be started easily and rapidly from various initial designs to enhance the probability of finding a global optimum; and the approximating equations are independent of the analysis or optimization codes used.

  16. Regression and local control rates after radiotherapy for jugulotympanic paragangliomas: Systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Hulsteijn, Leonie T. van; Corssmit, Eleonora P.M.; Coremans, Ida E.M.; Smit, Johannes W.A.; Jansen, Jeroen C.; Dekkers, Olaf M.

    2013-01-01

    The primary treatment goal of radiotherapy for paragangliomas of the head and neck region (HNPGLs) is local control of the tumor, i.e. stabilization of tumor volume. Interestingly, regression of tumor volume has also been reported. Up to the present, no meta-analysis has been performed giving an overview of regression rates after radiotherapy in HNPGLs. The main objective was to perform a systematic review and meta-analysis to assess regression of tumor volume in HNPGL-patients after radiotherapy. A second outcome was local tumor control. Design of the study is systematic review and meta-analysis. PubMed, EMBASE, Web of Science, COCHRANE and Academic Search Premier and references of key articles were searched in March 2012 to identify potentially relevant studies. Considering the indolent course of HNPGLs, only studies with ⩾12 months follow-up were eligible. Main outcomes were the pooled proportions of regression and local control after radiotherapy as initial, combined (i.e. directly post-operatively or post-embolization) or salvage treatment (i.e. after initial treatment has failed) for HNPGLs. A meta-analysis was performed with an exact likelihood approach using a logistic regression with a random effect at the study level. Pooled proportions with 95% confidence intervals (CI) were reported. Fifteen studies were included, concerning a total of 283 jugulotympanic HNPGLs in 276 patients. Pooled regression proportions for initial, combined and salvage treatment were respectively 21%, 33% and 52% in radiosurgery studies and 4%, 0% and 64% in external beam radiotherapy studies. Pooled local control proportions for radiotherapy as initial, combined and salvage treatment ranged from 79% to 100%. Radiotherapy for jugulotympanic paragangliomas results in excellent local tumor control and therefore is a valuable treatment for these types of tumors. The effects of radiotherapy on regression of tumor volume remain ambiguous, although the data suggest that regression can

  17. Robust analysis of trends in noisy tokamak confinement data using geodesic least squares regression

    Energy Technology Data Exchange (ETDEWEB)

    Verdoolaege, G., E-mail: geert.verdoolaege@ugent.be [Department of Applied Physics, Ghent University, B-9000 Ghent (Belgium); Laboratory for Plasma Physics, Royal Military Academy, B-1000 Brussels (Belgium); Shabbir, A. [Department of Applied Physics, Ghent University, B-9000 Ghent (Belgium); Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Hornung, G. [Department of Applied Physics, Ghent University, B-9000 Ghent (Belgium)

    2016-11-15

    Regression analysis is a very common activity in fusion science for unveiling trends and parametric dependencies, but it can be a difficult matter. We have recently developed the method of geodesic least squares (GLS) regression that is able to handle errors in all variables, is robust against data outliers and uncertainty in the regression model, and can be used with arbitrary distribution models and regression functions. We here report on first results of application of GLS to estimation of the multi-machine scaling law for the energy confinement time in tokamaks, demonstrating improved consistency of the GLS results compared to standard least squares.

  18. Meta-regression analysis of commensal and pathogenic Escherichia coli survival in soil and water.

    Science.gov (United States)

    Franz, Eelco; Schijven, Jack; de Roda Husman, Ana Maria; Blaak, Hetty

    2014-06-17

    The extent to which pathogenic and commensal E. coli (respectively PEC and CEC) can survive, and which factors predominantly determine the rate of decline, are crucial issues from a public health point of view. The goal of this study was to provide a quantitative summary of the variability in E. coli survival in soil and water over a broad range of individual studies and to identify the most important sources of variability. To that end, a meta-regression analysis on available literature data was conducted. The considerable variation in reported decline rates indicated that the persistence of E. coli is not easily predictable. The meta-analysis demonstrated that for soil and water, the type of experiment (laboratory or field), the matrix subtype (type of water and soil), and temperature were the main factors included in the regression analysis. A higher average decline rate in soil of PEC compared with CEC was observed. The regression models explained at best 57% of the variation in decline rate in soil and 41% of the variation in decline rate in water. This indicates that additional factors, not included in the current meta-regression analysis, are of importance but rarely reported. More complete reporting of experimental conditions may allow future inference on the global effects of these variables on the decline rate of E. coli.

  19. Neighborhood Characteristics and Disability in Older Adults

    Science.gov (United States)

    Blaney, Shannon; Cerda, Magda; Frye, Victoria; Lovasi, Gina S.; Ompad, Danielle; Rundle, Andrew; Vlahov, David

    2009-01-01

    Objective To characterize the influence of the residential neighborhood of older adults on the prevalence of disability. Methods We combined Census data on disability in older adults living in New York City with environmental information from a comprehensive geospatial database. We used factor analysis to derive dimensions of compositional and physical neighborhood characteristics and linear regression to model their association with levels of disability. Measures of neighborhood collective efficacy were added to these models to explore the impact of the social environment. Results Low neighborhood socioeconomic status, residential instability, living in areas with low proportions of foreign born and high proportions of Black residents, and negative street characteristics were associated with higher prevalence of both “physical” disability and “going outside the home” disability. High crime levels were additionally associated with physical disability, although this relationship disappeared when misdemeanor arrests were removed from the crime variable. Low levels of collective efficacy were associated with more going-outside-the-home disability, with racial/ethnic composition dropping out of this model to be replaced by an interaction term. Conclusion The urban environment may have a substantial impact on whether an older adult with a given level of functional impairment is able to age actively and remain independent. PMID:19181694

  20. Depression in older Chinese migrants to Auckland.

    Science.gov (United States)

    Abbott, Max W; Wong, Sai; Giles, Lynne C; Wong, Sue; Young, Wilson; Au, Ming

    2003-08-01

    This study was conducted to identify risk factors for depressive symptomatology among older Chinese migrants. One hundred and sixty-two Chinese migrants aged 55 years or older, living in the community and recruited via Chinese community organizations and general practitioners, were interviewed using a Chinese version of the Geriatric Depression Scale and measures of stressful life events, morbid conditions, self-rated health, acculturation, social support and service utilization. Twenty-six percent of participants met the criteria for depressive symptomatology. No recent migrants showed symptoms of depression. Multiple logistic regression analysis showed that lower emotional support, greater number of visits to a doctor, difficulties in accessing health services and low New Zealand cultural orientation increased the risk of showing symptoms of depression. Significant numbers of older Chinese migrants appear to be depressed or at risk for depression and, while participants with depressive symptoms consulted general practitioners more than their counterparts without such symptoms, they reported greater difficulty in accessing health services. The findings point to the need for further epidemiological study of this growing sector of the population and investigation of the nature of its engagement with health services. Social support and aspects of acculturation may play a significant role in preventing depression. This also requires further investigation.

  1. Older Korean adults have lower physical function despite longer exercise times compared to their Japanese counterparts: A Japan-Korea comparative study.

    Science.gov (United States)

    Jung, Songee; Okubo, Yoshiro; Osuka, Yosuke; Seino, Satoshi; Park, Joonsung; Nho, Hosung; Tanaka, Kiyoji

    2018-04-01

    We aimed to compare the level of physical function (PF) and habitual exercise between older Japanese and Korean adults. A comparative study was carried out on 1069 community-dwelling older Japanese and Korean adults (mean age 73.9 ± 5.2 years). The participants were asked to complete a self-reported questionnaire regarding habitual exercise and covariates. PF age, a composite measure of PF, was derived from the 12 items, using principal component analysis. PF age and habitual exercise were compared between the Japanese and Korean adults, using analysis of covariance (ancova) and multivariable logistic regression analysis adjusted for all covariates using propensity scores. ancova showed that PF age in older Japanese adults was significantly younger than in their Korean counterparts. Older Japanese adults exercised significantly less frequently than their Korean counterparts. Furthermore, older Japanese adults practiced significantly less walking, mountain climbing and bicycling, but more calisthenics, resistance training, ball games and dances than their Korean counterparts. We found that older Korean adults had lower PF (3.7 years older in PF age) than their Japanese counterparts. Although the overall frequency and amount of habitual exercise in older Korean adults were higher than those in their Japanese counterparts, particular types of exercise might have contributed to the higher PF levels among older Japanese adults. Thus, older Korean adults might need to engage more in habitual exercises that are specifically effective in maintaining PF. Geriatr Gerontol Int 2018; 18: 576-583. © 2017 Japan Geriatrics Society.

  2. Vector regression introduced

    Directory of Open Access Journals (Sweden)

    Mok Tik

    2014-06-01

    Full Text Available This study formulates regression of vector data that will enable statistical analysis of various geodetic phenomena such as, polar motion, ocean currents, typhoon/hurricane tracking, crustal deformations, and precursory earthquake signals. The observed vector variable of an event (dependent vector variable is expressed as a function of a number of hypothesized phenomena realized also as vector variables (independent vector variables and/or scalar variables that are likely to impact the dependent vector variable. The proposed representation has the unique property of solving the coefficients of independent vector variables (explanatory variables also as vectors, hence it supersedes multivariate multiple regression models, in which the unknown coefficients are scalar quantities. For the solution, complex numbers are used to rep- resent vector information, and the method of least squares is deployed to estimate the vector model parameters after transforming the complex vector regression model into a real vector regression model through isomorphism. Various operational statistics for testing the predictive significance of the estimated vector parameter coefficients are also derived. A simple numerical example demonstrates the use of the proposed vector regression analysis in modeling typhoon paths.

  3. Association of physical activity with a systolic blood pressure difference between arms in older people.

    Science.gov (United States)

    Sato, Koichi; Sugiura, Tomonori; Ohte, Nobuyuki; Dohi, Yasuaki

    2018-01-01

    A increase in interarm systolic blood pressure difference (IASBPD) is believed to lead to increased risk of cardiovascular disease and to be a predictor of future cardiovascular events. The purpose of the present study was to test the hypothesis that an increased IASBPD is associated with reduced physical activity in older people. Older people who used a geriatric health services facility (n = 147, mean age 83.3 years) were enrolled. The prevalence of IASBPD in individuals with different levels of physical activity and factors that have a crucial effect on IASBPD were investigated. The study participants were divided into three groups according to their physical activity; ambulant persons (group A), wheelchair users (group B) and bedridden persons (group C). Blood pressure around the both brachiums was simultaneously measured using two automated devices. An IASBPD of ≥10 mmHg was considered to be significant IASBPD. The median IASBPD was 4.5 mmHg in the present study participants, and 28 participants (19.0%) had an IASBPD ≥10 mmHg. The IASBPD in group C was greater than that in group A or B. Multivariate linear regression analysis showed that physical activity was the independent predictor of IASBPD after adjustment for possible factors. Furthermore, a logistic regression analysis with the end-point of significant IASBPD showed that physical activity is an independent predictor of significant IASBPD. Physical activity simply assessed by moving ability can predict IASBPD in older individuals. In older people, reduced physical activity might indicate the progression of silent or clinical atherosclerosis and an increased risk of cardiovascular disease. Geriatr Gerontol Int 2018; 18: 95-100. © 2017 Japan Geriatrics Society.

  4. Suicide among older psychiatric inpatients: an evidence-based study of a high risk group

    DEFF Research Database (Denmark)

    Erlangsen, Annette; Zarit, Steven H; Tu, Xin

    2006-01-01

    .1-0.3). In combination with other types of disorder, affective disorders were found to modify an increased risk of suicide. First versus later admission for depression was a better predictor for suicide than age at first hospitalization for depression (before or after age 60 years). More than half of suicides occurred......OBJECTIVE: Older adults have elevated suicide rates, especially in the presence of a psychiatric disorder, yet not much is known about predictors for suicide within this high-risk group. The current study examines the characteristics associated with suicide among older adults who are admitted...... to a psychiatric hospital. METHOD: All persons aged 60 and older living in Denmark who were hospitalized with psychiatric disorders during 1990-2000 were included in the study. Using a case-control design and logistic regression analysis, the authors calculated the suicide risk associated with specific patient...

  5. Comparative Study on Subjective Experience of Elder Abuse Between Older Korean Immigrants in the United States and Older Koreans in Korea.

    Science.gov (United States)

    Chang, Miya

    2018-01-01

    This study examines the prevalence of elder abuse and the relationship between sociodemographic factors and elder abuse among older Koreans in the United States and Korea. Survey data from older Koreans aged between 60 and 79 years from the two countries ( n = 480) were analyzed descriptively and in binary logistic regressions. This study found a similar prevalence of elder abuse in the two samples, with 26% of older Korean immigrants in the United States reporting abuse and 23% of older Koreans in Korea reporting abuse. However, there were significant differences in the types of emotional abuse experienced by older Koreans in both countries. Reports of some types of emotional abuse, such as 'name calling' and 'silent treatment,' were significantly higher in the United States than in Korea. These findings expand our knowledge of the experience of elder abuse among older Koreans in both countries.

  6. Repeated Results Analysis for Middleware Regression Benchmarking

    Czech Academy of Sciences Publication Activity Database

    Bulej, Lubomír; Kalibera, T.; Tůma, P.

    2005-01-01

    Roč. 60, - (2005), s. 345-358 ISSN 0166-5316 R&D Projects: GA ČR GA102/03/0672 Institutional research plan: CEZ:AV0Z10300504 Keywords : middleware benchmarking * regression benchmarking * regression testing Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.756, year: 2005

  7. Bayesian Analysis for Penalized Spline Regression Using WinBUGS

    Directory of Open Access Journals (Sweden)

    Ciprian M. Crainiceanu

    2005-09-01

    Full Text Available Penalized splines can be viewed as BLUPs in a mixed model framework, which allows the use of mixed model software for smoothing. Thus, software originally developed for Bayesian analysis of mixed models can be used for penalized spline regression. Bayesian inference for nonparametric models enjoys the flexibility of nonparametric models and the exact inference provided by the Bayesian inferential machinery. This paper provides a simple, yet comprehensive, set of programs for the implementation of nonparametric Bayesian analysis in WinBUGS. Good mixing properties of the MCMC chains are obtained by using low-rank thin-plate splines, while simulation times per iteration are reduced employing WinBUGS specific computational tricks.

  8. Kinesiophobia, Pain, Muscle Functions, and Functional Performances among Older Persons with Low Back Pain

    Directory of Open Access Journals (Sweden)

    Nor Azizah Ishak

    2017-01-01

    Full Text Available Objectives. This study aims (1 to determine the association between kinesiophobia and pain, muscle functions, and functional performances and (2 to determine whether kinesiophobia predicts pain, muscle functions, and functional performance among older persons with low back pain (LBP. Methods. This is a correlational study, involving 63 institutionalized older persons (age = 70.98±7.90 years diagnosed with LBP. Anthropometric characteristics (BMI and functional performances (lower limb function, balance and mobility, and hand grip strength were measured. Muscle strength (abdominal and back muscle strength was assessed using the Baseline® Mechanical Push/Pull Dynamometer, while muscle control (transverse abdominus and multifidus was measured by using the Pressure Biofeedback Unit. The pain intensity and the level of kinesiophobia were measured using Numerical Rating Scale and Tampa Scale of Kinesiophobia, respectively. Data were analyzed using Pearson’s correlation coefficients and multivariate linear regressions. Results. No significant correlations were found between kinesiophobia and pain and muscle functions (all p>0.05. Kinesiophobia was significantly correlated with mobility and balance (p=0.038, r=0.263. Regressions analysis showed that kinesiophobia was a significant predictor of mobility and balance (p=0.038. Conclusion. We can conclude that kinesiophobia predicted mobility and balance in older persons with LBP. Kinesiophobia should be continuously assessed in clinical settings to recognize the obstacles that may affect patient’s compliance towards a rehabilitation program in older persons with LBP.

  9. The relationship between attitudes toward aging and health-promoting behaviours in older adults.

    Science.gov (United States)

    Korkmaz Aslan, Gülbahar; Kartal, Asiye; Özen Çınar, İlgün; Koştu, Nazan

    2017-12-01

    Identifying the factors that are associated with health-promoting behaviours in older adults is necessary to increase their willingness and motivation to participate in health-promotion activities. Understanding context-specific attitudes in relation to their influence on health-promoting behaviours is crucial in designing efficient interventions that foster health-promoting behaviours among older adults. This study aimed to examine the relationships between attitudes towards aging and health-promoting behaviours in older adults in Turkey. The study used a descriptive-correlational design. A convenience sample of 448 community-dwelling older adults who were 65 years and older and cognitively intact were selected from 6 family health centres in the city of Denizli in Turkey. The data were collected between March and June of 2014 using the Attitudes to Aging Questionnaire and the Health-Promoting Lifestyle Profile II. Multiple linear regression analysis was performed to explore the predictors of health-promoting behaviours. Attitudes toward aging, the psychosocial loss subscale, and education were statistically significant predictors of health-promoting behaviours. Attitudes toward aging were the strongest predictor of health-promoting behaviours in older adults. Attitude towards aging is a factor that affects health-promoting behaviours, and it should be considered during interventions for improving health promoting behaviours. © 2017 John Wiley & Sons Australia, Ltd.

  10. Forecasting municipal solid waste generation using prognostic tools and regression analysis.

    Science.gov (United States)

    Ghinea, Cristina; Drăgoi, Elena Niculina; Comăniţă, Elena-Diana; Gavrilescu, Marius; Câmpean, Teofil; Curteanu, Silvia; Gavrilescu, Maria

    2016-11-01

    For an adequate planning of waste management systems the accurate forecast of waste generation is an essential step, since various factors can affect waste trends. The application of predictive and prognosis models are useful tools, as reliable support for decision making processes. In this paper some indicators such as: number of residents, population age, urban life expectancy, total municipal solid waste were used as input variables in prognostic models in order to predict the amount of solid waste fractions. We applied Waste Prognostic Tool, regression analysis and time series analysis to forecast municipal solid waste generation and composition by considering the Iasi Romania case study. Regression equations were determined for six solid waste fractions (paper, plastic, metal, glass, biodegradable and other waste). Accuracy Measures were calculated and the results showed that S-curve trend model is the most suitable for municipal solid waste (MSW) prediction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Obesity, sarcopenia, sarcopenic obesity and reduced mobility in Brazilian older people aged 80 years and over.

    Science.gov (United States)

    Santos, Vanessa Ribeiro Dos; Gomes, Igor Conterato; Bueno, Denise Rodrigues; Christofaro, Diego Giulliano Destro; Freitas, Ismael Forte; Gobbo, Luis Alberto

    2017-01-01

    To analyze which abnormalities in body composition (obesity, sarcopenia or sarcopenic obesity) are related to reduced mobility in older people aged 80 years and older. The sample included 116 subjects aged 80 years and older. The body composition was measured using dual-energy X-ray absorptiometry (DXA) and mobility was assessed by motor tests. The χ2 test was used to analyze the proportion of older people with sarcopenia, obesity and sarcopenic obesity based on sex as well as to indicate an association between obesity, sarcopenia, sarcopenic obesity and mobility. Binary logistic regression, adjusted for the variables (sex and osteoarticular diseases), was used to express the magnitude of these associations. One-way analysis of variance was used to compare the mobility of four groups (Normal, Obesity, Sarcopenia and Sarcopenic Obesity). The Sarcopenia Group had lower performance in the lower limbs strength test and in sum of two tests compared with Obesity and Normal Groups. Older people with sarcopenia had higher chance of reduced mobility (OR: 3.44; 95%CI: 1.12-10.52). Older people aged 80 years and older with sarcopenia have more chance for reduction in mobility.

  12. Social network types among older Korean adults: Associations with subjective health.

    Science.gov (United States)

    Sohn, Sung Yun; Joo, Won-Tak; Kim, Woo Jung; Kim, Se Joo; Youm, Yoosik; Kim, Hyeon Chang; Park, Yeong-Ran; Lee, Eun

    2017-01-01

    With population aging now a global phenomenon, the health of older adults is becoming an increasingly important issue. Because the Korean population is aging at an unprecedented rate, preparing for public health problems associated with old age is particularly salient in this country. As the physical and mental health of older adults is related to their social relationships, investigating the social networks of older adults and their relationship to health status is important for establishing public health policies. The aims of this study were to identify social network types among older adults in South Korea and to examine the relationship of these social network types with self-rated health and depression. Data from the Korean Social Life, Health, and Aging Project were analyzed. Model-based clustering using finite normal mixture modeling was conducted to identify the social network types based on ten criterion variables of social relationships and activities: marital status, number of children, number of close relatives, number of friends, frequency of attendance at religious services, attendance at organized group meetings, in-degree centrality, out-degree centrality, closeness centrality, and betweenness centrality. Multivariate regression analysis was conducted to examine associations between the identified social network types and self-rated health and depression. The model-based clustering analysis revealed that social networks clustered into five types: diverse, family, congregant, congregant-restricted, and restricted. Diverse or family social network types were significantly associated with more favorable subjective mental health, whereas the restricted network type was significantly associated with poorer ratings of mental and physical health. In addition, our analysis identified unique social network types related to religious activities. In summary, we developed a comprehensive social network typology for older Korean adults. Copyright © 2016

  13. Social network types and functional dependency in older adults in Mexico

    Directory of Open Access Journals (Sweden)

    Espinosa-Alarcón Patricia

    2010-02-01

    Full Text Available Abstract Background Social networks play a key role in caring for older adults. A better understanding of the characteristics of different social networks types (TSNs in a given community provides useful information for designing policies to care for this age group. Therefore this study has three objectives: 1 To derive the TSNs among older adults affiliated with the Mexican Institute of Social Security; 2 To describe the main characteristics of the older adults in each TSN, including the instrumental and economic support they receive and their satisfaction with the network; 3 To determine the association between functional dependency and the type of social network. Methods Secondary data analysis of the 2006 Survey of Autonomy and Dependency (N = 3,348. The TSNs were identified using the structural approach and cluster analysis. The association between functional dependency and the TSNs was evaluated with Poisson regression with robust variance analysis in which socio-demographic characteristics, lifestyle and medical history covariates were included. Results We identified five TSNs: diverse with community participation (12.1%, diverse without community participation (44.3%; widowed (32.0%; nonfriends-restricted (7.6%; nonfamily-restricted (4.0%. Older adults belonging to widowed and restricted networks showed a higher proportion of dependency, negative self-rated health and depression. Older adults with functional dependency more likely belonged to a widowed network (adjusted prevalence ratio 1.5; 95%CI: 1.1-2.1. Conclusion The derived TSNs were similar to those described in developed countries. However, we identified the existence of a diverse network without community participation and a widowed network that have not been previously described. These TSNs and restricted networks represent a potential unmet need of social security affiliates.

  14. Age is no barrier: predictors of academic success in older learners

    Science.gov (United States)

    Imlach, Abbie-Rose; Ward, David D.; Stuart, Kimberley E.; Summers, Mathew J.; Valenzuela, Michael J.; King, Anna E.; Saunders, Nichole L.; Summers, Jeffrey; Srikanth, Velandai K.; Robinson, Andrew; Vickers, James C.

    2017-11-01

    Although predictors of academic success have been identified in young adults, such predictors are unlikely to translate directly to an older student population, where such information is scarce. The current study aimed to examine cognitive, psychosocial, lifetime, and genetic predictors of university-level academic performance in older adults (50-79 years old). Participants were mostly female (71%) and had a greater than high school education level (M = 14.06 years, SD = 2.76), on average. Two multiple linear regression analyses were conducted. The first examined all potential predictors of grade point average (GPA) in the subset of participants who had volunteered samples for genetic analysis (N = 181). Significant predictors of GPA were then re-examined in a second multiple linear regression using the full sample (N = 329). Our data show that the cognitive domains of episodic memory and language processing, in conjunction with midlife engagement in cognitively stimulating activities, have a role in predicting academic performance as measured by GPA in the first year of study. In contrast, it was determined that age, IQ, gender, working memory, psychosocial factors, and common brain gene polymorphisms linked to brain function, plasticity and degeneration (APOE, BDNF, COMT, KIBRA, SERT) did not influence academic performance. These findings demonstrate that ageing does not impede academic achievement, and that discrete cognitive skills as well as lifetime engagement in cognitively stimulating activities can promote academic success in older adults.

  15. Development of Compressive Failure Strength for Composite Laminate Using Regression Analysis Method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung Keon [Agency for Defense Development, Daejeon (Korea, Republic of); Lee, Jeong Won; Yoon, Dong Hyun; Kim, Jae Hoon [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-10-15

    This paper provides the compressive failure strength value of composite laminate developed by using regression analysis method. Composite material in this document is a Carbon/Epoxy unidirection(UD) tape prepreg(Cycom G40-800/5276-1) cured at 350°F(177°C). The operating temperature is –60°F~+200°F(-55°C - +95°C). A total of 56 compression tests were conducted on specimens from eight (8) distinct laminates that were laid up by standard angle layers (0°, +45°, –45° and 90°). The ASTM-D-6484 standard was used for test method. The regression analysis was performed with the response variable being the laminate ultimate fracture strength and the regressor variables being two ply orientations (0° and ±45°)

  16. Development of Compressive Failure Strength for Composite Laminate Using Regression Analysis Method

    International Nuclear Information System (INIS)

    Lee, Myoung Keon; Lee, Jeong Won; Yoon, Dong Hyun; Kim, Jae Hoon

    2016-01-01

    This paper provides the compressive failure strength value of composite laminate developed by using regression analysis method. Composite material in this document is a Carbon/Epoxy unidirection(UD) tape prepreg(Cycom G40-800/5276-1) cured at 350°F(177°C). The operating temperature is –60°F~+200°F(-55°C - +95°C). A total of 56 compression tests were conducted on specimens from eight (8) distinct laminates that were laid up by standard angle layers (0°, +45°, –45° and 90°). The ASTM-D-6484 standard was used for test method. The regression analysis was performed with the response variable being the laminate ultimate fracture strength and the regressor variables being two ply orientations (0° and ±45°)

  17. Standards for Standardized Logistic Regression Coefficients

    Science.gov (United States)

    Menard, Scott

    2011-01-01

    Standardized coefficients in logistic regression analysis have the same utility as standardized coefficients in linear regression analysis. Although there has been no consensus on the best way to construct standardized logistic regression coefficients, there is now sufficient evidence to suggest a single best approach to the construction of a…

  18. CADDIS Volume 4. Data Analysis: PECBO Appendix - R Scripts for Non-Parametric Regressions

    Science.gov (United States)

    Script for computing nonparametric regression analysis. Overview of using scripts to infer environmental conditions from biological observations, statistically estimating species-environment relationships, statistical scripts.

  19. Problems and fall risk determinants of quality of life in older adults with increased risk of falling.

    Science.gov (United States)

    Lin, Sang-I; Chang, Ku-Chou; Lee, Hsuei-Chen; Yang, Yi-Ching; Tsauo, Jau-Yih

    2015-05-01

    Determine quality of life and its association with fall risk factors in older adults with increased risk of falling. A total of 597 community-dwelling Taiwanese older adults who were screened to have increased risk of falling participated in the present study. The fall risk factors included sociodemographics, physical and psychological function, Timed Up and Go, past fall/medical histories, fear of falling and medications. The Euro QOL EQ-5D was used to measure health-related quality of life. Pain/discomfort was the EQ-5D dimension most frequently reported to be impaired (35%), regardless of the level of fall risk or age groups, followed by mobility (25%). Hierarchical regression analysis showed that Geriatric Depression Scale, Mini-Mental State Examination, physiological function, up-and-go, fear of falling and psychotropic medication were independent predictors for total EQ-5D, explaining 68.37% of the variance. Logistic regression analysis showed that for the five EQ-5D dimensions, Geriatric Depression Scale and Up and Go time were the most common determinants. Pain/discomfort was the leading impairment, and greater Geriatric Depression Scale and longer up-and-go time were the main contributing factors in declines in quality of life in older adults with increased risk of falling. These factors are often modifiable, and their management might be considered a priority in falls prevention. © 2014 Japan Geriatrics Society.

  20. Aneurysmal subarachnoid hemorrhage prognostic decision-making algorithm using classification and regression tree analysis.

    Science.gov (United States)

    Lo, Benjamin W Y; Fukuda, Hitoshi; Angle, Mark; Teitelbaum, Jeanne; Macdonald, R Loch; Farrokhyar, Forough; Thabane, Lehana; Levine, Mitchell A H

    2016-01-01

    Classification and regression tree analysis involves the creation of a decision tree by recursive partitioning of a dataset into more homogeneous subgroups. Thus far, there is scarce literature on using this technique to create clinical prediction tools for aneurysmal subarachnoid hemorrhage (SAH). The classification and regression tree analysis technique was applied to the multicenter Tirilazad database (3551 patients) in order to create the decision-making algorithm. In order to elucidate prognostic subgroups in aneurysmal SAH, neurologic, systemic, and demographic factors were taken into account. The dependent variable used for analysis was the dichotomized Glasgow Outcome Score at 3 months. Classification and regression tree analysis revealed seven prognostic subgroups. Neurological grade, occurrence of post-admission stroke, occurrence of post-admission fever, and age represented the explanatory nodes of this decision tree. Split sample validation revealed classification accuracy of 79% for the training dataset and 77% for the testing dataset. In addition, the occurrence of fever at 1-week post-aneurysmal SAH is associated with increased odds of post-admission stroke (odds ratio: 1.83, 95% confidence interval: 1.56-2.45, P tree was generated, which serves as a prediction tool to guide bedside prognostication and clinical treatment decision making. This prognostic decision-making algorithm also shed light on the complex interactions between a number of risk factors in determining outcome after aneurysmal SAH.

  1. Smoking and cognitive impairment among older persons in Malaysia.

    Science.gov (United States)

    Momtaz, Yadollah Abolfathi; Ibrahim, Rahimah; Hamid, Tengku Aizan; Chai, Sen Tyng

    2015-06-01

    Previous studies have shown conflicting results on the association between smoking and cognitive function. This study aims to examine the relationship of smoking with cognitive function. Data for the study, consisting of 2553 older adults aged 60 years and older, were drawn from a nationwide household survey entitled "Determinants of Wellness among Older Malaysians: A Health Promotion Perspective" conducted in 2010. Current smokers had lower rates of cognitive impairment compared to never smokers (17.4% vs 25.9%), while cognitive function in former or ex-smokers was almost similar to that of the never smokers. Findings from multiple logistic regression analysis showed that current smokers were 37% less likely to be cognitively impaired, compared to the never smokers (odds ratio [OR] = .63; 95% confidence interval [CI]: .46-.86) while controlling for potential confounders. No difference in cognitive function was observed between former smokers and never smokers (OR = .94; 95% CI: .71-1.25). Although the findings indicated a negative association between cigarette smoking and cognitive impairment, we are unable to conclude whether this relationship is causal or affected by other unmeasured confounding factors, especially survival bias. © The Author(s) 2014.

  2. Inferring gene expression dynamics via functional regression analysis

    Directory of Open Access Journals (Sweden)

    Leng Xiaoyan

    2008-01-01

    Full Text Available Abstract Background Temporal gene expression profiles characterize the time-dynamics of expression of specific genes and are increasingly collected in current gene expression experiments. In the analysis of experiments where gene expression is obtained over the life cycle, it is of interest to relate temporal patterns of gene expression associated with different developmental stages to each other to study patterns of long-term developmental gene regulation. We use tools from functional data analysis to study dynamic changes by relating temporal gene expression profiles of different developmental stages to each other. Results We demonstrate that functional regression methodology can pinpoint relationships that exist between temporary gene expression profiles for different life cycle phases and incorporates dimension reduction as needed for these high-dimensional data. By applying these tools, gene expression profiles for pupa and adult phases are found to be strongly related to the profiles of the same genes obtained during the embryo phase. Moreover, one can distinguish between gene groups that exhibit relationships with positive and others with negative associations between later life and embryonal expression profiles. Specifically, we find a positive relationship in expression for muscle development related genes, and a negative relationship for strictly maternal genes for Drosophila, using temporal gene expression profiles. Conclusion Our findings point to specific reactivation patterns of gene expression during the Drosophila life cycle which differ in characteristic ways between various gene groups. Functional regression emerges as a useful tool for relating gene expression patterns from different developmental stages, and avoids the problems with large numbers of parameters and multiple testing that affect alternative approaches.

  3. Survival analysis II: Cox regression

    NARCIS (Netherlands)

    Stel, Vianda S.; Dekker, Friedo W.; Tripepi, Giovanni; Zoccali, Carmine; Jager, Kitty J.

    2011-01-01

    In contrast to the Kaplan-Meier method, Cox proportional hazards regression can provide an effect estimate by quantifying the difference in survival between patient groups and can adjust for confounding effects of other variables. The purpose of this article is to explain the basic concepts of the

  4. Use of generalized ordered logistic regression for the analysis of multidrug resistance data.

    Science.gov (United States)

    Agga, Getahun E; Scott, H Morgan

    2015-10-01

    Statistical analysis of antimicrobial resistance data largely focuses on individual antimicrobial's binary outcome (susceptible or resistant). However, bacteria are becoming increasingly multidrug resistant (MDR). Statistical analysis of MDR data is mostly descriptive often with tabular or graphical presentations. Here we report the applicability of generalized ordinal logistic regression model for the analysis of MDR data. A total of 1,152 Escherichia coli, isolated from the feces of weaned pigs experimentally supplemented with chlortetracycline (CTC) and copper, were tested for susceptibilities against 15 antimicrobials and were binary classified into resistant or susceptible. The 15 antimicrobial agents tested were grouped into eight different antimicrobial classes. We defined MDR as the number of antimicrobial classes to which E. coli isolates were resistant ranging from 0 to 8. Proportionality of the odds assumption of the ordinal logistic regression model was violated only for the effect of treatment period (pre-treatment, during-treatment and post-treatment); but not for the effect of CTC or copper supplementation. Subsequently, a partially constrained generalized ordinal logistic model was built that allows for the effect of treatment period to vary while constraining the effects of treatment (CTC and copper supplementation) to be constant across the levels of MDR classes. Copper (Proportional Odds Ratio [Prop OR]=1.03; 95% CI=0.73-1.47) and CTC (Prop OR=1.1; 95% CI=0.78-1.56) supplementation were not significantly associated with the level of MDR adjusted for the effect of treatment period. MDR generally declined over the trial period. In conclusion, generalized ordered logistic regression can be used for the analysis of ordinal data such as MDR data when the proportionality assumptions for ordered logistic regression are violated. Published by Elsevier B.V.

  5. Association between statin use and physical function among community-dwelling older Japanese adults.

    Science.gov (United States)

    Kawai, Hisashi; Ihara, Kazushige; Kera, Takeshi; Hirano, Hirohiko; Fujiwara, Yoshinori; Tanaka, Masashi; Kojima, Motonaga; Obuchi, Shuichi

    2018-04-01

    Statin-associated muscle symptoms (SAMS) are the muscle-related side-effects of statins, but the association between statin use and physical function among community-dwelling older adults is unclear. The objective of the present study was to examine the association between statin use and physical function among community-dwelling older Japanese adults by considering the risk factors of statin-associated muscle symptoms. The participants were 1022 community-dwelling older adults aged 65-88 years, who participated in comprehensive health checkups from 2013 to 2015. Statin use in the participants (381 men and 559 women) was verified by using data from their medicine notebooks. The differences between statin use (users and non-users) and physical functions (grip strength, knee extension torque, normal and maximum gait speed, Timed Up & Go test, one-legged stance, quadriceps muscle thickness and echo intensity) were analyzed using the t-test. Multiple regression analyses were also carried out to examine the association between statin use and physical function. A total of 93 men (24.4%) and 154 women (27.5%) were statin users. Grip strength, normal gait speed and one-legged stance declined significantly in statin users compared with the non-users. In multiple regression analysis while controlling for the risk factors of statin-associated muscle symptoms, including age, sex, body mass index and number of medicines, no independent association, between statin use and the reduction of physical functions, was observed. Statin use was not associated with the decline of physical function in community-dwelling older Japanese adults. Geriatr Gerontol Int 2018; 18: 623-630. © 2017 Japan Geriatrics Society.

  6. Falls among older adults in the South of Brazil: prevalence and determinants.

    Science.gov (United States)

    Vieira, Luna S; Gomes, Ana Paula; Bierhals, Isabel O; Farías-Antúnez, Simone; Ribeiro, Camila G; Miranda, Vanessa I A; Lutz, Bárbara H; Barbosa-Silva, Thiago G; Lima, Natália P; Bertoldi, Andréa D; Tomasi, Elaine

    2018-01-01

    OBJECTIVE Evaluate the prevalence and the factors associated with the occurrence of falls among older adults. METHODS A cross-sectional study with a representative sample of 1,451 elderly residents in the urban area of Pelotas, RS, in 2014. A descriptive analysis of the data was performed and the prevalence of falls in the last year was presented. The analysis of demographic, socioeconomic, behavioral and health factors associated with the outcome was performed using Poisson regression with adjustment for robust variance according to the hierarchical model. The variables were adjusted to each other within each level and for the higher level. Those with p ≤ 0.20 were maintained in the model for confounding control and those with p falls among older adults in the last year was 28.1% (95%CI 25.9-30.5), and most occurred in the person's own residence. Among the older adults who fell, 51.5% (95%CI 46.6-56.4) had a single fall and 12.1% (95%CI 8.9-15.3) had a fracture as a consequence, usually in the lower limbs. The prevalence of falls was higher in women, adults of advanced age, with lower income and schooling level, with functional incapacity for instrumental activities, and patients with diseases such as diabetes, heart disease, and arthritis. CONCLUSIONS The occurrence of falls reached almost a third of the older adults, and the prevalence was higher in specific segments of the population in question. About 12% of the older adults who fell fractured some bone. The factors associated with the occurrence of falls identified in this study may guide measures aimed at prevention in the older adult population.

  7. Regression analysis of growth responses to water depth in three wetland plant species

    DEFF Research Database (Denmark)

    Sorrell, Brian K; Tanner, Chris C; Brix, Hans

    2012-01-01

    depths from 0 – 0.5 m. Morphological and growth responses to depth were followed for 54 days before harvest, and then analysed by repeated measures analysis of covariance, and non-linear and quantile regression analysis (QRA), to compare flooding tolerances. Principal results Growth responses to depth...

  8. A SOCIOLOGICAL ANALYSIS OF THE CHILDBEARING COEFFICIENT IN THE ALTAI REGION BASED ON METHOD OF FUZZY LINEAR REGRESSION

    Directory of Open Access Journals (Sweden)

    Sergei Vladimirovich Varaksin

    2017-06-01

    Full Text Available Purpose. Construction of a mathematical model of the dynamics of childbearing change in the Altai region in 2000–2016, analysis of the dynamics of changes in birth rates for multiple age categories of women of childbearing age. Methodology. A auxiliary analysis element is the construction of linear mathematical models of the dynamics of childbearing by using fuzzy linear regression method based on fuzzy numbers. Fuzzy linear regression is considered as an alternative to standard statistical linear regression for short time series and unknown distribution law. The parameters of fuzzy linear and standard statistical regressions for childbearing time series were defined with using the built in language MatLab algorithm. Method of fuzzy linear regression is not used in sociological researches yet. Results. There are made the conclusions about the socio-demographic changes in society, the high efficiency of the demographic policy of the leadership of the region and the country, and the applicability of the method of fuzzy linear regression for sociological analysis.

  9. Multiple Logistic Regression Analysis of Cigarette Use among High School Students

    Science.gov (United States)

    Adwere-Boamah, Joseph

    2011-01-01

    A binary logistic regression analysis was performed to predict high school students' cigarette smoking behavior from selected predictors from 2009 CDC Youth Risk Behavior Surveillance Survey. The specific target student behavior of interest was frequent cigarette use. Five predictor variables included in the model were: a) race, b) frequency of…

  10. Prospective associations of social isolation and loneliness with poor sleep quality in older adults.

    Science.gov (United States)

    Yu, Bin; Steptoe, Andrew; Niu, Kaijun; Ku, Po-Wen; Chen, Li-Jung

    2018-03-01

    There is evidence for negative associations between social isolation and loneliness and sleep quality in older adults. However, it is unclear to what extent these two factors independently affect sleep quality. This study examined the simultaneous associations of social isolation and loneliness with sleep quality in a longitudinal study of older adults. Data were analyzed from the Social Environment and Biomarkers of Aging Study in Taiwan collected in 2000 and 2006, involving a cohort of 639 participants (mean age = 66.14, SD 7.26). Poisson regression models were conducted to examine the association of social isolation and/or loneliness with sleep quality at follow-up after adjusting for multiple confounding variables. Univariate analysis showed that sleep quality was inversely associated with both social isolation and loneliness. After demographic, health, cognitive factors, and depressive symptoms were controlled in multivariable analysis, social isolation at the baseline still predicted poor sleep quality 6 years later (incident rate ratio, IRR 1.14; 95% CI 1.04-1.24; p social isolation on the sleep quality of older adults, but indicate that this effect is independent of loneliness. Social isolation and loneliness seem to have distinct pathways in affecting the sleep quality of older adults.

  11. Pathways into chronic multidimensional poverty amongst older people: a longitudinal study.

    Science.gov (United States)

    Callander, Emily J; Schofield, Deborah J

    2016-03-07

    The use of multidimensional poverty measures is becoming more common for measuring the living standards of older people. However, the pathways into poverty are relatively unknown, nor is it known how this affects the length of time people are in poverty for. Using Waves 1 to 12 of the nationally representative Household, Income and Labour Dynamics in Australia (HILDA) survey, longitudinal analysis was undertaken to identify the order that key forms of disadvantage develop - poor health, low income and insufficient education attainment - amongst Australians aged 65 years and over in multidimensional poverty, and the relationship this has with chronic poverty. Path analysis and linear regression models were used. For all older people with at least a Year 10 level of education attainment earlier mental health was significantly related to later household income (p = 0.001) and wealth (p = 0.017). For all older people with at less than a Year 10 level of education attainment earlier household income was significantly related to later mental health (p = 0.021). When limited to those in multidimensional poverty who were in income poverty and also had poor health, older people generally fell into income poverty first and then developed poor health. The order in which income poverty and poor health were developed had a significant influence on the length of time older people with less than a Year 10 level of education attainment were in multidimensional poverty for. Those who developed poor health first then fell into income poverty spend significantly less time in multidimensional poverty (-4.90, p poverty then developed poor health. Knowing the order that different forms of disadvantage develop, and the influence this has on poverty entrenchment, is of use to policy makers wishing to provide interventions to prevent older people being in long-term multidimensional poverty.

  12. Multivariate analysis of lifestyle, constitutive and body composition factors influencing bone health in community-dwelling older adults from Madeira, Portugal.

    Science.gov (United States)

    Gouveia, Élvio Rúbio; Blimkie, Cameron Joseph; Maia, José António; Lopes, Carla; Gouveia, Bruna Raquel; Freitas, Duarte Luís

    2014-01-01

    This study describes the association between habitual physical activity (PA), other lifestyle/constitutive factors, body composition, and bone health/strength in a large sample of older adults from Madeira, Portugal. This cross-sectional study included 401 males and 401 females aged 60-79 years old. Femoral strength index (FSI) and bone mineral density (BMD) of the whole body, lumbar spine (LS), femoral neck (FN), and total lean tissue mass (TLTM) and total fat mass (TFM) were determined by dual-energy X-ray absorptiometry-DXA. PA was assessed during face-to-face interviews using the Baecke questionnaire and for a sub-sample by Tritrac accelerometer. Demographic and health history information were obtained by telephone interview through questionnaire. The relationship between habitual PA variables and bone health/strength indicators (whole body BMD, FNBMD, LSBMD, and FSI) investigated using Pearson product-moment correlation coefficient was similar for females (0.098≤r≤0.189) and males (0.104≤r≤0.105). Results from standard multiple regression analysis indicated that the primary and most significant predictors for FNBMD in both sexes were age, TLTM, and TFM. For LSBMD, the most significant predictor was TFM in men and TFM, age, and TLTM in females. Our regression model explained 8.3-14.2% and 14.8-29.6% of the total variance in LSBMD and FNBMD for males and females, respectively. This study suggests that habitual PA is minimally but positively associated with BMD and FSI among older adult males and females and that body composition factors like TLTM and TFM are the strongest determinants of BMD and FSI in this population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. THE PROGNOSIS OF RUSSIAN DEFENSE INDUSTRY DEVELOPMENT IMPLEMENTED THROUGH REGRESSION ANALYSIS

    Directory of Open Access Journals (Sweden)

    L.M. Kapustina

    2007-03-01

    Full Text Available The article illustrates the results of investigation the major internal and external factors which influence the development of the defense industry, as well as the results of regression analysis which quantitatively displays the factorial contribution in the growth rate of Russian defense industry. On the basis of calculated regression dependences the authors fulfilled the medium-term prognosis of defense industry. Optimistic and inertial versions of defense product growth rate for the period up to 2009 are based on scenario conditions in Russian economy worked out by the Ministry of economy and development. In conclusion authors point out which factors and conditions have the largest impact on successful and stable operation of Russian defense industry.

  14. A concept analysis of oral hygiene care in dependent older adults.

    Science.gov (United States)

    Coker, Esther; Ploeg, Jenny; Kaasalainen, Sharon; Fisher, Anita

    2013-10-01

    To report a concept analysis of oral hygiene care. Oral hygiene care, as it is provided to older patients in hospital and long-term care settings by nurses and their delegates, has the potential to contribute to the oral health of patients while preventing aspiration pneumonia as well as periodontitis, which itself has been associated with several systemic diseases. However, the state of oral cleanliness in such patients tends to be poor and despite the existence of guidelines, nursing care practices may be inadequate and not reflective of recent advances in knowledge. Concept analysis. A search of electronic databases (2002-2012), use of internet search engines, and hand searching yielded an international data set of 66 research studies, reviews, and practice guidelines. The concept analysis method of Walker and Avant was used to explore the concept of oral hygiene care in the context of frail older patients. Oral hygiene care involves approaches informed by knowing the patient, inspecting the oral cavity, removing plaque, cleansing the oral tissues, decontaminating the oral cavity, using fluoride products and maintaining oral tissue moisture. Those attributes, along with their antecedents and consequences, form a conceptual framework from which a middle-range theory of nurse-administered oral hygiene care is derived that could be tested, evaluated, modified, and translated into practice. Clarity around the concept of oral hygiene care as a nursing intervention could enable nurses to impact oral health outcomes and possibly prevent systemic diseases in older patients. © 2013 Blackwell Publishing Ltd.

  15. Applied linear regression

    CERN Document Server

    Weisberg, Sanford

    2013-01-01

    Praise for the Third Edition ""...this is an excellent book which could easily be used as a course text...""-International Statistical Institute The Fourth Edition of Applied Linear Regression provides a thorough update of the basic theory and methodology of linear regression modeling. Demonstrating the practical applications of linear regression analysis techniques, the Fourth Edition uses interesting, real-world exercises and examples. Stressing central concepts such as model building, understanding parameters, assessing fit and reliability, and drawing conclusions, the new edition illus

  16. Relationships between serum Omentin-1 levels and bone mineral density in older men with osteoporosis

    Institute of Scientific and Technical Information of China (English)

    Li Yang; Xin-Lan Zhao; Bin Liao; Ai-Ping Qin

    2016-01-01

    Objective: To investigate the correlation between serum Omentin-1 levels and the presence of osteoporosis in older men. Methods: Serum Omentin-1, bone turnover biochemical markers, and bone mineral density (BMD) were determined in 45 older men with osteoporosis or 45 older men without osteoporosis (65e70 years old). Results: Omentin-1 levels were increased in older men with osteoporosis, and the differences remained significant after con-trolling for fat mass. Omentin-1 was negatively correlated with BMD. In a multiple linear stepwise regression analysis, Omentin-1, lean mass, but not fat mass, were independent predictors of BMD for the combined group. Significant negative correlations between Omentin-1 and bone-specific alkaline phosphatase (BAP) and bone cross-linked N-telopeptides of typeⅠcollagen (NTX) were found. Omentin-1 was also independently associated with BMD and bone turnover markers in older men with osteoporosis and control groups that were considered separately. Conclusions: Omentin-1 is an independent predictor of BMD in older men with osteoporosis, and it is negatively correlated with bone turnover biochemical markers. It is suggested that Omentin-1 may exert a negative effect on bone mass through the regulation of the osteoblast differentiation in the older men with osteoporosis.

  17. Multitasking in older adults with type 2 diabetes: A cross-sectional analysis.

    Science.gov (United States)

    Rucker, Jason L; McDowd, Joan M; Mahnken, Jonathan D; Burns, Jeffrey M; Sabus, Carla H; Britton-Carpenter, Amanda J; Utech, Nora B; Kluding, Patricia M

    2017-01-01

    Deficits in the ability to multitask contribute to gait abnormalities and falls in many at-risk populations. However, it is unclear whether older adults with type 2 diabetes mellitus (DM) also demonstrate impairments in multitasking. The purpose of this study was to compare multitasking performance in cognitively intact older adults with and without DM and explore its relationship to measures of gait and functional ability. We performed a cross-sectional analysis of 40 individuals aged 60 and older with type 2 DM and a matched group of 40 cognitively intact older adults without DM. Multitasking was examined via the ambulatory Walking and Remembering Test (WART) and seated Pursuit Rotor Test (PRT). Self-selected normal and fast walking speed and stride length variability were quantitatively measured, and self-reported functional ability was assessed via the Late Life Function and Disability Index (LLFDI). Participants with DM walked slower and took more steps off path when multitasking during the WART. No between-group differences in multitasking performance were observed on the PRT. Multitasking performance demonstrated little correlation with gait and functional ability in either group. Older adults with DM appear to perform poorly on an ambulatory measure of multitasking. However, we analyzed a relatively small, homogenous sample of older adults with and without type 2 DM and factors such as peripheral neuropathy and the use of multiple comparisons complicate interpretation of the data. Future research should explore the interactions between multitasking and safety, fall risk, and function in this vulnerable population. Clinicians should recognize that an array of factors may contribute to gait and physical dysfunction in older adults with type 2 diabetes, and be prepared to assess and intervene appropriately.

  18. Noninvasive spectral imaging of skin chromophores based on multiple regression analysis aided by Monte Carlo simulation

    Science.gov (United States)

    Nishidate, Izumi; Wiswadarma, Aditya; Hase, Yota; Tanaka, Noriyuki; Maeda, Takaaki; Niizeki, Kyuichi; Aizu, Yoshihisa

    2011-08-01

    In order to visualize melanin and blood concentrations and oxygen saturation in human skin tissue, a simple imaging technique based on multispectral diffuse reflectance images acquired at six wavelengths (500, 520, 540, 560, 580 and 600nm) was developed. The technique utilizes multiple regression analysis aided by Monte Carlo simulation for diffuse reflectance spectra. Using the absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin, and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are deduced numerically in advance, while oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments with human skin of the human hand during upper limb occlusion and of the inner forearm exposed to UV irradiation demonstrated the ability of the method to evaluate physiological reactions of human skin tissue.

  19. Retrospective lifetime dietary patterns predict cognitive performance in community-dwelling older Australians.

    Science.gov (United States)

    Hosking, Diane E; Nettelbeck, Ted; Wilson, Carlene; Danthiir, Vanessa

    2014-07-28

    Dietary intake is a modifiable exposure that may have an impact on cognitive outcomes in older age. The long-term aetiology of cognitive decline and dementia, however, suggests that the relevance of dietary intake extends across the lifetime. In the present study, we tested whether retrospective dietary patterns from the life periods of childhood, early adulthood, adulthood and middle age predicted cognitive performance in a cognitively healthy sample of 352 older Australian adults >65 years. Participants completed the Lifetime Diet Questionnaire and a battery of cognitive tests designed to comprehensively assess multiple cognitive domains. In separate regression models, lifetime dietary patterns were the predictors of cognitive factor scores representing ten constructs derived by confirmatory factor analysis of the cognitive test battery. All regression models were progressively adjusted for the potential confounders of current diet, age, sex, years of education, English as native language, smoking history, income level, apoE ɛ4 status, physical activity, other past dietary patterns and health-related variables. In the adjusted models, lifetime dietary patterns predicted cognitive performance in this sample of older adults. In models additionally adjusted for intake from the other life periods and mechanistic health-related variables, dietary patterns from the childhood period alone reached significance. Higher consumption of the 'coffee and high-sugar, high-fat extras' pattern predicted poorer performance on simple/choice reaction time, working memory, retrieval fluency, short-term memory and reasoning. The 'vegetable and non-processed' pattern negatively predicted simple/choice reaction time, and the 'traditional Australian' pattern positively predicted perceptual speed and retrieval fluency. Identifying early-life dietary antecedents of older-age cognitive performance contributes to formulating strategies for delaying or preventing cognitive decline.

  20. Multiple Regression Analysis of Unconfined Compression Strength of Mine Tailings Matrices

    Directory of Open Access Journals (Sweden)

    Mahmood Ali A.

    2017-01-01

    Full Text Available As part of a novel approach of sustainable development of mine tailings, experimental and numerical analysis is carried out on newly formulated tailings matrices. Several physical characteristic tests are carried out including the unconfined compression strength test to ascertain the integrity of these matrices when subjected to loading. The current paper attempts a multiple regression analysis of the unconfined compressive strength test results of these matrices to investigate the most pertinent factors affecting their strength. Results of this analysis showed that the suggested equation is reasonably applicable to the range of binder combinations used.

  1. Urothelial cancer of bladder in young versus older adults: clinical and pathological characteristics and outcomes.

    Science.gov (United States)

    Telli, Onur; Sarici, Hasmet; Ozgur, Berat Cem; Doluoglu, Omer Gokhan; Sunay, Mehmet Melih; Bozkurt, Selen; Eroglu, Muzaffer

    2014-09-01

    Bladder urothelial carcinoma is rare in young adults and occurs more commonly in older individuals. The aim of this study was to compare the clinical behavior, pathologic characteristics, and prognosis of urothelial carcinoma of urinary bladder in young versus older adults. A retrospective review of our records between 2007 and 2013 identified 56 patients (42 males and 14 females) with transitional cell carcinoma of the bladder who were less than 40 years old. Clinical and pathological parameters of patients who were less than 40 years of age were compared with those of a series of patients older than 40 years of age (the control group) during the same period. A survival analysis was performed using the Kaplan-Meier method and log-rank test, and Cox regression was performed to identify clinical parameters that affected the clinical outcomes. The mean age was 29.21 years (range, 5-40 years) for patients less than 40 years old and 61.66 years (range, 41-75) for those older than 40 years. The mean follow-up was 40.26 months (range, 12-65 months) for young patients and 42.57 months (range, 12-72 months) for the older patients. Young bladder cancer patients had smaller-sized tumors (less than 3 cm), less high-grade cancers, higher papillary urothelial neoplasms of low malignant potential, and low-grade tumors than patients older than 40 years. Multivariate logistic regression analysis predicted tumor recurrence in young patients with high-grade tumors [odds ratio (OR), 1.959; 95% confidence interval (CI), 1.235-2.965; p = 0.046] and tumors larger than 3 cm (OR, 1.772; 95% CI, 1.416-1.942; p = 0.032). The 5-year overall survival rate was 100% for young patients and 88.1% for older patients. No difference was observed in the recurrence-free (p = 0.321) and progression-free (p = 0.422) survival rates between the two groups. We concluded that although the clinical stage distribution, natural history, and outcomes of bladder urothelial cancer in young adults are

  2. Genome-wide Meta-analysis on the Sense of Smell Among US Older Adults

    OpenAIRE

    Dong, Jing; Yang, Jingyun; Tranah, Greg; Franceschini, Nora; Parimi, Neeta; Alkorta-Aranburu, Gorka; Xu, Zongli; Alonso, Alvaro; Cummings, Steven R.; Fornage, Myriam; Huang, Xuemei; Kritchevsky, Stephen; Liu, Yongmei; London, Stephanie; Niu, Liang

    2015-01-01

    Abstract Olfactory dysfunction is common among older adults and affects their safety, nutrition, quality of life, and mortality. More importantly, the decreased sense of smell is an early symptom of neurodegenerative diseases such as Parkinson disease (PD) and Alzheimer disease. However, the genetic determinants for the sense of smell have been poorly investigated. We here performed the first genome-wide meta-analysis on the sense of smell among 6252 US older adults of European descent from t...

  3. The Regression Analysis of Individual Financial Performance: Evidence from Croatia

    OpenAIRE

    Bahovec, Vlasta; Barbić, Dajana; Palić, Irena

    2017-01-01

    Background: A large body of empirical literature indicates that gender and financial literacy are significant determinants of individual financial performance. Objectives: The purpose of this paper is to recognize the impact of the variable financial literacy and the variable gender on the variation of the financial performance using the regression analysis. Methods/Approach: The survey was conducted using the systematically chosen random sample of Croatian financial consumers. The cross sect...

  4. Ageing well? A cross-country analysis of the way older people are visually represented on websites of organizations for older people

    Directory of Open Access Journals (Sweden)

    Eugène Loos

    2017-12-01

    Full Text Available The ‘aging well’ discourse advances the idea of making older people responsible for their capability to stay healthy and active. In the context of an increased ageing population, which poses several challenges to countries’ government, this discourse has become dominant in Europe. We explore the way older people are visually represented on websites of organizations for older people in seven European countries (Finland, UK, the Netherlands, Spain, Italy, Poland and Romania, using an analytical approached based on visual content analysis, inspired by the dimensional model of national cultural differences from the Hofstede model (1991; 2001; 2011. We used two out of the five Hofstede dimensions: Individualism/Collectivism (IDV and Masculinity/Femininity (MAS. The results demonstrated that in all seven countries older people are mostly visually represented as healthy/active, which reflects a dominant ‘ageing well’ discourse in Europe. The results also demonstrated that in most cases older people tend to be represented together with others, which is not consonant with the dominant ‘ageing well’ discourse in Europe. A last finding was that the visual representation of older people is in about half of the cases in line with these Hofstede dimensions. We discuss the implications of these findings claiming that the ‘ageing well’ discourse might lead to ‘visual ageism’. Organizations could keep this in mind while using pictures for their website or in other media and consider to use various kind of pictures, or to avoid using pictures of older people that stigmatize, marginalize or injure. They could look into the cultural situatedness and intersectional character of age relations and consider alternative strategies of both visibility and invisibility to talk with and about our ageing societies.

  5. Diversity in Older Adults’ Use of the Internet: Identifying Subgroups Through Latent Class Analysis

    Science.gov (United States)

    van Boekel, Leonieke C; Peek, Sebastiaan TM; Luijkx, Katrien G

    2017-01-01

    Background As for all individuals, the Internet is important in the everyday life of older adults. Research on older adults’ use of the Internet has merely focused on users versus nonusers and consequences of Internet use and nonuse. Older adults are a heterogeneous group, which may implicate that their use of the Internet is diverse as well. Older adults can use the Internet for different activities, and this usage can be of influence on benefits the Internet can have for them. Objective The aim of this paper was to describe the diversity or heterogeneity in the activities for which older adults use the Internet and determine whether diversity is related to social or health-related variables. Methods We used data of a national representative Internet panel in the Netherlands. Panel members aged 65 years and older and who have access to and use the Internet were selected (N=1418). We conducted a latent class analysis based on the Internet activities that panel members reported to spend time on. Second, we described the identified clusters with descriptive statistics and compared the clusters using analysis of variance (ANOVA) and chi-square tests. Results Four clusters were distinguished. Cluster 1 was labeled as the “practical users” (36.88%, n=523). These respondents mainly used the Internet for practical and financial purposes such as searching for information, comparing products, and banking. Respondents in Cluster 2, the “minimizers” (32.23%, n=457), reported lowest frequency on most Internet activities, are older (mean age 73 years), and spent the smallest time on the Internet. Cluster 3 was labeled as the “maximizers” (17.77%, n=252); these respondents used the Internet for various activities, spent most time on the Internet, and were relatively younger (mean age below 70 years). Respondents in Cluster 4, the “social users,” mainly used the Internet for social and leisure-related activities such as gaming and social network sites. The

  6. A systematic review and meta-regression analysis of mivacurium for tracheal intubation

    NARCIS (Netherlands)

    Vanlinthout, L.E.H.; Mesfin, S.H.; Hens, N.; Vanacker, B.F.; Robertson, E.N.; Booij, L.H.D.J.

    2014-01-01

    We systematically reviewed factors associated with intubation conditions in randomised controlled trials of mivacurium, using random-effects meta-regression analysis. We included 29 studies of 1050 healthy participants. Four factors explained 72.9% of the variation in the probability of excellent

  7. Social Capital and Suicidal Ideation in Community-Dwelling Older Residents: A Multilevel Analysis of 10,094 Subjects in Japan.

    Science.gov (United States)

    Noguchi, Masayuki; Kobayashi, Tomoko; Iwase, Toshihide; Suzuki, Etsuji; Kawachi, Ichiro; Takao, Soshi

    2017-01-01

    Social capital, the collective resources of groups including perceptions of trust and reciprocity, is recognized as an important contributor to suicide. We examined the association of individual- and community-level social capital with suicidal ideation after adjusting for social support among older adults living in the community. In August 2010 we sent questionnaires to all residents aged 65 years and older living in 3 rural municipalities (N = 21,232) in Okayama Prefecture, Japan; 13,919 questionnaires were returned (response rate: 65.6%). The final analysis included 10,094 participants. The outcome variable was suicidal ideation. Exposure variables were individual-level mistrust and lack of reciprocity (level 1), and the aggregated responses of these variables from 35 communities in the municipalities (level 2). Covariates included age, sex, educational attainment, marital status, the number of cohabitants, years of residence, self-rated socioeconomic status, disability, social support, and psychological distress. Multilevel logistic regression analysis was performed to obtain odds ratios (ORs) and 95% confidence intervals (CIs). After adjusting for social support and psychological distress, we found that mistrust and lack of reciprocity were only associated with suicidal ideation at the individual level. Stratified analysis showed that among subjects with psychological distress, mistrust was associated with suicidal ideation at individual (OR: 1.88; 95% CI: 1.42-2.51) and community levels (OR: 1.98; 95% CI: 1.02-3.81). Our findings show that individual- and community-level social capital is a possible protective factor for suicidal ideation, particularly for people with psychological distress. Copyright © 2017 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. No rationale for 1 variable per 10 events criterion for binary logistic regression analysis.

    Science.gov (United States)

    van Smeden, Maarten; de Groot, Joris A H; Moons, Karel G M; Collins, Gary S; Altman, Douglas G; Eijkemans, Marinus J C; Reitsma, Johannes B

    2016-11-24

    Ten events per variable (EPV) is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies. The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth's correction, are compared. The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect ('separation'). We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth's correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation. The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.

  9. Estimate the contribution of incubation parameters influence egg hatchability using multiple linear regression analysis.

    Science.gov (United States)

    Khalil, Mohamed H; Shebl, Mostafa K; Kosba, Mohamed A; El-Sabrout, Karim; Zaki, Nesma

    2016-08-01

    This research was conducted to determine the most affecting parameters on hatchability of indigenous and improved local chickens' eggs. Five parameters were studied (fertility, early and late embryonic mortalities, shape index, egg weight, and egg weight loss) on four strains, namely Fayoumi, Alexandria, Matrouh, and Montazah. Multiple linear regression was performed on the studied parameters to determine the most influencing one on hatchability. The results showed significant differences in commercial and scientific hatchability among strains. Alexandria strain has the highest significant commercial hatchability (80.70%). Regarding the studied strains, highly significant differences in hatching chick weight among strains were observed. Using multiple linear regression analysis, fertility made the greatest percent contribution (71.31%) to hatchability, and the lowest percent contributions were made by shape index and egg weight loss. A prediction of hatchability using multiple regression analysis could be a good tool to improve hatchability percentage in chickens.

  10. Logistic Regression: Concept and Application

    Science.gov (United States)

    Cokluk, Omay

    2010-01-01

    The main focus of logistic regression analysis is classification of individuals in different groups. The aim of the present study is to explain basic concepts and processes of binary logistic regression analysis intended to determine the combination of independent variables which best explain the membership in certain groups called dichotomous…

  11. The contribution of postural balance analysis in older adult fallers: A narrative review.

    Science.gov (United States)

    Pizzigalli, L; Micheletti Cremasco, M; Mulasso, A; Rainoldi, A

    2016-04-01

    Falls are a serious health problem for older adults. Several studies have identified the decline of postural balance as one of the main risk factors for falls. Contrary to what may be believed, the capability of force platform measurements to predict falls remains uncertain. The focus of this narrative review is the identification of postural characteristics of older adults at risk of falling using both static and dynamic postural balance assessments. The literature analysis was conducted on Medline/PubMed. The search ended in May 2015. Centre of pressure (CoP) path length, CoP velocity and sway in medial lateral and anterior-posterior are the variables that distinguish older adult fallers from non-fallers. Recommendations to medical personnel on how to provide efficient balance training for older adults are offered, discussing the relevance and limitations of postural stability on static and dynamic board in falling risk prevention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. A Classification Regression Tree Analysis to Reduce Balance Impairments and Falls in the Older population: Impact on Resource Utilization and Clinical Decision-Making in USA Rehabilitation Service Delivery

    Directory of Open Access Journals (Sweden)

    Lucinda Pfalzer

    2013-06-01

    Full Text Available Background/Purpose: Over 1/3 of adults over age 65 experiences at least one fall each year. This pilot report uses a classification regression tree analysis (CART to model the outcomes for balance/risk of falls from the Gentiva® Safe Strides® Program (SSP. Methods/Outcomes: SSP is a home-based balance/fall prevention program designed to treat root causes of a patient

  13. Falls, a fear of falling and related factors in older adults with complex chronic disease.

    Science.gov (United States)

    Lee, JuHee; Choi, MoonKi; Kim, Chang Oh

    2017-12-01

    To identify factors influencing falls and the fear of falling among older adults with chronic diseases in Korea. The fear of falling and falls in older adults are significant health problems towards which healthcare providers should direct their attention. Further investigation is needed to improve nursing practice specifically decreasing risk of falls and the fear of falling in Korea. Descriptive, cross-sectional survey. A convenience sample of 108 patients was recruited at the geriatric outpatient department of a tertiary hospital in Seoul, Korea. Demographic characteristics, comorbidities, medication use, fall history, level of physical activity, activities of daily living, mobility, muscle strength, and a fear of falling were investigated. Student's t tests, chi-square tests and multiple linear regressions were used in statistical analysis. Thirty-six participants (33.3%) among 108 subjects reported experiencing ≥1 falls in the past year. Marital status and the use of antipsychotics were associated with falls, while other factors were not significantly related to falls. Only benign prostatic hypertrophy and polypharmacy were significantly related to the fear of falling in the analysis of the relationships between chronic disease, medication use and fear of falling. In the regression model, the number of comorbidities, level of physical activity, activities of daily living and mobility were predictors of a fear of falling. Medication use was marginally significant, in the model. Increasing physical activity, functional fitness and physical independence is important to decrease the fear of falling, and to encourage active and healthy lives in older adults. The findings from this study provide evidence for the development of nursing interventions for older adults. We recommend early screening for a fear of falling and nursing interventions to decrease the fear of falling through enhancing physical activity level and function. © 2017 John Wiley & Sons Ltd.

  14. Identifying Domain-General and Domain-Specific Predictors of Low Mathematics Performance: A Classification and Regression Tree Analysis

    Directory of Open Access Journals (Sweden)

    David J. Purpura

    2017-12-01

    Full Text Available Many children struggle to successfully acquire early mathematics skills. Theoretical and empirical evidence has pointed to deficits in domain-specific skills (e.g., non-symbolic mathematics skills or domain-general skills (e.g., executive functioning and language as underlying low mathematical performance. In the current study, we assessed a sample of 113 three- to five-year old preschool children on a battery of domain-specific and domain-general factors in the fall and spring of their preschool year to identify Time 1 (fall factors associated with low performance in mathematics knowledge at Time 2 (spring. We used the exploratory approach of classification and regression tree analyses, a strategy that uses step-wise partitioning to create subgroups from a larger sample using multiple predictors, to identify the factors that were the strongest classifiers of low performance for younger and older preschool children. Results indicated that the most consistent classifier of low mathematics performance at Time 2 was children’s Time 1 mathematical language skills. Further, other distinct classifiers of low performance emerged for younger and older children. These findings suggest that risk classification for low mathematics performance may differ depending on children’s age.

  15. A multiple regression analysis for accurate background subtraction in 99Tcm-DTPA renography

    International Nuclear Information System (INIS)

    Middleton, G.W.; Thomson, W.H.; Davies, I.H.; Morgan, A.

    1989-01-01

    A technique for accurate background subtraction in 99 Tc m -DTPA renography is described. The technique is based on a multiple regression analysis of the renal curves and separate heart and soft tissue curves which together represent background activity. It is compared, in over 100 renograms, with a previously described linear regression technique. Results show that the method provides accurate background subtraction, even in very poorly functioning kidneys, thus enabling relative renal filtration and excretion to be accurately estimated. (author)

  16. Development of an empirical model of turbine efficiency using the Taylor expansion and regression analysis

    International Nuclear Information System (INIS)

    Fang, Xiande; Xu, Yu

    2011-01-01

    The empirical model of turbine efficiency is necessary for the control- and/or diagnosis-oriented simulation and useful for the simulation and analysis of dynamic performances of the turbine equipment and systems, such as air cycle refrigeration systems, power plants, turbine engines, and turbochargers. Existing empirical models of turbine efficiency are insufficient because there is no suitable form available for air cycle refrigeration turbines. This work performs a critical review of empirical models (called mean value models in some literature) of turbine efficiency and develops an empirical model in the desired form for air cycle refrigeration, the dominant cooling approach in aircraft environmental control systems. The Taylor series and regression analysis are used to build the model, with the Taylor series being used to expand functions with the polytropic exponent and the regression analysis to finalize the model. The measured data of a turbocharger turbine and two air cycle refrigeration turbines are used for the regression analysis. The proposed model is compact and able to present the turbine efficiency map. Its predictions agree with the measured data very well, with the corrected coefficient of determination R c 2 ≥ 0.96 and the mean absolute percentage deviation = 1.19% for the three turbines. -- Highlights: → Performed a critical review of empirical models of turbine efficiency. → Developed an empirical model in the desired form for air cycle refrigeration, using the Taylor expansion and regression analysis. → Verified the method for developing the empirical model. → Verified the model.

  17. Social Isolation, Depression, and Psychological Distress Among Older Adults.

    Science.gov (United States)

    Taylor, Harry Owen; Taylor, Robert Joseph; Nguyen, Ann W; Chatters, Linda

    2018-02-01

    To investigate the impact of objective and subjective social isolation from extended family members and friends on depressive symptoms and psychological distress among a national sample of older adults. Data for older adults (55 years and above) from the National Survey of American Life ( N = 1,439) were used to assess level of objective social isolation and subjective social isolation and to test regression models examining their impact on depressive symptoms (Center for Epidemiologic Studies Depression [CES-D] Scale) and psychological distress (Kessler 6 [K6] Scale). The majority of respondents were not socially isolated from family or friends; 5% were objectively isolated from family and friends, and less than 1% were subjectively isolated from family and friends. Regression analyses using both social isolation measures indicated that objective social isolation was unrelated to depressive symptoms and psychological distress. However, subjective social isolation from both family and friends and from friends only was associated with more depressive symptoms, and subjective social isolation from friends only was associated with higher levels of psychological distress. Assessments of social isolation among older populations should account for both subjective and objective dimensions, as well as both family and friend social networks. Social isolation from friends is an important, but understudied, issue that has significant consequences for older adult mental health.

  18. Econometric analysis of realized covariation: high frequency based covariance, regression, and correlation in financial economics

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2004-01-01

    This paper analyses multivariate high frequency financial data using realized covariation. We provide a new asymptotic distribution theory for standard methods such as regression, correlation analysis, and covariance. It will be based on a fixed interval of time (e.g., a day or week), allowing...... the number of high frequency returns during this period to go to infinity. Our analysis allows us to study how high frequency correlations, regressions, and covariances change through time. In particular we provide confidence intervals for each of these quantities....

  19. Multitasking in older adults with type 2 diabetes: A cross-sectional analysis.

    Directory of Open Access Journals (Sweden)

    Jason L Rucker

    Full Text Available Deficits in the ability to multitask contribute to gait abnormalities and falls in many at-risk populations. However, it is unclear whether older adults with type 2 diabetes mellitus (DM also demonstrate impairments in multitasking. The purpose of this study was to compare multitasking performance in cognitively intact older adults with and without DM and explore its relationship to measures of gait and functional ability.We performed a cross-sectional analysis of 40 individuals aged 60 and older with type 2 DM and a matched group of 40 cognitively intact older adults without DM. Multitasking was examined via the ambulatory Walking and Remembering Test (WART and seated Pursuit Rotor Test (PRT. Self-selected normal and fast walking speed and stride length variability were quantitatively measured, and self-reported functional ability was assessed via the Late Life Function and Disability Index (LLFDI.Participants with DM walked slower and took more steps off path when multitasking during the WART. No between-group differences in multitasking performance were observed on the PRT. Multitasking performance demonstrated little correlation with gait and functional ability in either group.Older adults with DM appear to perform poorly on an ambulatory measure of multitasking. However, we analyzed a relatively small, homogenous sample of older adults with and without type 2 DM and factors such as peripheral neuropathy and the use of multiple comparisons complicate interpretation of the data. Future research should explore the interactions between multitasking and safety, fall risk, and function in this vulnerable population. Clinicians should recognize that an array of factors may contribute to gait and physical dysfunction in older adults with type 2 diabetes, and be prepared to assess and intervene appropriately.

  20. Health care: necessity or luxury good? A meta-regression analysis

    OpenAIRE

    Iordache, Ioana Raluca

    2014-01-01

    When estimating the influence income per capita exerts on health care expenditure, the research in the field offers mixed results. Studies employ different data, estimation techniques and models, which brings about the question whether these differences in research design play any part in explaining the heterogeneity of reported outcomes. By employing meta-regression analysis, the present paper analyzes 220 estimates of health spending income elasticity collected from 54 studies and finds tha...

  1. Distance Based Root Cause Analysis and Change Impact Analysis of Performance Regressions

    Directory of Open Access Journals (Sweden)

    Junzan Zhou

    2015-01-01

    Full Text Available Performance regression testing is applied to uncover both performance and functional problems of software releases. A performance problem revealed by performance testing can be high response time, low throughput, or even being out of service. Mature performance testing process helps systematically detect software performance problems. However, it is difficult to identify the root cause and evaluate the potential change impact. In this paper, we present an approach leveraging server side logs for identifying root causes of performance problems. Firstly, server side logs are used to recover call tree of each business transaction. We define a novel distance based metric computed from call trees for root cause analysis and apply inverted index from methods to business transactions for change impact analysis. Empirical studies show that our approach can effectively and efficiently help developers diagnose root cause of performance problems.

  2. Sarcopenia and mortality in older people living in a nursing home in Turkey.

    Science.gov (United States)

    Yalcin, Ahmet; Aras, Sevgi; Atmis, Volkan; Cengiz, Ozlem Karaarslan; Cinar, Esat; Atli, Teslime; Varli, Murat

    2017-07-01

    The aim of the present study was to evaluate the relationship between mortality and sarcopenia defined by the criteria of the European Working Group on Sarcopenia in Older People in older nursing home residents in Turkey. This was an observational prospective study. Nursing home residents who were aged older than 65 years and living in the Seyranbagları Nursing Home and Rehabilitation Center (Ankara, Turkey) were recruited for the study. The main outcome measure was the relationship between sarcopenia and mortality. Diagnosis of sarcopenia was carried out according to the European Working Group on Sarcopenia in Older People criteria. Bioelectrical impedance analysis was used for skeletal muscle mass measurement. Muscle strength and muscle performance were evaluated by handgrip testing and gait speed, respectively. Mortality was assessed at the end of 2 years. The Kaplan-Meier method and Cox regression analysis were used to evaluate the relationship between sarcopenia and all-cause mortality. The prevalence of sarcopenia and severe sarcopenia were 29% and 25.4%, respectively. A total of 44% (18) of sarcopenic participants died, whereas 15% (15) of participants without sarcopenia died after 2 years of follow up (P sarcopenia was associated with all-cause mortality among older nursing home residents in Turkey (HR 2.38, 95% CI 1.04-5.46; P = 0.039). However, sarcopenia was not significantly related with mortality after adjustment of MNA score (HR 2.04, 95% CI 0.85-4.9; P = 0.1). Sarcopenia independently increases all-cause mortality in older nursing home residents in Turkey. Nutritional status plays a role in sarcopenia-related mortality. Geriatr Gerontol Int 2017; 17: 1118-1124. © 2016 Japan Geriatrics Society.

  3. Risk Factors Associated with Falls in Older Adults with Dementia: A Systematic Review.

    Science.gov (United States)

    Fernando, Eresha; Fraser, Michelle; Hendriksen, Jane; Kim, Corey H; Muir-Hunter, Susan W

    2017-01-01

    Purpose: People with dementia fall more often than cognitively healthy older adults, but their risk factors are not well understood. A review is needed to determine a fall risk profile for this population. The objective was to critically evaluate the literature and identify the factors associated with fall risk in older adults with dementia. Methods: Articles published between January 1988 and October 2014 in EMBASE, PubMed, PsycINFO, and CINAHL were searched. Inclusion criteria were participants aged 55 years or older with dementia or cognitive impairment, prospective cohort design, detailed fall definition, falls as the primary outcome, and multi-variable regression analysis. Two authors independently reviewed and extracted data on study characteristics, quality assessment, and outcomes. Adjusted risk estimates were extracted from the articles. Results: A total of 17 studies met the inclusion criteria. Risk factors were categorized into demographic, balance, gait, vision, functional status, medications, psychosocial, severity of dementia, and other. Risk factors varied with living setting and were not consistent across all studies within a setting. Conclusion: Falls in older adults with dementia are associated with multiple intrinsic and extrinsic risk factors, some shared with older adults in general and others unique to the disease. Risk factors vary between community- and institution-dwelling samples of adults with dementia or cognitive impairment.

  4. Dynamics of Volunteering in Older Europeans

    Science.gov (United States)

    Hank, Karsten; Erlinghagen, Marcel

    2010-01-01

    Purpose: To investigate the dynamics of volunteering in the population aged 50 years or older across 11 Continental European countries. Design and Methods: Using longitudinal data from the first 2 waves of the Survey of Health, Ageing and Retirement in Europe, we run multivariate regressions on a set of binary-dependent variables indicating…

  5. Cohabitation among older adults: a national portrait.

    Science.gov (United States)

    Brown, Susan L; Lee, Gary R; Bulanda, Jennifer Roebuck

    2006-03-01

    Older adults are increasingly likely to experience cohabitation, or living together unmarried in an intimate, heterosexual union. In order to begin building a conceptual framework, we provide a descriptive portrait of older adult cohabitors, emphasizing how they compare to older remarrieds and unpartnereds. We used data from both Census 2000 and the 1998 Health and Retirement Study ( HRS; Health and Retirement Study, 1998) to estimate the size and composition of the cohabiting population aged 51 and older. Also, using HRS data, we estimated multinomial logistic regression models to identify the correlates associated with cohabitation and remarriage (vs being unpartnered) among women and men who were previously married. More than 1 million older adults, composing 4% of the unmarried population, currently cohabit. About 90% of these individuals were previously married. We identify significant differences among cohabitors, remarrieds, and unpartnereds across several dimensions, including sociodemographic characteristics, economic resources, physical health, and social relationships. Cohabitors appear to be more disadvantaged than remarrieds, and this is especially evident for women. Older cohabitors differ from individuals of other marital statuses, and therefore future work on marital status should explicitly incorporate cohabitation.

  6. Sparse multivariate factor analysis regression models and its applications to integrative genomics analysis.

    Science.gov (United States)

    Zhou, Yan; Wang, Pei; Wang, Xianlong; Zhu, Ji; Song, Peter X-K

    2017-01-01

    The multivariate regression model is a useful tool to explore complex associations between two kinds of molecular markers, which enables the understanding of the biological pathways underlying disease etiology. For a set of correlated response variables, accounting for such dependency can increase statistical power. Motivated by integrative genomic data analyses, we propose a new methodology-sparse multivariate factor analysis regression model (smFARM), in which correlations of response variables are assumed to follow a factor analysis model with latent factors. This proposed method not only allows us to address the challenge that the number of association parameters is larger than the sample size, but also to adjust for unobserved genetic and/or nongenetic factors that potentially conceal the underlying response-predictor associations. The proposed smFARM is implemented by the EM algorithm and the blockwise coordinate descent algorithm. The proposed methodology is evaluated and compared to the existing methods through extensive simulation studies. Our results show that accounting for latent factors through the proposed smFARM can improve sensitivity of signal detection and accuracy of sparse association map estimation. We illustrate smFARM by two integrative genomics analysis examples, a breast cancer dataset, and an ovarian cancer dataset, to assess the relationship between DNA copy numbers and gene expression arrays to understand genetic regulatory patterns relevant to the disease. We identify two trans-hub regions: one in cytoband 17q12 whose amplification influences the RNA expression levels of important breast cancer genes, and the other in cytoband 9q21.32-33, which is associated with chemoresistance in ovarian cancer. © 2016 WILEY PERIODICALS, INC.

  7. Advanced statistics: linear regression, part II: multiple linear regression.

    Science.gov (United States)

    Marill, Keith A

    2004-01-01

    The applications of simple linear regression in medical research are limited, because in most situations, there are multiple relevant predictor variables. Univariate statistical techniques such as simple linear regression use a single predictor variable, and they often may be mathematically correct but clinically misleading. Multiple linear regression is a mathematical technique used to model the relationship between multiple independent predictor variables and a single dependent outcome variable. It is used in medical research to model observational data, as well as in diagnostic and therapeutic studies in which the outcome is dependent on more than one factor. Although the technique generally is limited to data that can be expressed with a linear function, it benefits from a well-developed mathematical framework that yields unique solutions and exact confidence intervals for regression coefficients. Building on Part I of this series, this article acquaints the reader with some of the important concepts in multiple regression analysis. These include multicollinearity, interaction effects, and an expansion of the discussion of inference testing, leverage, and variable transformations to multivariate models. Examples from the first article in this series are expanded on using a primarily graphic, rather than mathematical, approach. The importance of the relationships among the predictor variables and the dependence of the multivariate model coefficients on the choice of these variables are stressed. Finally, concepts in regression model building are discussed.

  8. Risk Factors for Hip Fracture in Japanese Older Adults

    Directory of Open Access Journals (Sweden)

    Takashi Yamashita

    2012-09-01

    Full Text Available Risk factors for hip fracture in Japanese older populations are understudied compared with Western countries arguably due to the relatively lower prevalence rates in Japan. Nationally representative data from the Nihon University Japanese Longitudinal Study of Aging were analyzed using logistic regression to examine possible risk factors of hip fractures, separately for older women (n = 2,859 and older men (n = 2,108. Results showed that older Japanese women with difficulty bending their knees (OR = 1.9, with diabetes (OR = 1.7 times, and/or with more activity of daily living limitations (OR = 1.1 had higher risks of hip fracture. Older Japanese men with difficulty bending their knees (OR = 2.6, who use more external prescription drugs (OR = 1.9, and with cancer (OR = 2.0 times had higher risks of hip fracture. Further considerations of gender- and culture-specific factors along with the identified risk factors may provide insights into future intervention programs for hip fracture in Japanese older populations.

  9. Falls among older adults in the South of Brazil: prevalence and determinants

    Directory of Open Access Journals (Sweden)

    Luna S Vieira

    2018-02-01

    Full Text Available ABSTRACT OBJECTIVE Evaluate the prevalence and the factors associated with the occurrence of falls among older adults. METHODS A cross-sectional study with a representative sample of 1,451 elderly residents in the urban area of Pelotas, RS, in 2014. A descriptive analysis of the data was performed and the prevalence of falls in the last year was presented. The analysis of demographic, socioeconomic, behavioral and health factors associated with the outcome was performed using Poisson regression with adjustment for robust variance according to the hierarchical model. The variables were adjusted to each other within each level and for the higher level. Those with p ≤ 0.20 were maintained in the model for confounding control and those with p < 0.05 were considered to be associated with the outcome. RESULTS The prevalence of falls among older adults in the last year was 28.1% (95%CI 25.9–30.5, and most occurred in the person’s own residence. Among the older adults who fell, 51.5% (95%CI 46.6–56.4 had a single fall and 12.1% (95%CI 8.9–15.3 had a fracture as a consequence, usually in the lower limbs. The prevalence of falls was higher in women, adults of advanced age, with lower income and schooling level, with functional incapacity for instrumental activities, and patients with diseases such as diabetes, heart disease, and arthritis. CONCLUSIONS The occurrence of falls reached almost a third of the older adults, and the prevalence was higher in specific segments of the population in question. About 12% of the older adults who fell fractured some bone. The factors associated with the occurrence of falls identified in this study may guide measures aimed at prevention in the older adult population.

  10. Relationship between general health of older health service users and their self-esteem in Isfahan in 2014.

    Science.gov (United States)

    Molavi, Razieh; Alavi, Mousa; Keshvari, Mahrokh

    2015-01-01

    Self-esteem is known to be one of the most important markers of successful aging. Older people's self-esteem is influenced by several factors that particularly may be health related. Therefore, this study aimed to explore some important general health-related predictors of the older people's self-esteem. In this study, 200 people, aged 65 years and older, who referred to health care centers were selected through stratified random sampling method. Data were collected by using Rosenberg's self-esteem scale and the 28-item Goldberg's general health questionnaire. Data were analyzed by Pearson's coefficient tests and multiple regression analysis. Findings showed that the entered predictor variables accounted for 49% of the total variance (R(2)) of self-esteem in the model (P self-esteem. The results emphasized on the determinant role of both physical (somatic signs) and mental (anxiety/insomnia and depression) aspects of health in older patients' self-esteem. The significant general health-related predictors found in the present study emphasize on some of the significant points that should be considered in planning for improving older patients' self-esteem.

  11. No rationale for 1 variable per 10 events criterion for binary logistic regression analysis

    Directory of Open Access Journals (Sweden)

    Maarten van Smeden

    2016-11-01

    Full Text Available Abstract Background Ten events per variable (EPV is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies. Methods The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth’s correction, are compared. Results The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect (‘separation’. We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth’s correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation. Conclusions The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.

  12. Sparse Regression by Projection and Sparse Discriminant Analysis

    KAUST Repository

    Qi, Xin; Luo, Ruiyan; Carroll, Raymond J.; Zhao, Hongyu

    2015-01-01

    predictions. We introduce a new framework, regression by projection, and its sparse version to analyze high-dimensional data. The unique nature of this framework is that the directions of the regression coefficients are inferred first, and the lengths

  13. Same-sex partner bereavement in older women: an interpretative phenomenological analysis.

    Science.gov (United States)

    Ingham, Charlotte F A; Eccles, Fiona J R; Armitage, Jocelyn R; Murray, Craig D

    2017-09-01

    Due to the lack of existing literature, the current research explored experiences of same-sex partner bereavement in women over the age of 60. Semi-structured interviews were conducted with eight women. Transcripts were analysed using interpretative phenomenological analysis. Three themes were identified which elaborated the experiences of older women who had lost a same-sex partner: (1) being left alone encapsulated feelings of isolation and exclusion; (2) navigating visibility centred on how homophobia led to a lack of recognition of the women's grief; and (3) finding new places to be authentic related women's need for new relationships in which they could be themselves. The findings indicate that existing models of partner bereavement may provide useful frameworks when seeking to understand the experiences of older women who have lost their same-sex partners. The findings indicate that in addition to the experiences of partner bereavement noted in research with heterosexual widows, older women who lose same-sex partners may face particular challenges, which can impact upon psychological well-being and adjustment to loss. These challenges appear to result from past and current homophobic and heterosexist attitudes within the UK culture. A range of interventions at individual, group, health service, and societal levels may be beneficial in improving the psychological well-being of older women who lose a same-sex partner.

  14. Religiousness/Spirituality and anger management in community-dwelling older persons.

    Science.gov (United States)

    Mefford, Linda; Thomas, Sandra P; Callen, Bonnie; Groer, Maureen

    2014-04-01

    Mismanaged anger is associated with adverse health outcomes. This study examined whether dimensions of religiousness/spirituality could predict healthy anger management in a sample of 82 community-dwelling older Americans. A correlational research design was employed using the Deffenbacher Anger Scale and the Brief Multidimensional Measure of Religiousness/Spirituality. Higher scores on Forgiveness, Daily Spiritual Experiences, Religiousness/Spirituality as Coping, and Self-Ranking of Religiousness/Spirituality were correlated with healthier anger management; however forgiveness was the only significant predictor in the regression analysis. Interventions to facilitate forgiveness may promote healthy anger management and minimize the adverse health effects of mismanaged anger.

  15. Statistical methods and regression analysis of stratospheric ozone and meteorological variables in Isfahan

    Science.gov (United States)

    Hassanzadeh, S.; Hosseinibalam, F.; Omidvari, M.

    2008-04-01

    Data of seven meteorological variables (relative humidity, wet temperature, dry temperature, maximum temperature, minimum temperature, ground temperature and sun radiation time) and ozone values have been used for statistical analysis. Meteorological variables and ozone values were analyzed using both multiple linear regression and principal component methods. Data for the period 1999-2004 are analyzed jointly using both methods. For all periods, temperature dependent variables were highly correlated, but were all negatively correlated with relative humidity. Multiple regression analysis was used to fit the meteorological variables using the meteorological variables as predictors. A variable selection method based on high loading of varimax rotated principal components was used to obtain subsets of the predictor variables to be included in the linear regression model of the meteorological variables. In 1999, 2001 and 2002 one of the meteorological variables was weakly influenced predominantly by the ozone concentrations. However, the model did not predict that the meteorological variables for the year 2000 were not influenced predominantly by the ozone concentrations that point to variation in sun radiation. This could be due to other factors that were not explicitly considered in this study.

  16. Trust in the Internet as a Health Resource Among Older Adults: Analysis of Data from a Nationally Representative Survey

    Science.gov (United States)

    Kirch, Matthias; Zheng, Kai; An, Lawrence C

    2011-01-01

    Background Distrust in the Internet as a source of health information remains common among older adults. The influence of this distrust on Internet use for health-related purposes, however, is unclear. Objective The objective of our study was to explore how older adults’ trust in the Internet influences their online health-related activities, and to identify potential targets for improving health-related Internet resources for older adults. Methods Data were obtained from a nationally representative, random digit-dial telephone survey of 1450 adults 50 years of age and older in the United States. A model was developed to conceptualize the hypothesized relationships among individual characteristics, distrust, and avoidance of the Internet as a health resource. Multivariate logistic regression analyses were conducted to examine the association between trust in online health information and use of the Internet for health-related purposes. Additional multivariate logistic regression analyses were conducted to identify the key characteristics associated with trust in online health information, adding sequentially the variables hypothesized to account for distrust among older adults: sociodemographic and health characteristics, inexperience and technical difficulties with the Internet, negative feelings toward the Internet, and lack of awareness about the sources providing the health information found online. Results The mean (SD) age of the study population was 63.7 (10.6) years. Of the 823 (56.8%) Internet users, 628 (76.3%) reported using the Internet as a health resource. Trust in the Internet as a source of health information was associated with using the Internet for a number of health activities, including searching for information about a specific health condition (adjusted OR 4.43, P purchasing prescription drugs (adjusted OR 2.61, P = .03), and talking with a health care provider about information found online (adjusted OR 2.54, P = .002). Older adults (age

  17. Predicting Help-Seeking Attitudes Toward Mental Health Services Among American Indian Older Adults: Is Andersen's Behavioral Model a Good Fit?

    Science.gov (United States)

    Roh, Soonhee; Burnette, Catherine E; Lee, Kyoung Hag; Lee, Yeon-Shim; Martin, James I; Lawler, Michael J

    2017-01-01

    American Indian (AI) older adults are vulnerable to mental health disparities, yet very little is known about the factors associated with help-seeking for mental health services among them. The purpose of this study was to investigate the utility of Andersen's Behavioral Model in explaining AI older adults' help-seeking attitudes toward professional mental health services. Hierarchical regression analysis was used to examine predisposing, enabling, and need variables as predictors of help-seeking attitudes toward mental health services in a sample of 233 AI older adults from the Midwest. The model was found to have limited utility in the context of older AI help-seeking attitudes, as the proportion of explained variance was low. Gender, perceived stigma, social support, and physical health were significant predictors, whereas age, perceived mental health, and health insurance were not. © The Author(s) 2014.

  18. Trust in the internet as a health resource among older adults: analysis of data from a nationally representative survey.

    Science.gov (United States)

    Zulman, Donna M; Kirch, Matthias; Zheng, Kai; An, Lawrence C

    2011-02-16

    Distrust in the Internet as a source of health information remains common among older adults. The influence of this distrust on Internet use for health-related purposes, however, is unclear. The objective of our study was to explore how older adults' trust in the Internet influences their online health-related activities, and to identify potential targets for improving health-related Internet resources for older adults. Data were obtained from a nationally representative, random digit-dial telephone survey of 1450 adults 50 years of age and older in the United States. A model was developed to conceptualize the hypothesized relationships among individual characteristics, distrust, and avoidance of the Internet as a health resource. Multivariate logistic regression analyses were conducted to examine the association between trust in online health information and use of the Internet for health-related purposes. Additional multivariate logistic regression analyses were conducted to identify the key characteristics associated with trust in online health information, adding sequentially the variables hypothesized to account for distrust among older adults: sociodemographic and health characteristics, inexperience and technical difficulties with the Internet, negative feelings toward the Internet, and lack of awareness about the sources providing the health information found online. The mean (SD) age of the study population was 63.7 (10.6) years. Of the 823 (56.8%) Internet users, 628 (76.3%) reported using the Internet as a health resource. Trust in the Internet as a source of health information was associated with using the Internet for a number of health activities, including searching for information about a specific health condition (adjusted OR 4.43, P Internet as a source of health information (OR 0.63, P = .04), even after adjusting for other sociodemographic characteristics and health and function. This age effect was only slightly attenuated (adjusted OR 0.69, P

  19. Hand-grip strength among older adults in Singapore: a comparison with international norms and associative factors.

    Science.gov (United States)

    Ong, Hui Lin; Abdin, Edimansyah; Chua, Boon Yiang; Zhang, Yunjue; Seow, Esmond; Vaingankar, Janhavi Ajit; Chong, Siow Ann; Subramaniam, Mythily

    2017-08-04

    Hand-grip strength (HGS) serves as a proxy measure for muscle function and physical health. Studies have shown that low HGS is associated with common age-related disorders including frailty and sarcopenia. The aim of the present study was to establish the normative values of HGS among older adults in Singapore and to compare it with data from Western and other Asian countries. The study also aimed to explore the sociodemographic and anthropometric correlates of HGS. Data were collected from 2043 men and women aged 60 years and above who took part in the Well-being of the Singapore Elderly study in 2013. HGS was obtained using a Jamar Plus + digital hand dynamometer. Normative data were stratified by; 5-year age groups, sex and ethnicity. Relationships between the HGS with various sociodemographic and anthropometric correlates were examined using multiple linear regression analysis. The mean HGS demonstrate a decreasing trend with increased age across all ethnic groups and sexes. HGS among Singapore older adults were relatively low compared to Western and other Asian countries. Males in the youngest age group (60-64) and of Chinese ethnicity attained greater HGS values than their counterparts. When the regression analysis was stratified for sex, significant associations were found between height, upper arm circumference with HGS in the males sample, and between height, weight, waist circumference and HGS in the females sample. Older adults in Singapore have a relatively weak HGS compared to other countries. Greater height and weight, and smaller waist circumference are independently associated with greater HGS in females but not males. These results facilitate the interpretation of HGS conducting using Jamar digital-type dynamometers among the older adults in Singapore.

  20. Diversity in Older Adults' Use of the Internet: Identifying Subgroups Through Latent Class Analysis.

    Science.gov (United States)

    van Boekel, Leonieke C; Peek, Sebastiaan Tm; Luijkx, Katrien G

    2017-05-24

    As for all individuals, the Internet is important in the everyday life of older adults. Research on older adults' use of the Internet has merely focused on users versus nonusers and consequences of Internet use and nonuse. Older adults are a heterogeneous group, which may implicate that their use of the Internet is diverse as well. Older adults can use the Internet for different activities, and this usage can be of influence on benefits the Internet can have for them. The aim of this paper was to describe the diversity or heterogeneity in the activities for which older adults use the Internet and determine whether diversity is related to social or health-related variables. We used data of a national representative Internet panel in the Netherlands. Panel members aged 65 years and older and who have access to and use the Internet were selected (N=1418). We conducted a latent class analysis based on the Internet activities that panel members reported to spend time on. Second, we described the identified clusters with descriptive statistics and compared the clusters using analysis of variance (ANOVA) and chi-square tests. Four clusters were distinguished. Cluster 1 was labeled as the "practical users" (36.88%, n=523). These respondents mainly used the Internet for practical and financial purposes such as searching for information, comparing products, and banking. Respondents in Cluster 2, the "minimizers" (32.23%, n=457), reported lowest frequency on most Internet activities, are older (mean age 73 years), and spent the smallest time on the Internet. Cluster 3 was labeled as the "maximizers" (17.77%, n=252); these respondents used the Internet for various activities, spent most time on the Internet, and were relatively younger (mean age below 70 years). Respondents in Cluster 4, the "social users," mainly used the Internet for social and leisure-related activities such as gaming and social network sites. The identified clusters significantly differed in age (PInternet

  1. Multivariate regression analysis for determining short-term values of radon and its decay products from filter measurements

    International Nuclear Information System (INIS)

    Kraut, W.; Schwarz, W.; Wilhelm, A.

    1994-01-01

    A multivariate regression analysis is applied to decay measurements of α-resp. β-filter activcity. Activity concentrations for Po-218, Pb-214 and Bi-214, resp. for the Rn-222 equilibrium equivalent concentration are obtained explicitly. The regression analysis takes into account properly the variances of the measured count rates and their influence on the resulting activity concentrations. (orig.) [de

  2. Cognitive Reserve as a Protective Factor in Older HIV-Positive Patients at Risk for Cognitive Decline

    OpenAIRE

    Foley, Jessica M.; Ettenhofer, Mark L.; Kim, Michelle S.; Behdin, Nina; Castellon, Steven A.; Hinkin, Charles H.

    2012-01-01

    The present study examined the impact of cognitive reserve in maintaining intact neuropsychological (NP) function among older HIV-positive individuals, a uniquely at-risk subgroup. Participants included 129 individuals classified by HIV serostatus, age group, and NP impairment. A three-way analysis of variance (ANOVA) followed by a series of within-group ANOVA and multiple regression analyses were conducted to investigate the pattern of cognitive reserve (vs. other protective) influence among...

  3. Medical and obstetric complications among pregnant women aged 45 and older.

    Directory of Open Access Journals (Sweden)

    Chad A Grotegut

    Full Text Available The number of women aged 45 and older who become pregnant is increasing. The objective of this study was to estimate the risk of medical and obstetric complications among women aged 45 and older.The Nationwide Inpatient Sample was used to identify pregnant woman during admission for delivery. Deliveries were identified using International Classification of Diseases, Ninth Revision (ICD-9-CM codes. Using ICD-9-CM codes, pre-existing medical conditions and medical and obstetric complications were identified in women at the time of delivery and were compared for women aged 45 years and older to women under age 35. Outcomes among women aged 35-44 were also compared to women under age 35 to determine if women in this group demonstrated intermediate risk between the older and younger groups. Logistic regression analyses were used to calculate odds ratios with 95% confidence intervals for pre-existing medical conditions and medical and obstetric complications for both older groups relative to women under 35. Multivariable logistic regression analyses were also developed for outcomes at delivery among older women, while controlling for pre-existing medical conditions, multiple gestation, and insurance status, to determine the effect of age on the studied outcomes.Women aged 45 and older had higher adjusted odds for death, transfusion, myocardial infarction/ischemia, cardiac arrest, acute heart failure, pulmonary embolism, deep vein thrombosis, acute renal failure, cesarean delivery, gestational diabetes, fetal demise, fetal chromosomal anomaly, and placenta previa compared to women under 35.Pregnant women aged 45 and older experience significantly more medical and obstetric complications and are more likely to die at the time of a delivery than women under age 35, though the absolute risks are low and these events are rare. Further research is needed to determine what associated factors among pregnant women aged 45 and older may contribute to these

  4. An Econometric Analysis of Modulated Realised Covariance, Regression and Correlation in Noisy Diffusion Models

    DEFF Research Database (Denmark)

    Kinnebrock, Silja; Podolskij, Mark

    This paper introduces a new estimator to measure the ex-post covariation between high-frequency financial time series under market microstructure noise. We provide an asymptotic limit theory (including feasible central limit theorems) for standard methods such as regression, correlation analysis...... process can be relaxed and how our method can be applied to non-synchronous observations. We also present an empirical study of how high-frequency correlations, regressions and covariances change through time....

  5. A menu-driven software package of Bayesian nonparametric (and parametric) mixed models for regression analysis and density estimation.

    Science.gov (United States)

    Karabatsos, George

    2017-02-01

    Most of applied statistics involves regression analysis of data. In practice, it is important to specify a regression model that has minimal assumptions which are not violated by data, to ensure that statistical inferences from the model are informative and not misleading. This paper presents a stand-alone and menu-driven software package, Bayesian Regression: Nonparametric and Parametric Models, constructed from MATLAB Compiler. Currently, this package gives the user a choice from 83 Bayesian models for data analysis. They include 47 Bayesian nonparametric (BNP) infinite-mixture regression models; 5 BNP infinite-mixture models for density estimation; and 31 normal random effects models (HLMs), including normal linear models. Each of the 78 regression models handles either a continuous, binary, or ordinal dependent variable, and can handle multi-level (grouped) data. All 83 Bayesian models can handle the analysis of weighted observations (e.g., for meta-analysis), and the analysis of left-censored, right-censored, and/or interval-censored data. Each BNP infinite-mixture model has a mixture distribution assigned one of various BNP prior distributions, including priors defined by either the Dirichlet process, Pitman-Yor process (including the normalized stable process), beta (two-parameter) process, normalized inverse-Gaussian process, geometric weights prior, dependent Dirichlet process, or the dependent infinite-probits prior. The software user can mouse-click to select a Bayesian model and perform data analysis via Markov chain Monte Carlo (MCMC) sampling. After the sampling completes, the software automatically opens text output that reports MCMC-based estimates of the model's posterior distribution and model predictive fit to the data. Additional text and/or graphical output can be generated by mouse-clicking other menu options. This includes output of MCMC convergence analyses, and estimates of the model's posterior predictive distribution, for selected

  6. Interventions for addressing low balance confidence in older adults: a systematic review and meta-analysis.

    Science.gov (United States)

    Rand, Debbie; Miller, William C; Yiu, Jeanne; Eng, Janice J

    2011-05-01

    low balance confidence is a major health problem among older adults restricting their participation in daily life. to determine what interventions are most effective in increasing balance confidence in older adults. systematic review with meta-analysis of randomised controlled trials including at least one continuous end point of balance confidence. Studies, including adults 60 years or older without a neurological condition, were included in our study. the standardised mean difference (SMD) of continuous end points of balance confidence was calculated to estimate the pooled effect size with random-effect models. Methodological quality of trials was assessed using the Physical Therapy Evidence Database (PEDro) Scale. thirty studies were included in this review and a meta-analysis was conducted for 24 studies. Interventions were pooled into exercise (n = 9 trials, 453 subjects), Tai Chi (n = 5 trials, 468 subjects), multifactorial intervention (n = 10 trials, 1,233 subjects). Low significant effects were found for exercise and multifactorial interventions (SMD 0.22-0.31) and medium (SMD 0.48) significant effects were found for Tai Chi. Tai chi interventions are the most beneficial in increasing the balance confidence of older adults.

  7. Mental health implications for older adults after natural disasters--a systematic review and meta-analysis.

    Science.gov (United States)

    Parker, Georgina; Lie, David; Siskind, Dan J; Martin-Khan, Melinda; Raphael, Beverly; Crompton, David; Kisely, Steve

    2016-01-01

    Natural disasters affect the health and well-being of adults throughout the world. There is some debate in the literature as to whether older persons have increased risk of mental health outcomes after exposure to natural disasters when compared with younger adults. To date, no systematic review has evaluated this. We aimed to synthesize the available evidence on the impact of natural disasters on the mental health and psychological distress experienced by older adults. A meta-analysis was conducted on papers identified through a systematic review. The primary outcomes measured were post-traumatic stress disorder (PTSD), depression, anxiety disorders, adjustment disorder, and psychological distress. We identified six papers with sufficient data for a random effects meta-analysis. Older adults were 2.11 times more likely to experience PTSD symptoms and 1.73 more likely to develop adjustment disorder when exposed to natural disasters when compared with younger adults. Given the global rise in the number of older adults affected by natural disasters, mental health services need to be prepared to meet their needs following natural disasters, particularly around the early detection and management of PTSD.

  8. Regression analysis of mixed recurrent-event and panel-count data.

    Science.gov (United States)

    Zhu, Liang; Tong, Xinwei; Sun, Jianguo; Chen, Manhua; Srivastava, Deo Kumar; Leisenring, Wendy; Robison, Leslie L

    2014-07-01

    In event history studies concerning recurrent events, two types of data have been extensively discussed. One is recurrent-event data (Cook and Lawless, 2007. The Analysis of Recurrent Event Data. New York: Springer), and the other is panel-count data (Zhao and others, 2010. Nonparametric inference based on panel-count data. Test 20: , 1-42). In the former case, all study subjects are monitored continuously; thus, complete information is available for the underlying recurrent-event processes of interest. In the latter case, study subjects are monitored periodically; thus, only incomplete information is available for the processes of interest. In reality, however, a third type of data could occur in which some study subjects are monitored continuously, but others are monitored periodically. When this occurs, we have mixed recurrent-event and panel-count data. This paper discusses regression analysis of such mixed data and presents two estimation procedures for the problem. One is a maximum likelihood estimation procedure, and the other is an estimating equation procedure. The asymptotic properties of both resulting estimators of regression parameters are established. Also, the methods are applied to a set of mixed recurrent-event and panel-count data that arose from a Childhood Cancer Survivor Study and motivated this investigation. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. [Application of negative binomial regression and modified Poisson regression in the research of risk factors for injury frequency].

    Science.gov (United States)

    Cao, Qingqing; Wu, Zhenqiang; Sun, Ying; Wang, Tiezhu; Han, Tengwei; Gu, Chaomei; Sun, Yehuan

    2011-11-01

    To Eexplore the application of negative binomial regression and modified Poisson regression analysis in analyzing the influential factors for injury frequency and the risk factors leading to the increase of injury frequency. 2917 primary and secondary school students were selected from Hefei by cluster random sampling method and surveyed by questionnaire. The data on the count event-based injuries used to fitted modified Poisson regression and negative binomial regression model. The risk factors incurring the increase of unintentional injury frequency for juvenile students was explored, so as to probe the efficiency of these two models in studying the influential factors for injury frequency. The Poisson model existed over-dispersion (P Poisson regression and negative binomial regression model, was fitted better. respectively. Both showed that male gender, younger age, father working outside of the hometown, the level of the guardian being above junior high school and smoking might be the results of higher injury frequencies. On a tendency of clustered frequency data on injury event, both the modified Poisson regression analysis and negative binomial regression analysis can be used. However, based on our data, the modified Poisson regression fitted better and this model could give a more accurate interpretation of relevant factors affecting the frequency of injury.

  10. Medication management strategies used by older adults with heart failure: A systems-based analysis.

    Science.gov (United States)

    Mickelson, Robin S; Holden, Richard J

    2017-09-01

    Older adults with heart failure use strategies to cope with the constraining barriers impeding medication management. Strategies are behavioral adaptations that allow goal achievement despite these constraining conditions. When strategies do not exist, are ineffective or maladaptive, medication performance and health outcomes are at risk. While constraints to medication adherence are described in literature, strategies used by patients to manage medications are less well-described or understood. Guided by cognitive engineering concepts, the aim of this study was to describe and analyze the strategies used by older adults with heart failure to achieve their medication management goals. This mixed methods study employed an empirical strategies analysis method to elicit medication management strategies used by older adults with heart failure. Observation and interview data collected from 61 older adults with heart failure and 31 caregivers were analyzed using qualitative content analysis to derive categories, patterns and themes within and across cases. Data derived thematic sub-categories described planned and ad hoc methods of strategic adaptations. Stable strategies proactively adjusted the medication management process, environment, or the patients themselves. Patients applied situational strategies (planned or ad hoc) to irregular or unexpected situations. Medication non-adherence was a strategy employed when life goals conflicted with medication adherence. The health system was a source of constraints without providing commensurate strategies. Patients strived to control their medication system and achieve goals using adaptive strategies. Future patient self-mangement research can benefit from methods and theories used to study professional work, such as strategies analysis.

  11. Problem Gambling in a Sample of Older Adult Casino Gamblers.

    Science.gov (United States)

    van der Maas, Mark; Mann, Robert E; McCready, John; Matheson, Flora I; Turner, Nigel E; Hamilton, Hayley A; Schrans, Tracy; Ialomiteanu, Anca

    2017-01-01

    As older adults continue to make up a greater proportion of the Canadian population, it becomes more important to understand the implications that their leisure activities have for their physical and mental health. Gambling, in particular, is a form of leisure that is becoming more widely available and has important implications for the mental health and financial well-being of older adults. This study examines a large sample (2103) of casino-going Ontarian adults over the age of 55 and identifies those features of their gambling participation that are associated with problem gambling. Logistic regression analysis is used to analyze the data. Focusing on types of gambling participated in and motivations for visiting the casino, this study finds that several forms of gambling and motivations to gamble are associated with greater risk of problem gambling. It also finds that some motivations are associated with lower risk of problem gambling. The findings of this study have implications related to gambling availability within an aging population.

  12. Gender Differences in Hypertension Control Among Older Korean Adults: Korean Social Life, Health, and Aging Project

    Directory of Open Access Journals (Sweden)

    Sang Hui Chu

    2015-01-01

    Full Text Available Objectives: Controlling blood pressure is a key step in reducing cardiovascular mortality in older adults. Gender differences in patients’ attitudes after disease diagnosis and their management of the disease have been identified. However, it is unclear whether gender differences exist in hypertension management among older adults. We hypothesized that gender differences would exist among factors associated with hypertension diagnosis and control among community-dwelling, older adults. Methods: This cross-sectional study analyzed data from 653 Koreans aged ≥60 years who participated in the Korean Social Life, Health, and Aging Project. Multiple logistic regression was used to compare several variables between undiagnosed and diagnosed hypertension, and between uncontrolled and controlled hypertension. Results: Diabetes was more prevalent in men and women who had uncontrolled hypertension than those with controlled hypertension or undiagnosed hypertension. High body mass index was significantly associated with uncontrolled hypertension only in men. Multiple logistic regression analysis indicated that in women, awareness of one’s blood pressure level (odds ratio [OR], 2.86; p=0.003 and the number of blood pressure checkups over the previous year (OR, 1.06; p=0.011 might influence the likelihood of being diagnosed with hypertension. More highly educated women were more likely to have controlled hypertension than non-educated women (OR, 5.23; p=0.013. Conclusions: This study suggests that gender differences exist among factors associated with hypertension diagnosis and control in the study population of community-dwelling, older adults. Education-based health promotion strategies for hypertension control might be more effective in elderly women than in elderly men. Gender-specific approaches may be required to effectively control hypertension among older adults.

  13. Forecasting Model for IPTV Service in Korea Using Bootstrap Ridge Regression Analysis

    Science.gov (United States)

    Lee, Byoung Chul; Kee, Seho; Kim, Jae Bum; Kim, Yun Bae

    The telecom firms in Korea are taking new step to prepare for the next generation of convergence services, IPTV. In this paper we described our analysis on the effective method for demand forecasting about IPTV broadcasting. We have tried according to 3 types of scenarios based on some aspects of IPTV potential market and made a comparison among the results. The forecasting method used in this paper is the multi generation substitution model with bootstrap ridge regression analysis.

  14. An Additive-Multiplicative Cox-Aalen Regression Model

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    2002-01-01

    Aalen model; additive risk model; counting processes; Cox regression; survival analysis; time-varying effects......Aalen model; additive risk model; counting processes; Cox regression; survival analysis; time-varying effects...

  15. Economic Adversity Transitions From Childhood to Older Adulthood Are Differentially Associated With Later-Life Physical Performance Measures in Men and Women in Middle and High-Income Sites.

    Science.gov (United States)

    Hwang, Phoebe W; Dos Santos Gomes, Cristiano; Auais, Mohammad; Braun, Kathryn L; Guralnik, Jack M; Pirkle, Catherine M

    2017-10-01

    This study examines the relationship between economic adversity transitions from childhood to older adulthood and older adulthood physical performance among 1,998 community-dwelling older adults from five demographically diverse sites from middle and high-income countries. The principal exposure variable was economic adversity transition. No adversity encompassed not experiencing poverty in both childhood and older adulthood, improved described having only experienced poverty in childhood, worsened captured having experienced poverty in older adulthood, and severe is having experienced poverty in both childhood and older adulthood. The short physical performance battery (SPPB) was used for outcome measures. Analyses of the continuous SPPB score used linear regression, while analysis of a binary outcome (SPPB < 8 vs. ≥8) used Poisson regression models with robust error variance, both adjusting for sex, education, and site location. In sex-stratified models, the SPPB < 8 prevalence rate ratio (PRR) was higher for the severe (PRR: 2.80, 95% confidence interval [CI] = [1.70, 4.61]), worsened (PRR: 2.40, 95% CI = [1.41, 4.09]), and improved (PRR: 1.82, 95% CI = [1.11, 3.01]) groups, compared with those with no adversity in childhood or as adults, but only for females. Findings from this study indicate that persistent economic adversity has a negative effect on older adult physical performance, especially among women.

  16. Constructing definitions of safety risks while nurses care for hospitalised older people: Secondary analysis of qualitative data.

    Science.gov (United States)

    Dahlke, Sherry; Hall, Wendy A; Baumbusch, Jennifer

    2017-09-01

    The aim of this secondary qualitative descriptive analysis was to examine how nurses construct a definition of older peoples' safety risks and provide care while working within organisational contexts that are focused on diminishing patient risks. Numbers of older patients are increasing in acute hospital contexts-contexts that place their focus on patient safety. Nurses need to manage tensions between older peoples' risks, evidence-informed practice decisions, limited resources and organisational emphases on patient falls. To date, their practice dilemmas have not been well examined. A secondary qualitative descriptive analysis was conducted using data that were collected between June 2010 and May 2011 to examine nursing practice with hospitalised older people. All field notes and transcribed data were reviewed to generate themes representing 18 Registered Nurses' perceptions about safe care for hospitalised older people. The first author generated categories that described how nurses construct definitions of safety risks for older people. All authors engaged in an iterative analytic process that resulted in themes capturing nurses' efforts to provide care in limited resource environments while considering older peoples' safety risks. Nurses constructed definitions of patient safety risks in the context of institutional directives. Nurses provided care using available resources as efficiently as possible and accessing co-worker support. They also minimised the importance of older people's functional abilities by setting priorities for medically delegated tasks and immobilising their patients to reduce their risks. Nurses' definitions of patient risk, which were shaped by impoverished institutional resources and nurses' lack of valuing of functional abilities, contributed to suboptimal care for older adults. Nurses' definitions of risk as physical injury reduced their attention to patients' functional abilities, which nurses reported suffered declines as a result

  17. Factors affecting mortality in older trauma patients-A systematic review and meta-analysis.

    Science.gov (United States)

    Sammy, Ian; Lecky, Fiona; Sutton, Anthea; Leaviss, Joanna; O'Cathain, Alicia

    2016-06-01

    Major trauma in older people is a significant health burden in the developed world. The aging of the population has resulted in larger numbers of older patients suffering serious injury. Older trauma patients are at greater risk of death from major trauma, but the reasons for this are less well understood. The aim of this review was to identify the factors affecting mortality in older patients suffering major injury. A systematic review of Medline, Cinhal and the Cochrane database, supplemented by a manual search of relevant papers was undertaken, with meta-analysis. Multi-centre cohort studies of existing trauma registries that reported risk-adjusted mortality (adjusted odds ratios, AOR) in their outcomes and which analysed patients aged 65 and older as a separate cohort were included in the review. 3609 papers were identified from the electronic databases, and 28 from manual searches. Of these, 15 papers fulfilled the inclusion criteria. Demographic variables (age and gender), pre-existing conditions (comorbidities and medication), and injury-related factors (injury severity, pattern and mechanism) were found to affect mortality. The 'oldest old', aged 75 and older, had higher mortality rates than younger patients, aged 65-74 years. Older men had a significantly higher mortality rate than women (cumulative odds ratio 1.51, 95% CI 1.37-1.66). Three papers reported a higher risk of death in patients with pre-existing conditions. Two studies reported increased mortality in patients on warfarin (cumulative odds ratio 1.32, 95% CI 1.05-1.66). Higher mortality was seen in patients with lower Glasgow coma scores and systolic blood pressures. Mortality increased with increased injury severity and number of injuries sustained. Low level falls were associated with higher mortality than motor vehicle collisions (cumulative odds ratio 2.88, 95% CI 1.26-6.60). Multiple factors contribute to mortality risk in older trauma patients. The relation between these factors and

  18. Weight change and all-cause mortality in older adults: A meta-analysis

    Science.gov (United States)

    This meta-analysis of observational cohort studies examined the association between weight change (weight loss, weight gain, and weight fluctuation) and all-cause mortality among older adults. We used PubMed (MEDLINE), Web of Science, and Cochrane Library to identify prospective studies published in...

  19. Religiousness affects mental health, pain and quality of life in older people in an outpatient rehabilitation setting.

    Science.gov (United States)

    Lucchetti, Giancarlo; Lucchetti, Alessandra Granero; Badan-Neto, Antonio M; Peres, Patricia T; Peres, Mario F P; Moreira-Almeida, Alexander; Gomes, Cláudio; Koenig, Harold G

    2011-03-01

    To evaluate the relationship between religiousness and mental health, hospitalization, pain, disability and quality of life in older adults from an outpatient rehabilitation setting in Sao Paulo, Brazil. Cross-sectional study. A total of 110 patients aged 60 years or older were interviewed during attendance at an outpatient rehabilitation service. Researchers administered a standardized questionnaire that assessed socio-demographic data, religiousness, self-reported quality of life, anxiety, physical activity limitation, depression, pain and cognition. Predictors were included in each model analysis, and a backward conditional method was used for variable selection using logistic regression (categorical outcomes) or linear regression (continuous outcomes). Thirty-one patients (28.2%) fulfilled criteria for significant depressive symptoms, 27 (24.5%) for anxiety, and 10 (9.6%) for cognitive impairment. Pain was present in 89 (80.7%) patients. Limited depressive symptoms (as assessed by the Geriatric Depression Scale), and greater self-reported quality of life were related to greater self-reported religiousness, as were scores on the Mini-Mental State Examination (less cognitive impairment), and lower ratings of pain. Religiousness is related to significantly less depressive symptoms, better quality of life, less cognitive impairment, and less perceived pain. Clinicians should consider taking a spiritual history and ensuring that spiritual needs are addressed among older patients in rehabilitation settings.

  20. Driven Factors Analysis of China’s Irrigation Water Use Efficiency by Stepwise Regression and Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Renfu Jia

    2016-01-01

    Full Text Available This paper introduces an integrated approach to find out the major factors influencing efficiency of irrigation water use in China. It combines multiple stepwise regression (MSR and principal component analysis (PCA to obtain more realistic results. In real world case studies, classical linear regression model often involves too many explanatory variables and the linear correlation issue among variables cannot be eliminated. Linearly correlated variables will cause the invalidity of the factor analysis results. To overcome this issue and reduce the number of the variables, PCA technique has been used combining with MSR. As such, the irrigation water use status in China was analyzed to find out the five major factors that have significant impacts on irrigation water use efficiency. To illustrate the performance of the proposed approach, the calculation based on real data was conducted and the results were shown in this paper.

  1. A regression analysis of the effect of energy use in agriculture

    International Nuclear Information System (INIS)

    Karkacier, Osman; Gokalp Goktolga, Z.; Cicek, Adnan

    2006-01-01

    This study investigates the impacts of energy use on productivity of Turkey's agriculture. It reports the results of a regression analysis of the relationship between energy use and agricultural productivity. The study is based on the analysis of the yearbook data for the period 1971-2003. Agricultural productivity was specified as a function of its energy consumption (TOE) and gross additions of fixed assets during the year. Least square (LS) was employed to estimate equation parameters. The data of this study comes from the State Institute of Statistics (SIS) and The Ministry of Energy of Turkey

  2. Association Between Depressive Symptoms, Multiple Dimensions of Depression, and Elder Abuse: A Cross-Sectional, Population-Based Analysis of Older Adults in Urban Chicago.

    Science.gov (United States)

    Roepke-Buehler, Susan K; Simon, Melissa; Dong, XinQi

    2015-09-01

    Depression is conceptualized as both a risk factor for and a consequence of elder abuse; however, current research is equivocal. This study examined associations between elder abuse and dimensions of depressive symptoms in older adults. Participants were 10,419 older adults enrolled in theChicago Health and Aging Project (CHAP), a population-based study of older adults. Regression was used to determine the relationships between depressive symptoms, depression dimensions, and abuse variables. Depressive symptoms were consistently associated with elder abuse. Participants in the highest tertile of depressive symptoms were twice as likely to have confirmed abuse with a perpetrator (odds ratio = 2.07, 95% confidence interval = [1.21, 3.52], p = .008). Elder abuse subtypes and depression dimensions were differentially associated. These findings highlight the importance of routine depression screening in older adults as a component of abuse prevention and intervention. They also provide profiles of depressive symptoms that may more accurately characterize risk for specific types of abuse. © The Author(s) 2015.

  3. Characteristics of communication with older people in home care: A qualitative analysis of audio recordings of home care visits.

    Science.gov (United States)

    Kristensen, Dorte V; Sundler, Annelie J; Eide, Hilde; Hafskjold, Linda; Ruud, Iren; Holmström, Inger K

    2017-12-01

    To describe the characteristics of communication practice in home care visits between older people (over 65 years old) and nurse assistants and to discuss the findings from a person-centered perspective. The older population is increasing worldwide, along with the need for healthcare services in the person's home. To achieve a high-quality care, person-centered communication is crucial. A descriptive design with a qualitative inductive approach was used. Fifteen audio recordings of naturally occurring conversations between 12 nurse assistants and 13 older people in Norway were analysed by qualitative content analysis. Four categories were revealed through analysis: (i) supporting older people's connection to everyday life; (ii) supporting older people's involvement in their own care; (iii) attention to older people's bodily and existential needs; and (iv) the impact of continuity and predictability on older people's well-being. The communication between the older people and the nurse assistants during home care visits was mainly task-oriented, but also related to the person. The older people were involved in the tasks to be carried out and humour was part of the communication. Greater attention was paid to bodily than existential needs. The communication was connected with the older people's everyday life in several ways. Time frames and interruptions concern the older people; hearing and speech impairments were a challenge to communication. To enhance person-centred communication, further studies are needed, especially intervention studies for healthcare professionals and students. Being responsive to older people's subjective experiences is important in meeting their needs in home care. Communication that addresses the need for trust and predictability is important for older people. Responding to existential needs require more attention. The home care setting has an impact on communication. © 2017 John Wiley & Sons Ltd.

  4. Prediction of hearing outcomes by multiple regression analysis in patients with idiopathic sudden sensorineural hearing loss.

    Science.gov (United States)

    Suzuki, Hideaki; Tabata, Takahisa; Koizumi, Hiroki; Hohchi, Nobusuke; Takeuchi, Shoko; Kitamura, Takuro; Fujino, Yoshihisa; Ohbuchi, Toyoaki

    2014-12-01

    This study aimed to create a multiple regression model for predicting hearing outcomes of idiopathic sudden sensorineural hearing loss (ISSNHL). The participants were 205 consecutive patients (205 ears) with ISSNHL (hearing level ≥ 40 dB, interval between onset and treatment ≤ 30 days). They received systemic steroid administration combined with intratympanic steroid injection. Data were examined by simple and multiple regression analyses. Three hearing indices (percentage hearing improvement, hearing gain, and posttreatment hearing level [HLpost]) and 7 prognostic factors (age, days from onset to treatment, initial hearing level, initial hearing level at low frequencies, initial hearing level at high frequencies, presence of vertigo, and contralateral hearing level) were included in the multiple regression analysis as dependent and explanatory variables, respectively. In the simple regression analysis, the percentage hearing improvement, hearing gain, and HLpost showed significant correlation with 2, 5, and 6 of the 7 prognostic factors, respectively. The multiple correlation coefficients were 0.396, 0.503, and 0.714 for the percentage hearing improvement, hearing gain, and HLpost, respectively. Predicted values of HLpost calculated by the multiple regression equation were reliable with 70% probability with a 40-dB-width prediction interval. Prediction of HLpost by the multiple regression model may be useful to estimate the hearing prognosis of ISSNHL. © The Author(s) 2014.

  5. Regression of environmental noise in LIGO data

    International Nuclear Information System (INIS)

    Tiwari, V; Klimenko, S; Mitselmakher, G; Necula, V; Drago, M; Prodi, G; Frolov, V; Yakushin, I; Re, V; Salemi, F; Vedovato, G

    2015-01-01

    We address the problem of noise regression in the output of gravitational-wave (GW) interferometers, using data from the physical environmental monitors (PEM). The objective of the regression analysis is to predict environmental noise in the GW channel from the PEM measurements. One of the most promising regression methods is based on the construction of Wiener–Kolmogorov (WK) filters. Using this method, the seismic noise cancellation from the LIGO GW channel has already been performed. In the presented approach the WK method has been extended, incorporating banks of Wiener filters in the time–frequency domain, multi-channel analysis and regulation schemes, which greatly enhance the versatility of the regression analysis. Also we present the first results on regression of the bi-coherent noise in the LIGO data. (paper)

  6. [Multiple linear regression analysis of X-ray measurement and WOMAC scores of knee osteoarthritis].

    Science.gov (United States)

    Ma, Yu-Feng; Wang, Qing-Fu; Chen, Zhao-Jun; Du, Chun-Lin; Li, Jun-Hai; Huang, Hu; Shi, Zong-Ting; Yin, Yue-Shan; Zhang, Lei; A-Di, Li-Jiang; Dong, Shi-Yu; Wu, Ji

    2012-05-01

    To perform Multiple Linear Regression analysis of X-ray measurement and WOMAC scores of knee osteoarthritis, and to analyze their relationship with clinical and biomechanical concepts. From March 2011 to July 2011, 140 patients (250 knees) were reviewed, including 132 knees in the left and 118 knees in the right; ranging in age from 40 to 71 years, with an average of 54.68 years. The MB-RULER measurement software was applied to measure femoral angle, tibial angle, femorotibial angle, joint gap angle from antero-posterir and lateral position of X-rays. The WOMAC scores were also collected. Then multiple regression equations was applied for the linear regression analysis of correlation between the X-ray measurement and WOMAC scores. There was statistical significance in the regression equation of AP X-rays value and WOMAC scores (Pregression equation of lateral X-ray value and WOMAC scores (P>0.05). 1) X-ray measurement of knee joint can reflect the WOMAC scores to a certain extent. 2) It is necessary to measure the X-ray mechanical axis of knee, which is important for diagnosis and treatment of osteoarthritis. 3) The correlation between tibial angle,joint gap angle on antero-posterior X-ray and WOMAC scores is significant, which can be used to assess the functional recovery of patients before and after treatment.

  7. Neck-focused panic attacks among Cambodian refugees; a logistic and linear regression analysis.

    Science.gov (United States)

    Hinton, Devon E; Chhean, Dara; Pich, Vuth; Um, Khin; Fama, Jeanne M; Pollack, Mark H

    2006-01-01

    Consecutive Cambodian refugees attending a psychiatric clinic were assessed for the presence and severity of current--i.e., at least one episode in the last month--neck-focused panic. Among the whole sample (N=130), in a logistic regression analysis, the Anxiety Sensitivity Index (ASI; odds ratio=3.70) and the Clinician-Administered PTSD Scale (CAPS; odds ratio=2.61) significantly predicted the presence of current neck panic (NP). Among the neck panic patients (N=60), in the linear regression analysis, NP severity was significantly predicted by NP-associated flashbacks (beta=.42), NP-associated catastrophic cognitions (beta=.22), and CAPS score (beta=.28). Further analysis revealed the effect of the CAPS score to be significantly mediated (Sobel test [Baron, R. M., & Kenny, D. A. (1986). The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173-1182]) by both NP-associated flashbacks and catastrophic cognitions. In the care of traumatized Cambodian refugees, NP severity, as well as NP-associated flashbacks and catastrophic cognitions, should be specifically assessed and treated.

  8. Finding determinants of audit delay by pooled OLS regression analysis

    OpenAIRE

    Vuko, Tina; Čular, Marko

    2014-01-01

    The aim of this paper is to investigate determinants of audit delay. Audit delay is measured as the length of time (i.e. the number of calendar days) from the fiscal year-end to the audit report date. It is important to understand factors that influence audit delay since it directly affects the timeliness of financial reporting. The research is conducted on a sample of Croatian listed companies, covering the period of four years (from 2008 to 2011). We use pooled OLS regression analysis, mode...

  9. A Seemingly Unrelated Poisson Regression Model

    OpenAIRE

    King, Gary

    1989-01-01

    This article introduces a new estimator for the analysis of two contemporaneously correlated endogenous event count variables. This seemingly unrelated Poisson regression model (SUPREME) estimator combines the efficiencies created by single equation Poisson regression model estimators and insights from "seemingly unrelated" linear regression models.

  10. Dose-Dependent Effects of Statins for Patients with Aneurysmal Subarachnoid Hemorrhage: Meta-Regression Analysis.

    Science.gov (United States)

    To, Minh-Son; Prakash, Shivesh; Poonnoose, Santosh I; Bihari, Shailesh

    2018-05-01

    The study uses meta-regression analysis to quantify the dose-dependent effects of statin pharmacotherapy on vasospasm, delayed ischemic neurologic deficits (DIND), and mortality in aneurysmal subarachnoid hemorrhage. Prospective, retrospective observational studies, and randomized controlled trials (RCTs) were retrieved by a systematic database search. Summary estimates were expressed as absolute risk (AR) for a given statin dose or control (placebo). Meta-regression using inverse variance weighting and robust variance estimation was performed to assess the effect of statin dose on transformed AR in a random effects model. Dose-dependence of predicted AR with 95% confidence interval (CI) was recovered by using Miller's Freeman-Tukey inverse. The database search and study selection criteria yielded 18 studies (2594 patients) for analysis. These included 12 RCTs, 4 retrospective observational studies, and 2 prospective observational studies. Twelve studies investigated simvastatin, whereas the remaining studies investigated atorvastatin, pravastatin, or pitavastatin, with simvastatin-equivalent doses ranging from 20 to 80 mg. Meta-regression revealed dose-dependent reductions in Freeman-Tukey-transformed AR of vasospasm (slope coefficient -0.00404, 95% CI -0.00720 to -0.00087; P = 0.0321), DIND (slope coefficient -0.00316, 95% CI -0.00586 to -0.00047; P = 0.0392), and mortality (slope coefficient -0.00345, 95% CI -0.00623 to -0.00067; P = 0.0352). The present meta-regression provides weak evidence for dose-dependent reductions in vasospasm, DIND and mortality associated with acute statin use after aneurysmal subarachnoid hemorrhage. However, the analysis was limited by substantial heterogeneity among individual studies. Greater dosing strategies are a potential consideration for future RCTs. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Social capital and self-rated health among older Korean immigrants.

    Science.gov (United States)

    Kim, Bum Jung; Harris, Lesley Maradik

    2013-12-01

    The objective of this article is to investigate determinants of self-rated health and describe their association with social capital and socioeconomic characteristics among older Korean immigrants. A cross-sectional study of 205 older Korean immigrants (aged 60 years and older) was conducted in Los Angeles county. Independent variables included age, gender, marital status, income of the older Koreans, and social capital included social norms, trust, partnership with the community, information sharing, and political participation. Self-rated health was the dependent variable. Descriptive analyses were done to show group differences in self-rated health and logistic regression analyses to identify determinants of self-rated health. Gender (male), high income, and high levels of information sharing were significant determinants of high self-rated health status among older Korean immigrants. This population-based study provides empirical evidence that gender, income, and information sharing are directly associated with the self-rated health status of older Korean immigrants.

  12. Quantile regression theory and applications

    CERN Document Server

    Davino, Cristina; Vistocco, Domenico

    2013-01-01

    A guide to the implementation and interpretation of Quantile Regression models This book explores the theory and numerous applications of quantile regression, offering empirical data analysis as well as the software tools to implement the methods. The main focus of this book is to provide the reader with a comprehensivedescription of the main issues concerning quantile regression; these include basic modeling, geometrical interpretation, estimation and inference for quantile regression, as well as issues on validity of the model, diagnostic tools. Each methodological aspect is explored and

  13. Functional abilities in older adults with mild cognitive impairment.

    Science.gov (United States)

    Burton, Catherine L; Strauss, Esther; Bunce, David; Hunter, Michael A; Hultsch, David F

    2009-01-01

    A classification scheme and general set of criteria for diagnosing mild cognitive impairment (MCI) were recently proposed by a multidisciplinary group of experts who met at an international symposium on MCI. One of the proposed criteria included preserved basic activities of daily living and minimal impairment in complex instrumental activities of daily living (IADLs). To investigate whether older adults with MCI classified according to the subtypes identified by the Working Group (i.e. amnestic, single non-memory domain, and multiple domain with or without a memory component) differed from cognitively intact older adults on a variety of measures indexing IADLs and to examine how well measures of IADL predict concurrent MCI status. Two hundred and fifty community-dwelling older adults, ranging in age from 66 to 92, completed self-report measures of IADLs (Lawton and Brody IADL Scale, Scales of Independent Behaviour-Revised--SIB-R) and a measure of everyday problem solving indexing IADLs (Everyday Problems Test--EPT). Ratings of participants' IADL functioning were also obtained from informants (e.g. spouse, adult child and friend). Older adults with multiple-domain MCI demonstrated poorer IADL functioning than older adults with no cognitive impairment on the EPT and the SIB-R (both self- and informant-report versions). The multiple-domain MCI participants also demonstrated poorer IADLs than MCI participants with impairments in a single cognitive domain on the self-reported SIB-R and EPT. The single-domain MCI groups demonstrated poorer IADLs than older adults without cognitive impairment on the informant-reported SIB-R and EPT. No significant group differences were found on the Lawton and Brody IADL Scale. Using the EPT and SIB-R as predictors in a multinomial regression analysis, MCI group status was reliably predicted, but the classification rate was poor. Individuals with MCI demonstrated poorer IADL functioning compared to cognitively intact older adults

  14. The role of cognitive flexibility in cognitive restructuring skill acquisition among older adults.

    Science.gov (United States)

    Johnco, C; Wuthrich, V M; Rapee, R M

    2013-08-01

    Cognitive flexibility is one aspect of executive functioning that encompasses the ability to produce diverse ideas, consider response alternatives, and modify behaviors to manage changing circumstances. These processes are likely to be important for implementing cognitive restructuring. The present study investigated the impact of cognitive flexibility on older adults' ability to learn cognitive restructuring. Neuropsychological measures of cognitive flexibility were administered to 40 normal community-dwelling older adult volunteers and their ability to implement cognitive restructuring was coded and analyzed. Results indicated that the majority of participants showed good cognitive restructuring skill acquisition with brief training. The multiple regression analysis suggested that those with poorer cognitive flexibility on neuropsychological testing demonstrated poorer quality cognitive restructuring. In particular, perseverative thinking styles appear to negatively impact the ability to learn cognitive restructuring. Further research is needed to clarify whether older adults with poor cognitive flexibility can improve their cognitive restructuring skills with repetition over treatment or whether alternative skills should be considered. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  15. Donepezil is associated with decreased in-hospital mortality as a result of pneumonia among older patients with dementia: A retrospective cohort study.

    Science.gov (United States)

    Abe, Yasuko; Shimokado, Kentaro; Fushimi, Kiyohide

    2018-02-01

    Pneumonia is one of the major causes of mortality in older adults. As the average lifespan has extended and new modalities to prevent or treat pneumonia are developed, the factors that affect the length of hospital stay (LHS) and in-hospital mortality of older patients with pneumonia have changed. The object of the present study was to determine the factors associated with LHS and mortality as a result of pneumonia among older patients with dementia. With a retrospective cohort study design, we used the data derived from the Japanese Administrative Database and diagnosis procedure combination/per diem payment system (DPC/PDPS) database. There were 39 336 admissions of older patients for pneumonia between August 2010 and March 2012. Patients with incomplete data were excluded, leaving 25 602 patients for analysis. Having dementia decreased mortality (OR 0.71, P LHS. Multiple logistic regression analysis identified donepezil as an independent factor that decreased mortality in patients with dementia (OR 0.36, P LHS and mortality were similar to those reported by others. Donepezil seems to decrease in-hospital mortality as a result of pneumonia among older patients with dementia. Geriatr Gerontol Int 2018; 18: 269-275. © 2017 Japan Geriatrics Society.

  16. Use of clozapine in older Asian patients with schizophrenia between 2001 and 2009.

    Directory of Open Access Journals (Sweden)

    Yu-Tao Xiang

    Full Text Available BACKGROUND: To date there has been no large-scale international study that examined the use of clozapine in older patients with schizophrenia. This study examined the use of clozapine and its demographic and clinical correlates in older patients with schizophrenia in East Asia during the period between 2001 and 2009. METHOD: Information on 1,157 hospitalized patients with schizophrenia aged 50 or older in five East Asian countries and territories (China, Hong Kong, Korea, Singapore and Taiwan was extracted from the database of the Research on Asian Psychotropic Prescription Patterns (REAP project. Socio-demographic and clinical characteristics and prescription of psychotropic medications were recorded. RESULTS: Clozapine was prescribed for 20.6% of the pooled sample; 19.0% in 2001, 19.4% in 2004 and 22.9% in 2009. Multiple logistic regression analysis of the whole sample revealed that patients taking clozapine had a longer duration of illness, more negative symptoms and were less likely to receive first generation antipsychotic and anticholinergic drugs, but more likely to report weight gain compared to those not receiving clozapine. Compared to those in other sites, older patients in China were more likely to receive clozapine. CONCLUSIONS: The prescription of clozapine for older Asian schizophrenia inpatients has remained at a stable level during the past decade. The appropriateness of use of clozapine in China needs to be further explored.

  17. Logistic Regression and Path Analysis Method to Analyze Factors influencing Students’ Achievement

    Science.gov (United States)

    Noeryanti, N.; Suryowati, K.; Setyawan, Y.; Aulia, R. R.

    2018-04-01

    Students' academic achievement cannot be separated from the influence of two factors namely internal and external factors. The first factors of the student (internal factors) consist of intelligence (X1), health (X2), interest (X3), and motivation of students (X4). The external factors consist of family environment (X5), school environment (X6), and society environment (X7). The objects of this research are eighth grade students of the school year 2016/2017 at SMPN 1 Jiwan Madiun sampled by using simple random sampling. Primary data are obtained by distributing questionnaires. The method used in this study is binary logistic regression analysis that aims to identify internal and external factors that affect student’s achievement and how the trends of them. Path Analysis was used to determine the factors that influence directly, indirectly or totally on student’s achievement. Based on the results of binary logistic regression, variables that affect student’s achievement are interest and motivation. And based on the results obtained by path analysis, factors that have a direct impact on student’s achievement are students’ interest (59%) and students’ motivation (27%). While the factors that have indirect influences on students’ achievement, are family environment (97%) and school environment (37).

  18. The importance of job training to job satisfaction of older workers.

    Science.gov (United States)

    Leppel, Karen; Brucker, Eric; Cochran, Jeremy

    2012-01-01

    If job training has positive impacts on worker satisfaction, then job training can have desirable consequences for an organization that result both directly through its effects on productivity and indirectly through its effects on job satisfaction. Furthermore, the aging of the workforce implies that older workers will become increasingly important to firms and to the economy. This study, therefore, seeks to examine the relationship between job training and job satisfaction, focusing in particular on U.S. workers born in 1964 or earlier. The results of ordered logit regression analysis indicate that availability and quality of training received directly affect job satisfaction.

  19. Evaluation of successful aging among older people in China: Results from China health and retirement longitudinal study.

    Science.gov (United States)

    Liu, Huaqing; Byles, Julie E; Xu, Xiaoyue; Zhang, Min; Wu, Xuesen; Hall, John J

    2017-08-01

    China faces a "time-bomb" of the aging population. Successful aging has long been a goal in the field of gerontology. The present study aimed to evaluate successful aging among Chinese older adults. Data on a total of 7102 people in the China Health and Retirement Study aged ≥60 years were analyzed in the present study. Successful aging is defined by the model of Rowe and Kahn including the following five indicators: "no major diseases," "no disability," "high cognitive functioning," "high physical functioning" and "active engagement with life." Using logistic regression analysis, crude and adjusted odds ratios with 95% confidence intervals were calculated to evaluate the relationship between sociodemographic parameters and successful aging. The prevalence of successful aging was 13.2% among Chinese older people. The percentage of older people with the five indicators, "no major diseases," "no disability," "high cognitive functioning," "high physical functioning," and "active engagement with life" was 41.7%, 92.1%, 54.2%, 70.2% and 46.0%, respectively. Multiple logistic regression showed people who had received education of high/vocational school or above had significantly greater odds of successful aging compared with those with less than primary school education (P aging than those from an agricultural Hukou. Older people living in the central, northeast or western regions had lower odds of successful aging relative to those living in the east coast region (0.72, 0.72 and 0.56, respectively). The prevalence of successful aging is low among Chinese older people, and is affected by sociodemographic factors, such as education, Hukou and regions. Geriatr Gerontol Int 2017; 17: 1183-1190. © 2016 Japan Geriatrics Society.

  20. Beyond the mean estimate: a quantile regression analysis of inequalities in educational outcomes using INVALSI survey data

    Directory of Open Access Journals (Sweden)

    Antonella Costanzo

    2017-09-01

    Full Text Available Abstract The number of studies addressing issues of inequality in educational outcomes using cognitive achievement tests and variables from large-scale assessment data has increased. Here the value of using a quantile regression approach is compared with a classical regression analysis approach to study the relationships between educational outcomes and likely predictor variables. Italian primary school data from INVALSI large-scale assessments were analyzed using both quantile and standard regression approaches. Mathematics and reading scores were regressed on students' characteristics and geographical variables selected for their theoretical and policy relevance. The results demonstrated that, in Italy, the role of gender and immigrant status varied across the entire conditional distribution of students’ performance. Analogous results emerged pertaining to the difference in students’ performance across Italian geographic areas. These findings suggest that quantile regression analysis is a useful tool to explore the determinants and mechanisms of inequality in educational outcomes. A proper interpretation of quantile estimates may enable teachers to identify effective learning activities and help policymakers to develop tailored programs that increase equity in education.

  1. Dental caries, periodontal disease, and cardiac arrhythmias in community-dwelling older persons aged 80 and older: is there a link?

    DEFF Research Database (Denmark)

    Holm-Pedersen, Poul; Avlund, Kirsten; Morse, Douglas E

    2005-01-01

    lesions had 2.8 times higher odds (95% confidence interval=1.1-7.0) of arrhythmia than persons without active coronal caries, but there was no greater risk for persons with three or more coronal caries lesions. There was no association between periodontal disease and arrhythmia. CONCLUSION: The findings......OBJECTIVES: To examine whether caries or periodontitis is associated with cardiac arrhythmias in community-dwelling people aged 80 and older. SETTING: Urban, community-based population in Stockholm, Sweden. DESIGN: Cross-sectional. PARTICIPANTS: Eligible persons were identified through...... by a physician or the Stockholm Inpatient Register. Active root caries, active coronal caries, and periodontitis were assessed using previously defined National Institute of Dental and Craniofacial Research diagnostic criteria. RESULTS: The primary finding of the multivariate logistic regression analysis...

  2. Weighted functional linear regression models for gene-based association analysis.

    Science.gov (United States)

    Belonogova, Nadezhda M; Svishcheva, Gulnara R; Wilson, James F; Campbell, Harry; Axenovich, Tatiana I

    2018-01-01

    Functional linear regression models are effectively used in gene-based association analysis of complex traits. These models combine information about individual genetic variants, taking into account their positions and reducing the influence of noise and/or observation errors. To increase the power of methods, where several differently informative components are combined, weights are introduced to give the advantage to more informative components. Allele-specific weights have been introduced to collapsing and kernel-based approaches to gene-based association analysis. Here we have for the first time introduced weights to functional linear regression models adapted for both independent and family samples. Using data simulated on the basis of GAW17 genotypes and weights defined by allele frequencies via the beta distribution, we demonstrated that type I errors correspond to declared values and that increasing the weights of causal variants allows the power of functional linear models to be increased. We applied the new method to real data on blood pressure from the ORCADES sample. Five of the six known genes with P models. Moreover, we found an association between diastolic blood pressure and the VMP1 gene (P = 8.18×10-6), when we used a weighted functional model. For this gene, the unweighted functional and weighted kernel-based models had P = 0.004 and 0.006, respectively. The new method has been implemented in the program package FREGAT, which is freely available at https://cran.r-project.org/web/packages/FREGAT/index.html.

  3. Nonimaging clinical assessment of impaired swallowing in community-dwelling older adults in Taiwan.

    Science.gov (United States)

    Chen, Miao-Yen; Lin, Li-Chan

    2012-12-01

    Impaired swallowing is common in elderly patients as well as those with neurological disorders and degenerative diseases. Convenient and accurate assessments should be available to community-dwelling older adults to diagnose and provide early management and care of swallowing difficulties, an important factor of influence on elderly life quality. This study used convenient nonimaging methods to assess swallowing functions in community-dwelling older adults and estimated the prevalence of swallowing difficulties. The study adopted a survey method and recruited 216 community-dwelling older adults over 65 years old in northern Taiwan. Researchers used tools including a swallowing test, questionnaire, water test, peripheral arterial pulse oximeter, and laryngeal S-EMG to assess participant swallowing functions and the prevalence of impaired swallowing. We found a 9.5% prevalence of impaired swallowing based on swallow questionnaire and water test results. Age correlated negatively with swallowing speed. A one-way ANOVA showed a significant difference in swallowing speed among the four age groups (F = 6.478, p < .00). A post hoc Scheffe comparison showed significant differences in swallowing time between the 60- to 69- and 70- to 79-year-old groups and 60- to 69- and 80- to 89-year-old groups. Multiple regression of impaired swallowing on various independent variables showed a significant standardized coefficient of 0.163 for age (t = 2.328, p = .021). Logistic regression showed a significant Wals test value for age (p = .007). The Kappa value was 0.307 for agreement analysis between impaired swallowing and SaO(2) value reduction of more than 2%. Swallowing function deteriorates with age. Results of this study provide an assessment of the prevalence of impaired swallowing in community-dwelling older adults in Taiwan. Results can help guide clinical nurses to enhance their objective assessment of impaired swallowing to improve patient quality of life.

  4. Data analysis and approximate models model choice, location-scale, analysis of variance, nonparametric regression and image analysis

    CERN Document Server

    Davies, Patrick Laurie

    2014-01-01

    Introduction IntroductionApproximate Models Notation Two Modes of Statistical AnalysisTowards One Mode of Analysis Approximation, Randomness, Chaos, Determinism ApproximationA Concept of Approximation Approximation Approximating a Data Set by a Model Approximation Regions Functionals and EquivarianceRegularization and Optimality Metrics and DiscrepanciesStrong and Weak Topologies On Being (almost) Honest Simulations and Tables Degree of Approximation and p-values ScalesStability of Analysis The Choice of En(α, P) Independence Procedures, Approximation and VaguenessDiscrete Models The Empirical Density Metrics and Discrepancies The Total Variation Metric The Kullback-Leibler and Chi-Squared Discrepancies The Po(λ) ModelThe b(k, p) and nb(k, p) Models The Flying Bomb Data The Student Study Times Data OutliersOutliers, Data Analysis and Models Breakdown Points and Equivariance Identifying Outliers and Breakdown Outliers in Multivariate Data Outliers in Linear Regression Outliers in Structured Data The Location...

  5. Regression analysis of mixed panel count data with dependent terminal events.

    Science.gov (United States)

    Yu, Guanglei; Zhu, Liang; Li, Yang; Sun, Jianguo; Robison, Leslie L

    2017-05-10

    Event history studies are commonly conducted in many fields, and a great deal of literature has been established for the analysis of the two types of data commonly arising from these studies: recurrent event data and panel count data. The former arises if all study subjects are followed continuously, while the latter means that each study subject is observed only at discrete time points. In reality, a third type of data, a mixture of the two types of the data earlier, may occur and furthermore, as with the first two types of the data, there may exist a dependent terminal event, which may preclude the occurrences of recurrent events of interest. This paper discusses regression analysis of mixed recurrent event and panel count data in the presence of a terminal event and an estimating equation-based approach is proposed for estimation of regression parameters of interest. In addition, the asymptotic properties of the proposed estimator are established, and a simulation study conducted to assess the finite-sample performance of the proposed method suggests that it works well in practical situations. Finally, the methodology is applied to a childhood cancer study that motivated this study. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Risk of suicide according to the level of psychiatric contact in the older people: Analysis of national health insurance databases in Taiwan.

    Science.gov (United States)

    Yeh, Shin-Ting; Ng, Yee-Yung; Wu, Shiao-Chi

    2017-04-01

    Suicide in the older people is a serious problem worldwide; however the effect of psychiatric contact on the risk of suicide has not been fully explored. The aim of this study was to investigate the relationship between psychiatric contact and suicide in the older people in Taiwan. A population-based database was used in this national case-control study. Propensity score matching was used to match older people who did and did not commit suicide from 2010 to 2012 by calendar year, gender, age, and area of residence. The level of psychiatric contact in the preceding year was classified as "no psychiatric contact," "only outpatient psychiatric contact," "psychiatric emergency room contact," or "psychiatric hospital admission". Conditional logistic regression analysis was used to assess associations between variables and the risk of suicide. A total of 2528 older people committed suicide from 2010 to 2012, with a crude suicide mortality rate of 3.37/10,000. Compared to those who had no psychiatric contact in the preceding year, the adjusted odds ratios of suicide were 10.15 (95% CI=5.8-17.7) for those who had psychiatric emergency room contact, 6.57 (95% CI=3.7-11.6) for those who had psychiatric hospital admissions, and 3.64 (95% CI=3.0-4.4) for those with only outpatient psychiatric contact. The risk of suicide was higher in those who had depression (OR=3.49, 95% CI=2.2-5.4) and bipolar disorder (OR=1.98, 95% CI=1.1-3.6). Patients with cancer were associated with suicide (OR=8.96, 95% CI=5.6-14.4). The positive association with suicide and the level of psychiatric contact in the preceding year in older people indicated that the health personnel need to do a better job in determining possible risk for older people who had psychiatric contact, especially in emergency visit or psychiatric admission. A systematic approach to quality improvement in these settings is both available and necessary. Careful discharge planning and safe transitions of care to outpatient

  7. CUSUM-Logistic Regression analysis for the rapid detection of errors in clinical laboratory test results.

    Science.gov (United States)

    Sampson, Maureen L; Gounden, Verena; van Deventer, Hendrik E; Remaley, Alan T

    2016-02-01

    The main drawback of the periodic analysis of quality control (QC) material is that test performance is not monitored in time periods between QC analyses, potentially leading to the reporting of faulty test results. The objective of this study was to develop a patient based QC procedure for the more timely detection of test errors. Results from a Chem-14 panel measured on the Beckman LX20 analyzer were used to develop the model. Each test result was predicted from the other 13 members of the panel by multiple regression, which resulted in correlation coefficients between the predicted and measured result of >0.7 for 8 of the 14 tests. A logistic regression model, which utilized the measured test result, the predicted test result, the day of the week and time of day, was then developed for predicting test errors. The output of the logistic regression was tallied by a daily CUSUM approach and used to predict test errors, with a fixed specificity of 90%. The mean average run length (ARL) before error detection by CUSUM-Logistic Regression (CSLR) was 20 with a mean sensitivity of 97%, which was considerably shorter than the mean ARL of 53 (sensitivity 87.5%) for a simple prediction model that only used the measured result for error detection. A CUSUM-Logistic Regression analysis of patient laboratory data can be an effective approach for the rapid and sensitive detection of clinical laboratory errors. Published by Elsevier Inc.

  8. Unipedal stance testing as an indicator of fall risk among older outpatients.

    Science.gov (United States)

    Hurvitz, E A; Richardson, J K; Werner, R A; Ruhl, A M; Dixon, M R

    2000-05-01

    To test the hypothesis that a decreased unipedal stance time (UST) is associated with a history of falling among older persons. Fifty-three subjects underwent a standardized history and physical examination and three trials of timed unipedal stance. The electroneuromyography laboratories of tertiary care Veterans Administration and university hospitals. Ambulatory outpatients 50 years and older referred for electrodiagnostic studies. UST and fall histories during the previous year. Twenty subjects (38%) reported falling. Compared with the subjects who had not fallen, those who fell had a significantly shorter UST (9.6 [SD 11.6] vs 31.3 [SD 16.3] seconds, using the longest of the three trials, p risk of having fallen on univariate analysis and in a regression model (odds ratio 108; 95% confidence interval 3.8, >100; p falls. UST of falling, while a UST of > or = 30sec is associated with a low risk of falling.

  9. Microstructural integrity of white matter tracts amongst older fallers: A DTI study.

    Directory of Open Access Journals (Sweden)

    Yoke Queen Wong

    Full Text Available This study assesses the whole brain microstructural integrity of white matter tracts (WMT among older individuals with a history of falls compared to non-fallers.85 participants (43 fallers, 42 non-fallers were evaluated with conventional MRI and diffusion tensor imaging (DTI sequences of the brain. DTI metrics were obtained from selected WMT using tract-based spatial statistics (TBSS method. This was followed by binary logistic regression to investigate the clinical variables that could act as confounding elements on the outcomes. The TBSS analysis was then repeated, but this time including all significant predictor variables from the regression analysis as TBSS covariates.The mean diffusivity (MD and axial diffusivity (AD and to a lesser extent radial diffusivity (RD values of the projection fibers and commissural bundles were significantly different in fallers (p < 0.05 compared to non-fallers. However, the final logistic regression model obtained showed that only functional reach, white matter lesion volume, hypertension and orthostatic hypotension demonstrated statistical significant differences between fallers and non-fallers. No significant differences were found in the DTI metrics when taking into account age and the four variables as covariates in the repeated analysis.This DTI study of 85 subjects, do not support DTI metrics as a singular factor that contributes independently to the fall outcomes. Other clinical and imaging factors have to be taken into account.

  10. Using Structured Observation and Content Analysis to Explore the Presence of Older People in Public Fora in Developing Countries

    Directory of Open Access Journals (Sweden)

    Geraldine Nosowska

    2014-01-01

    Full Text Available There is a lack of research on the everyday lives of older people in developing countries. This exploratory study used structured observation and content analysis to examine the presence of older people in public fora and considered the methods’ potential for understanding older people’s social integration and inclusion. Structured observation occurred of public social spaces in six cities each located in a different developing country and in one city in the United Kingdom, together with content analysis of the presence of people in newspaper pictures and on television in the selected countries. Results indicated that across all fieldwork sites and data sources, there was a low presence of older people, with women considerably less present than men in developing countries. There was variation across fieldwork sites in older people’s presence by place and time of day and in their accompanied status. The presence of older people in images drawn from newspapers was associated with the news/non-news nature of the source. The utility of the study’s methodological approach is considered, as is the degree to which the presence of older people in public fora might relate to social integration and inclusion in different cultural contexts.

  11. Predictors of chewing ability among community-residing older adults in Korea.

    Science.gov (United States)

    Park, Kyongok; Hong, Gwi-Ryung Son

    2017-01-01

    Decreased chewing ability in older adults can lead to poor nutritional and physical conditions, and eventually death. The present study examined the relationships between chewing ability and related characteristics (e.g. health promotion habits, health status and functional status), and identified predictors of chewing ability in community-residing older adults. Among the total of 11 542 participants in the 2011 National Survey on Older Adults in Korea, data from 10 543 participants were used for analysis. Chewing ability was evaluated using a self-report of chewing ability. Exercise ability was assessed by objective exercise ability and perceived exercise ability in both the upper and lower extremities. Depression and cognitive functions were measured using the Geriatric Depression Scale-Short Form and the Mini-Mental State Examination, respectively. A total of 56.9% of participants had poor chewing abilities. After adjusting for age and sex, logistic regression analysis showed that depression (OR 1.76, 95% CI 1.60-1.92), cognitive impairment (OR 1.28, 95% CI 1.17-1.40), objective exercise ability (OR 1.24, 95% CI 1.11-1.41), regular exercise habits (OR 1.23, 95% CI 1.13-1.34), medical check-up history (OR 1.17, 95% CI 1.05-1.32), number of chronic diseases (OR 1.12, 95% CI 1.09-1.15) and perceived exercise ability in the lower extremities (OR 1.08, 95% CI 1.05-1.10) were significant predictors of chewing ability. Chewing ability in older adults should be improved in consideration of mental and general health condition. Geriatr Gerontol Int 2017; 17: 78-84. © 2015 Japan Geriatrics Society.

  12. Psychosocial and perceived environmental correlates of physical activity in rural and older african american and white women.

    Science.gov (United States)

    Wilcox, Sara; Bopp, Melissa; Oberrecht, Larissa; Kammermann, Sandra K; McElmurray, Charles T

    2003-11-01

    African American and rural older women are among the least active segments of the population. This study, guided by social cognitive theory, examined the correlates of physical activity (PA) in 102 rural older women (41% African American; 70.6 +/- 9.2 years). In bivariate associations, education, marital status, self-efficacy, greater pros than cons, perceived stress, social support, and perceived neighborhood safety were positively associated with PA; age, depressive symptoms, perceived sidewalks, health care provider discussion of PA, and perceived traffic were negatively associated with PA. In a hierarchical regression analysis, the sociodemographic (R(2) = 23%), psychological (IR(2) = 9%), social (IR(2) = 6%), and perceived physical environmental (IR(2) = 9%) sets of variables were significant (p motivators; falls, injuries, and heart attacks were identified most often as risks. These findings support the importance of multilevel influences on PA in older rural women and are useful for informing PA interventions.

  13. Palonosetron versus older 5-HT3 receptor antagonists for nausea prevention in patients receiving chemotherapy: a multistudy analysis.

    Science.gov (United States)

    Morrow, Gary R; Schwartzberg, Lee; Barbour, Sally Y; Ballinari, Gianluca; Thorn, Michael D; Cox, David

    2014-07-01

    No clinical standard currently exists for the optimal management of nausea induced by emetogenic chemotherapy, 7particularly delayed nausea. To compare the effcacy and safety of palonosetron with older 5-HT3 receptor antagonists (RAs) in preventing chemotherapy-induced nausea. Data were pooled from 4 similarly designed multicenter, randomized, double-blind, clinical trials that compared single intravenous doses of palonosetron 0.25 mg or 0.75 mg with ondansetron 32 mg, dolasetron 100 mg, or granisetron 40 μg/kg, administered 30 minutes before moderately emetogenic chemotherapy (MEC) or highly emetogenic chemotherapy (HEC). Pooled data within each chemotherapy category (MEC: n = 1,132; HEC: n = 1,781) were analyzed by a logistic regression model. Nausea endpoints were complete control rates (ie, no more than mild nausea, no vomiting, and no rescue medication), nausea-free rates, nausea severity, and requirement for rescue antiemetic/antinausea medication over 5 days following chemotherapy. Pooled safety data were summarized descriptively. Numerically more palonosetron-treated patients were nausea-free on each day, and fewer had moderate-severe nausea. Similarly, usage of rescue medication was less frequent among palonosetron-treated patients. Complete control rates for palonosetron and older 5-HT3 RAs in the acute phase were 66% vs 63%, 52% vs 42% in the delayed phase (24-120 hours), and 46% vs 37% in the overall phase. The incidence of adverse events was similar for palonosetron and older 5-HT3 RAs. This post hoc analysis summarized data for palonosetron and several other 5-HT3 RAs but was not powered for statistical comparisons between individual agents. Because nausea is inherently subjective, the reliability of assessments of some aspects (eg, severity) may be infuenced by interindividual variability. Palonosetron may be more effective than older 5-HT3 RAs in preventing nausea, with comparable tolerability. Dr Schwartzberg is a consultant to and Dr Cox an

  14. Analysis of sparse data in logistic regression in medical research: A newer approach

    Directory of Open Access Journals (Sweden)

    S Devika

    2016-01-01

    Full Text Available Background and Objective: In the analysis of dichotomous type response variable, logistic regression is usually used. However, the performance of logistic regression in the presence of sparse data is questionable. In such a situation, a common problem is the presence of high odds ratios (ORs with very wide 95% confidence interval (CI (OR: >999.999, 95% CI: 999.999. In this paper, we addressed this issue by using penalized logistic regression (PLR method. Materials and Methods: Data from case-control study on hyponatremia and hiccups conducted in Christian Medical College, Vellore, Tamil Nadu, India was used. The outcome variable was the presence/absence of hiccups and the main exposure variable was the status of hyponatremia. Simulation dataset was created with different sample sizes and with a different number of covariates. Results: A total of 23 cases and 50 controls were used for the analysis of ordinary and PLR methods. The main exposure variable hyponatremia was present in nine (39.13% of the cases and in four (8.0% of the controls. Of the 23 hiccup cases, all were males and among the controls, 46 (92.0% were males. Thus, the complete separation between gender and the disease group led into an infinite OR with 95% CI (OR: >999.999, 95% CI: 999.999 whereas there was a finite and consistent regression coefficient for gender (OR: 5.35; 95% CI: 0.42, 816.48 using PLR. After adjusting for all the confounding variables, hyponatremia entailed 7.9 (95% CI: 2.06, 38.86 times higher risk for the development of hiccups as was found using PLR whereas there was an overestimation of risk OR: 10.76 (95% CI: 2.17, 53.41 using the conventional method. Simulation experiment shows that the estimated coverage probability of this method is near the nominal level of 95% even for small sample sizes and for a large number of covariates. Conclusions: PLR is almost equal to the ordinary logistic regression when the sample size is large and is superior in small cell

  15. Multiple Linear Regression Analysis of Factors Affecting Real Property Price Index From Case Study Research In Istanbul/Turkey

    Science.gov (United States)

    Denli, H. H.; Koc, Z.

    2015-12-01

    Estimation of real properties depending on standards is difficult to apply in time and location. Regression analysis construct mathematical models which describe or explain relationships that may exist between variables. The problem of identifying price differences of properties to obtain a price index can be converted into a regression problem, and standard techniques of regression analysis can be used to estimate the index. Considering regression analysis for real estate valuation, which are presented in real marketing process with its current characteristics and quantifiers, the method will help us to find the effective factors or variables in the formation of the value. In this study, prices of housing for sale in Zeytinburnu, a district in Istanbul, are associated with its characteristics to find a price index, based on information received from a real estate web page. The associated variables used for the analysis are age, size in m2, number of floors having the house, floor number of the estate and number of rooms. The price of the estate represents the dependent variable, whereas the rest are independent variables. Prices from 60 real estates have been used for the analysis. Same price valued locations have been found and plotted on the map and equivalence curves have been drawn identifying the same valued zones as lines.

  16. Prevalence of treponema species detected in endodontic infections: systematic review and meta-regression analysis.

    Science.gov (United States)

    Leite, Fábio R M; Nascimento, Gustavo G; Demarco, Flávio F; Gomes, Brenda P F A; Pucci, Cesar R; Martinho, Frederico C

    2015-05-01

    This systematic review and meta-regression analysis aimed to calculate a combined prevalence estimate and evaluate the prevalence of different Treponema species in primary and secondary endodontic infections, including symptomatic and asymptomatic cases. The MEDLINE/PubMed, Embase, Scielo, Web of Knowledge, and Scopus databases were searched without starting date restriction up to and including March 2014. Only reports in English were included. The selected literature was reviewed by 2 authors and classified as suitable or not to be included in this review. Lists were compared, and, in case of disagreements, decisions were made after a discussion based on inclusion and exclusion criteria. A pooled prevalence of Treponema species in endodontic infections was estimated. Additionally, a meta-regression analysis was performed. Among the 265 articles identified in the initial search, only 51 were included in the final analysis. The studies were classified into 2 different groups according to the type of endodontic infection and whether it was an exclusively primary/secondary study (n = 36) or a primary/secondary comparison (n = 15). The pooled prevalence of Treponema species was 41.5% (95% confidence interval, 35.9-47.0). In the multivariate model of meta-regression analysis, primary endodontic infections (P apical abscess, symptomatic apical periodontitis (P < .001), and concomitant presence of 2 or more species (P = .028) explained the heterogeneity regarding the prevalence rates of Treponema species. Our findings suggest that Treponema species are important pathogens involved in endodontic infections, particularly in cases of primary and acute infections. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Influences on emergency department length of stay for older people.

    Science.gov (United States)

    Street, Maryann; Mohebbi, Mohammadreza; Berry, Debra; Cross, Anthony; Considine, Julie

    2018-02-14

    The aim of this study was to examine the influences on emergency department (ED) length of stay (LOS) for older people and develop a predictive model for an ED LOS more than 4 h. This retrospective cohort study used organizational data linkage at the patient level from a major Australian health service. The study population was aged 65 years or older, attending an ED during the 2013/2014 financial year. We developed and internally validated a clinical prediction rule. Discriminatory performance of the model was evaluated by receiver operating characteristic (ROC) curve analysis. An integer-based risk score was developed using multivariate logistic regression. The risk score was evaluated using ROC analysis. There were 33 926 ED attendances: 57.5% (n=19 517) had an ED LOS more than 4 h. The area under ROC for age, usual accommodation, triage category, arrival by ambulance, arrival overnight, imaging, laboratory investigations, overcrowding, time to be seen by doctor, ED visits with admission and access block relating to ED LOS more than 4 h was 0.796, indicating good performance. In the validation set, area under ROC was 0.80, P-value was 0.36 and prediction mean square error was 0.18, indicating good calibration. The risk score value attributed to each risk factor ranged from 2 to 68 points. The clinical prediction rule stratified patients into five levels of risk on the basis of the total risk score. Objective identification of older people at intermediate and high risk of an ED LOS more than 4 h early in ED care enables targeted approaches to streamline the patient journey, decrease ED LOS and optimize emergency care for older people.

  18. Evaluation of logistic regression models and effect of covariates for case-control study in RNA-Seq analysis.

    Science.gov (United States)

    Choi, Seung Hoan; Labadorf, Adam T; Myers, Richard H; Lunetta, Kathryn L; Dupuis, Josée; DeStefano, Anita L

    2017-02-06

    Next generation sequencing provides a count of RNA molecules in the form of short reads, yielding discrete, often highly non-normally distributed gene expression measurements. Although Negative Binomial (NB) regression has been generally accepted in the analysis of RNA sequencing (RNA-Seq) data, its appropriateness has not been exhaustively evaluated. We explore logistic regression as an alternative method for RNA-Seq studies designed to compare cases and controls, where disease status is modeled as a function of RNA-Seq reads using simulated and Huntington disease data. We evaluate the effect of adjusting for covariates that have an unknown relationship with gene expression. Finally, we incorporate the data adaptive method in order to compare false positive rates. When the sample size is small or the expression levels of a gene are highly dispersed, the NB regression shows inflated Type-I error rates but the Classical logistic and Bayes logistic (BL) regressions are conservative. Firth's logistic (FL) regression performs well or is slightly conservative. Large sample size and low dispersion generally make Type-I error rates of all methods close to nominal alpha levels of 0.05 and 0.01. However, Type-I error rates are controlled after applying the data adaptive method. The NB, BL, and FL regressions gain increased power with large sample size, large log2 fold-change, and low dispersion. The FL regression has comparable power to NB regression. We conclude that implementing the data adaptive method appropriately controls Type-I error rates in RNA-Seq analysis. Firth's logistic regression provides a concise statistical inference process and reduces spurious associations from inaccurately estimated dispersion parameters in the negative binomial framework.

  19. Age and Gender Differences in Social Network Composition and Social Support Among Older Rural South Africans: Findings From the HAALSI Study.

    Science.gov (United States)

    Harling, Guy; Morris, Katherine Ann; Manderson, Lenore; Perkins, Jessica M; Berkman, Lisa F

    2018-03-26

    Drawing on the "Health and Aging in Africa: A Longitudinal Study of an INDEPTH community in South Africa" (HAALSI) baseline survey, we present data on older adults' social networks and receipt of social support in rural South Africa. We examine how age and gender differences in social network characteristics matched with patterns predicted by theories of choice- and constraint-based network contraction in older adults. We used regression analysis on data for 5,059 South African adults aged 40 and older. Older respondents reported fewer important social contacts and less frequent communication than their middle-aged peers, largely due to fewer nonkin connections. Network size difference between older and younger respondents was greater for women than for men. These gender and age differences were explicable by much higher levels of widowhood among older women compared to younger women and older men. There was no evidence for employment-related network contraction or selective retention of emotionally supportive ties. Marriage-related structural constraints impacted on older women's social networks in rural South Africa, but did not explain choice-based network contraction. These findings suggest that many older women in rural Africa, a growing population, may have an unmet need for social support.

  20. What Satisfies Students?: Mining Student-Opinion Data with Regression and Decision Tree Analysis

    Science.gov (United States)

    Thomas, Emily H.; Galambos, Nora

    2004-01-01

    To investigate how students' characteristics and experiences affect satisfaction, this study uses regression and decision tree analysis with the CHAID algorithm to analyze student-opinion data. A data mining approach identifies the specific aspects of students' university experience that most influence three measures of general satisfaction. The…

  1. Ca analysis: an Excel based program for the analysis of intracellular calcium transients including multiple, simultaneous regression analysis.

    Science.gov (United States)

    Greensmith, David J

    2014-01-01

    Here I present an Excel based program for the analysis of intracellular Ca transients recorded using fluorescent indicators. The program can perform all the necessary steps which convert recorded raw voltage changes into meaningful physiological information. The program performs two fundamental processes. (1) It can prepare the raw signal by several methods. (2) It can then be used to analyze the prepared data to provide information such as absolute intracellular Ca levels. Also, the rates of change of Ca can be measured using multiple, simultaneous regression analysis. I demonstrate that this program performs equally well as commercially available software, but has numerous advantages, namely creating a simplified, self-contained analysis workflow. Copyright © 2013 The Author. Published by Elsevier Ireland Ltd.. All rights reserved.

  2. Implementing the chronic care model for frail older adults in the Netherlands: study protocol of ACT (frail older adults: care in transition

    Directory of Open Access Journals (Sweden)

    Muntinga Maaike E

    2012-04-01

    Full Text Available Abstract Background Care for older adults is facing a number of challenges: health problems are not consistently identified at a timely stage, older adults report a lack of autonomy in their care process, and care systems are often confronted with the need for better coordination between health care professionals. We aim to address these challenges by introducing the geriatric care model, based on the chronic care model, and to evaluate its effects on the quality of life of community-dwelling frail older adults. Methods/design In a 2-year stepped-wedge cluster randomised clinical trial with 6-monthly measurements, the chronic care model will be compared with usual care. The trial will be carried out among 35 primary care practices in two regions in the Netherlands. Per region, practices will be randomly allocated to four allocation arms designating the starting point of the intervention. Participants: 1200 community-dwelling older adults aged 65 or over and their primary informal caregivers. Primary care physicians will identify frail individuals based on a composite definition of frailty and a polypharmacy criterion. Final inclusion criterion: scoring 3 or more on a disability case-finding tool. Intervention: Every 6 months patients will receive a geriatric in-home assessment by a practice nurse, followed by a tailored care plan. Expert teams will manage and train practice nurses. Patients with complex care needs will be reviewed in interdisciplinary consultations. Evaluation: We will perform an effect evaluation, an economic evaluation, and a process evaluation. Primary outcome is quality of life as measured with the Short Form-12 questionnaire. Effect analyses will be based on the “intention-to-treat” principle, using multilevel regression analysis. Cost measurements will be administered continually during the study period. A cost-effectiveness analysis and cost-utility analysis will be conducted comparing mean total costs to functional

  3. Going outdoors and cognitive function among community-dwelling older adults: Moderating role of physical function.

    Science.gov (United States)

    Harada, Kazuhiro; Lee, Sangyoon; Park, Hyuntae; Shimada, Hiroyuki; Makizako, Hyuma; Doi, Takehiko; Yoshida, Daisuke; Tsutsumimoto, Kota; Anan, Yuya; Uemura, Kazuki; Suzuki, Takao

    2016-01-01

    Identifying the risk factors of cognitive impairment is essential for implementing effective prevention strategies for dementia. Previous studies have shown that the frequency of going outdoors is inversely associated with cognitive decline. Little research has examined whether the relationship between going outdoors and cognitive decline varies with physical functioning in older adults. The aim of the present study was to examine the relationship between going outdoors and cognitive function in older adults with and without physical function limitations. The present study analyzed the data of 4450 individuals (aged 65 years or older) who participated in the Obu Study of Health Promotion for the Elderly. The measures were the Mini-Mental State Examination (MMSE), going outdoors (at least once a week or not), self-reported physical function limitations (with or without), and demographic and health-related factors as potential confounders. Analysis of covariance and post-hoc comparisons showed that although going outdoors at least once a week was associated with higher MMSE scores among older adults with limited physical function, it was not significantly associated with the MMSE scores among older adults without limited physical function. Similarly, logistic regression analyses, stratified by physical function, showed a significant association between going outdoors and MMSE (older adults with limited physical function. The results show that going outdoors less than once a week is associated with decreased cognitive function among older adults with limited physical function, but it is not associated with cognitive function among older adults without limited physical function. © 2015 Japan Geriatrics Society.

  4. Social and health determinants of gender differences in disability amongst older adults in South Africa

    Directory of Open Access Journals (Sweden)

    Nancy Phaswana-Mafuya

    2013-09-01

    Full Text Available There has been an unprecedented increase in population ageing resulting in the increase in prevalence of various health conditions, including disability and associated risk factors. This study aimed to investigate the prevalence and predictors of functional status and disability amongst older South Africans. Little is known about disability amongst older South Africans because most previous health research has focused on younger individuals and infectious diseases. We conducted a national population-based cross-sectional study with a sample of 3840 subjects aged 50 years or older in South Africa. Multivariable regression analysis was performed in order to assess the association of social factors, health variables and functional disability. Overall, 37.2%of the respondents had moderate or severe and/or very severe functional disability, this being higher amongst women. The highest disability was found for the mobility, cognition and participation domains. In all domains, except for the self-care domain, women had a higher disability prevalence. Multivariable analysis amongst men revealed that older age, having some or primary education, being from Indian or Asian race, having chronic conditions, physical inactivity and a lower quality of life were associated with functional disability. Amongst women, older age, as well as having chronic conditions and a lower quality of life, were associated with functional disability. This study has implications for health-sector strategic plans aimed at preventing disabilities, ensuring access to curative and rehabilitative care. This study forms an evidence base upon which future policies and health care management systems can be based.

  5. Plasma biomarkers of depressive symptoms in older adults.

    Science.gov (United States)

    Arnold, S E; Xie, S X; Leung, Y-Y; Wang, L-S; Kling, M A; Han, X; Kim, E J; Wolk, D A; Bennett, D A; Chen-Plotkin, A; Grossman, M; Hu, W; Lee, V M-Y; Mackin, R Scott; Trojanowski, J Q; Wilson, R S; Shaw, L M

    2012-01-03

    The pathophysiology of negative affect states in older adults is complex, and a host of central nervous system and peripheral systemic mechanisms may play primary or contributing roles. We conducted an unbiased analysis of 146 plasma analytes in a multiplex biochemical biomarker study in relation to number of depressive symptoms endorsed by 566 participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI) at their baseline and 1-year assessments. Analytes that were most highly associated with depressive symptoms included hepatocyte growth factor, insulin polypeptides, pregnancy-associated plasma protein-A and vascular endothelial growth factor. Separate regression models assessed contributions of past history of psychiatric illness, antidepressant or other psychotropic medicine, apolipoprotein E genotype, body mass index, serum glucose and cerebrospinal fluid (CSF) τ and amyloid levels, and none of these values significantly attenuated the main effects of the candidate analyte levels for depressive symptoms score. Ensemble machine learning with Random Forests found good accuracy (~80%) in classifying groups with and without depressive symptoms. These data begin to identify biochemical biomarkers of depressive symptoms in older adults that may be useful in investigations of pathophysiological mechanisms of depression in aging and neurodegenerative dementias and as targets of novel treatment approaches.

  6. Robust Regression and its Application in Financial Data Analysis

    OpenAIRE

    Mansoor Momeni; Mahmoud Dehghan Nayeri; Ali Faal Ghayoumi; Hoda Ghorbani

    2010-01-01

    This research is aimed to describe the application of robust regression and its advantages over the least square regression method in analyzing financial data. To do this, relationship between earning per share, book value of equity per share and share price as price model and earning per share, annual change of earning per share and return of stock as return model is discussed using both robust and least square regressions, and finally the outcomes are compared. Comparing the results from th...

  7. Social support and depressive symptom disparity between urban and rural older adults in China.

    Science.gov (United States)

    Hu, Hongwei; Cao, Qi; Shi, Zhenzhen; Lin, Weixia; Jiang, Haixia; Hou, Yucheng

    2018-09-01

    Depressive symptom disparity between urban and rural older adults is an important public health issue in China. Social support is considered as an effective way to alleviate depression of older adults. This study aimed to investigate the extent to which social support could explain the depressive symptom disparity between urban and rural older adults in China. This study used data drawn from the 2011 China Health and Retirement Longitudinal Study with 6,772 observations. Multiple data analysis strategies were adopted, including descriptive analyses, bivariate analyses, regression analyses and decomposition analyses. There were significant depressive symptom disparities between urban and rural older adults in China. Social support had significant association with depressive symptom of older adults while adjusting for covariates. About 25%-28% of the depressive symptom disparities could be attributed to urban-rural gaps in social support, in which community support contributed 21%-25%. Educational level and physical health status also contributed to the disparities. This study only established correlations between social support and depressive symptom disparity rather than casual relationships; and the self-reported measurement of depressive symptom and the unobservable cultural factors might cause limitations. The urban-rural gap in social support, especially community support was a prime explanation for depressive symptom disparities between urban and rural older adults in China. To reduce the depressive symptom disparities, effective community construction in rural China should be put into place, including improving the infrastructure construction, strengthening the role of social organizations, and encouraging community interpersonal interactions for older adults. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Support vector methods for survival analysis: a comparison between ranking and regression approaches.

    Science.gov (United States)

    Van Belle, Vanya; Pelckmans, Kristiaan; Van Huffel, Sabine; Suykens, Johan A K

    2011-10-01

    To compare and evaluate ranking, regression and combined machine learning approaches for the analysis of survival data. The literature describes two approaches based on support vector machines to deal with censored observations. In the first approach the key idea is to rephrase the task as a ranking problem via the concordance index, a problem which can be solved efficiently in a context of structural risk minimization and convex optimization techniques. In a second approach, one uses a regression approach, dealing with censoring by means of inequality constraints. The goal of this paper is then twofold: (i) introducing a new model combining the ranking and regression strategy, which retains the link with existing survival models such as the proportional hazards model via transformation models; and (ii) comparison of the three techniques on 6 clinical and 3 high-dimensional datasets and discussing the relevance of these techniques over classical approaches fur survival data. We compare svm-based survival models based on ranking constraints, based on regression constraints and models based on both ranking and regression constraints. The performance of the models is compared by means of three different measures: (i) the concordance index, measuring the model's discriminating ability; (ii) the logrank test statistic, indicating whether patients with a prognostic index lower than the median prognostic index have a significant different survival than patients with a prognostic index higher than the median; and (iii) the hazard ratio after normalization to restrict the prognostic index between 0 and 1. Our results indicate a significantly better performance for models including regression constraints above models only based on ranking constraints. This work gives empirical evidence that svm-based models using regression constraints perform significantly better than svm-based models based on ranking constraints. Our experiments show a comparable performance for methods

  9. Cognitive Strategies and Physical Activity in Older Adults: A Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    Nathalie André

    2018-01-01

    Full Text Available Background. Although a number of studies have examined sociodemographic, psychosocial, and environmental determinants of the level of physical activity (PA for older people, little attention has been paid to the predictive power of cognitive strategies for independently living older adults. However, cognitive strategies have recently been considered to be critical in the management of day-to-day living. Methods. Data were collected from 243 men and women aged 55 years and older living in France using face-to-face interviews between 2011 and 2013. Results. A stepwise discriminant analysis selected five predictor variables (age, perceived health status, barriers’ self-efficacy, internal memory, and attentional control strategies of the level of PA. The function showed that the rate of correct prediction was 73% for the level of PA. The calculated discriminant function based on the five predictor variables is useful for detecting individuals at high risk of lapses once engaged in regular PA. Conclusions. This study highlighted the need to consider cognitive functions as a determinant of the level of PA and, more specifically, those cognitive functions related to executive functions (internal memory and attentional control, to facilitate the maintenance of regular PA. These results are discussed in relation to successful aging.

  10. Regression Analysis for Multivariate Dependent Count Data Using Convolved Gaussian Processes

    OpenAIRE

    Sofro, A'yunin; Shi, Jian Qing; Cao, Chunzheng

    2017-01-01

    Research on Poisson regression analysis for dependent data has been developed rapidly in the last decade. One of difficult problems in a multivariate case is how to construct a cross-correlation structure and at the meantime make sure that the covariance matrix is positive definite. To address the issue, we propose to use convolved Gaussian process (CGP) in this paper. The approach provides a semi-parametric model and offers a natural framework for modeling common mean structure and covarianc...

  11. High Prevalence of Physical Frailty Among Community-Dwelling Malnourished Older Adults-A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Verlaan, Sjors; Ligthart-Melis, Gerdien C; Wijers, Sander L J; Cederholm, Tommy; Maier, Andrea B; de van der Schueren, Marian A E

    2017-05-01

    Malnutrition and frailty are two geriatric syndromes that significantly affect independent living and health in community-dwelling older adults. Although the pathophysiology of malnutrition and physical frailty share common pathways, it is unknown to what extent these syndromes overlap and how they relate to each other. A systematic review was performed resulting in a selection of 28 studies that assessed both malnutrition and frailty in community-dwelling older adults. Furthermore, a meta-analysis was performed on 10 studies that used Mini- Nutritional Assessment and the Fried frailty phenotype to estimate the prevalence of malnutrition within physical frailty and vice versa. In the systematic review, 25 of the 28 studies used the Mini-Nutritional Assessment (long or short form) for malnutrition screening. For frailty assessment, 23 of the 28 studies focused on the physical frailty phenotype, of which 19 followed the original Fried phenotype. Fifteen studies analyzed the association between malnutrition and frailty, which was significant in 12 of these. The meta-analysis included 10 studies with a total of 5447 older adults. In this pooled population of community-dwelling older adults [mean (standard deviation) age: 77.2 (6.7) years], 2.3% was characterized as malnourished and 19.1% as physically frail. The prevalence of malnutrition was significantly associated with the prevalence of physical frailty (P dwelling older adults are related, but not interchangeable geriatric syndromes. Two out of 3 malnourished older adults were physically frail, whereas close to 10% of the physically frail older adults was identified as malnourished. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  12. Case-mix analysis and variation in rates of non-surgical treatment of older women with operable breast cancer.

    Science.gov (United States)

    Morgan, J; Richards, P; Ward, S; Francis, M; Lawrence, G; Collins, K; Reed, M; Wyld, L

    2015-08-01

    Non-surgical management of older women with oestrogen receptor (ER)-positive operable breast cancer is common in the UK, with up to 40 per cent of women aged over 70 years receiving primary endocrine therapy. Although this may be appropriate for frailer patients, for some it may result in treatment failure, contributing to the poor outcomes seen in this age group. Wide variation in the rates of non-operative management of breast cancer in older women exists across the UK. Case mix may explain some of this variation in practice. Data from two UK regional cancer registries were analysed to determine whether variation in treatment observed between 2002 and 2010 at hospital and clinician level persisted after adjustment for case mix. Expected case mix-adjusted surgery rates were derived by logistic regression using the variables age, proxy Charlson co-morbidity score, deprivation quintile, method of cancer detection, tumour size, stage, grade and node status. Data on 17,129 women aged 70 years or more with ER-positive operable breast cancer were analysed. There was considerable variation in rates of surgery at both hospital and clinician level. Despite adjusting for case mix, this variation persisted at hospital level, although not at clinician level. This study demonstrates variation in selection criteria for older women for operative treatment of early breast cancer, indicating that some older women may be undertreated or overtreated, and may partly explain the inferior disease outcomes in this age group. It emphasizes the urgent need for evidence-based guidelines for treatment selection criteria in older women with breast cancer. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

  13. Fear of falling and its association with life-space mobility of older adults: a cross-sectional analysis using data from five international sites.

    Science.gov (United States)

    Auais, Mohammad; Alvarado, Beatriz; Guerra, Ricardo; Curcio, Carmen; Freeman, Ellen E; Ylli, Alban; Guralnik, Jack; Deshpande, Nandini

    2017-05-01

    fear of falling (FOF) is a major health concern among community-dwelling older adults that could restrict mobility. to examine the association of FOF with life-space mobility (i.e. the spatial area a person moves through in daily life) of community-dwelling older adults from five diverse sites. in total, 1,841 older adults (65-74 years) were recruited from Kingston, Canada; Saint-Hyacinthe, Canada; Tirana, Albania; Manizales, Colombia and Natal, Brazil. FOF was assessed using the Fall Efficacy Scale-International (FES-I total score), and the life space was quantified using the Life-Space Assessment (LSA), a scale that runs from 0 (minimum life space) to 120 (maximum life space). the overall average LSA total score was 68.7 (SD: 21.2). Multiple-linear regression analysis demonstrated a significant relationship of FOF with life-space mobility, even after adjusting for functional, clinical and sociodemographic confounders (B = -0.15, 95% confidence interval (CI) -0.26 to -0.04). The FOF × site interaction term was significant with a stronger linear relationship found in the Canadian sites and Tirana compared with the South American sites. After adjusting for all confounders, the association between FOF with LSA remained significant at Kingston (B = -0.32, 95% CI -0.62 to -0.01), Saint-Hyacinthe (B = -0.81, 95% CI -1.31 to -0.32) and Tirana (B = -0.57, 95% CI -0.89 to -0.24). FOF is an important psychological factor that is associated with reduction in life space of older adults in different social and cultural contexts, and the strength of this association is site specific. Addressing FOF among older adults would help improve their mobility in local communities, which in turn would improve social participation and health-related quality of life. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.All rights reserved. For permissions, please email: journals.permissions@oup.com

  14. Comparison of logistic regression and artificial neural network in low back pain prediction: second national health survey.

    Science.gov (United States)

    Parsaeian, M; Mohammad, K; Mahmoudi, M; Zeraati, H

    2012-01-01

    The purpose of this investigation was to compare empirically predictive ability of an artificial neural network with a logistic regression in prediction of low back pain. Data from the second national health survey were considered in this investigation. This data includes the information of low back pain and its associated risk factors among Iranian people aged 15 years and older. Artificial neural network and logistic regression models were developed using a set of 17294 data and they were validated in a test set of 17295 data. Hosmer and Lemeshow recommendation for model selection was used in fitting the logistic regression. A three-layer perceptron with 9 inputs, 3 hidden and 1 output neurons was employed. The efficiency of two models was compared by receiver operating characteristic analysis, root mean square and -2 Loglikelihood criteria. The area under the ROC curve (SE), root mean square and -2Loglikelihood of the logistic regression was 0.752 (0.004), 0.3832 and 14769.2, respectively. The area under the ROC curve (SE), root mean square and -2Loglikelihood of the artificial neural network was 0.754 (0.004), 0.3770 and 14757.6, respectively. Based on these three criteria, artificial neural network would give better performance than logistic regression. Although, the difference is statistically significant, it does not seem to be clinically significant.

  15. Perceived Need for Mental Health Care Among Community-Dwelling Older Adults

    OpenAIRE

    Garrido, Melissa M.; Kane, Robert L.; Kaas, Merrie; Kane, Rosalie A.

    2009-01-01

    Only half of older adults with a mental disorder use mental health services, and little is known about the causes of perceived need for mental health care (MHC). We used logistic regression to examine relationships among depression, anxiety, chronic physical illness, alcohol abuse and/or dependence, sociodemographics, and perceived need among a national sample of community-dwelling individuals 65 years of age and older (the Collaborative Psychiatric Epidemiology Surveys data set). Less than h...

  16. Robust best linear estimation for regression analysis using surrogate and instrumental variables.

    Science.gov (United States)

    Wang, C Y

    2012-04-01

    We investigate methods for regression analysis when covariates are measured with errors. In a subset of the whole cohort, a surrogate variable is available for the true unobserved exposure variable. The surrogate variable satisfies the classical measurement error model, but it may not have repeated measurements. In addition to the surrogate variables that are available among the subjects in the calibration sample, we assume that there is an instrumental variable (IV) that is available for all study subjects. An IV is correlated with the unobserved true exposure variable and hence can be useful in the estimation of the regression coefficients. We propose a robust best linear estimator that uses all the available data, which is the most efficient among a class of consistent estimators. The proposed estimator is shown to be consistent and asymptotically normal under very weak distributional assumptions. For Poisson or linear regression, the proposed estimator is consistent even if the measurement error from the surrogate or IV is heteroscedastic. Finite-sample performance of the proposed estimator is examined and compared with other estimators via intensive simulation studies. The proposed method and other methods are applied to a bladder cancer case-control study.

  17. Count me in: response to sexual orientation measures among older adults.

    Science.gov (United States)

    Fredriksen-Goldsen, Karen I; Kim, Hyun-Jun

    2015-07-01

    Health disparities exist among sexual minority older adults. Yet, health and aging surveys rarely include sexual orientation measures and when they do, they often exclude older adults from being asked about sexual orientation. This is the first population-based study to assess item nonresponse to sexual orientation measures by age and change over time. We compare response rates and examine time trends in response patterns using adjusted logistic regressions. Among adults aged 65 and older, the nonresponse rate on sexual orientation is lower than income. While older adults show higher nonresponse rates on sexual orientation than younger adults, the nonresponse rates have significantly decreased over time. By 2010, only 1.23% of older adults responded don't know/not sure, with 1.55% refusing to answer sexual orientation questions. Decisions to not ask sexual orientation among older adults must be reconsidered, given documented health disparities and rapidly changing social trends in the understanding of diverse sexualities. © The Author(s) 2014.

  18. Predictors of Discharge Disposition in Older Adults With Burns: A Study of the Burn Model Systems.

    Science.gov (United States)

    Pham, Tam N; Carrougher, Gretchen J; Martinez, Erin; Lezotte, Dennis; Rietschel, Carly; Holavanahalli, Radha; Kowalske, Karen; Esselman, Peter C

    2015-01-01

    Older patients with burn injury have a greater likelihood for discharge to nursing facilities. Recent research indicates that older patients discharged to nursing facilities are two to three times as likely to die within a 3-year period relative to those discharged to home. In light of these poor long-term outcomes, we conducted this study to identify predictors for discharge to independent vs nonindependent living status in older patients hospitalized for burns. We retrospectively reviewed all older adults (age ≥ 55 years) who were prospectively enrolled in a longitudinal multicenter study of outcomes from 1993 to 2011. Patient, injury, and treatment outcomes data were analyzed. Recognizing that transfer to inpatient rehabilitation may have impacted final hospital discharge disposition: we assessed the likelihood of inpatient rehabilitation stay, based on identified predictors of inpatient rehabilitation. We subsequently performed a logistic regression analysis on the clustered, propensity-matched cohort to assess associations of burn and injury characteristics on the primary outcome of final discharge status. A total of 591 patients aged ≥55 years were treated and discharged alive from three participating U.S. burn centers during the study period. Mean burn size was 14.8% (SD 11.2%) and mean age was 66.7 years (SD 9.3 years). Ninety-three patients had an inpatient rehabilitation stay before discharge (15.7%). Significant factors predictive of inpatient rehabilitation included a burn >20% TBSA, mechanical ventilation, older age, range of motion deficits at acute care discharge, and study site. These factors were included in the propensity model. Four hundred seventy-one patients (80%) were discharged to independent living status. By matched propensity analysis, older age was significantly associated with a higher likelihood of discharge to nonindependent living (P burn centers need to be elucidated to better understand discharge disposition status in older

  19. Sensitivity of Microstructural Factors Influencing the Impact Toughness of Hypoeutectoid Steels with Ferrite-Pearlite Structure using Multiple Regression Analysis

    International Nuclear Information System (INIS)

    Lee, Seung-Yong; Lee, Sang-In; Hwang, Byoung-chul

    2016-01-01

    In this study, the effect of microstructural factors on the impact toughness of hypoeutectoid steels with ferrite-pearlite structure was quantitatively investigated using multiple regression analysis. Microstructural analysis results showed that the pearlite fraction increased with increasing austenitizing temperature and decreasing transformation temperature which substantially decreased the pearlite interlamellar spacing and cementite thickness depending on carbon content. The impact toughness of hypoeutectoid steels usually increased as interlamellar spacing or cementite thickness decreased, although the impact toughness was largely associated with pearlite fraction. Based on these results, multiple regression analysis was performed to understand the individual effect of pearlite fraction, interlamellar spacing, and cementite thickness on the impact toughness. The regression analysis results revealed that pearlite fraction significantly affected impact toughness at room temperature, while cementite thickness did at low temperature.

  20. Predicting Insolvency : A comparison between discriminant analysis and logistic regression using principal components

    OpenAIRE

    Geroukis, Asterios; Brorson, Erik

    2014-01-01

    In this study, we compare the two statistical techniques logistic regression and discriminant analysis to see how well they classify companies based on clusters – made from the solvency ratio ­– using principal components as independent variables. The principal components are made with different financial ratios. We use cluster analysis to find groups with low, medium and high solvency ratio of 1200 different companies found on the NASDAQ stock market and use this as an apriori definition of ...

  1. A REVIEW ON THE USE OF REGRESSION ANALYSIS IN STUDIES OF AUDIT QUALITY

    Directory of Open Access Journals (Sweden)

    Agung Dodit Muliawan

    2015-07-01

    Full Text Available This study aimed to review how regression analysis has been used in studies of abstract phenomenon, such as audit quality, an importance concept in the auditing practice (Schroeder et al., 1986, yet is not well defined. The articles reviewed were the research articles that include audit quality as research variable, either as dependent or independent variables. The articles were purposefully selected to represent balance combination between audit specific and more general accounting journals and between Anglo Saxon and Anglo American journals. The articles were published between 1983-2011 and from the A/A class journal based on ERA 2010’s classifications. The study found that most of the articles reviewed used multiple regression analysis and treated audit quality as dependent variable and measured it by using a proxy. This study also highlights the size of data sample used and the lack of discussions about the assumptions of the statistical analysis used in most of the articles reviewed. This study concluded that the effectiveness and validity of multiple regressions do not only depends on its application by the researchers but also on how the researchers communicate their findings to the audience. KEYWORDS Audit quality, regression analysis ABSTRAK Kajian ini bertujuan untuk mereviu bagaimana analisa regresi digunakan dalam suatu fenomena abstrak seperti kualitas audit, suatu konsep yang penting dalam praktik audit (Schroeder et al., 1986 namun belum terdefinisi dengan jelas. Artikel yang direviu dalam kajian ini adalah artikel penelitian yang memasukkan kualitas audit sebagai variabel penelitian, baik sebagai variabel independen maupun dependen. Artikel-artikel tersebut dipilih dengan cara purposif sampling untuk mendapatkan keterwakilan yang seimbang antara artikel jurnal khusus audit dan akuntansi secara umum, serta mewakili jurnal Anglo Saxon dan Anglo American. Artikel yang direviu diterbitkan pada periode 1983-2011 oleh jurnal yang

  2. Factors associated with poor balance ability in older adults of nine high-altitude communities.

    Science.gov (United States)

    Urrunaga-Pastor, Diego; Moncada-Mapelli, Enrique; Runzer-Colmenares, Fernando M; Bailon-Valdez, Zaira; Samper-Ternent, Rafael; Rodriguez-Mañas, Leocadio; Parodi, Jose F

    2018-05-01

    Poor balance ability in older adults result in multiple complications. Poor balance ability has not been studied among older adults living at high altitudes. In this study, we analysed factors associated with poor balance ability by using the Functional Reach (FR) among older adults living in nine high-altitude communities. Analytical cross-sectional study, carried out in inhabitants aged 60 or over from nine high-altitude Andean communities of Peru during 2013-2016. FR was divided according to the cut-off point of 8 inches (20.32 cm) and two groups were generated: poor balance ability (FR less or equal than 20.32 cm) and good balance ability (greater than 20.32 cm). Additionally, we collected socio-demographic, medical, functional and cognitive assessment information. Poisson regression models were constructed to identify factors associated with poor balance ability. Prevalence ratio (PR) with 95% confidence intervals (95CI%) are presented. A total of 365 older adults were studied. The average age was 73.0 ± 6.9 years (range: 60-91 years), and 180 (49.3%) participants had poor balance ability. In the adjusted Poisson regression analysis, the factors associated with poor balance ability were: alcohol consumption (PR = 1.35; 95%CI: 1.05-1.73), exhaustion (PR = 2.22; 95%CI: 1.49-3.31), gait speed (PR = 0.67; 95%CI: 0.50-0.90), having had at least one fall in the last year (PR = 2.03; 95%CI: 1.19-3.46), having at least one comorbidity (PR = 1.60; 95%CI: 1.10-2.35) and having two or more comorbidities (PR = 1.61; 95%CI: 1.07-2.42) compared to none. Approximately a half of the older adults from these high-altitude communities had poor balance ability. Interventions need to be designed to target these balance issues and prevent adverse events from concurring to these individuals. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Logistic regression applied to natural hazards: rare event logistic regression with replications

    OpenAIRE

    Guns, M.; Vanacker, Veerle

    2012-01-01

    Statistical analysis of natural hazards needs particular attention, as most of these phenomena are rare events. This study shows that the ordinary rare event logistic regression, as it is now commonly used in geomorphologic studies, does not always lead to a robust detection of controlling factors, as the results can be strongly sample-dependent. In this paper, we introduce some concepts of Monte Carlo simulations in rare event logistic regression. This technique, so-called rare event logisti...

  4. Differentiating regressed melanoma from regressed lichenoid keratosis.

    Science.gov (United States)

    Chan, Aegean H; Shulman, Kenneth J; Lee, Bonnie A

    2017-04-01

    Distinguishing regressed lichen planus-like keratosis (LPLK) from regressed melanoma can be difficult on histopathologic examination, potentially resulting in mismanagement of patients. We aimed to identify histopathologic features by which regressed melanoma can be differentiated from regressed LPLK. Twenty actively inflamed LPLK, 12 LPLK with regression and 15 melanomas with regression were compared and evaluated by hematoxylin and eosin staining as well as Melan-A, microphthalmia transcription factor (MiTF) and cytokeratin (AE1/AE3) immunostaining. (1) A total of 40% of regressed melanomas showed complete or near complete loss of melanocytes within the epidermis with Melan-A and MiTF immunostaining, while 8% of regressed LPLK exhibited this finding. (2) Necrotic keratinocytes were seen in the epidermis in 33% regressed melanomas as opposed to all of the regressed LPLK. (3) A dense infiltrate of melanophages in the papillary dermis was seen in 40% of regressed melanomas, a feature not seen in regressed LPLK. In summary, our findings suggest that a complete or near complete loss of melanocytes within the epidermis strongly favors a regressed melanoma over a regressed LPLK. In addition, necrotic epidermal keratinocytes and the presence of a dense band-like distribution of dermal melanophages can be helpful in differentiating these lesions. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Going outdoors daily predicts long-term functional and health benefits among ambulatory older people.

    Science.gov (United States)

    Jacobs, Jeremy M; Cohen, Aaron; Hammerman-Rozenberg, Robert; Azoulay, Daniel; Maaravi, Yoram; Stessman, Jochanan

    2008-04-01

    This article examines the association between frequency of going out of the house and health and functional status among older people. A randomly chosen cohort of ambulatory participants born in 1920 or 1921 from the Jerusalem Longitudinal Study underwent assessments for health, functional, and psychosocial variables at ages 70 and 77. Twelve-year mortality data were collected. Women went out daily less than did men. Participants going out daily at age 70 reported significantly fewer new complaints at age 77 of musculoskeletal pain, sleep problems, urinary incontinence, and decline in activities of daily living (ADLs). Logistic regression analysis indicated that not going out daily at age 70 was predictive of subsequent dependence in ADL, poor self-rated health, and urinary incontinence at age 77. Going out daily is beneficial among independent older people, correlating with reduced functional decline and improved health measures.

  6. Determinants of poor cognitive function using A-IQCODE among Lebanese older adults: a cross-sectional study.

    Science.gov (United States)

    Bou-Orm, Ibrahim R; Khamis, Assem M; Chaaya, Monique

    2018-06-01

    Dementia characterized by gradual cognitive decline is an increasing public health problem due to population ageing. This study aims at assessing the prevalence and determinants of cognitive decline among Lebanese older adults. Secondary analysis of data from a cross-sectional sample of 502 elders from two Lebanese governorates was conducted. Cognitive decline was assessed using the Arabic Version of 16-item Informant Questionnaire on Cognitive Decline for the older adults (A-IQCODE 16). A multivariable logistic regression model assessed the associations of socio-demographic, clinical and behavioral factors with the presence of cognitive decline. Almost one of six Lebanese older adults (14.8%) scored below 3.34. Higher odds of cognitive decline were associated with higher age, being female, having heart disease and suffering from depression. Pack-years of cigarette smoking showed a protective effect and this relationship seems to be only statistically significant among older adults aged more than 75 years. Screening programs of cardiovascular risk factors and early detection of depression are 'best buy' public health interventions that could prevent cognitive decline among Lebanese older adults. Differential survival bias seems the reasonable explanation for the protective effect of smoking that is not the common finding from the literature.

  7. Prevalence of Risk Factors for the Refeeding Syndrome in Older Hospitalized Patients.

    Science.gov (United States)

    Pourhassan, M; Cuvelier, I; Gehrke, I; Marburger, C; Modreker, M K; Volkert, D; Willschrei, H P; Wirth, R

    2018-01-01

    The incidence of refeeding syndrome (RFS) in older patients is not well-known. The aim of the study was to determine the prevalence of known risk factors for RFS in older individuals during hospitalization at geriatric hospital departments. 342 consecutive older participants (222 females) who admitted at acute geriatric hospital wards were included in a cross-sectional study. We applied the National Institute for Health and Clinical Excellence (NICE) criteria for determining patients at risk of RFS. In addition, Mini Nutritional Assessment Short Form (MNA®-SF) was used to identify patients at risk of malnutrition. Weight and height were assessed. The degree of weight loss was obtained by interview. Serum phosphate, magnesium, potassium, sodium, calcium, creatinine and urea were analyzed according to standard procedures. Of 342 older participants included in the study (mean age 83.1 ± 6.8, BMI range of 14.7-43.6 kg/m2), 239 (69.9%) were considered to be at risk of RFS, in which 43.5% and 11.7% were at risk of malnutrition and malnourished, respectively, according to MNA-SF. Patients in the risk group had significantly higher weight loss, lower phosphate and magnesium levels. In a multivariate logistic regression analysis, low levels of phosphate and magnesium followed by weight loss were the major risk factors for fulfilling the NICE criteria. The incidence of risk factors for RFS was relatively high in older individuals acutely admitted in geriatric hospital units, suggesting that, RFS maybe more frequent among older persons than we are aware of. Patients with low serum levels of phosphate and magnesium and higher weight loss are at increased risk of RFS. The clinical characteristics of the older participants at risk of RFS indicate that these patients had a relatively poor nutritional status which can help us better understand the potential scale of RFS on admission or during the hospital stay.

  8. The relationship among unawareness of memory impairment, depression, and dementia in older adults with memory impairment in Singapore.

    Science.gov (United States)

    Liu, Jianlin; Abdin, Edimansyah; Vaingankar, Janhavi A; Shafie, Saleha B; Jeyagurunathan, Anitha; Shahwan, Shazana; Magadi, Harish; Ng, Li Ling; Chong, Siow Ann; Subramaniam, Mythily

    2017-11-01

    Previous research has studied the relationships among unawareness of memory impairment, depression, and dementia in older adults with severe dementia, but it has not considered the associations and clinical implications at earlier stages of memory impairment. This study therefore sought to examine the relationship among unawareness of memory impairment, depression, and dementia in older adults with memory impairment in Singapore. The participants were 751 older adults with memory impairment in Singapore. They were assessed for objective and subjective memory loss, depression, and dementia severity. Participants' subjective memory loss was determined based on a self-appraisal question on memory, and their objective memory loss was calculated based on their performance on three cognitive tasks. Unawareness was assessed based on the contrast between subjective and objective memory loss. Descriptive statistics revealed a high prevalence of unawareness (80.4%). Logistic regression analysis revealed that gender and marital status were significantly associated with unawareness. Men (odds ratio (OR) = 2.5) and those who were divorced or separated (OR = 23.0) were more likely to be unaware than women and those who were married, respectively. After chronic conditions and demographic characteristics were controlled for, multivariate logistic regression analyses revealed that older adults with depression were less likely (OR = 0.2) to be unaware than those without depression. Unawareness was also related with dementia severity; older adults with questionable (OR = 0.3) and mild dementia (OR = 0.4) were less likely to be unaware than someone without dementia. Unawareness of memory impairment was common among older adults with memory impairment. However, unawareness may be the result of denial as a strategy for coping with memory loss of which the older adult is aware. Psychological care should be integrated into the overall treatment management of dementia to

  9. High-throughput quantitative biochemical characterization of algal biomass by NIR spectroscopy; multiple linear regression and multivariate linear regression analysis.

    Science.gov (United States)

    Laurens, L M L; Wolfrum, E J

    2013-12-18

    One of the challenges associated with microalgal biomass characterization and the comparison of microalgal strains and conversion processes is the rapid determination of the composition of algae. We have developed and applied a high-throughput screening technology based on near-infrared (NIR) spectroscopy for the rapid and accurate determination of algal biomass composition. We show that NIR spectroscopy can accurately predict the full composition using multivariate linear regression analysis of varying lipid, protein, and carbohydrate content of algal biomass samples from three strains. We also demonstrate a high quality of predictions of an independent validation set. A high-throughput 96-well configuration for spectroscopy gives equally good prediction relative to a ring-cup configuration, and thus, spectra can be obtained from as little as 10-20 mg of material. We found that lipids exhibit a dominant, distinct, and unique fingerprint in the NIR spectrum that allows for the use of single and multiple linear regression of respective wavelengths for the prediction of the biomass lipid content. This is not the case for carbohydrate and protein content, and thus, the use of multivariate statistical modeling approaches remains necessary.

  10. Outdoor activities and depressive symptoms in displaced older adults following natural disaster: community cohesion as mediator and moderator.

    Science.gov (United States)

    Chao, Shiau-Fang

    2016-09-01

    This investigation examined whether community cohesion mediates or moderates the relationship between outdoor activities and depressive symptoms in older adults displaced by Typhoon Morakot in Taiwan. This cross-sectional study included 292 adults aged 65 years or older who were relocated to permanent houses after Typhoon Morakot damaged their homes on 8th August 2009. Multiple regression analysis was applied to test the role of community cohesion on the association between outdoor activities and depressive symptoms. The sample of displaced older adults displayed higher prevalence of depressive symptoms than the average for community dwelling older people in Taiwan. Community cohesion fully mediated the relationship between outdoor activities and depressive symptoms. Community cohesion also moderated the relationship between outdoor activities and depressive symptoms. Community cohesion occupies a key role on the link between outdoor activities and depressive symptoms. Participation in outdoor activities was associated positively with community cohesion, while high community cohesion was related negatively to depressive symptoms. Additionally, the benefit of outdoor activities to fewer depressive symptoms only manifested in older adults with high community cohesion. Programs and services should be designed to enhance community cohesion in order to maximize the benefit of outdoor activities to the mental health of displaced older adults after natural disasters.

  11. Identification of cotton properties to improve yarn count quality by using regression analysis

    International Nuclear Information System (INIS)

    Amin, M.; Ullah, M.; Akbar, A.

    2014-01-01

    Identification of raw material characteristics towards yarn count variation was studied by using statistical techniques. Regression analysis is used to meet the objective. Stepwise regression is used for mode) selection, and coefficient of determination and mean squared error (MSE) criteria are used to identify the contributing factors of cotton properties for yam count. Statistical assumptions of normality, autocorrelation and multicollinearity are evaluated by using probability plot, Durbin Watson test, variance inflation factor (VIF), and then model fitting is carried out. It is found that, invisible (INV), nepness (Nep), grayness (RD), cotton trash (TR) and uniformity index (VI) are the main contributing cotton properties for yarn count variation. The results are also verified by Pareto chart. (author)

  12. Stereotype Threat Effects on Older Adults' Episodic and Working Memory: A Meta-Analysis.

    Science.gov (United States)

    Armstrong, Bonnie; Gallant, Sara N; Li, Lingqian; Patel, Khushi; Wong, Brenda I

    2017-08-01

    Prior research has shown that exposure to negative age-based stereotype threat (ST) can undermine older adults' memory performance. The objective of the current meta-analysis was to examine the reliability and magnitude of ST effects on older adults' episodic and working memory performance-two forms of memory that typically show the greatest age-related declines. In addition, we examined potential moderators of age-based ST including type of ST manipulation, type and timing of memory task, participant age and education level. A total of 23 samples for episodic memory and 15 samples for working memory were derived from 19 published and 4 unpublished articles and analyzed in two separate meta-analyses. Analyses revealed a reliable effect of ST on both older adults' episodic (d = 0.373) and working memory performance (d = 0.253). Interestingly, the age-based ST effect was only significant when blatant ST manipulations were used with episodic memory tasks or when subtle ST manipulations were used with working memory tasks. Moreover, within episodic memory, the ST effect only reached significance for recall but not cued-recall or recognition performance, and for immediate but not delayed tests of memory. Neither age nor level of education moderated the association between ST and older adults' memory performance. These results highlight the vulnerability of both older adults' episodic and working memory performance to age-based ST. When measuring older adults' memory performance in a research context, we must therefore be wary of exposing participants to common stereotypes about aging and memory. © The Author 2017. 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.

  13. A tandem regression-outlier analysis of a ligand cellular system for key structural modifications around ligand binding.

    Science.gov (United States)

    Lin, Ying-Ting

    2013-04-30

    A tandem technique of hard equipment is often used for the chemical analysis of a single cell to first isolate and then detect the wanted identities. The first part is the separation of wanted chemicals from the bulk of a cell; the second part is the actual detection of the important identities. To identify the key structural modifications around ligand binding, the present study aims to develop a counterpart of tandem technique for cheminformatics. A statistical regression and its outliers act as a computational technique for separation. A PPARγ (peroxisome proliferator-activated receptor gamma) agonist cellular system was subjected to such an investigation. Results show that this tandem regression-outlier analysis, or the prioritization of the context equations tagged with features of the outliers, is an effective regression technique of cheminformatics to detect key structural modifications, as well as their tendency of impact to ligand binding. The key structural modifications around ligand binding are effectively extracted or characterized out of cellular reactions. This is because molecular binding is the paramount factor in such ligand cellular system and key structural modifications around ligand binding are expected to create outliers. Therefore, such outliers can be captured by this tandem regression-outlier analysis.

  14. Regression analysis: An evaluation of the inuences behindthe pricing of beer

    OpenAIRE

    Eriksson, Sara; Häggmark, Jonas

    2017-01-01

    This bachelor thesis in applied mathematics is an analysis of which factors affect the pricing of beer at the Swedish market. A multiple linear regression model is created with the statistical programming language R through a study of the influences for several explanatory variables. For example these variables include country of origin, beer style, volume sold and a Bayesian weighted mean rating from RateBeer, a popular website for beer enthusiasts. The main goal of the project is to find si...

  15. Few crystal balls are crystal clear : eyeballing regression

    International Nuclear Information System (INIS)

    Wittebrood, R.T.

    1998-01-01

    The theory of regression and statistical analysis as it applies to reservoir analysis was discussed. It was argued that regression lines are not always the final truth. It was suggested that regression lines and eyeballed lines are often equally accurate. The many conditions that must be fulfilled to calculate a proper regression were discussed. Mentioned among these conditions were the distribution of the data, hidden variables, knowledge of how the data was obtained, the need for causal correlation of the variables, and knowledge of the manner in which the regression results are going to be used. 1 tab., 13 figs

  16. A meta-analysis of third wave mindfulness-based cognitive behavioral therapies for older people.

    Science.gov (United States)

    Kishita, Naoko; Takei, Yuko; Stewart, Ian

    2017-12-01

    The aim of this study is to review the effectiveness of third wave mindfulness-based cognitive behavioral therapies (CBTs) for depressive or anxiety symptomatology in older adults across a wide range of physical and psychological conditions. Electronic literature databases were searched for articles, and random-effects meta-analysis was conducted. Ten studies met the inclusion criteria, of which nine reported the efficacy of interventions on depressive symptoms and seven on anxiety symptoms. Effect-size estimates suggested that mindfulness-based CBT is moderately effective on depressive symptoms in older adults (g = 0.55). The results demonstrated a similar level of overall effect size for anxiety symptoms (g = 0.58). However, there was a large heterogeneity, and publication bias was evident in studies reporting outcomes on anxiety symptoms, and thus, this observed efficacy for late-life anxiety may not be robust. The quality of the included studies varied. Only one study used an active psychological control condition. There were a limited number of studies that used an intent-to-treat (last observation carried forward method) analysis and reported appropriate methods for clinical trials (e.g., treatment-integrity reporting). Third wave mindfulness-based CBT may be robust in particular for depressive symptoms in older adults. We recommend that future studies (i) conduct randomized controlled trials with intent-to-treat to compare mindfulness-based CBT with other types of psychotherapy in older people and (ii) improve study quality by using appropriate methods for checking treatment adherence, randomization, and blinding of assessors. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Role of regression analysis and variation of rheological data in calculation of pressure drop for sludge pipelines.

    Science.gov (United States)

    Farno, E; Coventry, K; Slatter, P; Eshtiaghi, N

    2018-06-15

    Sludge pumps in wastewater treatment plants are often oversized due to uncertainty in calculation of pressure drop. This issue costs millions of dollars for industry to purchase and operate the oversized pumps. Besides costs, higher electricity consumption is associated with extra CO 2 emission which creates huge environmental impacts. Calculation of pressure drop via current pipe flow theory requires model estimation of flow curve data which depends on regression analysis and also varies with natural variation of rheological data. This study investigates impact of variation of rheological data and regression analysis on variation of pressure drop calculated via current pipe flow theories. Results compare the variation of calculated pressure drop between different models and regression methods and suggest on the suitability of each method. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Restrictions of physical activity participation in older adults with disability: employing keyword network analysis.

    Science.gov (United States)

    Koo, Kyo-Man; Kim, Chun-Jong; Park, Chae-Hee; Byeun, Jung-Kyun; Seo, Geon-Woo

    2016-08-01

    Older adults with disability might have been increasing due to the rapid aging of society. Many studies showed that physical activity is an essential part for improving quality of life in later lives. Regular physical activity is an efficient means that has roles of primary prevention and secondary prevention. However, there were few studies regarding older adults with disability and physical activity participation. The purpose of this current study was to investigate restriction factors to regularly participate older adults with disability in physical activity by employing keyword network analysis. Two hundred twenty-nine older adults with disability who were over 65 including aging with disability and disability with aging in type of physical disability and brain lesions defined by disabled person welfare law partook in the open questionnaire assessing barriers to participate in physical activity. The results showed that the keyword the most often used was 'Traffic' which was total of 21 times (3.47%) and the same proportion as in the 'personal' and 'economical'. Exercise was considered the most central keyword for participating in physical activity and keywords such as facility, physical activity, disabled, program, transportation, gym, discomfort, opportunity, and leisure activity were associated with exercise. In conclusion, it is necessary to educate older persons with disability about a true meaning of physical activity and providing more physical activity opportunities and decreasing inconvenience should be systematically structured in Korea.

  19. Cost-effectiveness analysis of a multifactorial fall prevention intervention in older home care clients at risk for falling.

    Science.gov (United States)

    Isaranuwatchai, Wanrudee; Perdrizet, Johnna; Markle-Reid, Maureen; Hoch, Jeffrey S

    2017-09-01

    Falls among older adults can cause serious morbidity and pose economic burdens on society. Older age is a known risk factor for falls and age has been shown to influence the effectiveness of fall prevention programs. To our knowledge, no studies have explicitly investigated whether cost-effectiveness of a multifactorial fall prevention intervention (the intervention) is influenced by age. This economic evaluation explores: 1) the cost-effectiveness of a multifactorial fall prevention intervention compared to usual care for community-dwelling adults ≥ 75 years at risk of falling in Canada; and 2) the influence of age on the cost-effectiveness of the intervention. Net benefit regression was used to examine the cost-effectiveness of the intervention with willingness-to-pay values ranging from $0-$50,000. Effects were measured as change in the number of falls, from baseline to 6-month follow-up. Costs were measured using a societal perspective. The cost-effectiveness analysis was conducted for both the total sample and by age subgroups (75-84 and 85+ years). For the total sample, the intervention was not economically attractive. However, the intervention was cost-effective at higher willingness-to-pay (WTP) (≥ $25,000) for adults 75-84 years and at lower WTP (cost-effectiveness of the intervention depends on age and decision makers' WTP to prevent falls. Understanding the influence of age on the cost-effectiveness of an intervention may help to target resources to those who benefit most. Retrospectively registered. Clinicaltrials.gov identifier: NCT00463658 (18 April 2007).

  20. From Advance Euthanasia Directive to Euthanasia: Stable Preference in Older People?

    Science.gov (United States)

    Bolt, Eva E; Pasman, H Roeline W; Deeg, Dorly J H; Onwuteaka-Philipsen, Bregje D

    2016-08-01

    To determine whether older people with advance directive for euthanasia (ADEs) are stable in their advance desire for euthanasia in the last years of life, how frequently older people with an ADE eventually request euthanasia, and what factors determine this. Mortality follow-back study nested in a cohort study. The Netherlands. Proxies of deceased members of a cohort representative of Dutch older people (n = 168) and a cohort of people with advance directives (n = 154). Data from cohort members (possession of ADE) combined with after-death proxy information on cohort members' last 3 months of life. Multiple logistic regression analysis was performed on determinants of a euthanasia request in individuals with an ADE. Response rate was 65%. One hundred forty-two cohort members had an ADE at baseline. Three months before death, 87% remained stable in their desire for euthanasia; 47% eventually requested euthanasia (vs 6% without an ADE), and 16% died after euthanasia. People with an ADE were more likely to request euthanasia if they worried about loss of dignity. The majority of older adults who complete an ADE will have a stable preference over time, but an advance desire for euthanasia does not necessarily result in a euthanasia request. Writing an ADE may reflect a person's need for reassurance that they can request euthanasia in the future. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  1. COLOR IMAGE RETRIEVAL BASED ON FEATURE FUSION THROUGH MULTIPLE LINEAR REGRESSION ANALYSIS

    Directory of Open Access Journals (Sweden)

    K. Seetharaman

    2015-08-01

    Full Text Available This paper proposes a novel technique based on feature fusion using multiple linear regression analysis, and the least-square estimation method is employed to estimate the parameters. The given input query image is segmented into various regions according to the structure of the image. The color and texture features are extracted on each region of the query image, and the features are fused together using the multiple linear regression model. The estimated parameters of the model, which is modeled based on the features, are formed as a vector called a feature vector. The Canberra distance measure is adopted to compare the feature vectors of the query and target images. The F-measure is applied to evaluate the performance of the proposed technique. The obtained results expose that the proposed technique is comparable to the other existing techniques.

  2. Genome-wide Meta-analysis on the Sense of Smell Among US Older Adults.

    Science.gov (United States)

    Dong, Jing; Yang, Jingyun; Tranah, Greg; Franceschini, Nora; Parimi, Neeta; Alkorta-Aranburu, Gorka; Xu, Zongli; Alonso, Alvaro; Cummings, Steven R; Fornage, Myriam; Huang, Xuemei; Kritchevsky, Stephen; Liu, Yongmei; London, Stephanie; Niu, Liang; Wilson, Robert S; De Jager, Philip L; Yu, Lei; Singleton, Andrew B; Harris, Tamara; Mosley, Thomas H; Pinto, Jayant M; Bennett, David A; Chen, Honglei

    2015-11-01

    Olfactory dysfunction is common among older adults and affects their safety, nutrition, quality of life, and mortality. More importantly, the decreased sense of smell is an early symptom of neurodegenerative diseases such as Parkinson disease (PD) and Alzheimer disease. However, the genetic determinants for the sense of smell have been poorly investigated. We here performed the first genome-wide meta-analysis on the sense of smell among 6252 US older adults of European descent from the Atherosclerosis Risk in Communities (ARIC) study, the Health, Aging, and Body Composition (Health ABC) study, and the Religious Orders Study and the Rush Memory and Aging Project (ROS/MAP). Genome-wide association study analysis was performed first by individual cohorts and then meta-analyzed using fixed-effect models with inverse variance weights. Although no SNPs reached genome-wide statistical significance, we identified 13 loci with suggestive evidence for an association with the sense of smell (Pmeta < 1 × 10). Of these, 2 SNPs at chromosome 17q21.31 (rs199443 in NSF, P = 3.02 × 10; and rs2732614 in KIAA1267-LRRC37A, P = 6.65 × 10) exhibited cis effects on the expression of microtubule-associated protein tau (MAPT, 17q21.31) in 447 frontal-cortex samples obtained postmortem and profiled by RNA-seq (P < 1 × 10). Gene-based and pathway-enrichment analyses further implicated MAPT in regulating the sense of smell in older adults. Similar results were obtained after excluding participants who reported a physician-diagnosed PD or use of PD medications. In conclusion, we provide preliminary evidence that the MAPT locus may play a role in regulating the sense of smell in older adults and therefore offer a potential genetic link between poor sense of smell and major neurodegenerative diseases.

  3. The Relationship between Urbanization, the Built Environment, and Physical Activity among Older Adults in Taiwan

    Directory of Open Access Journals (Sweden)

    Nuan-Ching Huang

    2018-04-01

    Full Text Available Urbanization and ageing are global phenomena and offer unique challenges in different countries. A supportive environment plays a critical role in addressing the issue of behavioral change and health promotion among older adults. Many studies in the U.S., EU, and Australia have considered promoting physical activity in the community based on ecological models, whereas very few Asian studies have examined the relationships among urbanization, the built environment and physical activity in elderly at the ecological level, especially from a multi-level perspective. Due to the prevalence of post-war baby boomers and a very low birth-rate, the older population (aged 65 years old and older in Taiwan has increased rapidly since 2011 and has exceeded the younger generation (0–14 years old in 2017. Hence, the purpose of this study was first to examine the degree of urbanization in townships and the status of related built environments in Taiwan and then to investigate whether the built environment is associated with recommended amounts of physical activity among older adults. Three national datasets and a multi-level design were used in this research. Data at the individual level was obtained from the 2009 National Health Interview Survey (NHIS which was taken from June 2009 to February 2010. Ecological data was obtained from the 2006 National Land Use Investigation of the National Geographic Information System and the 2010 Population and Housing Census. The analyses included a descriptive analysis, a bivariate analysis, a multiple logistic regression, and a multi-level analysis, utilizing a mostly hierarchical linear model (HLM. The results showed a significant relationship between factors at the environmental levels and physical activity in older adults. Urbanization, the built environment, and the median income of townships were positively correlated to the physical activity of the older adults. After controlling for individual-level factors

  4. Linear regression in astronomy. II

    Science.gov (United States)

    Feigelson, Eric D.; Babu, Gutti J.

    1992-01-01

    A wide variety of least-squares linear regression procedures used in observational astronomy, particularly investigations of the cosmic distance scale, are presented and discussed. The classes of linear models considered are (1) unweighted regression lines, with bootstrap and jackknife resampling; (2) regression solutions when measurement error, in one or both variables, dominates the scatter; (3) methods to apply a calibration line to new data; (4) truncated regression models, which apply to flux-limited data sets; and (5) censored regression models, which apply when nondetections are present. For the calibration problem we develop two new procedures: a formula for the intercept offset between two parallel data sets, which propagates slope errors from one regression to the other; and a generalization of the Working-Hotelling confidence bands to nonstandard least-squares lines. They can provide improved error analysis for Faber-Jackson, Tully-Fisher, and similar cosmic distance scale relations.

  5. Factors associated with regular physical exercise and consumption of fruits and vegetables among Mexican older adults.

    Science.gov (United States)

    Doubova, Svetlana V; Sánchez-García, Sergio; Infante-Castañeda, Claudia; Pérez-Cuevas, Ricardo

    2016-09-09

    To analyze the factors associated with regular physical exercise and routine consumption of fruits and vegetables, and both healthy behaviors among Mexican older adults. We conducted a secondary data analysis of the baseline data (2014) of the Study on Obesity, Sarcopenia and Fragility in older adults affiliated with the Mexican Institute of Social Security. The study included 948 adults who were ≥60 years of age. Multiple Poisson regression was performed. Routine consumption of fruits and vegetables was reported by 53.8 % of older adults, 42.7 % reported engaging in regular physical exercise and 23.1 % reported participating in both types of healthy behaviors. Women, adults with a stable income, those with a self-perception of good health and those with a history of physical exercise at the age of 50 years had an increased likelihood of engaging in healthy eating and regular physical activity. Many older adults do not routinely consume fruits and vegetables or engage in regular physical exercise despite the fact that most have a fixed income and a social network. It is relevant to conduct research-based interventions that take into account the contextual factors to promote healthy behaviors.

  6. Developing a Tool for Measuring the Decision-Making Competence of Older Adults

    Science.gov (United States)

    Finucane, Melissa L.; Gullion, Christina M.

    2010-01-01

    The authors evaluated the reliability and validity of a tool for measuring older adults’ decision-making competence (DMC). Two-hundred-five younger adults (25-45 years), 208 young-older adults (65-74 years), and 198 old-older adults (75-97 years) made judgments and decisions related to health, finance, and nutrition. Reliable indices of comprehension, dimension weighting, and cognitive reflection were developed. Unlike previous research, the authors were able to compare old-older with young-older adults’ performance. As hypothesized, old-older adults performed more poorly than young-older adults; both groups of older adults performed more poorly than younger adults. Hierarchical regression analyses showed that a large amount of variance in decision performance across age groups (including mean trends) could be accounted for by social variables, health measures, basic cognitive skills, attitudinal measures, and numeracy. Structural equation modeling revealed significant pathways from three exogenous latent factors (crystallized intelligence, other cognitive abilities, and age) to the endogenous DMC latent factor. Further research is needed to validate the meaning of performance on these tasks for real-life decision making. PMID:20545413

  7. PATH ANALYSIS WITH LOGISTIC REGRESSION MODELS : EFFECT ANALYSIS OF FULLY RECURSIVE CAUSAL SYSTEMS OF CATEGORICAL VARIABLES

    OpenAIRE

    Nobuoki, Eshima; Minoru, Tabata; Geng, Zhi; Department of Medical Information Analysis, Faculty of Medicine, Oita Medical University; Department of Applied Mathematics, Faculty of Engineering, Kobe University; Department of Probability and Statistics, Peking University

    2001-01-01

    This paper discusses path analysis of categorical variables with logistic regression models. The total, direct and indirect effects in fully recursive causal systems are considered by using model parameters. These effects can be explained in terms of log odds ratios, uncertainty differences, and an inner product of explanatory variables and a response variable. A study on food choice of alligators as a numerical exampleis reanalysed to illustrate the present approach.

  8. Análise de fatores e regressão bissegmentada em estudos de estratificação ambiental e adaptabilidade em milho Factor analysis and bissegmented regression for studies about environmental stratification and maize adaptability

    Directory of Open Access Journals (Sweden)

    Deoclécio Domingos Garbuglio

    2007-02-01

    Full Text Available O objetivo deste trabalho foi verificar possíveis divergências entre os resultados obtidos nas avaliações da adaptabilidade de 27 genótipos de milho (Zea mays L., e na estratificação de 22 ambientes no Estado do Paraná, por meio de técnicas baseadas na análise de fatores e regressão bissegmentada. As estratificações ambientais foram feitas por meio do método tradicional e por análise de fatores, aliada ao porcentual da porção simples da interação GxA (PS%. As análises de adaptabilidade foram realizadas por meio de regressão bissegmentada e análise de fatores. Pela análise de regressão bissegmentada, os genótipos estudados apresentaram alta performance produtiva; no entanto, não foi constatado o genótipo considerado como ideal. A adaptabilidade dos genótipos, analisada por meio de plotagens gráficas, apresentou respostas diferenciadas quando comparada à regressão bissegmentada. A análise de fatores mostrou-se eficiente nos processos de estratificação ambiental e adaptabilidade dos genótipos de milho.The objective of this work was to verify possible divergences among results obtained on adaptability evaluations of 27 maize genotypes (Zea mays L., and on stratification of 22 environments on Paraná State, Brazil, through techniques of factor analysis and bissegmented regression. The environmental stratifications were made through the traditional methodology and by factor analysis, allied to the percentage of the simple portion of GxE interaction (PS%. Adaptability analyses were carried out through bissegmented regression and factor analysis. By the analysis of bissegmented regression, studied genotypes had presented high productive performance; however, it was not evidenced the genotype considered as ideal. The adaptability of the genotypes, analyzed through graphs, presented different answers when compared to bissegmented regression. Factor analysis was efficient in the processes of environment stratification and

  9. Insomnia and risk of dementia in older adults: Systematic review and meta-analysis.

    Science.gov (United States)

    de Almondes, Katie Moraes; Costa, Mônica Vieira; Malloy-Diniz, Leandro Fernandes; Diniz, Breno Satler

    2016-06-01

    There are cross-sectional evidences of an association between sleep disorders and cognitive impairment on older adults. However, there are no consensus by means of longitudinal studies data on the increased risk of developing dementia related to insomnia. We conduct a systematic review and meta-analysis to evaluate the risk of incident all-cause dementia in individuals with insomnia in population-based prospective cohort studies. Five studies of 5.242 retrieved references were included in the meta-analysis. We used the generic inverse variance method with a random effects model to calculate the pooled risk of dementia in older adults with insomnia. We assessed heterogeneity in the meta-analysis by means of the Q-test and I2 index. Study quality was assessed with the Newcastle-Ottawa Scale The results showed that Insomnia was associated with a significant risk of all-cause dementia (RR = 1.53 CI95% (1.07-2.18), z = 2.36, p = 0.02). There was evidence for significant heterogeneity in the analysis (q-value = 2.4, p < 0.001 I2 = 82%). Insomnia is associated with an increased risk for dementia. This results provide evidences that future studies should investigate dementia prevention among elderly individuals through screening and proper management of insomnia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Older Age Predicts Decreased Metastasis and Prostate Cancer-Specific Death for Men Treated With Radiation Therapy: Meta-Analysis of Radiation Therapy Oncology Group Trials

    Energy Technology Data Exchange (ETDEWEB)

    Hamstra, Daniel A., E-mail: dhamm@umich.edu [University of Michigan, Ann Arbor, Michigan (United States); Bae, Kyounghwa [Radiation Therapy Oncology Group, Philadelphia, Pennsylvania (United States); Pilepich, Miljenko V. [UCLA Medical Center, Los Angeles, California (United States); Hanks, Gerald E. [Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Grignon, David J. [Indiana University-Purdue University Indianapolis, Indiana (United States); McGowan, David G. [Cross Cancer Institute, Edmonton, Alberta (Canada); Roach, Mack [UCSF, San Francisco, California (United States); Lawton, Colleen [Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Lee, R. Jeffrey [Intermountain Medical Center, Salt Lake City, Utah (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, California (United States)

    2011-12-01

    Purpose: The impact of age on prostate cancer (PCa) outcome has been controversial; therefore, we analyzed the effect of age on overall survival (OS), distant metastasis, prostate cancer-specific death (PCSD), and nonprostate cancer death (NPCD) on patients with locally advanced PCa. Methods and Materials: Patients who participated in four Radiation Therapy Oncology Group (RTOG) phase III trials, 8531, 8610, 9202, and 9413, were studied. Cox proportional hazards regression was used for OS analysis, and cumulative events analysis with Fine and Gray's regression was used for analyses of metastasis, PCSD, and NPCD. Results: Median follow-up of 4,128 patients with median age of 70 (range, 43-88 years) was 7.3 years. Most patients had high-risk disease: cT3 to cT4 (54%) and Gleason scores (GS) of 7 (45%) and 8 to 10 (27%). Older age ({<=}70 vs. >70 years) predicted for decreased OS (10-year rate, 55% vs. 41%, respectively; p < 0.0001) and increased NPCD (10-year rate, 28% vs. 46%, respectively; p < 0.0001) but decreased metastasis (10-year rate, 27% vs. 20%, respectively; p < 0.0001) and PCSD (10-year rate, 18% vs. 14%, respectively; p < 0.0001). To account for competing risks, outcomes were analyzed in 2-year intervals, and age-dependent differences in metastasis and PCSD persisted, even in the earliest time periods. When adjusted for other covariates, an age of >70 years remained associated with decreased OS (hazard ratio [HR], 1.56 [95% confidence interval [CI], 1.43-1.70] p < 0.0001) but with decreased metastasis (HR, 0.72 [95% CI, 0.63-0.83] p < 0.0001) and PCSD (HR, 0.78 [95% CI, 0.66-0.92] p < 0.0001). Finally, the impact of the duration of androgen deprivation therapy as a function of age was evaluated. Conclusions: These data support less aggressive PCa in older men, independent of other clinical features. While the biological underpinning of this finding remains unknown, stratification by age in future trials appears to be warranted.

  11. Evaluation of Blood Biomarkers Associated with Risk of Malnutrition in Older Adults: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Zhang, Zhiying; Pereira, Suzette L; Luo, Menghua; Matheson, Eric M

    2017-08-03

    Malnutrition is a common yet under-recognized problem in hospitalized patients. The aim of this paper was to systematically review and evaluate malnutrition biomarkers among order adults. Eligible studies were identified through Cochrane, PubMed and the ProQuest Dialog. A meta-regression was performed on concentrations of biomarkers according to malnutrition risks classified by validated nutrition assessment tools. A total of 111 studies were included, representing 52,911 participants (55% female, 72 ± 17 years old) from various clinical settings (hospital, community, care homes). The estimated BMI ( p malnutrition risk by MNA were significantly lower than those without a risk. Similar results were observed for malnutrition identified by SGA and NRS-2002. A sensitivity analysis by including patients with acute illness showed that albumin and prealbumin concentrations were dramatically reduced, indicating that they must be carefully interpreted in acute care settings. This review showed that BMI, hemoglobin, and total cholesterol are useful biomarkers of malnutrition in older adults. The reference ranges and cut-offs may need to be updated to avoid underdiagnosis of malnutrition.

  12. Efficacy of physical exercise in preventing falls in older adults with cognitive impairment: a systematic review and meta-analysis.

    Science.gov (United States)

    Chan, Wai Chi; Yeung, Jerry Wing Fai; Wong, Corine Sau Man; Lam, Linda Chiu Wa; Chung, Ka Fai; Luk, James Ka Hay; Lee, Jenny Shun Wah; Law, Andrew Chi Kin

    2015-02-01

    Numerous studies have reported the prevention of falls through exercise among cognitively healthy older people. This study aimed to determine whether the current evidence supports that physical exercise is also efficacious in preventing falls in older adults with cognitive impairment. Two independent reviewers searched MEDLINE; EMBASE; PsycINFO; the Cumulative Index to Nursing & Allied Health Literature; the Cochrane Central Register of Controlled Trials; the Cochrane Bone, Joint, and Muscle Trauma Group Specialized Register; ClinicalTrials.gov; and the UK Clinical Research Network Study Portfolio up to July 2013 without language restriction. We included randomized controlled trials that examined the efficacy of physical exercise in older adults with cognitive impairment. The methodological qualities of the included trials were appraised according to the criteria developed for the Cochrane review of fall prevention trials. The primary outcome measure was the rate ratio of falls. A meta-analysis was performed to estimate the pooled rate ratio and summarize the results of the trials on fall prevention through physical exercise. Seven randomized controlled trials involving 781 participants were included, 4 of which examined solely older people with cognitive impairment. Subgroup data on persons with cognitive impairment were obtained from the other 3 trials that targeted older populations in general. The meta-analysis showed that physical exercise had a significant effect in preventing falls in older adults with cognitive impairment, with a pooled estimate of rate ratio of 0.68 (95% confidence interval 0.51-0.91). The present analysis suggests that physical exercise has a positive effect on preventing falls in older adults with cognitive impairment. Further studies will be required to determine the modality and frequency of exercise that are optimal for the prevention of falls in this population. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care

  13. Determinants of orphan drugs prices in France: a regression analysis.

    Science.gov (United States)

    Korchagina, Daria; Millier, Aurelie; Vataire, Anne-Lise; Aballea, Samuel; Falissard, Bruno; Toumi, Mondher

    2017-04-21

    The introduction of the orphan drug legislation led to the increase in the number of available orphan drugs, but the access to them is often limited due to the high price. Social preferences regarding funding orphan drugs as well as the criteria taken into consideration while setting the price remain unclear. The study aimed at identifying the determinant of orphan drug prices in France using a regression analysis. All drugs with a valid orphan designation at the moment of launch for which the price was available in France were included in the analysis. The selection of covariates was based on a literature review and included drug characteristics (Anatomical Therapeutic Chemical (ATC) class, treatment line, age of target population), diseases characteristics (severity, prevalence, availability of alternative therapeutic options), health technology assessment (HTA) details (actual benefit (AB) and improvement in actual benefit (IAB) scores, delay between the HTA and commercialisation), and study characteristics (type of study, comparator, type of endpoint). The main data sources were European public assessment reports, HTA reports, summaries of opinion on orphan designation of the European Medicines Agency, and the French insurance database of drugs and tariffs. A generalized regression model was developed to test the association between the annual treatment cost and selected covariates. A total of 68 drugs were included. The mean annual treatment cost was €96,518. In the univariate analysis, the ATC class (p = 0.01), availability of alternative treatment options (p = 0.02) and the prevalence (p = 0.02) showed a significant correlation with the annual cost. The multivariate analysis demonstrated significant association between the annual cost and availability of alternative treatment options, ATC class, IAB score, type of comparator in the pivotal clinical trial, as well as commercialisation date and delay between the HTA and commercialisation. The

  14. Logistic regression applied to natural hazards: rare event logistic regression with replications

    Science.gov (United States)

    Guns, M.; Vanacker, V.

    2012-06-01

    Statistical analysis of natural hazards needs particular attention, as most of these phenomena are rare events. This study shows that the ordinary rare event logistic regression, as it is now commonly used in geomorphologic studies, does not always lead to a robust detection of controlling factors, as the results can be strongly sample-dependent. In this paper, we introduce some concepts of Monte Carlo simulations in rare event logistic regression. This technique, so-called rare event logistic regression with replications, combines the strength of probabilistic and statistical methods, and allows overcoming some of the limitations of previous developments through robust variable selection. This technique was here developed for the analyses of landslide controlling factors, but the concept is widely applicable for statistical analyses of natural hazards.

  15. Stepwise versus Hierarchical Regression: Pros and Cons

    Science.gov (United States)

    Lewis, Mitzi

    2007-01-01

    Multiple regression is commonly used in social and behavioral data analysis. In multiple regression contexts, researchers are very often interested in determining the "best" predictors in the analysis. This focus may stem from a need to identify those predictors that are supportive of theory. Alternatively, the researcher may simply be interested…

  16. Self- Perception of Body Weight Status in Older Dutch Adults.

    Science.gov (United States)

    Monteagudo, C; Dijkstra, S C; Visser, M

    2015-06-01

    The prevalence of obesity is highest in older persons and a correct self-perception of body weight status is necessary for optimal weight control. The aim of this study was to determine self-perception of, and satisfaction with, body weight status, and to compare current versus ideal body image in a large, nationally representative sample of older people. Furthermore, determinants of misperception were explored. A cross-sectional study. The Longitudinal Aging Study Amsterdam (LASA), conducted in a population-based sample in the Netherlands. 1295 men and women aged 60-96 years. Body weight status was assessed using measured weight and height. Self-perceived body weight status, satisfaction with body weight and current and ideal body image were also assessed. Multiple logistic regression analysis was used to investigate the association of age, educational level and objectively measured BMI with underestimation of body weight status. The prevalence of obesity was 19.9% in men and 29.3% in women. The agreement between objective and self-perceived body weight status was low (Kappa 99% of obese participants desired to be thinner (ideal body image < current image). Only 4.4% of obese men and 12.3% of obese women perceived their body weight status correctly. Higher age (women), lower educational level (men) and higher BMI (all) were associated with greater underestimation of body weight status. Many older persons misperceive their body weight status. Future actions to improve body weight perception in older persons are necessary to increase the impact of public health campaigns focussing on a healthy body weight in old age.

  17. Casino gambling among older adults in North Dakota: a policy analysis.

    Science.gov (United States)

    Bjelde, Kristine; Chromy, Barbara; Pankow, Debra

    2008-12-01

    This article examined social issues surrounding casino gambling among older adults both nationally and in the state of North Dakota. An exploratory review of gambling trends among older adults and an examination of policies to protect older gamblers revealed that older adults are targeted by the gaming industry as a lucrative market (Singh et al. J Retail Leisure Property 2007, 6(1):61-68). The authors used the national literature to frame their qualitative study, which explored gambling issues among older adults in North Dakota from the perspective of six counselors trained in gambling addiction who provide treatment services in the state. Findings indicated that relatively few policies existed at the state and national levels to protect older, more vulnerable adults who gamble. Further, the six casinos in North Dakota were viewed as very effective in marketing their casino gaming opportunities to older citizens by the gambling treatment providers interviewed. Additionally, barriers to gambling addiction treatment involved lack of available services and distance to receive services in this rural state. Based on the findings of this study, social policy changes which could lead to increased protection for older adult gamblers in the state were included.

  18. Bayesian Nonparametric Regression Analysis of Data with Random Effects Covariates from Longitudinal Measurements

    KAUST Repository

    Ryu, Duchwan

    2010-09-28

    We consider nonparametric regression analysis in a generalized linear model (GLM) framework for data with covariates that are the subject-specific random effects of longitudinal measurements. The usual assumption that the effects of the longitudinal covariate processes are linear in the GLM may be unrealistic and if this happens it can cast doubt on the inference of observed covariate effects. Allowing the regression functions to be unknown, we propose to apply Bayesian nonparametric methods including cubic smoothing splines or P-splines for the possible nonlinearity and use an additive model in this complex setting. To improve computational efficiency, we propose the use of data-augmentation schemes. The approach allows flexible covariance structures for the random effects and within-subject measurement errors of the longitudinal processes. The posterior model space is explored through a Markov chain Monte Carlo (MCMC) sampler. The proposed methods are illustrated and compared to other approaches, the "naive" approach and the regression calibration, via simulations and by an application that investigates the relationship between obesity in adulthood and childhood growth curves. © 2010, The International Biometric Society.

  19. RECRUITING OLDER VOLUNTEERS: FINDINGS FROM THE BELGIAN AGEING STUDIES

    Directory of Open Access Journals (Sweden)

    Sarah DURY

    2010-01-01

    Full Text Available Although there is a significant body of work concerning voluntary work, hardly any attention is given to volunteering of older individuals. Moreover, the potential volunteers among older adults is even less examined. Next to volunteering among olde r adults, the neighbou rhood becomes more salient when people age and this due to their more intense use and time spent in the neighbourhood. In response to these lacunae, the main purpose of this contribution is to examine the impact of subjective neighbourhood features on the recruitment potential for volunteering among older people. This study uses data collected from the Belgian Ageing Studies. 59.977 adults aged sixty and over living self-reliantly in 127 Flemish municipalities in Belgium participated in this study. A binary logistic regression is ap plied to analyse the key va riables characterizing potential volunteers. Our findings stress the need for recognizing the crucial importance of the locality when recruiting older adults for volunteer activities.

  20. Non-Digital Game Playing by Older Adults.

    Science.gov (United States)

    Mortenson, W Ben; Sixsmith, Andrew; Kaufman, David

    2017-09-01

    Research on video games' effect on cognition and behaviour has been extensive, yet little research has explored non-digital forms of game playing, especially among older adults. As part of a larger survey on game playing, 886 respondents (≥ age 55) filled out questionnaires about non-digital game play. The study aims were to determine perceived benefits of non-digital game play and to determine socio-demographic factors that might predict perceived benefits. Survey results indicate that non-digital game playing is social in nature and common (73% of respondents) among older adults. Older adults play for fun, but also to help maintain their cognition. Regression analyses indicated various socio-demographic factors - age, education, gender, and race - were independently associated with perceived benefits from game playing. The results thus emphasize the importance of non-digital game playing in this population and suggest that efforts to facilitate game playing may improve social interactions and quality of life.

  1. Detrended fluctuation analysis as a regression framework: Estimating dependence at different scales

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2015-01-01

    Roč. 91, č. 1 (2015), 022802-1-022802-5 ISSN 1539-3755 R&D Projects: GA ČR(CZ) GP14-11402P Grant - others:GA ČR(CZ) GAP402/11/0948 Program:GA Institutional support: RVO:67985556 Keywords : Detrended cross-correlation analysis * Regression * Scales Subject RIV: AH - Economics Impact factor: 2.288, year: 2014 http://library.utia.cas.cz/separaty/2015/E/kristoufek-0452315.pdf

  2. MULTIPLE LINEAR REGRESSION ANALYSIS FOR PREDICTION OF BOILER LOSSES AND BOILER EFFICIENCY

    OpenAIRE

    Chayalakshmi C.L

    2018-01-01

    MULTIPLE LINEAR REGRESSION ANALYSIS FOR PREDICTION OF BOILER LOSSES AND BOILER EFFICIENCY ABSTRACT Calculation of boiler efficiency is essential if its parameters need to be controlled for either maintaining or enhancing its efficiency. But determination of boiler efficiency using conventional method is time consuming and very expensive. Hence, it is not recommended to find boiler efficiency frequently. The work presented in this paper deals with establishing the statistical mo...

  3. Statistical learning method in regression analysis of simulated positron spectral data

    International Nuclear Information System (INIS)

    Avdic, S. Dz.

    2005-01-01

    Positron lifetime spectroscopy is a non-destructive tool for detection of radiation induced defects in nuclear reactor materials. This work concerns the applicability of the support vector machines method for the input data compression in the neural network analysis of positron lifetime spectra. It has been demonstrated that the SVM technique can be successfully applied to regression analysis of positron spectra. A substantial data compression of about 50 % and 8 % of the whole training set with two and three spectral components respectively has been achieved including a high accuracy of the spectra approximation. However, some parameters in the SVM approach such as the insensitivity zone e and the penalty parameter C have to be chosen carefully to obtain a good performance. (author)

  4. A support network typology for application in older populations with a preponderance of multigenerational households.

    Science.gov (United States)

    Burholt, Vanessa; Dobbs, Christine

    2014-08-01

    This paper considers the support networks of older people in populations with a preponderance of multigenerational households and examines the most vulnerable network types in terms of loneliness and isolation. Current common typologies of support networks may not be sensitive to differences within and between different cultures. This paper uses cross-sectional data drawn from 590 elders (Gujaratis, Punjabis and Sylhetis) living in the United Kingdom and South Asia. Six variables were used in K-means cluster analysis to establish a new network typology. Two logistic regression models using loneliness and isolation as dependent variables assessed the contribution of the new network type to wellbeing. Four support networks were identified: 'Multigenerational Households: Older Integrated Networks', 'Multigenerational Households: Younger Family Networks', 'Family and Friends Integrated Networks' and 'Non-kin Restricted Networks'. Older South Asians with 'Non-kin Restricted Networks' were more likely to be lonely and isolated compared to others. Using network typologies developed with individualistically oriented cultures, distributions are skewed towards more robust network types and could underestimate the support needs of older people from familistic cultures, who may be isolated and lonely and with limited informal sources of help. The new typology identifies different network types within multigenerational households, identifies a greater proportion of older people with vulnerable networks and could positively contribute to service planning.

  5. Social change and birth cohort increase in loneliness among Chinese older adults: a cross-temporal meta-analysis, 1995-2011.

    Science.gov (United States)

    Yan, Zhimin; Yang, Xun; Wang, Lei; Zhao, Yuhan; Yu, Lin

    2014-11-01

    In China, rapid economic growth and increasing social problems constitute the two basic characteristics underlying contemporary social change. With dramatic social change, loneliness in older adults may have changed across birth cohorts, thus altering older adults' mental health. The present study aims to identify birth cohort changes in Chinese older adults' loneliness and the social indicators underlying these changes. Cross-temporal meta-analysis was utilized to investigate changes in Chinese older adults' loneliness from 1995 to 2011. We analyzed 25 studies (N = 13,280 adults; age ≥ 60 years) employing the University of California at Los Angeles Loneliness Scale. We correlated loneliness scores with social indicators and matched these correlations for three periods: ten years before the data collection, five years before data collection, and during the year of data collection. Loneliness levels in Chinese older adults have increased by 1.02 standard deviations from 1995 to 2011. Social indicators such as increased urbanization level, personal medical expenditure, divorce rate, the Gini coefficient, and unemployment rate significantly predicted loneliness in Chinese older adults. Decrease in social connectedness and increase in levels of health threat may be responsible for the observed increase in levels of loneliness. Cross-temporal meta-analysis revealed a birth cohort increase in loneliness among Chinese older adults. We conclude that changes in social connectedness and levels of health threat likely play an important role in predicting loneliness in the population of Chinese elderly adults.

  6. Use of generalized regression models for the analysis of stress-rupture data

    International Nuclear Information System (INIS)

    Booker, M.K.

    1978-01-01

    The design of components for operation in an elevated-temperature environment often requires a detailed consideration of the creep and creep-rupture properties of the construction materials involved. Techniques for the analysis and extrapolation of creep data have been widely discussed. The paper presents a generalized regression approach to the analysis of such data. This approach has been applied to multiple heat data sets for types 304 and 316 austenitic stainless steel, ferritic 2 1 / 4 Cr-1 Mo steel, and the high-nickel austenitic alloy 800H. Analyses of data for single heats of several materials are also presented. All results appear good. The techniques presented represent a simple yet flexible and powerful means for the analysis and extrapolation of creep and creep-rupture data

  7. Effect of endurance exercise training on left ventricular size and remodeling in older adults with hypertension.

    Science.gov (United States)

    Turner, M J; Spina, R J; Kohrt, W M; Ehsani, A A

    2000-04-01

    It is not known whether exercise training can induce a reduction of blood pressure (BP) and a regression of left ventricular hypertrophy (LVH) in older hypertensive subjects. This study was designed to determine whether endurance exercise training, by lowering BP, can induce regression of LVH and left ventricular (LV) concentric remodeling in older hypertensive adults. We studied 11 older adults with mild to moderate hypertension (BP 152.0 +/- 2.5/91.3 +/- 1.5 mm Hg, mean +/- SE), 65.5 +/- 1.2 years old, who exercised for 6.8 +/- 3.8 months. Seven sedentary hypertensive (BP 153 +/- 3/89 +/- 2 mm Hg) subjects, 68.5 +/- 1 years old, served as controls. LV size and geometry and function were assessed with the use of two-dimensional echocardiography. Exercise training increased aerobic power by 16% (p hypertension.

  8. Regression: The Apple Does Not Fall Far From the Tree.

    Science.gov (United States)

    Vetter, Thomas R; Schober, Patrick

    2018-05-15

    Researchers and clinicians are frequently interested in either: (1) assessing whether there is a relationship or association between 2 or more variables and quantifying this association; or (2) determining whether 1 or more variables can predict another variable. The strength of such an association is mainly described by the correlation. However, regression analysis and regression models can be used not only to identify whether there is a significant relationship or association between variables but also to generate estimations of such a predictive relationship between variables. This basic statistical tutorial discusses the fundamental concepts and techniques related to the most common types of regression analysis and modeling, including simple linear regression, multiple regression, logistic regression, ordinal regression, and Poisson regression, as well as the common yet often underrecognized phenomenon of regression toward the mean. The various types of regression analysis are powerful statistical techniques, which when appropriately applied, can allow for the valid interpretation of complex, multifactorial data. Regression analysis and models can assess whether there is a relationship or association between 2 or more observed variables and estimate the strength of this association, as well as determine whether 1 or more variables can predict another variable. Regression is thus being applied more commonly in anesthesia, perioperative, critical care, and pain research. However, it is crucial to note that regression can identify plausible risk factors; it does not prove causation (a definitive cause and effect relationship). The results of a regression analysis instead identify independent (predictor) variable(s) associated with the dependent (outcome) variable. As with other statistical methods, applying regression requires that certain assumptions be met, which can be tested with specific diagnostics.

  9. Regression Analysis

    CERN Document Server

    Freund, Rudolf J; Sa, Ping

    2006-01-01

    The book provides complete coverage of the classical methods of statistical analysis. It is designed to give students an understanding of the purpose of statistical analyses, to allow the student to determine, at least to some degree, the correct type of statistical analyses to be performed in a given situation, and have some appreciation of what constitutes good experimental design

  10. Systematic review, meta-analysis, and meta-regression: Successful second-line treatment for Helicobacter pylori.

    Science.gov (United States)

    Muñoz, Neus; Sánchez-Delgado, Jordi; Baylina, Mireia; Puig, Ignasi; López-Góngora, Sheila; Suarez, David; Calvet, Xavier

    2018-06-01

    Multiple Helicobacter pylori second-line schedules have been described as potentially useful. It remains unclear, however, which are the best combinations, and which features of second-line treatments are related to better cure rates. The aim of this study was to determine that second-line treatments achieved excellent (>90%) cure rates by performing a systematic review and when possible a meta-analysis. A meta-regression was planned to determine the characteristics of treatments achieving excellent cure rates. A systematic review for studies evaluating second-line Helicobacter pylori treatment was carried out in multiple databases. A formal meta-analysis was performed when an adequate number of comparative studies was found, using RevMan5.3. A meta-regression for evaluating factors predicting cure rates >90% was performed using Stata Statistical Software. The systematic review identified 115 eligible studies, including 203 evaluable treatment arms. The results were extremely heterogeneous, with 61 treatment arms (30%) achieving optimal (>90%) cure rates. The meta-analysis favored quadruple therapies over triple (83.2% vs 76.1%, OR: 0.59:0.38-0.93; P = .02) and 14-day quadruple treatments over 7-day treatments (91.2% vs 81.5%, OR; 95% CI: 0.42:0.24-0.73; P = .002), although the differences were significant only in the per-protocol analysis. The meta-regression did not find any particular characteristics of the studies to be associated with excellent cure rates. Second-line Helicobacter pylori treatments achieving>90% cure rates are extremely heterogeneous. Quadruple therapy and 14-day treatments seem better than triple therapies and 7-day ones. No single characteristic of the treatments was related to excellent cure rates. Future approaches suitable for infectious diseases-thus considering antibiotic resistances-are needed to design rescue treatments that consistently achieve excellent cure rates. © 2018 John Wiley & Sons Ltd.

  11. Xerostomia Among Older Adults With Low Income: Nuisance or Warning?

    Science.gov (United States)

    Lee, Young-Shin; Kim, Hee-Gerl; Moreno, Kim

    2016-01-01

    The purpose of this study was to identify the prevalence of xerostomia and related factors among low-income older adults in South Korea. A cross-sectional, population-based study. Using data from the Home Healthcare Service Project, a population-based interview survey with home healthcare service, a total of 9,840 adults 65 years of age and older were assessed for the presence of xerostomia in association with aspects of health lifestyles, chronic disease, oral conditions, and oral function. Overall, 40% of participants reported experiencing xerostomia. Multivariate regression analysis indicated xerostomia was more likely to be reported by women having symptoms of gingival bleeding/pain, having difficulty swallowing liquid or chewing solid food, and having multiple chronic diseases. Interestingly, older adults who live alone and drink alcohol (two or more times per week) reported fewer problems with xerostomia. Increased focus on the detrimental health consequences of xerostomia would make treatment a higher priority. Improved assessment of at-risk populations, particularly among the elderly, could lead to earlier preventative interventions, lessening the negative impact on quality of life. Health professionals along with the general public need increased knowledge about the detrimental effects of xerostomia on overall health. There is a need for earlier assessment and treatment to facilitate optimal health promotion and disease prevention. © 2015 Sigma Theta Tau International.

  12. Multiple regression and beyond an introduction to multiple regression and structural equation modeling

    CERN Document Server

    Keith, Timothy Z

    2014-01-01

    Multiple Regression and Beyond offers a conceptually oriented introduction to multiple regression (MR) analysis and structural equation modeling (SEM), along with analyses that flow naturally from those methods. By focusing on the concepts and purposes of MR and related methods, rather than the derivation and calculation of formulae, this book introduces material to students more clearly, and in a less threatening way. In addition to illuminating content necessary for coursework, the accessibility of this approach means students are more likely to be able to conduct research using MR or SEM--and more likely to use the methods wisely. Covers both MR and SEM, while explaining their relevance to one another Also includes path analysis, confirmatory factor analysis, and latent growth modeling Figures and tables throughout provide examples and illustrate key concepts and techniques For additional resources, please visit: http://tzkeith.com/.

  13. Comparison of Factors Associated with Fear of Falling between Older Adults with and without a Fall History.

    Science.gov (United States)

    Lee, Seonhye; Oh, Eunmi; Hong, Gwi-Ryung Son

    2018-05-14

    Background : Although fear of falling (FOF) has been studied since FOF has negative consequences for the elderly, there is limited information about the risk factors of FOF, including the environment. The purpose of this study was to describe individual and environmental factors of FOF between those with and without a fall history from an ecological aspect and to examine whether individual and environmental factors differently affect the FOF according to the state of fall history in community-dwelling older adults in Korea. Methods : Data from the 2014 Survey of Living Conditions and Welfare Needs of Korean Older Adults were used. Participants were 7730 older adults. Hierarchical logistic regression analysis was conducted to examine the predictors of FOF. Results : According to the ecological model, female and discomfort with the neighborhood environment were significantly associated with greater odds of reporting FOF in both older adults with fall history and those without. A significant interaction was not observed between any variable of FOF in participants with and without a fall history. Conclusions : An ecological model including individual and environmental factors should be considered when conducting research and designing programs and decision policies related to FOF for older adults with and without a history of falling.

  14. Relationship between general health of older health service users and their self-esteem in Isfahan in 2014

    Directory of Open Access Journals (Sweden)

    Razieh Molavi

    2015-01-01

    Full Text Available Background: Self-esteem is known to be one of the most important markers of successful aging. Older people's self-esteem is influenced by several factors that particularly may be health related. Therefore, this study aimed to explore some important general health-related predictors of the older people's self-esteem. Materials and Methods: In this study, 200 people, aged 65 years and older, who referred to health care centers were selected through stratified random sampling method. Data were collected by using Rosenberg's self-esteem scale and the 28-item Goldberg's general health questionnaire. Data were analyzed by Pearson's coefficient tests and multiple regression analysis. Results: Findings showed that the entered predictor variables accounted for 49% of the total variance (R2 of self-esteem in the model (P < 0.001, F4,195 = 46.717. Three out of the four predictor variables including somatic signs, anxiety/insomnia, and depression, significantly predicted the self-esteem. The results emphasized on the determinant role of both physical (somatic signs and mental (anxiety/insomnia and depression aspects of health in older patients' self-esteem. Conclusions: The significant general health-related predictors found in the present study emphasize on some of the significant points that should be considered in planning for improving older patients' self-esteem.

  15. Regression Association Analysis of Yield-Related Traits with RAPD Molecular Markers in Pistachio (Pistacia vera L.

    Directory of Open Access Journals (Sweden)

    Saeid Mirzaei

    2017-10-01

    Full Text Available Introduction: The pistachio (Pistacia vera, a member of the cashew family, is a small tree originating from Central Asia and the Middle East. The tree produces seeds that are widely consumed as food. Pistacia vera often is confused with other species in the genus Pistacia that are also known as pistachio. These other species can be distinguished by their geographic distributions and their seeds which are much smaller and have a soft shell. Continual advances in crop improvement through plant breeding are driven by the available genetic diversity. Therefore, the recognition and measurement of such diversity is crucial to breeding programs. In the past 20 years, the major effort in plant breeding has changed from quantitative to molecular genetics with emphasis on quantitative trait loci (QTL identification and marker assisted selection (MAS. The germplasm-regression-combined association studies not only allow mapping of genes/QTLs with higher level of confidence, but also allow detection of genes/QTLs, which will otherwise escape detection in linkage-based QTL studies based on the planned populations. The development of the marker-based technology offers a fast, reliable, and easy way to perform multiple regression analysis and comprise an alternative approach to breeding in diverse species of plants. The availability of many makers and morphological traits can help to regression analysis between these markers and morphological traits. Materials and Methods: In this study, 20 genotypes of Pistachio were studied and yield related traits were measured. Young well-expanded leaves were collected for DNA extraction and total genomic DNA was extracted. Genotyping was performed using 15 RAPD primers and PCR amplification products were visualized by gel electrophoresis. The reproducible RAPD fragments were scored on the basis of present (1 or absent (0 bands and a binary matrix constructed using each molecular marker. Association analysis between

  16. Memory training interventions for older adults: a meta-analysis.

    Science.gov (United States)

    Gross, Alden L; Parisi, Jeanine M; Spira, Adam P; Kueider, Alexandra M; Ko, Jean Y; Saczynski, Jane S; Samus, Quincy M; Rebok, George W

    2012-01-01

    A systematic review and meta-analysis of memory training research was conducted to characterize the effect of memory strategies on memory performance among cognitively intact, community-dwelling older adults, and to identify characteristics of individuals and of programs associated with improved memory. The review identified 402 publications, of which 35 studies met criteria for inclusion. The overall effect size estimate, representing the mean standardized difference in pre-post change between memory-trained and control groups, was 0.31 standard deviations (SD; 95% confidence interval (CI): 0.22, 0.39). The pre-post training effect for memory-trained interventions was 0.43 SD (95% CI: 0.29, 0.57) and the practice effect for control groups was 0.06 SD (95% CI: 0.05, 0.16). Among 10 distinct memory strategies identified in studies, meta-analytic methods revealed that training multiple strategies was associated with larger training gains (p=0.04), although this association did not reach statistical significance after adjusting for multiple comparisons. Treatment gains among memory-trained individuals were not better after training in any particular strategy, or by the average age of participants, session length, or type of control condition. These findings can inform the design of future memory training programs for older adults.

  17. Supporting frail older people and their family carers at home using information and communication technology: cost analysis.

    Science.gov (United States)

    Magnusson, Lennart; Hanson, Elizabeth

    2005-09-01

    This paper describes a cost analysis of a home-based support service for frail older people and their family carers in two municipalities in West Sweden and using information and communication technology. A key challenge facing nurse managers across Europe is an increasingly aged population, combined with reduced numbers of young adults of working age. New solutions are needed to provide quality, cost-effective community care services to frail older people and their family carers. A case study methodology involving five families was used, and included a detailed cost description of the technology-based service compared with usual services. Cost data were collected in June 2002. This work formed part of a larger project exploring the impact of a technology-based service known as, Assisting Carers using Telematics Interventions to meet Older Persons' Needs (ACTION). In addition to cost data, information was gathered on the quality of life of frail older people and their family carers, and the job satisfaction and work methods of nurses and other practitioners based in the community. The cost analysis comprised a description of the family and their caring situation, the perceived benefits of the telematic based support service and an assessment of its impact on the use of other care services. These analyses were carried out with the help of needs assessors who were known to the families, and nurses working in the ACTION call centre. All results were validated by the five participating families. Cost savings were achieved in all cases, and the benefits to older people and their carers were also considerable. As a result of the cost analysis and overall evaluation data, ACTION has been implemented as a mainstream service in the municipalities involved. Researchers, nurses, other practitioners and community care managers can work together with frail older people and their family carers to develop quality, cost-effective support services that reduce demands on staff

  18. Same-sex partner bereavement in older women:an interpretative phenomenological analysis

    OpenAIRE

    Ingham, Charlotte; Eccles, Fiona Juliet Rosalind; Armitage, Jocelyn Rebecca; Murray, Craig David

    2017-01-01

    Objectives: Due to the lack of existing literature, the current research explored experiences of same-sex partner bereavement in women over the age of 60. Method: Semi-structured interviews were conducted with eight women. Transcripts were analysed using interpretative phenomenological analysis. Results: Three themes were identified which elaborated the experiences of older women who had lost a same-sex partner: (1) being left alone encapsulated feelings of isolation and exclusion; (2) naviga...

  19. Intermediate and advanced topics in multilevel logistic regression analysis.

    Science.gov (United States)

    Austin, Peter C; Merlo, Juan

    2017-09-10

    Multilevel data occur frequently in health services, population and public health, and epidemiologic research. In such research, binary outcomes are common. Multilevel logistic regression models allow one to account for the clustering of subjects within clusters of higher-level units when estimating the effect of subject and cluster characteristics on subject outcomes. A search of the PubMed database demonstrated that the use of multilevel or hierarchical regression models is increasing rapidly. However, our impression is that many analysts simply use multilevel regression models to account for the nuisance of within-cluster homogeneity that is induced by clustering. In this article, we describe a suite of analyses that can complement the fitting of multilevel logistic regression models. These ancillary analyses permit analysts to estimate the marginal or population-average effect of covariates measured at the subject and cluster level, in contrast to the within-cluster or cluster-specific effects arising from the original multilevel logistic regression model. We describe the interval odds ratio and the proportion of opposed odds ratios, which are summary measures of effect for cluster-level covariates. We describe the variance partition coefficient and the median odds ratio which are measures of components of variance and heterogeneity in outcomes. These measures allow one to quantify the magnitude of the general contextual effect. We describe an R 2 measure that allows analysts to quantify the proportion of variation explained by different multilevel logistic regression models. We illustrate the application and interpretation of these measures by analyzing mortality in patients hospitalized with a diagnosis of acute myocardial infarction. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

  20. Regression models of reactor diagnostic signals

    International Nuclear Information System (INIS)

    Vavrin, J.

    1989-01-01

    The application is described of an autoregression model as the simplest regression model of diagnostic signals in experimental analysis of diagnostic systems, in in-service monitoring of normal and anomalous conditions and their diagnostics. The method of diagnostics is described using a regression type diagnostic data base and regression spectral diagnostics. The diagnostics is described of neutron noise signals from anomalous modes in the experimental fuel assembly of a reactor. (author)

  1. Sarcopenia and post-hospital outcomes in older adults: A longitudinal study.

    Science.gov (United States)

    Pérez-Zepeda, Mario Ulises; Sgaravatti, Aldo; Dent, Elsa

    Sarcopenia poses a significant problem for older adults, yet very little is known about this medical condition in the hospital setting. The aims of this hospital-based study were to determine: (i) the prevalence of sarcopenia; (ii) factors associated with sarcopenia; and (iii) the association of sarcopenia with adverse clinical outcomes post-hospitalisation. This is a longitudinal analysis of consecutive patients aged ≥70 years admitted to a Geriatric Management and Evaluation Unit (GEMU) ward. Sarcopenia was classified using the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm, which included: handgrip strength, gait speed, and muscle mass using Bioelectrical Impedance Analysis (BIA). Outcomes were assessed at 12-months post-hospital discharge, and included both mortality and admission to a hospital Emergency Department (ED). Kaplan-Meier methods were used to estimate survival, with Cox proportion hazard models then applied. All regression analyses controlled for age, sex, and co-morbidity. 172 patients (72% female) with a mean (SD) age of 85.2 (6.4) years were included. Sarcopenia was present in 69 (40.1%) of patients. Patients with sarcopenia were twice as likely to die in the 12-months post-hospitalisation (HR, 95% CI=2.23, 1.15-4.34), but did not have an increased likelihood of ED admission. Sarcopenia showed an independent association with 12-month post-hospital mortality in older adults. With the new recognition of sarcopenia as a medical condition with its own unique ICD-10-CM code, awareness and diagnosis of sarcopenia in clinical settings is paramount. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. [Falls and fractures among older adults living in long-term care].

    Science.gov (United States)

    Del Duca, Giovâni Firpo; Antes, Danielle Ledur; Hallal, Pedro Curi

    2013-03-01

    To investigate the prevalence of falls and fractures over the past 12 months and associated factors among older adults living in long-term care. Census of all long-term care located in the city of Pelotas, Brazil, in 2008. Falls over the past 12 months were assessed using the following question: "Over the last 12 months, have you fallen?" For those who replied positively, another question was asked: "In any of these falls, have you fractured a bone?" Sex, age, schooling, disability relating to basic activities of daily living, type of financing of the long-term care and hospital admissions were the independent variables. We used chi-square tests for heterogeneity and linear trend in the unadjusted analysis, and Poisson regression with robust variance in the adjusted one. Within the 24 long-term care studied, we collected data for 466 individuals. The prevalence of falls in the past year was 38.9% (95%CI 34.5; 43.4). Among those who have fallen, 19.2% had fractures. Femur (hip) was the most frequent site fractured (43.4%), followed by wrist (10%). In the adjusted analysis, older age, disability for 1-5 basic activities of daily living, living in public institutions and hospital admissions in the last year were associated with higher risk of falls. The high prevalence of falls and fractures highlights the fragility of the individuals living in long-term care. Special attention should be paid to older adults and those with hospital admissions in the last year.

  3. Comparison of Classical Linear Regression and Orthogonal Regression According to the Sum of Squares Perpendicular Distances

    OpenAIRE

    KELEŞ, Taliha; ALTUN, Murat

    2016-01-01

    Regression analysis is a statistical technique for investigating and modeling the relationship between variables. The purpose of this study was the trivial presentation of the equation for orthogonal regression (OR) and the comparison of classical linear regression (CLR) and OR techniques with respect to the sum of squared perpendicular distances. For that purpose, the analyses were shown by an example. It was found that the sum of squared perpendicular distances of OR is smaller. Thus, it wa...

  4. Online Statistical Modeling (Regression Analysis) for Independent Responses

    Science.gov (United States)

    Made Tirta, I.; Anggraeni, Dian; Pandutama, Martinus

    2017-06-01

    Regression analysis (statistical analmodelling) are among statistical methods which are frequently needed in analyzing quantitative data, especially to model relationship between response and explanatory variables. Nowadays, statistical models have been developed into various directions to model various type and complex relationship of data. Rich varieties of advanced and recent statistical modelling are mostly available on open source software (one of them is R). However, these advanced statistical modelling, are not very friendly to novice R users, since they are based on programming script or command line interface. Our research aims to developed web interface (based on R and shiny), so that most recent and advanced statistical modelling are readily available, accessible and applicable on web. We have previously made interface in the form of e-tutorial for several modern and advanced statistical modelling on R especially for independent responses (including linear models/LM, generalized linier models/GLM, generalized additive model/GAM and generalized additive model for location scale and shape/GAMLSS). In this research we unified them in the form of data analysis, including model using Computer Intensive Statistics (Bootstrap and Markov Chain Monte Carlo/ MCMC). All are readily accessible on our online Virtual Statistics Laboratory. The web (interface) make the statistical modeling becomes easier to apply and easier to compare them in order to find the most appropriate model for the data.

  5. A Simple Linear Regression Method for Quantitative Trait Loci Linkage Analysis With Censored Observations

    OpenAIRE

    Anderson, Carl A.; McRae, Allan F.; Visscher, Peter M.

    2006-01-01

    Standard quantitative trait loci (QTL) mapping techniques commonly assume that the trait is both fully observed and normally distributed. When considering survival or age-at-onset traits these assumptions are often incorrect. Methods have been developed to map QTL for survival traits; however, they are both computationally intensive and not available in standard genome analysis software packages. We propose a grouped linear regression method for the analysis of continuous survival data. Using...

  6. Logistic regression applied to natural hazards: rare event logistic regression with replications

    Directory of Open Access Journals (Sweden)

    M. Guns

    2012-06-01

    Full Text Available Statistical analysis of natural hazards needs particular attention, as most of these phenomena are rare events. This study shows that the ordinary rare event logistic regression, as it is now commonly used in geomorphologic studies, does not always lead to a robust detection of controlling factors, as the results can be strongly sample-dependent. In this paper, we introduce some concepts of Monte Carlo simulations in rare event logistic regression. This technique, so-called rare event logistic regression with replications, combines the strength of probabilistic and statistical methods, and allows overcoming some of the limitations of previous developments through robust variable selection. This technique was here developed for the analyses of landslide controlling factors, but the concept is widely applicable for statistical analyses of natural hazards.

  7. Concern about HIV and AIDS among older people in the slums of Nairobi, Kenya.

    Science.gov (United States)

    Chepngeno-Langat, Gloria; Falkingham, Jane C; Madise, Nyovani J; Evandrou, Maria

    2012-09-01

    The article explores the way that social networks and personal experiences affect perceived HIV-related concerns among people aged 50 years or older living in a low resource neighborhood with high HIV prevalence in Nairobi, Kenya. Multiple logistic regression is used to model the association between the reporting of an HIV-related concern and individual-level characteristics, personal experiences, and social interaction. The main concerns regarding HIV reported by older people in the study included caring for orphaned children (65%), caring for people with AIDS (48%), and losing material and social support from adult children (36%). Interestingly, 38% of respondents voiced concerns about HIV infection among older people. Respondents who had been individually affected by HIV and AIDS, who were part of a wide social network, or who participated in community activities were frequently more likely to report a concern. The findings highlight the significance of the role of social interaction and social networks in the diffusion of information and knowledge. These findings have implications for HIV and AIDS policy and programs, highlighting the potential for social networks and community-level interventions to educate and increase awareness about HIV and AIDS among older people. Community leaders can make good peer educators and communication agents for HIV/AIDS campaigns. Additionally, the recognized high level of personal vulnerability to HIV infection among older people suggests the need for targeted sexual behavior change programs among this often neglected group. © 2012 Society for Risk Analysis.

  8. Depression and medication adherence among older Korean patients with hypertension: Mediating role of self-efficacy.

    Science.gov (United States)

    Son, Youn-Jung; Won, Mi Hwa

    2017-06-01

    Many studies have reported the negative effects of depression on adherence to antihypertensive medication. However, little is known about the mechanism underlying this relationship in elderly patients with hypertension. The aim of this cross-sectional study is to examine the mediating role of self-efficacy in the relationship between depression and medication adherence among older patients with hypertension. The data were collected from October to December 2014. A total of 255 older patients with hypertension were assessed using the Geriatric Depression Scale, the Self-efficacy for Appropriate Medication Use Scale, and the Morisky Medication Adherence Scale. Hierarchical linear regression analysis and the Sobel test were used to examine the mediating role of self-efficacy in the relationship between depression and medication adherence. Depression and self-efficacy were statistically significant predictors of medication adherence in older patients with hypertension. Self-efficacy partially mediated the relationship between depression and medication adherence. Interventions targeting self-efficacy could increase the confidence of patients in their ability to actively take their medicines. Moreover, health care providers should be aware of the importance of early detection of depression in older patients with hypertension. Future studies with longitudinal data are warranted to clarify the multidirectional relationships between depression, self-efficacy, and medication adherence. © 2017 John Wiley & Sons Australia, Ltd.

  9. Robust Methods for Moderation Analysis with a Two-Level Regression Model.

    Science.gov (United States)

    Yang, Miao; Yuan, Ke-Hai

    2016-01-01

    Moderation analysis has many applications in social sciences. Most widely used estimation methods for moderation analysis assume that errors are normally distributed and homoscedastic. When these assumptions are not met, the results from a classical moderation analysis can be misleading. For more reliable moderation analysis, this article proposes two robust methods with a two-level regression model when the predictors do not contain measurement error. One method is based on maximum likelihood with Student's t distribution and the other is based on M-estimators with Huber-type weights. An algorithm for obtaining the robust estimators is developed. Consistent estimates of standard errors of the robust estimators are provided. The robust approaches are compared against normal-distribution-based maximum likelihood (NML) with respect to power and accuracy of parameter estimates through a simulation study. Results show that the robust approaches outperform NML under various distributional conditions. Application of the robust methods is illustrated through a real data example. An R program is developed and documented to facilitate the application of the robust methods.

  10. Oil and gas pipeline construction cost analysis and developing regression models for cost estimation

    Science.gov (United States)

    Thaduri, Ravi Kiran

    In this study, cost data for 180 pipelines and 136 compressor stations have been analyzed. On the basis of the distribution analysis, regression models have been developed. Material, Labor, ROW and miscellaneous costs make up the total cost of a pipeline construction. The pipelines are analyzed based on different pipeline lengths, diameter, location, pipeline volume and year of completion. In a pipeline construction, labor costs dominate the total costs with a share of about 40%. Multiple non-linear regression models are developed to estimate the component costs of pipelines for various cross-sectional areas, lengths and locations. The Compressor stations are analyzed based on the capacity, year of completion and location. Unlike the pipeline costs, material costs dominate the total costs in the construction of compressor station, with an average share of about 50.6%. Land costs have very little influence on the total costs. Similar regression models are developed to estimate the component costs of compressor station for various capacities and locations.

  11. Biomechanical analysis of effects of neuromusculoskeletal training for older adults on the likelihood of slip-induced falls.

    OpenAIRE

    Kim, Sukwon

    2006-01-01

    Overview of the Study Title Biomechanical Analysis for Effects of Neuromusculoskeletal Training for Older Adults on Outcomes of Slip-induced Falls. Research Objectives The objective of this study was to evaluate if neuromusculoskeletal training (i.e., weight and balance training) for older adults could reduce the likelihood of slip-induced fall accidents. The study focused on evaluating biomechanics among the elderly at pre- and post-training stages during processes associated w...

  12. Intensity of Care at the End of Life Among Older Adults in Korea.

    Science.gov (United States)

    Kim, Su Hyun; Kang, Sangwook; Song, Mi-Kyung

    2018-01-01

    To examine the intensity of care at the end of life among older adults in Korea and to identify the individual and institutional factors associated with care intensity. This secondary data analysis included a sample of 6278 decedents aged 65 years or older who were identified from the 2009 to 2010 Korean National Health Insurance Service-National Sample Cohort Claims data. We examined the medical care received by the cohort in the last 30 days of their lives. Overall, 36.5% of the sample received at least 1 intensive care procedure in the last 30 days of their lives; 26.3% of patients experienced intensive care unit admission, with an average stay of 7.45 days, 19.5% received mechanical ventilation, 12.3% received cardiopulmonary resuscitation, and 15.5% had a feeding tube placement. A statistical analysis using a multiple logistic regression model with random effects showed that younger age, higher household income, primary diagnoses of diseases (ischemic heart disease, infectious disease, chronic lung disease, or chronic heart disease), and characteristics of care setting (large hospitals and facilities located in metropolitan areas) were significantly associated with the likelihood of receiving high-intensity care at the end of life. A substantial number of older adults in Korea experienced high-intensity end-of-life care. Both individual and institutional factors were associated with the likelihood of receiving high-intensity care. Gaining an understanding of the intensity of care at the end of life and the impact of the determinants would advance efforts to improve quality of care at the end of life for older adults in Korea.

  13. Fear of falling and its predictors among community-living older adults in Korea.

    Science.gov (United States)

    Oh, Eunmi; Hong, Gwi-Ryung Son; Lee, Seonhye; Han, Soojeong

    2017-04-01

    To explore the prevalence and predicting factors of fear of falling (FOF) among community-living older adults in Korea. Secondary data analysis of the 2011 Korean National Elderly Living Conditions and Welfare Desire Survey was used. Logistic regression analysis was conducted to examine the predictors of FOF. In total, 75.6% of older adults with normal cognition have FOF. Factors associated with an increased risk of FOF in older adults are previous experience with falling (OR = 3.734, 95% CI = 2.996-4.655), limitations in the performance of exercise involving lower extremities (OR = 2.428, 95% CI = 2.063-2.858), being female (OR = 2.335, 95% CI = 2.023-2.694), having more than three chronic diseases (OR = 1.994, 95% CI = 1.625-2.446), limitations in instrumental activities of daily living (IADLs) (OR = 1.745, 95% CI = 1.230-2.477), limitations in the performance of exercise involving upper extremities (OR = 1.646, 95% CI = 1.357-1.997), living without a spouse (OR = 1.626, 95% CI = 1.357-1.948), having poor self-rated health (OR = 1.571, 95% CI = 1.356-1.821), limitations in muscle strength (OR = 1.455, 95% CI = 1.150-1.841), age (≥75 years) (OR = 1.320, 95% CI = 1.150-1.516), lower levels of education (0-6 years) (OR = 1.231, 95% CI = 1.075-1.409), and life satisfaction (OR = 1.104, 95% CI = 1.065-1.114). A multidimensional construct of general characteristics, physical, and psychosocial variables act as risk factors for FOF. Preventive intervention should be developed to decrease the FOF among Korean older adults.

  14. Behavioral Observation and Microbiological Analysis of Older Adult Consumers' Cross-Contamination Practices in a Model Domestic Kitchen.

    Science.gov (United States)

    Evans, Ellen W; Redmond, Elizabeth C

    2018-04-01

    The incidence of foodborne illness is higher in older adults because of their increased susceptibility; therefore, food safety practices are important. However, inadequate knowledge and negative attitudes toward food safety have been reported, which may increase use of unsafe food handling practices. Data on the actual food safety behaviors of older adults are lacking. In this study, food safety practices of older adults were observed and linked to microbiological analysis of kitchen surfaces to identify suspected routes of contamination. Older adults (≥60 years, n = 100) prepared a set meal in a model domestic kitchen sanitized according to a validated protocol to ensure minimal and consistent microbiological loads. Food safety behaviors were observed using ceiling-mounted cameras and recorded using a predetermined behavioral checklist. Surface microbiological contamination also was determined after food preparation. Overall, older adults frequently implemented unsafe food handling practices; 90% failed to implement adequate hand decontamination immediately after handling raw chicken. For older adults who used a larger number of adequate hand decontamination attempts, microbiological contamination levels in the kitchen following the food preparation session were significantly lower ( P food handling practices as suspected routes of microbiological cross-contamination in a model domestic kitchen. Findings indicate the potential impact on domestic food safety of unsafe food handling practices used by older adult consumers. This innovative approach revealed that a large proportion of older adults implement behaviors resulting in microbiological cross-contamination that may increase the risk of foodborne illness in the home.

  15. Living arrangements and suicidal ideation among the Korean older adults.

    Science.gov (United States)

    Kim, Jibum; Lee, Yun-Suk; Lee, Jinkook

    2016-12-01

    This study examines how living arrangements are associated with suicidal ideation for older adults in South Korea, which has the highest suicide rate among OECD countries, and a particularly high suicide rate for older persons. Analyzing a sample of 5795 women and 3758 men aged 65 and older from a nationwide representative cross-sectional data-set, we examined how many older adults think about suicide over a one-year period, why they think about suicide, and whether living arrangements are associated with suicidal ideation. About 1 out of 12 respondents in our sample reported suicidal ideation. While women and men did not differ in the prevalence of suicidal ideation, women attributed their suicidal feelings to health problems, while men attributed theirs to economic difficulties. Logistic regression results indicated that living arrangements are associated with suicidal ideation for men but not women. Older men living with a spouse were less likely to have suicidal ideation than older men with other living arrangements (i.e., living alone, living with children without spouse, living with spouse, and others). Our results highlight the importance of living arrangements to older men's suicidal ideation. We discuss gender differences in the implications of living arrangements to suicidal ideation within the context of Confucian culture.

  16. Clinically Relevant Cut-off Points for the Diagnosis of Sarcopenia in Older Korean People.

    Science.gov (United States)

    Choe, Yu-Ri; Joh, Ju-Youn; Kim, Yeon-Pyo

    2017-11-09

    The optimal criteria applied to older Korean people have not been defined. We aimed to define clinically relevant cut-off points for older Korean people and to compare the predictive validity with other definitions of sarcopenia. Nine hundred and sixteen older Koreans (≥65 years) were included in this cross-sectional observational study. We used conditional inference tree analysis to determine cut-off points for height-adjusted grip strength (GS) and appendicular skeletal muscle mass (ASM), for use in the diagnosis of sarcopenia. We then compared the Korean sarcopenia criteria with the Foundation for the National Institutes of Health and Asian Working Group for Sarcopenia criteria, using frailty, assessed with the Korean Frailty Index, as an outcome variable. For men, a residual GS (GSre) of ≤ 0.25 was defined as weak, and a residual ASM (ASMre) of ≤ 1.29 was defined as low. Corresponding cut-off points for women were a GSre of ≤ 0.17 and an ASMre of ≤ 0.69. GSre and ASMre values were adjusted for height. In logistic regression analysis with new cut-off points, the adjusted odds ratios for pre-frail or frail status in the sarcopenia group were 3.23 (95% confidence interval [CI] 1.33-7.83) for the men and 1.74 (95% CI 0.91-3.35) for the women. In receiver operating characteristic curve analysis, the unadjusted area under the curve for Korean sarcopenia criteria in men and women were 0.653 and 0.608, respectively (p sarcopenia in older Korean people. © The Author 2017. 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.

  17. Sleep Apnea and Obstructive Airway Disease in Older Men: Outcomes of Sleep Disorders in Older Men Study.

    Science.gov (United States)

    Zhao, Ying Y; Blackwell, Terri; Ensrud, Kristine E; Stone, Katie L; Omachi, Theodore A; Redline, Susan

    2016-07-01

    To evaluate the association between obstructive airway disease (OAD) and sleep apnea in older men. A community-based cross-sectional study of 853 community-dwelling older men (mean age 80.7 ± 4.1 years [range 73 to 90]) across 6 centers in the United States from the Outcomes of Sleep Disorders in Older Men Study. Sleep was objectively measured using full in-home polysomnography and lung function was objectively measured using spirometry. The association of OAD (pre-bronchodilator FEV1/FVC ratio sleep apnea (apnea-hypopnea index [AHI] ≥ 15 events/hour) was assessed using logistic regression. OAD and sleep apnea were identified in 111 (13.0%) and 247 (29.0%) men, respectively. In univariate analysis, participants with OAD had a lower AHI (mean ± SD; 8.7 ± 11.7 vs. 12.7 ± 13.8, P = 0.0009) and a lower prevalence of sleep apnea (14.4 vs. 31.1%, P = 0.0003) compared to participants without OAD. OAD remained independently associated with a lower odds of sleep apnea (odds ratio 0.30, 95% CI 0.16 to 0.55, P = 0.0001) after adjustment for demographics, body composition, smoking, and potential mediators (arousal index, time spent in rapid eye movement sleep). Individuals with OAD and sleep apnea (n = 16) had an increased arousal index and lower oxygen saturation level as compared to individuals with OAD alone (P values sleep apnea in a cohort of community-dwelling elderly men, and unexplained by differences in adiposity or sleep architecture. Although uncommon in this cohort, coexisting sleep apnea and OAD was associated with increased sleep fragmentation and nocturnal oxygen desaturation compared to OAD alone. © 2016 Associated Professional Sleep Societies, LLC.

  18. Understanding interprofessional collaboration in the context of chronic disease management for older adults living in communities: a concept analysis.

    Science.gov (United States)

    Bookey-Bassett, Sue; Markle-Reid, Maureen; Mckey, Colleen A; Akhtar-Danesh, Noori

    2017-01-01

    To report a concept analysis of interprofessional collaboration in the context of chronic disease management, for older adults living in communities. Increasing prevalence of chronic disease among older adults is creating significant burden for patients, families and healthcare systems. Managing chronic disease for older adults living in the community requires interprofessional collaboration across different health and other care providers, organizations and sectors. However, there is a lack of consensus about the definition and use of interprofessional collaboration for community-based chronic disease management. Concept analysis. Electronic databases CINAHL, Medline, HealthStar, EMBASE, PsychINFO, Ageline and Cochrane Database were searched from 2000 - 2013. Rodgers' evolutionary method for concept analysis. The most common surrogate term was interdisciplinary collaboration. Related terms were interprofessional team, multidisciplinary team and teamwork. Attributes included: an evolving interpersonal process; shared goals, decision-making and care planning; interdependence; effective and frequent communication; evaluation of team processes; involving older adults and family members in the team; and diverse and flexible team membership. Antecedents comprised: role awareness; interprofessional education; trust between team members; belief that interprofessional collaboration improves care; and organizational support. Consequences included impacts on team composition and function, care planning processes and providers' knowledge, confidence and job satisfaction. Interprofessional collaboration is a complex evolving concept. Key components of interprofessional collaboration in chronic disease management for community-living older adults are identified. Implications for nursing practice, education and research are proposed. © 2016 John Wiley & Sons Ltd.

  19. Weibull and lognormal Taguchi analysis using multiple linear regression

    International Nuclear Information System (INIS)

    Piña-Monarrez, Manuel R.; Ortiz-Yañez, Jesús F.

    2015-01-01

    The paper provides to reliability practitioners with a method (1) to estimate the robust Weibull family when the Taguchi method (TM) is applied, (2) to estimate the normal operational Weibull family in an accelerated life testing (ALT) analysis to give confidence to the extrapolation and (3) to perform the ANOVA analysis to both the robust and the normal operational Weibull family. On the other hand, because the Weibull distribution neither has the normal additive property nor has a direct relationship with the normal parameters (µ, σ), in this paper, the issues of estimating a Weibull family by using a design of experiment (DOE) are first addressed by using an L_9 (3"4) orthogonal array (OA) in both the TM and in the Weibull proportional hazard model approach (WPHM). Then, by using the Weibull/Gumbel and the lognormal/normal relationships and multiple linear regression, the direct relationships between the Weibull and the lifetime parameters are derived and used to formulate the proposed method. Moreover, since the derived direct relationships always hold, the method is generalized to the lognormal and ALT analysis. Finally, the method’s efficiency is shown through its application to the used OA and to a set of ALT data. - Highlights: • It gives the statistical relations and steps to use the Taguchi Method (TM) to analyze Weibull data. • It gives the steps to determine the unknown Weibull family to both the robust TM setting and the normal ALT level. • It gives a method to determine the expected lifetimes and to perform its ANOVA analysis in TM and ALT analysis. • It gives a method to give confidence to the extrapolation in an ALT analysis by using the Weibull family of the normal level.

  20. Framing an Nuclear Emergency Plan using Qualitative Regression Analysis

    International Nuclear Information System (INIS)

    Amy Hamijah Abdul Hamid; Ibrahim, M.Z.A.; Deris, S.R.

    2014-01-01

    Since the arising on safety maintenance issues due to post-Fukushima disaster, as well as, lack of literatures on disaster scenario investigation and theory development. This study is dealing with the initiation difficulty on the research purpose which is related to content and problem setting of the phenomenon. Therefore, the research design of this study refers to inductive approach which is interpreted and codified qualitatively according to primary findings and written reports. These data need to be classified inductively into thematic analysis as to develop conceptual framework related to several theoretical lenses. Moreover, the framing of the expected framework of the respective emergency plan as the improvised business process models are abundant of unstructured data abstraction and simplification. The structural methods of Qualitative Regression Analysis (QRA) and Work System snapshot applied to form the data into the proposed model conceptualization using rigorous analyses. These methods were helpful in organising and summarizing the snapshot into an ' as-is ' work system that being recommended as ' to-be' w ork system towards business process modelling. We conclude that these methods are useful to develop comprehensive and structured research framework for future enhancement in business process simulation. (author)

  1. Children's Divorce and Parent-Child Contact: A Within-Family Analysis of Older European Parents.

    Science.gov (United States)

    Kalmijn, Matthijs

    2016-03-01

    Studies have shown that a parental divorce has a negative effect on parent-child relations. This study examines how adult children's divorce affects the amount of contact children have with older parents, making a distinction between the effects of being single on the one hand and the effects of divorce on the other hand. Using data on older adults in 11 European countries, I estimate within-family regression models to compare multiple adult children per parent (19,454 children aged 30-49; 10,476 parents aged 50-96). I analyze contact frequency while taking into account coresidence and distance. When comparing single divorced children and married children, no difference in contact is observed, but divorced children are more likely to live with their parents. When comparing among children who are single, divorced children have less frequent contact with parents than never-married children. This negative divorce effect exists for sons and daughters and is found in 9 of the 11 countries. The divorce of a child has a double meaning: it leads to being single, which is associated with stronger intergenerational ties, but it is also a non-normative and stressful life event, which is associated with weaker intergenerational ties. © The Author 2014. 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.

  2. Targeted individual exercise programmes for older medical patients are feasible, and may change hospital and patient outcomes: a service improvement project

    Directory of Open Access Journals (Sweden)

    Thomas Susie

    2008-12-01

    Full Text Available Abstract Background The aim of this project was primarily to assess the feasibility of individual exercise programs for older hospitalised patients at risk of functional decline, and secondarily to evaluate impact on discharge outcomes. Methods Design: Cohort service improvement project Setting: 500 bed acute metropolitan hospital Subjects: Patients aged 70 and older admitted to Flinders Medical Centre under the general medical, aged care and respiratory units from June to November 2006, at intermediate or high risk of functional decline, and able to commence exercise within 48 hours of admission Intervention: Functional Maintenance Program (FMP; an individually tailored exercise program to maintain functional mobility, prescribed and progressed by a physiotherapist, and supervised by an Allied Health Assistant (AHA, provided in addition to usual physiotherapy care Outcome measures: Feasibility (number of admissions suitable, commencing and complying with FMP. Impact (length of hospital stay (LOS, Aged Care Assessment Team (ACAT referrals and approvals, hospital readmissions within 28 days, and functional mobility (Elderly Mobility Scale Data Analysis: Descriptive and logistic regression analysis Results Of 1021 admissions of patients aged 70 or older to general medical, aged care and respiratory units, 22% (n = 220 were identified within 48 hours as suitable for FMP: 196 (89% commenced FMP within 48 hours of admission (FMP patients; 24 (11% received usual physiotherapy (usual care patients. Feasibility of individually tailored exercise programs for older medical patients was supported by high uptake (89%, low withdrawal (17% shown by those who commenced FMP, and good compliance with exercise sessions (70%. Logistic regression analysis showed a statistically significant decreased likelihood of referral for nursing home admission (OR = 0.228, 95% CI 0.088–0.587 and decreased likelihood of approval for admission to residential care (OR = 0

  3. A new approach to nuclear reactor design optimization using genetic algorithms and regression analysis

    International Nuclear Information System (INIS)

    Kumar, Akansha; Tsvetkov, Pavel V.

    2015-01-01

    Highlights: • This paper presents a new method useful for the optimization of complex dynamic systems. • The method uses the strengths of; genetic algorithms (GA), and regression splines. • The method is applied to the design of a gas cooled fast breeder reactor design. • Tools like Java, R, and codes like MCNP, Matlab are used in this research. - Abstract: A module based optimization method using genetic algorithms (GA), and multivariate regression analysis has been developed to optimize a set of parameters in the design of a nuclear reactor. GA simulates natural evolution to perform optimization, and is widely used in recent times by the scientific community. The GA fits a population of random solutions to the optimized solution of a specific problem. In this work, we have developed a genetic algorithm to determine the values for a set of nuclear reactor parameters to design a gas cooled fast breeder reactor core including a basis thermal–hydraulics analysis, and energy transfer. Multivariate regression is implemented using regression splines (RS). Reactor designs are usually complex and a simulation needs a significantly large amount of time to execute, hence the implementation of GA or any other global optimization techniques is not feasible, therefore we present a new method of using RS in conjunction with GA. Due to using RS, we do not necessarily need to run the neutronics simulation for all the inputs generated from the GA module rather, run the simulations for a predefined set of inputs, build a multivariate regression fit to the input and the output parameters, and then use this fit to predict the output parameters for the inputs generated by GA. The reactor parameters are given by the, radius of a fuel pin cell, isotopic enrichment of the fissile material in the fuel, mass flow rate of the coolant, and temperature of the coolant at the core inlet. And, the optimization objectives for the reactor core are, high breeding of U-233 and Pu-239 in

  4. Robust estimation for homoscedastic regression in the secondary analysis of case-control data

    KAUST Repository

    Wei, Jiawei; Carroll, Raymond J.; Mü ller, Ursula U.; Keilegom, Ingrid Van; Chatterjee, Nilanjan

    2012-01-01

    Primary analysis of case-control studies focuses on the relationship between disease D and a set of covariates of interest (Y, X). A secondary application of the case-control study, which is often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated owing to the case-control sampling, where the regression of Y on X is different from what it is in the population. Previous work has assumed a parametric distribution for Y given X and derived semiparametric efficient estimation and inference without any distributional assumptions about X. We take up the issue of estimation of a regression function when Y given X follows a homoscedastic regression model, but otherwise the distribution of Y is unspecified. The semiparametric efficient approaches can be used to construct semiparametric efficient estimates, but they suffer from a lack of robustness to the assumed model for Y given X. We take an entirely different approach. We show how to estimate the regression parameters consistently even if the assumed model for Y given X is incorrect, and thus the estimates are model robust. For this we make the assumption that the disease rate is known or well estimated. The assumption can be dropped when the disease is rare, which is typically so for most case-control studies, and the estimation algorithm simplifies. Simulations and empirical examples are used to illustrate the approach.

  5. Robust estimation for homoscedastic regression in the secondary analysis of case-control data

    KAUST Repository

    Wei, Jiawei

    2012-12-04

    Primary analysis of case-control studies focuses on the relationship between disease D and a set of covariates of interest (Y, X). A secondary application of the case-control study, which is often invoked in modern genetic epidemiologic association studies, is to investigate the interrelationship between the covariates themselves. The task is complicated owing to the case-control sampling, where the regression of Y on X is different from what it is in the population. Previous work has assumed a parametric distribution for Y given X and derived semiparametric efficient estimation and inference without any distributional assumptions about X. We take up the issue of estimation of a regression function when Y given X follows a homoscedastic regression model, but otherwise the distribution of Y is unspecified. The semiparametric efficient approaches can be used to construct semiparametric efficient estimates, but they suffer from a lack of robustness to the assumed model for Y given X. We take an entirely different approach. We show how to estimate the regression parameters consistently even if the assumed model for Y given X is incorrect, and thus the estimates are model robust. For this we make the assumption that the disease rate is known or well estimated. The assumption can be dropped when the disease is rare, which is typically so for most case-control studies, and the estimation algorithm simplifies. Simulations and empirical examples are used to illustrate the approach.

  6. Irrational ideas. Older vs. younger inpatients.

    Science.gov (United States)

    Hyer, L A; Jacobsen, R; Harrison, W R

    1985-04-01

    The relationship to age of irrational beliefs among psychiatric inpatients has not been explored using the rational-emotive model. This study addressed the following two questions: 1) Do older and younger psychiatric inpatients differ in irrational beliefs? 2) Do older depressives differ from older nondepressives in irrational beliefs? Upon admission to a large medical center, 58 younger (less than 45 years old) and 54 older (greater than 55 years old) subjects were assessed on a battery of psychological tests, including the Idea Inventory and the Beck Depression Inventory. Results showed that older and younger inpatients did not differ on irrational beliefs. Results also showed that older and younger groups of depressives did not differ on the irrationality scores. When a correlational analysis was used, depression was related to irrationality within the older group but not within the younger group.

  7. Access to healthcare and financial risk protection for older adults in Mexico: secondary data analysis of a national survey.

    Science.gov (United States)

    Doubova, Svetlana V; Pérez-Cuevas, Ricardo; Canning, David; Reich, Michael R

    2015-07-21

    While the benefits of Seguro Popular health insurance in Mexico relative to no insurance have been widely documented, little has been reported on its effects relative to the pre-existing Social Security health insurance. We analyse the effects of Social Security and Seguro Popular health insurances in Mexico on access to healthcare of older adults, and on financial risk protection to their households, compared with older adults without health insurance. Secondary data analysis was performed using the 2012 Mexican Survey of Health and Nutrition (ENSANUT). The study population comprised 18,847 older adults and 13,180 households that have an elderly member. The dependent variables were access to healthcare given the reported need, the financial burden imposed by health expenditures measured through catastrophic health-related expenditures, and using savings for health-related expenditures. Separate propensity score matching analyses were conducted for each comparison. The analysis for access was performed at the individual level, and the analysis for financial burden at the household level. In each case, matching on a wide set of relevant characteristics was achieved. Seguro Popular showed a protective effect against lack of access to healthcare for older adults compared with those with no insurance. The average treatment effect on the treated (ATET) was ascertained through using the nearest-neighbour matching (-8.1%, t-stat -2.305) analysis. However, Seguro Popular did not show a protective effect against catastrophic expenditures in a household where an older adult lived. Social Security showed increased access to healthcare (ATET -11.3%, t-stat -3.138), and protective effect against catastrophic expenditures for households with an elderly member (ATET -1.9%, t-stat -2.178). Seguro Popular increased access to healthcare for Mexican older adults. Social Security showed a significant protective effect against lack of access and catastrophic expenditures compared with

  8. Variable and subset selection in PLS regression

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2001-01-01

    The purpose of this paper is to present some useful methods for introductory analysis of variables and subsets in relation to PLS regression. We present here methods that are efficient in finding the appropriate variables or subset to use in the PLS regression. The general conclusion...... is that variable selection is important for successful analysis of chemometric data. An important aspect of the results presented is that lack of variable selection can spoil the PLS regression, and that cross-validation measures using a test set can show larger variation, when we use different subsets of X, than...

  9. Logistic regression analysis of conventional ultrasonography, strain elastosonography, and contrast-enhanced ultrasound characteristics for the differentiation of benign and malignant thyroid nodules.

    Science.gov (United States)

    Pang, Tiantian; Huang, Leidan; Deng, Yingyuan; Wang, Tianfu; Chen, Siping; Gong, Xuehao; Liu, Weixiang

    2017-01-01

    The aim of the study is to screen the significant sonographic features by logistic regression analysis and fit a model to diagnose thyroid nodules. A total of 525 pathological thyroid nodules were retrospectively analyzed. All the nodules underwent conventional ultrasonography (US), strain elastosonography (SE), and contrast -enhanced ultrasound (CEUS). Those nodules' 12 suspicious sonographic features were used to assess thyroid nodules. The significant features of diagnosing thyroid nodules were picked out by logistic regression analysis. All variables that were statistically related to diagnosis of thyroid nodules, at a level of p regression analysis model. The significant features in the logistic regression model of diagnosing thyroid nodules were calcification, suspected cervical lymph node metastasis, hypoenhancement pattern, margin, shape, vascularity, posterior acoustic, echogenicity, and elastography score. According to the results of logistic regression analysis, the formula that could predict whether or not thyroid nodules are malignant was established. The area under the receiver operating curve (ROC) was 0.930 and the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 83.77%, 89.56%, 87.05%, 86.04%, and 87.79% respectively.

  10. Interactions between cadmium and decabrominated diphenyl ether on blood cells count in rats—Multiple factorial regression analysis

    International Nuclear Information System (INIS)

    Curcic, Marijana; Buha, Aleksandra; Stankovic, Sanja; Milovanovic, Vesna; Bulat, Zorica; Đukić-Ćosić, Danijela; Antonijević, Evica; Vučinić, Slavica; Matović, Vesna; Antonijevic, Biljana

    2017-01-01

    The objective of this study was to assess toxicity of Cd and BDE-209 mixture on haematological parameters in subacutely exposed rats and to determine the presence and type of interactions between these two chemicals using multiple factorial regression analysis. Furthermore, for the assessment of interaction type, an isobologram based methodology was applied and compared with multiple factorial regression analysis. Chemicals were given by oral gavage to the male Wistar rats weighing 200–240 g for 28 days. Animals were divided in 16 groups (8/group): control vehiculum group, three groups of rats were treated with 2.5, 7.5 or 15 mg Cd/kg/day. These doses were chosen on the bases of literature data and reflect relatively high Cd environmental exposure, three groups of rats were treated with 1000, 2000 or 4000 mg BDE-209/kg/bw/day, doses proved to induce toxic effects in rats. Furthermore, nine groups of animals were treated with different mixtures of Cd and BDE-209 containing doses of Cd and BDE-209 stated above. Blood samples were taken at the end of experiment and red blood cells, white blood cells and platelets counts were determined. For interaction assessment multiple factorial regression analysis and fitted isobologram approach were used. In this study, we focused on multiple factorial regression analysis as a method for interaction assessment. We also investigated the interactions between Cd and BDE-209 by the derived model for the description of the obtained fitted isobologram curves. Current study indicated that co-exposure to Cd and BDE-209 can result in significant decrease in RBC count, increase in WBC count and decrease in PLT count, when compared with controls. Multiple factorial regression analysis used for the assessment of interactions type between Cd and BDE-209 indicated synergism for the effect on RBC count and no interactions i.e. additivity for the effects on WBC and PLT counts. On the other hand, isobologram based approach showed slight

  11. Multicollinearity in Regression Analyses Conducted in Epidemiologic Studies.

    Science.gov (United States)

    Vatcheva, Kristina P; Lee, MinJae; McCormick, Joseph B; Rahbar, Mohammad H

    2016-04-01

    The adverse impact of ignoring multicollinearity on findings and data interpretation in regression analysis is very well documented in the statistical literature. The failure to identify and report multicollinearity could result in misleading interpretations of the results. A review of epidemiological literature in PubMed from January 2004 to December 2013, illustrated the need for a greater attention to identifying and minimizing the effect of multicollinearity in analysis of data from epidemiologic studies. We used simulated datasets and real life data from the Cameron County Hispanic Cohort to demonstrate the adverse effects of multicollinearity in the regression analysis and encourage researchers to consider the diagnostic for multicollinearity as one of the steps in regression analysis.

  12. Factors associated with improved survival among older colorectal cancer patients in the US: a population-based analysis

    Directory of Open Access Journals (Sweden)

    Earle Craig C

    2009-07-01

    Full Text Available Abstract Background The purpose of this study was to estimate the relative impact of changes in demographics, stage at detection, treatment mix, and medical technology on 5-year survival among older colorectal cancer (CRC patients. Methods We selected older patients diagnosed with CRC between 1992 and 2000 from the SEER-Medicare database and followed them through 2005. Trends in demographic characteristics, stage at detection and initial treatment mix were evaluated descriptively. Separate multivariate logistic regression models for colon (CC and rectal cancer (RC patients were estimated to isolate the independent effects of these factors along with technological change (proxied by cohort year on 5-year survival. Results Our sample included 37,808 CC and 13,619 RC patients (combined mean ± SD age: 77.2 ± 7.0 years; 55% female; 87% white. In recent years, more CC patients were diagnosed at Stage I and fewer at Stages II and IV, and more RC patients were diagnosed at Stage I and fewer at Stages II and III. CC and RC patients diagnosed in later years were slightly older with somewhat better Charlson scores and were more likely to be female, from the Northeast, and from areas with higher average education levels. Surgery alone was more common in later years for CC patients while combined surgery, chemotherapy, and radiotherapy was more common for RC patients. Between 1992 and 2000, 5-year observed survival improved from 43.0% to 46.3% for CC patients and from 39.4% to 42.2% for RC patients. Multivariate logistic regressions indicate that patients diagnosed in 2000 had significantly greater odds of 5-year survival than those diagnosed in 1992 (OR: 1.35 for CC, 1.38 for RC. Our decomposition suggests that early detection had little impact on survival; rather, technological improvements (e.g., new medical technologies or more effective use of existing technologies and changing demographics were responsible for the largest share of the change in 5

  13. Testing contingency hypotheses in budgetary research: An evaluation of the use of moderated regression analysis

    NARCIS (Netherlands)

    Hartmann, Frank G.H.; Moers, Frank

    1999-01-01

    In the contingency literature on the behavioral and organizational effects of budgeting, use of the Moderated Regression Analysis (MRA) technique is prevalent. This technique is used to test contingency hypotheses that predict interaction effects between budgetary and contextual variables. This

  14. Risk factors for unplanned readmissions in older adult trauma patients in Washington State: a competing risk analysis.

    Science.gov (United States)

    Fawcett, Vanessa J; Flynn-O'Brien, Katherine T; Shorter, Zeynep; Davidson, Giana H; Bulger, Eileen; Rivara, Frederick P; Arbabi, Saman

    2015-03-01

    Hospital readmission is a significant contributor to increasing health care use related to caring for older trauma patients. This study was undertaken with the following aims: determine the proportion of older adult trauma patients who experience unplanned readmission, as well as risk factors for these readmissions and identify the most common readmission diagnoses among these patients. We conducted a retrospective cohort study of trauma patients age 55 years and older who survived their hospitalization at a statewide trauma center between 2009 and 2010. Linking 3 statewide databases, nonelective readmission rates were calculated for 30 days, 6 months, and 1 year after index discharge. Competing risk regression was used to determine risk factors for readmission and account for the competing risk of dying without first being readmitted. Subhazard ratios (SHR) are reported, indicating the relative risk of readmission by 30 days, 6 months, and 1 year. The cumulative readmission rates for the 14,536 participants were 7.9%, 18.9%, and 25.2% at 30 days, 6 months, and 1 year, respectively. In multivariable models, the strongest risk factors for readmission at 1 year (based on magnitude of SHR) were severe head injury (adjusted SHR = 1.47; 95% CI, 1.24-1.73) and disposition to a skilled nursing facility (SHR = 1.54; 95% CI, 1.39-1.71). The diagnoses most commonly associated with readmission were atrial fibrillation, anemia, and congestive heart failure. In this statewide study, unplanned readmissions after older adult trauma occurred frequently up to 1 year after discharge, particularly for patients who sustained severe head trauma and who could not be discharged home independently. Examining common readmission diagnoses might inform the development of interventions to prevent unplanned readmissions. Copyright © 2015 American College of Surgeons. All rights reserved.

  15. Modified Regression Correlation Coefficient for Poisson Regression Model

    Science.gov (United States)

    Kaengthong, Nattacha; Domthong, Uthumporn

    2017-09-01

    This study gives attention to indicators in predictive power of the Generalized Linear Model (GLM) which are widely used; however, often having some restrictions. We are interested in regression correlation coefficient for a Poisson regression model. This is a measure of predictive power, and defined by the relationship between the dependent variable (Y) and the expected value of the dependent variable given the independent variables [E(Y|X)] for the Poisson regression model. The dependent variable is distributed as Poisson. The purpose of this research was modifying regression correlation coefficient for Poisson regression model. We also compare the proposed modified regression correlation coefficient with the traditional regression correlation coefficient in the case of two or more independent variables, and having multicollinearity in independent variables. The result shows that the proposed regression correlation coefficient is better than the traditional regression correlation coefficient based on Bias and the Root Mean Square Error (RMSE).

  16. Social Network Types and Mental Health Among LGBT Older Adults

    Science.gov (United States)

    Kim, Hyun-Jun; Fredriksen-Goldsen, Karen I.; Bryan, Amanda E. B.; Muraco, Anna

    2017-01-01

    Purpose of the Study: This study was designed to identify social network types among lesbian, gay, bisexual, and transgender (LGBT) older adults and examine the relationship between social network type and mental health. Design and Methods: We analyzed the 2014 survey data of LGBT adults aged 50 and older (N = 2,450) from Aging with Pride: National Health, Aging, and Sexuality/Gender Study. Latent profile analyses were conducted to identify clusters of social network ties based on 11 indicators. Multiple regression analysis was performed to examine the association between social network types and mental health. Results: We found five social network types. Ordered from greatest to least access to family, friend, and other non-family network ties, they were diverse, diverse/no children, immediate family-focused, friend-centered/restricted, and fully restricted. The friend-centered/restricted (33%) and diverse/no children network types (31%) were the most prevalent. Among individuals with the friend-centered/restricted type, access to social networks was limited to friends, and across both types children were not present. The least prevalent type was the fully restricted network type (6%). Social network type was significantly associated with mental health, after controlling for background characteristics and total social network size; those with the fully restricted type showed the poorest mental health. Implications: Unique social network types (diverse/no children and friend-centered/restricted) emerge among LGBT older adults. Moreover, individuals with fully restricted social networks are at particular risk due to heightened health needs and limited social resources. This study highlights the importance of understanding heterogeneous social relations and developing tailored interventions to promote social connectedness and mental health in LGBT older adults. PMID:28087798

  17. Functional Balance and Its Determinants in Older People with Diabetes.

    Science.gov (United States)

    Tsai, Yi-Ju; Yang, Yi-Ching; Lu, Feng-Hwa; Lee, Pei-Yun; Lee, I-Ting; Lin, Sang-I

    2016-01-01

    To determine functional balance abilities of older adults with diabetes, and identify determinants of these abilities. Eighty diabetic and 67 healthy non-diabetic community-dwelling older adults completed the Mini Mental Status Examination (MMSE) and questionnaires about their medical and fall histories. Participants were also assessed for vision, plantar sensitivity, muscle strength, and functional balance, including Functional Reach (FR), Five Times Sit-to-Stand (FTSTS), and 180° turn (TURN). In addition to between-group comparisons, hierarchical regression analysis was conducted to identify the independent determinants for each of the individual balance tasks for the diabetes and control group separately. The diabetes group had significantly greater body mass index, higher rate of cardiac disease, and poorer plantar sensitivity, mental status, grip and lower limb strength. The diabetes group performed significantly poorer in FTSTS and TURN (both pdeterminants for the balance tasks varied substantially between tasks and groups. For the diabetes group, they included visual and plantar sensitivity and MMSE for FR (R2 = 0.39), ankle dorsiflexion strength for FTSTS (R2 = 0.377), and plantar sensitivity, knee extension strength and MMSE for TURN (R2 = 0.391). For the control group, knee extension strength emerged as the common and only significant determinant and only explained approximately 10% of the variance for FR and TURN. Impairments in functional balance abilities were evident for older adults with diabetes. Their underpinning functional limitations were different for different tasks and were also different from those of the control group. Screening of functional balance and mental status, lower limb strength and sensory function, and interventions to address these impairments may be important to maintain function, independence and safety for older clients with diabetes.

  18. Clinical benefit from pharmacological elevation of high-density lipoprotein cholesterol: meta-regression analysis.

    Science.gov (United States)

    Hourcade-Potelleret, F; Laporte, S; Lehnert, V; Delmar, P; Benghozi, Renée; Torriani, U; Koch, R; Mismetti, P

    2015-06-01

    Epidemiological evidence that the risk of coronary heart disease is inversely associated with the level of high-density lipoprotein cholesterol (HDL-C) has motivated several phase III programmes with cholesteryl ester transfer protein (CETP) inhibitors. To assess alternative methods to predict clinical response of CETP inhibitors. Meta-regression analysis on raising HDL-C drugs (statins, fibrates, niacin) in randomised controlled trials. 51 trials in secondary prevention with a total of 167,311 patients for a follow-up >1 year where HDL-C was measured at baseline and during treatment. The meta-regression analysis showed no significant association between change in HDL-C (treatment vs comparator) and log risk ratio (RR) of clinical endpoint (non-fatal myocardial infarction or cardiac death). CETP inhibitors data are consistent with this finding (RR: 1.03; P5-P95: 0.99-1.21). A prespecified sensitivity analysis by drug class suggested that the strength of relationship might differ between pharmacological groups. A significant association for both statins (p<0.02, log RR=-0.169-0.0499*HDL-C change, R(2)=0.21) and niacin (p=0.02, log RR=1.07-0.185*HDL-C change, R(2)=0.61) but not fibrates (p=0.18, log RR=-0.367+0.077*HDL-C change, R(2)=0.40) was shown. However, the association was no longer detectable after adjustment for low-density lipoprotein cholesterol for statins or exclusion of open trials for niacin. Meta-regression suggested that CETP inhibitors might not influence coronary risk. The relation between change in HDL-C level and clinical endpoint may be drug dependent, which limits the use of HDL-C as a surrogate marker of coronary events. Other markers of HDL function may be more relevant. 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.

  19. Impact of multidimensional poverty on the self-efficacy of older people: Results from an Australian longitudinal study.

    Science.gov (United States)

    Callander, Emily J; Schofield, Deborah J

    2017-02-01

    Self-efficacy has numerous benefits for active and healthy aging, including giving the people the ability to make positive changes to their living standards and lifestyles. The present study aims to determine whether falling into multidimensional poverty lowers self-efficacy. Longitudinal analysis of waves 7-11 (2007-2011) of the nationally representative Household, Income and Labor Dynamics in Australia survey using linear regression models. The analysis focused on the Australian population aged 65 years and older. The Freedom Poverty Measure was used to identify those in multidimensional poverty. Those who fell into multidimensional poverty for 3 or 4 years between 2007 and 2011 had their self-efficacy scores decline by an average of 27 points (SD 21.2). Those who fell into poverty had significantly lower self-efficacy scores in 2011 - up to 57% lower (-66.6%, -45.7% P poverty for 3 or 4 years between 2007 and 2011 than those who were never in poverty. Falling into multidimensional poverty lowers the self-efficacy scores of older people. In order to improve the chances of older people making long-term changes to improve their living standards, feelings of self-efficacy should first be assessed and improved. Geriatr Gerontol Int 2017; 17: 308-314. © 2015 Japan Geriatrics Society.

  20. Trend Analysis of Cancer Mortality and Incidence in Panama, Using Joinpoint Regression Analysis.

    Science.gov (United States)

    Politis, Michael; Higuera, Gladys; Chang, Lissette Raquel; Gomez, Beatriz; Bares, Juan; Motta, Jorge

    2015-06-01

    Cancer is one of the leading causes of death worldwide and its incidence is expected to increase in the future. In Panama, cancer is also one of the leading causes of death. In 1964, a nationwide cancer registry was started and it was restructured and improved in 2012. The aim of this study is to utilize Joinpoint regression analysis to study the trends of the incidence and mortality of cancer in Panama in the last decade. Cancer mortality was estimated from the Panamanian National Institute of Census and Statistics Registry for the period 2001 to 2011. Cancer incidence was estimated from the Panamanian National Cancer Registry for the period 2000 to 2009. The Joinpoint Regression Analysis program, version 4.0.4, was used to calculate trends by age-adjusted incidence and mortality rates for selected cancers. Overall, the trend of age-adjusted cancer mortality in Panama has declined over the last 10 years (-1.12% per year). The cancers for which there was a significant increase in the trend of mortality were female breast cancer and ovarian cancer; while the highest increases in incidence were shown for breast cancer, liver cancer, and prostate cancer. Significant decrease in the trend of mortality was evidenced for the following: prostate cancer, lung and bronchus cancer, and cervical cancer; with respect to incidence, only oral and pharynx cancer in both sexes had a significant decrease. Some cancers showed no significant trends in incidence or mortality. This study reveals contrasting trends in cancer incidence and mortality in Panama in the last decade. Although Panama is considered an upper middle income nation, this study demonstrates that some cancer mortality trends, like the ones seen in cervical and lung cancer, behave similarly to the ones seen in high income countries. In contrast, other types, like breast cancer, follow a pattern seen in countries undergoing a transition to a developed economy with its associated lifestyle, nutrition, and body weight

  1. Self-reported Discrimination and Depressive Symptoms Among Older Chinese Adults in Chicago.

    Science.gov (United States)

    Li, Lydia W; Dong, XinQi

    2017-07-01

    Discrimination is part of life for many Americans, especially ethnic minorities. Focusing on older Chinese Americans, this study examines the association between self-reported discrimination and depressive symptoms and identifies subgroups that are more likely to report experiencing discrimination. We conducted cross-sectional analysis of data collected from adults (age 60+ years) of Chinese origin residing in the Greater Chicago area (N = 3,004). Self-reported discrimination was assessed by the Experiences of Discrimination instrument and was dichotomized (yes vs no). Depressive symptoms were measured by the Patient Health Questionnaire (PHQ-9). Logistic regression of self-reported discrimination and negative binominal regression of depressive symptoms were conducted. About 21.5% of the sample reported having experienced discrimination. The odds of reporting discrimination are higher for those who are younger, have higher education and income, are more acculturated, have been in the United States longer, live outside Chinatown, and have higher levels of neuroticism and conscientiousness. Self-reported discrimination is significantly and positively associated with depressive symptoms, independent of sociodemographic characteristics, migration-related variables, and personality factors. Findings suggest a robust relationship between self-reported discrimination and depressive symptoms in older Chinese Americans. They further suggest that the relatively advantaged groups-younger, higher socioeconomic status, more acculturated, and living outside Chinatown-are more likely to report experiencing discrimination. © The Author 2017. 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.

  2. Selenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression

    Science.gov (United States)

    Cai, Xianlei; Wang, Chen; Yu, Wanqi; Fan, Wenjie; Wang, Shan; Shen, Ning; Wu, Pengcheng; Li, Xiuyang; Wang, Fudi

    2016-01-01

    The objective of this study was to investigate the associations between selenium exposure and cancer risk. We identified 69 studies and applied meta-analysis, meta-regression and dose-response analysis to obtain available evidence. The results indicated that high selenium exposure had a protective effect on cancer risk (pooled OR = 0.78; 95%CI: 0.73–0.83). The results of linear and nonlinear dose-response analysis indicated that high serum/plasma selenium and toenail selenium had the efficacy on cancer prevention. However, we did not find a protective efficacy of selenium supplement. High selenium exposure may have different effects on specific types of cancer. It decreased the risk of breast cancer, lung cancer, esophageal cancer, gastric cancer, and prostate cancer, but it was not associated with colorectal cancer, bladder cancer, and skin cancer. PMID:26786590

  3. Experience of elder abuse among older Korean immigrants.

    Science.gov (United States)

    Chang, Miya

    2016-01-01

    Studies on the scope and nature of Asian American elder abuse conducted with older immigrants are extremely limited. The overall purpose of this study was to examine the extent and type of elder abuse among older Korean immigrants, and to investigate critical predictors of elder abuse in this population. The sample consisted of 200 older Korean immigrants aged 60 to 90 years who resided in Los Angeles County in 2008. One of the key findings indicated that 58.3% of respondents experienced one or more types of elder abuse. Logistic regression indicated that the victims' health status and educational level were statistically significant predictors of the likelihood of experiencing abuse. The present study, although limited in sample size, measures, sampling methods, and population representation, has contributed to this important area of knowledge. It is recommended that future studies conduct research on elder abuse with more representative national samples that can measure the extent of abuse and neglect more accurately.

  4. Correlates of housing affordability stress among older Australians.

    Science.gov (United States)

    Temple, Jeromey B

    2008-03-01

    The purpose of this study was to examine the prevalence and correlates of housing affordability stress among community-dwelling older Australians. The 2002 ABS General Social Survey was used to measure the prevalence of housing affordability stress. Rare event logistic regression was used to measure the potential correlates of housing affordability stress. Almost 5% of Australians aged 55 years and older, and 20% of those younger than 55 years, are estimated to experience housing affordability stress. Men and women living alone are more likely to experience affordability stress when compared to couples. Low-income earners, those with a consumer debt or who do not hold assets, are at a heightened risk of such stress. Home ownership, regardless of income, is the strongest buffer against housing affordability problems in old age. Although the prevalence of housing affordability stress is low among older Australians when compared to the younger population, a definite social gradient exists in those at risk.

  5. Factors related to tinnitus and hyperacusis handicap in older people.

    Science.gov (United States)

    Aazh, Hashir; Lammaing, Karen; Moore, Brian C J

    2017-09-01

    The aim was to assess factors related to tinnitus and hyperacusis handicap in older people. Retrospective cross-sectional. Data were gathered for 184 patients with an average age of 69 years. Tinnitus handicap as measured via the Tinnitus Handicap Inventory (THI) was significantly predicted by tinnitus annoyance as measured via the visual analogue scale (VAS) (regression coefficient, b = 2.9, p tinnitus on the patient's life as measured via the VAS (b = 3.9, p tinnitus annoyance significantly predicts tinnitus handicap, it is important to explore factors associated with annoyance that may be useful in designing appropriate rehabilitative interventions aimed at reducing tinnitus handicap in older people. Future studies should explore whether hyperacusis and insomnia in older people with tinnitus need to be managed in conjunction with treatment for depression.

  6. Predictive model of Amorphophallus muelleri growth in some agroforestry in East Java by multiple regression analysis

    Directory of Open Access Journals (Sweden)

    BUDIMAN

    2012-01-01

    Full Text Available Budiman, Arisoesilaningsih E. 2012. Predictive model of Amorphophallus muelleri growth in some agroforestry in East Java by multiple regression analysis. Biodiversitas 13: 18-22. The aims of this research was to determine the multiple regression models of vegetative and corm growth of Amorphophallus muelleri Blume in some age variations and habitat conditions of agroforestry in East Java. Descriptive exploratory research method was conducted by systematic random sampling at five agroforestries on four plantations in East Java: Saradan, Bojonegoro, Nganjuk and Blitar. In each agroforestry, we observed A. muelleri vegetative and corm growth on four growing age (1, 2, 3 and 4 years old respectively as well as environmental variables such as altitude, vegetation, climate and soil conditions. Data were analyzed using descriptive statistics to compare A. muelleri habitat in five agroforestries. Meanwhile, the influence and contribution of each environmental variable to the growth of A. muelleri vegetative and corm were determined using multiple regression analysis of SPSS 17.0. The multiple regression models of A. muelleri vegetative and corm growth were generated based on some characteristics of agroforestries and age showed high validity with R2 = 88-99%. Regression model showed that age, monthly temperatures, percentage of radiation and soil calcium (Ca content either simultaneously or partially determined the growth of A. muelleri vegetative and corm. Based on these models, the A. muelleri corm reached the optimal growth after four years of cultivation and they will be ready to be harvested. Additionally, the soil Ca content should reach 25.3 me.hg-1 as Sugihwaras agroforestry, with the maximal radiation of 60%.

  7. Factors associated with regular physical exercise and consumption of fruits and vegetables among Mexican older adults

    Directory of Open Access Journals (Sweden)

    Svetlana V. Doubova

    2016-09-01

    Full Text Available Abstract Background To analyze the factors associated with regular physical exercise and routine consumption of fruits and vegetables, and both healthy behaviors among Mexican older adults. Methods We conducted a secondary data analysis of the baseline data (2014 of the Study on Obesity, Sarcopenia and Fragility in older adults affiliated with the Mexican Institute of Social Security. The study included 948 adults who were ≥60 years of age. Multiple Poisson regression was performed. Results Routine consumption of fruits and vegetables was reported by 53.8 % of older adults, 42.7 % reported engaging in regular physical exercise and 23.1 % reported participating in both types of healthy behaviors. Women, adults with a stable income, those with a self-perception of good health and those with a history of physical exercise at the age of 50 years had an increased likelihood of engaging in healthy eating and regular physical activity. Conclusions Many older adults do not routinely consume fruits and vegetables or engage in regular physical exercise despite the fact that most have a fixed income and a social network. It is relevant to conduct research-based interventions that take into account the contextual factors to promote healthy behaviors.

  8. Predicting which older adults will or will not fall using the Fullerton Advanced Balance scale.

    Science.gov (United States)

    Hernandez, Danielle; Rose, Debra J

    2008-12-01

    The purpose of this study was to determine if the Fullerton Advanced Balance (FAB) scale can predict faller status in a group of independently functioning older adults. A cross-sectional design was used to establish the sensitivity and specificity of the FAB scale to predict faller status based on a retrospective self-reported fall history. For the purpose of this study, a faller was classified as an older adult with a history of 2 or more falls in the previous 12 months. Multipurpose senior centers in an urban community. A sample of independently functioning older adults (N=192; mean age+/-SD, 77+/-6.5 y). Not applicable. FAB scale, a retrospective history of falls. Binary logistic regression analysis indicated that the total FAB scale score could be used to predict faller status (as determined by a retrospective self-reported fall history). In the present sample, the probability of falling increased by 8% with each 1-point decrease in total FAB scale score. Receiver operating characteristic analysis determined that a cut-off score of 25 out of 40 on the FAB scale produced the highest sensitivity (74.6%) and specificity (52.6%) in predicting faller status. Five individual test items on the FAB scale were particularly predictive of faller status and could be combined to form a short version of the scale that may be even more predictive of faller status and require less time to administer. The FAB scale is a predictive measure of faller status when used with independently functioning older adults. A practitioner can be confident in more than 7 out of 10 cases that an older adult who scores 25 or lower on the FAB scale is at high risk for falls and in need of immediate intervention.

  9. Association of Functional Ability and Benign Prostatic Hyperplasia With Urinary Incontinence in Older Korean Men

    Directory of Open Access Journals (Sweden)

    Jeongok Park

    2016-06-01

    Full Text Available Purpose: The purpose of this study was to determine the prevalence of urinary incontinence (UI and analyze its association with instrumental activities of daily living (IADL and benign prostatic hyperplasia (BPH in community-dwelling older men in Korea. Methods: This study was a secondary analysis of data from the Actual Living Condition of the Elderly and Welfare Need Survey conducted in the year 2008. Data was subjected to hierarchical logistic regression analysis to examine the association of IADL and BPH with UI in older men, entering IADL and BPH in model 1, and age, body mass index (BMI and education in model 2, and then comorbidities and walking speed in model 3. Results: Of 6,185 men, 243 (3.9% had self-reported UI. The prevalence of UI was 1.8% in men aged 60–64 years and 11.7% in those aged 85 years and above, indicating an increase in the prevalence of UI with their age. IADL and BPH remained the only significant factors associated with UI in model 1 (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.44–1.64 and OR, 2.73; 95% CI, 1.47–5.10, respectively, model 2 (OR, 1.50; 95% CI, 1.40–1.61 and OR, 2.68; 95% CI, 1.42–5.07, and model 3 (OR, 1.43; 95% CI, 1.32–1.54 and OR, 2.58; 95% CI, 1.36–4.90. Conclusions: IADL limitations and presence of BPH were associated with UI in older men after controlling for BMI, education, comorbidities, and walking speed. Thus, UI should be assessed in older Korean men with IADL decline and BPH. Gender-sensitive interventions to attenuate IADL limitations and manage BPH should be developed and applied to improve UI in older men.

  10. Volunteering by older adults and risk of mortality: a meta-analysis.

    Science.gov (United States)

    Okun, Morris A; Yeung, Ellen WanHeung; Brown, Stephanie

    2013-06-01

    Organizational volunteering has been touted as an effective strategy for older adults to help themselves while helping others. Extending previous reviews, we carried out a meta-analysis of the relation between organizational volunteering by late-middle-aged and older adults (minimum age = 55 years old) and risk of mortality. We focused on unadjusted effect sizes (i.e., bivariate relations), adjusted effect sizes (i.e., controlling for other variables such as health), and interaction effect sizes (e.g., the joint effect of volunteering and religiosity). For unadjusted effect sizes, on average, volunteering reduced mortality risk by 47%, with a 95% confidence interval ranging from 38% to 55%. For adjusted effect sizes, on average, volunteering reduced mortality risk by 24%, with a 95% confidence interval ranging from 16% to 31%. For interaction effect sizes, we found preliminary support that as public religiosity increases, the inverse relation between volunteering and mortality risk becomes stronger. The discussion identifies several unresolved issues and directions for future research. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  11. Incidence and predicting factors of falls of older inpatients

    Directory of Open Access Journals (Sweden)

    Hellen Cristina de Almeida Abreu

    2015-01-01

    Full Text Available OBJECTIVE To estimate the incidence and predicting factors associated with falls among older inpatients. METHODS Prospective cohort study conducted in clinical units of three hospitals in Cuiaba, MT, Midwestern Brazil, from March to August 2013. In this study, 221 inpatients aged 60 or over were followed until hospital discharge, death, or fall. The method of incidence density was used to calculate incidence rates. Bivariate analysis was performed by Chi-square test, and multiple analysis was performed by Cox regression. RESULTS The incidence of falls was 12.6 per 1,000 patients/day. Predicting factors for falls during hospitalization were: low educational level (RR = 2.48; 95%CI 1.17;5.25, polypharmacy (RR = 4.42; 95%CI 1.77;11.05, visual impairment (RR = 2.06; 95%CI 1.01;4.23, gait and balance impairment (RR = 2.95; 95%CI 1.22;7.14, urinary incontinence (RR = 5.67; 95%CI 2.58;12.44 and use of laxatives (RR = 4.21; 95%CI 1.15;15.39 and antipsychotics (RR = 4.10; 95%CI 1.38;12.13. CONCLUSIONS The incidence of falls of older inpatients is high. Predicting factors found for falls were low education level, polypharmacy, visual impairment, gait and balance impairment, urinary incontinence and use of laxatives and antipsychotics. Measures to prevent falls in hospitals are needed to reduce the incidence of this event.

  12. Longitudinal beta regression models for analyzing health-related quality of life scores over time

    Directory of Open Access Journals (Sweden)

    Hunger Matthias

    2012-09-01

    Full Text Available Abstract Background Health-related quality of life (HRQL has become an increasingly important outcome parameter in clinical trials and epidemiological research. HRQL scores are typically bounded at both ends of the scale and often highly skewed. Several regression techniques have been proposed to model such data in cross-sectional studies, however, methods applicable in longitudinal research are less well researched. This study examined the use of beta regression models for analyzing longitudinal HRQL data using two empirical examples with distributional features typically encountered in practice. Methods We used SF-6D utility data from a German older age cohort study and stroke-specific HRQL data from a randomized controlled trial. We described the conceptual differences between mixed and marginal beta regression models and compared both models to the commonly used linear mixed model in terms of overall fit and predictive accuracy. Results At any measurement time, the beta distribution fitted the SF-6D utility data and stroke-specific HRQL data better than the normal distribution. The mixed beta model showed better likelihood-based fit statistics than the linear mixed model and respected the boundedness of the outcome variable. However, it tended to underestimate the true mean at the upper part of the distribution. Adjusted group means from marginal beta model and linear mixed model were nearly identical but differences could be observed with respect to standard errors. Conclusions Understanding the conceptual differences between mixed and marginal beta regression models is important for their proper use in the analysis of longitudinal HRQL data. Beta regression fits the typical distribution of HRQL data better than linear mixed models, however, if focus is on estimating group mean scores rather than making individual predictions, the two methods might not differ substantially.

  13. The Effects of Quality of Life and Ability to Perform Activities of Daily Living on Mild Cognitive Impairment in Older People Living in Publicly Managed Congregate Housing.

    Science.gov (United States)

    Chang, Chun-Feng; Yang, Rea-Jeng; Chang, Shu-Fang; Chou, Yuan Hwa; Huang, Ean-Wen

    2017-06-01

    Mild cognitive impairment (MCI) is characterized by a decrease in cognitive abilities that does not affect the ability to perform activities of daily living (ADLs). Therefore, this condition is easily overlooked. The prevalence and factors of influence for MCI in older people living in publicly managed congregate housing are currently unknown. This study investigated the prevalence and distribution of MCI in older people living in publicly managed congregate housing and assessed the correlations among quality of life (QoL), ADL, and MCI. This study applied a correlational study design. The participants were older people who met the study criteria and who lived in public housing in Wanhua District, Taipei City, Taiwan. One-on-one interviews were conducted to measure the cognitive abilities of the participants, and 299 valid samples were collected. The prevalence of MCI in older people living in publicly managed congregate housing was 16.1%. The χ test was employed to evaluate the distribution of MCI prevalence and indicated that the group with higher MCI prevalence exhibited the following characteristics: older than 81 years; married; lived in public housing for more than 20 years; cohabiting; had a history of drinking; and exhibited severe memory regression, physical disabilities, psychological distress, and low QoL. The difference between the groups achieved statistical significance (p < .05). After performing logistical regression analysis to control demographic variables, we found that QoL and ADL were critical for predicting MCI. This study confirmed that QoL and ADL correlate significantly with MCI in older people. Maintaining an open and supportive community enables older people to maintain sufficient mental activity, which has been shown to reduce MCI. These findings may provide an important reference for policy makers, educators, researchers, and community practitioners in their development of service strategies for older people.

  14. Survival analysis of increases in care needs associated with dementia and living alone among older long-term care service users in Japan.

    Science.gov (United States)

    Lin, Huei-Ru; Otsubo, Tetsuya; Imanaka, Yuichi

    2017-08-15

    Japan is known for its long life expectancy and rapidly aging society that there are various demands of older adults need to be fulfilled with, and one of them is long-term care needs. Therefore, Japan implemented the Long-Term Care Insurance in year 2000 for citizens who are above 65-year old and citizens who are above 40-year old in needs of long-term care services. This study was undertaken to longitudinally examine the influence of dementia and living alone on care needs increases among older long-term care insurance service users in Japan. Long-term care insurance claims data were used to identify enrollees who applied for long-term care services between October 2010 and September 2011, and subjects were tracked until March 2015. A Kaplan-Meier survival analysis was conducted to examine increases in care needs over time in months. Cox regression models were used to examine the effects of dementia and living alone on care needs increases. The cumulative survival rates before care needs increased over the 4.5-year observation period were 17.6% in the dementia group and 31.9% in the non-dementia group. After adjusting for age, sex, care needs level, and status of living alone, the risk of care needs increases was found to be 1.5 times higher in the dementia group. Living alone was not a significant risk factor of care needs increases, but people with dementia who lived alone had a higher risk of care needs increases than those without dementia. Dementia, older age, the female sex, and lower care needs levels were associated with a higher risk of care needs increases over the study period. Among these variables, dementia had the strongest impact on care needs increases, especially in persons who lived alone.

  15. Interpreting Bivariate Regression Coefficients: Going beyond the Average

    Science.gov (United States)

    Halcoussis, Dennis; Phillips, G. Michael

    2010-01-01

    Statistics, econometrics, investment analysis, and data analysis classes often review the calculation of several types of averages, including the arithmetic mean, geometric mean, harmonic mean, and various weighted averages. This note shows how each of these can be computed using a basic regression framework. By recognizing when a regression model…

  16. Statistical analysis of sediment toxicity by additive monotone regression splines

    NARCIS (Netherlands)

    Boer, de W.J.; Besten, den P.J.; Braak, ter C.J.F.

    2002-01-01

    Modeling nonlinearity and thresholds in dose-effect relations is a major challenge, particularly in noisy data sets. Here we show the utility of nonlinear regression with additive monotone regression splines. These splines lead almost automatically to the estimation of thresholds. We applied this

  17. A Visual Analytics Approach for Correlation, Classification, and Regression Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Steed, Chad A [ORNL; SwanII, J. Edward [Mississippi State University (MSU); Fitzpatrick, Patrick J. [Mississippi State University (MSU); Jankun-Kelly, T.J. [Mississippi State University (MSU)

    2012-02-01

    New approaches that combine the strengths of humans and machines are necessary to equip analysts with the proper tools for exploring today's increasing complex, multivariate data sets. In this paper, a novel visual data mining framework, called the Multidimensional Data eXplorer (MDX), is described that addresses the challenges of today's data by combining automated statistical analytics with a highly interactive parallel coordinates based canvas. In addition to several intuitive interaction capabilities, this framework offers a rich set of graphical statistical indicators, interactive regression analysis, visual correlation mining, automated axis arrangements and filtering, and data classification techniques. The current work provides a detailed description of the system as well as a discussion of key design aspects and critical feedback from domain experts.

  18. Spatial-Temporal Variations of Turbidity and Ocean Current Velocity of the Ariake Sea Area, Kyushu, Japan Through Regression Analysis with Remote Sensing Satellite Data

    OpenAIRE

    Yuichi Sarusawa; Kohei Arai

    2013-01-01

    Regression analysis based method for turbidity and ocean current velocity estimation with remote sensing satellite data is proposed. Through regressive analysis with MODIS data and measured data of turbidity and ocean current velocity, regressive equation which allows estimation of turbidity and ocean current velocity is obtained. With the regressive equation as well as long term MODIS data, turbidity and ocean current velocity trends in Ariake Sea area are clarified. It is also confirmed tha...

  19. Barriers to physical activity in older adults in Germany: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Moschny Anna

    2011-11-01

    Full Text Available Abstract Background Data on barriers to physical activity in older adults in Germany are scarce. The aim of this study was to analyse barriers to physical activity in a cohort of older adults, allowing comparisons between men and women, and age groups. Methods 1,937 older adults with a median age of 77 (range 72-93 years (53.3% female took part in the 7-year follow-up telephone interviews of the getABI cohort. Participants who stated that they did not get enough physical activity were surveyed with respect to barriers to physical activity. Barriers were analysed for all respondents, as well as by sex and age group for cases with complete data. Multivariate logistic regression analysis was performed to evaluate differences between sexes and age groups. The level of significance (alpha Results 1,607 (83.0% participants stated that they were sufficiently physically active. 286 participants rated their physical activity as insufficient and responded to questions on barriers to physical activity completely. The three most frequently cited barriers were poor health (57.7%, lack of company (43.0%, and lack of interest (36.7%. Lack of opportunities for sports or leisure activities (30.3% vs. 15.6%, and lack of transport (29.0% vs. 7.1% were more frequently stated by female respondents than male respondents. These differences between men and women were significant (p = .003; p Conclusions The present study provides relevant data on barriers to physical activity in older adults. By revealing appreciable differences between men and women, and age groups, this study has implications for efforts to increase older adults' physical activity. Promotion and intervention strategies should consider the barriers and tailor measures to the specific needs of older adults in order to reduce their constraints to physical activity.

  20. Characterization of sonographically indeterminate ovarian tumors with MR imaging. A logistic regression analysis

    International Nuclear Information System (INIS)

    Yamashita, Y.; Hatanaka, Y.; Torashima, M.; Takahashi, M.; Miyazaki, K.; Okamura, H.

    1997-01-01

    Purpose: The goal of this study was to maximize the discrimination between benign and malignant masses in patients with sonographically indeterminate ovarian lesions by means of unenhanced and contrast-enhanced MR imaging, and to develop a computer-assisted diagnosis system. Material and Methods: Findings in precontrast and Gd-DTPA contrast-enhanced MR images of 104 patients with 115 sonographically indeterminate ovarian masses were analyzed, and the results were correlated with histopathological findings. Of 115 lesions, 65 were benign (23 cystadenomas, 13 complex cysts, 11 teratomas, 6 fibrothecomas, 12 others) and 50 were malignant (32 ovarian carcinomas, 7 metastatic tumors of the ovary, 4 carcinomas of the fallopian tubes, 7 others). A logistic regression analysis was performed to discriminate between benign and malignant lesions, and a model of a computer-assisted diagnosis was developed. This model was prospectively tested in 75 cases of ovarian tumors found at other institutions. Results: From the univariate analysis, the following parameters were selected as significant for predicting malignancy (p≤0.05): A solid or cystic mass with a large solid component or wall thickness greater than 3 mm; complex internal architecture; ascites; and bilaterality. Based on these parameters, a model of a computer-assisted diagnosis system was developed with the logistic regression analysis. To distinguish benign from malignant lesions, the maximum cut-off point was obtained between 0.47 and 0.51. In a prospective application of this model, 87% of the lesions were accurately identified as benign or malignant. (orig.)