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Sample records for prevalence rates estimated

  1. Gambling disorder: estimated prevalence rates and risk factors in Macao.

    Science.gov (United States)

    Wu, Anise M S; Lai, Mark H C; Tong, Kwok-Kit

    2014-12-01

    An excessive, problematic gambling pattern has been regarded as a mental disorder in the Diagnostic and Statistical Manual for Mental Disorders (DSM) for more than 3 decades (American Psychiatric Association [APA], 1980). In this study, its latest prevalence in Macao (one of very few cities with legalized gambling in China and the Far East) was estimated with 2 major changes in the diagnostic criteria, suggested by the 5th edition of DSM (APA, 2013): (a) removing the "Illegal Act" criterion, and (b) lowering the threshold for diagnosis. A random, representative sample of 1,018 Macao residents was surveyed with a phone poll design in January 2013. After the 2 changes were adopted, the present study showed that the estimated prevalence rate of gambling disorder was 2.1% of the Macao adult population. Moreover, the present findings also provided empirical support to the application of these 2 recommended changes when assessing symptoms of gambling disorder among Chinese community adults. Personal risk factors of gambling disorder, namely being male, having low education, a preference for casino gambling, as well as high materialism, were identified.

  2. Segmented polynomials for incidence rate estimation from prevalence data.

    Science.gov (United States)

    Mahiané, Severin Guy; Laeyendecker, Oliver

    2017-01-30

    The study considers the problem of estimating incidence of a non remissible infection (or disease) with possibly differential mortality using data from a(several) cross-sectional prevalence survey(s). Fitting segmented polynomial models is proposed to estimate the incidence as a function of age, using the maximum likelihood method. The approach allows automatic search for optimal position of knots, and model selection is performed using the Akaike information criterion. The method is applied to simulated data and to estimate HIV incidence among men in Zimbabwe using data from both the NIMH Project Accept (HPTN 043) and Zimbabwe Demographic Health Surveys (2005-2006). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Estimation of the prevalence and rate of acute transfusion reactions occurring in Windhoek, Namibia

    Science.gov (United States)

    Meza, Benjamin P.L.; Lohrke, Britta; Wilkinson, Robert; Pitman, John P.; Shiraishi, Ray W.; Bock, Naomi; Lowrance, David W.; Kuehnert, Matthew J.; Mataranyika, Mary; Basavaraju, Sridhar V.

    2014-01-01

    Background Acute transfusion reactions are probably common in sub-Saharan Africa, but transfusion reaction surveillance systems have not been widely established. In 2008, the Blood Transfusion Service of Namibia implemented a national acute transfusion reaction surveillance system, but substantial under-reporting was suspected. We estimated the actual prevalence and rate of acute transfusion reactions occurring in Windhoek, Namibia. Methods The percentage of transfusion events resulting in a reported acute transfusion reaction was calculated. Actual percentage and rates of acute transfusion reactions per 1,000 transfused units were estimated by reviewing patients’ records from six hospitals, which transfuse >99% of all blood in Windhoek. Patients’ records for 1,162 transfusion events occurring between 1st January – 31st December 2011 were randomly selected. Clinical and demographic information were abstracted and Centers for Disease Control and Prevention National Healthcare Safety Network criteria were applied to categorize acute transfusion reactions1. Results From January 1 – December 31, 2011, there were 3,697 transfusion events (involving 10,338 blood units) in the selected hospitals. Eight (0.2%) acute transfusion reactions were reported to the surveillance system. Of the 1,162 transfusion events selected, medical records for 785 transfusion events were analysed, and 28 acute transfusion reactions were detected, of which only one had also been reported to the surveillance system. An estimated 3.4% (95% confidence interval [CI]: 2.3–4.4) of transfusion events in Windhoek resulted in an acute transfusion reaction, with an estimated rate of 11.5 (95% CI: 7.6–14.5) acute transfusion reactions per 1,000 transfused units. Conclusion The estimated actual rate of acute transfusion reactions is higher than the rate reported to the national haemovigilance system. Improved surveillance and interventions to reduce transfusion-related morbidity and mortality

  4. Estimating HIV prevalence from surveys with low individual consent rates: annealing individual and pooled samples.

    Science.gov (United States)

    Hund, Lauren; Pagano, Marcello

    2013-02-27

    : Many HIV prevalence surveys are plagued by the problem that a sizeable number of surveyed individuals do not consent to contribute blood samples for testing. One can ignore this problem, as is often done, but the resultant bias can be of sufficient magnitude to invalidate the results of the survey, especially if the number of non-responders is high and the reason for refusing to participate is related to the individual's HIV status. One reason for refusing to participate may be for reasons of privacy. For those individuals, we suggest offering the option of being tested in a pool. This form of testing is less certain than individual testing, but, if it convinces more people to submit to testing, it should reduce the potential for bias and give a cleaner answer to the question of prevalence. This paper explores the logistics of implementing a combined individual and pooled testing approach and evaluates the analytical advantages to such a combined testing strategy. We quantify improvements in a prevalence estimator based on this combined testing strategy, relative to an individual testing only approach and a pooled testing only approach. Minimizing non-response is key for reducing bias, and, if pooled testing assuages privacy concerns, offering a pooled testing strategy has the potential to substantially improve HIV prevalence estimates.

  5. The Influence of Survey Methodology in Estimating Prevalence Rates of Childhood Sexual Abuse Among Navy Recruits

    National Research Council Canada - National Science Library

    Olson, Cheryl B; Stander, Valerie A; Merril, Lex L

    2000-01-01

    ...% of the participants self-defined themselves as abused. Despite these differences in abuse rates, data from the SHIP survey, from SRB operational definitions, and from SRB self-definitions all independently accounted for variability in participants...

  6. Prevalence of hypothyroidism in nondiabetic chronic kidney disease and effect of thyroxine replacement on estimated glomerular filtration rate

    Directory of Open Access Journals (Sweden)

    S Bajaj

    2017-01-01

    Full Text Available Reduced T3 and free T4, elevated thyroid stimulating hormone, and hyporesponsiveness to thyrotropin releasing hormone raise questions about the presence of hypothyroidism in chronic kidney disease (CKD and raise the possibility of benefit from thyroxine supplementation. A prospective cohort study was conducted on 73 nondiabetic CKD cases. Hypothyroid patients were started on levothyroxine and were reviewed after 3 and 6 months. The mean age of study population was 42.3 ± 16.8 years. Of the total population, 32 (43.8% cases had hypothyroidism, among whom 2 (2.7% had overt hypothyroidism and 30 (41.1% had subclinical hypothyroidism. Prevalence of hypothyroidism increased with increasing severity of CKD. There were 1 (3.1% case with hypothyroidism in stage 3b, 8 (25% cases in stage 4, and 23 (71.9% cases in stage 5. The mean estimated glomerular filtration rate (ml/min/1.73 m2 at baseline was 13.7 ± 8.9 which increased to 17.5 ± 6.8 and 22.4 ± 9.3 after 3 and 6 months of thyroid hormone replacement therapy (THRT, respectively (P < 0.001. Hypothyroidism is commonly associated with nondiabetic CKD and its prevalence increases with declining renal function. THRT significantly improves renal function in nondiabetic CKD with hypothyroidism.

  7. Estimating Plasmodium falciparum transmission rates in low-endemic settings using a combination of community prevalence and health facility data.

    Directory of Open Access Journals (Sweden)

    Joshua Yukich

    Full Text Available As some malaria control programs shift focus from disease control to transmission reduction, there is a need for transmission data to monitor progress. At lower levels of transmission, it becomes increasingly more difficult to measure precisely, for example through entomological studies. Many programs conduct regular cross sectional parasite prevalence surveys, and have access to malaria treatment data routinely collected by ministries of health, often in health management information systems. However, by themselves, these data are poor measures of transmission. In this paper, we propose an approach for combining annual parasite incidence and treatment data with cross-sectional parasite prevalence and treatment seeking survey data to estimate the incidence of new infections in the human population, also known as the force of infection. The approach is based on extension of a reversible catalytic model. The accuracy of the estimates from this model appears to be highly dependent on levels of detectability and treatment in the community, indicating the importance of information on private sector treatment seeking and access to effective and appropriate treatment.

  8. Dutch diabetes prevalence estimates (DUDE-1)

    NARCIS (Netherlands)

    Kleefstra, Nanne; Landman, Gijsw. D.; Van Hateren, Kornelis J. J.; Meulepas, Marianne; Romeijnders, Arnold; Rutten, Guy E. H.; Klomp, Maarten; Houweling, Sebastiaan T.; Bilo, Henk J. G.

    2016-01-01

    Background: Recent decades have seen a constant upward projection in the prevalence of diabetes. Attempts to estimate diabetes prevalence rates based on relatively small population samples quite often result in underestimation. The aim of the present study was to investigate whether the Dutch

  9. [Prevalence of chronic renal insufficiency in diabetic type 2 diabetes patients based on the estimated glomerular filtration rate and relation with cardiovascular risk].

    Science.gov (United States)

    Mur Martí, Teresa; Villaró Gabarrós, Mercè; Porta Martínez, Nuria; Jaén Manzanera, Angels

    2013-05-04

    The aim of this study was: to estimate the prevalence of chronic renal insufficiency (CRI) in diabetic type 2 (DM2) patients treated in Primary Care based on the estimated glomerular filtration rate (GFe); to determine associated factors with CRI, and to evaluate the relationship of GF rate and risk of cardiovascular disease. This was a descriptive cross-sectional study. We included 500 medical histories randomly selected in a total of 2,950 DM2 patients. We registered sociodemographic data, comorbidities, cardiovascular risk factors and laboratory data. CRI definition was based on GFe rate and classified according to the K/DOQI Clinical Practice Guidelines for Chronic Kidney Disease. The prevalence of CRI was 23.2%. There were 51.6% females and the mean age was 66.2 years; 70,4% had hypertension and 67% dyslipidemia. The presence of CRI was related with older age, females, smoking habit, plasma creatinine value, microalbuminuria, and history of hypertension, dyslipidemia and cardiovascular disease. After analysing the data according to the category of GF rate, only the significant relationship with smoking habit disappeared. Multivariate statistic analysis supports a relation with older age, female gender, dyslipidemia and heart disease. We confirm a high prevalence of CRI in DM2 patients and their relationship with the presence of cardiovascular disease. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  10. Prevalence of Reduced Kidney Function by Estimated Glomerular Filtration Rate Using an Equation Based on Creatinine and Cystatin C in Metabolic Syndrome and Its Components in Korean Adults.

    Science.gov (United States)

    Kang, Yang Ho; Jeong, Dong Wook; Son, Seok Man

    2016-09-01

    It is known that metabolic syndrome (MetS) is associated with chronic kidney disease. We evaluated and compared the prevalence of reduced kidney function in MetS and its components by estimated glomerular filtration rate (eGFR) using an equation based on creatinine (eGFRcr), cystatin C (eGFRcys), and combined creatinine-cystatin C (eGFRcr-cys) in Korean adults. We analyzed data from 3,649 adults who participated in a comprehensive health examination. Mean values of eGFRcys were higher compared with mean values of eGFRcr (96.1±18.2 mL/min/1.73 m² vs. 91.2±13.6 mL/min/1.73 m²) in total subjects. The prevalence of reduced kidney function increased with age (9.6% for eGFRcys vs. 5.8% for eGFRcr-cys vs. 4.9% for eGFRcr, in subjects aged ≥60 years), and significantly increased with MetS, abdominal obesity, hypertension, high triglyceride, low high density lipoprotein (HDL), and high insulin resistance. The prevalence of MetS, abdominal obesity, hypertension, high insulin resistance, low HDL, and hepatic steatosis was significantly increased in subjects with reduced kidney function. This increased prevalence and the odds ratio of reduced kidney function for prevalence of MetS was highest for eGFRcys, followed by those of eGFRcr-cys, and eGFRcr. The prevalence of reduced kidney function by eGFR was significantly increased in subjects with MetS and its related components. eGFRcys and eGFRcr-cys were superior to eGFRcr in detecting reduced kidney function.

  11. Prevalence of Reduced Kidney Function by Estimated Glomerular Filtration Rate Using an Equation Based on Creatinine and Cystatin C in Metabolic Syndrome and Its Components in Korean Adults

    Directory of Open Access Journals (Sweden)

    Yang Ho Kang

    2016-09-01

    Full Text Available BackgroundIt is known that metabolic syndrome (MetS is associated with chronic kidney disease. We evaluated and compared the prevalence of reduced kidney function in MetS and its components by estimated glomerular filtration rate (eGFR using an equation based on creatinine (eGFRcr, cystatin C (eGFRcys, and combined creatinine-cystatin C (eGFRcr-cys in Korean adults.MethodsWe analyzed data from 3,649 adults who participated in a comprehensive health examination.ResultsMean values of eGFRcys were higher compared with mean values of eGFRcr (96.1±18.2 mL/min/1.73 m2 vs. 91.2±13.6 mL/min/1.73 m2 in total subjects. The prevalence of reduced kidney function increased with age (9.6% for eGFRcys vs. 5.8% for eGFRcr-cys vs. 4.9% for eGFRcr, in subjects aged ≥60 years, and significantly increased with MetS, abdominal obesity, hypertension, high triglyceride, low high density lipoprotein (HDL, and high insulin resistance. The prevalence of MetS, abdominal obesity, hypertension, high insulin resistance, low HDL, and hepatic steatosis was significantly increased in subjects with reduced kidney function. This increased prevalence and the odds ratio of reduced kidney function for prevalence of MetS was highest for eGFRcys, followed by those of eGFRcr-cys, and eGFRcr.ConclusionThe prevalence of reduced kidney function by eGFR was significantly increased in subjects with MetS and its related components. eGFRcys and eGFRcr-cys were superior to eGFRcr in detecting reduced kidney function.

  12. Prevalence and determinants of differences in cystatin C and creatinine-based estimated glomerular filtration rate in community-dwelling older adults: a cross-sectional study.

    Science.gov (United States)

    Legrand, Helen; Werner, Karin; Christensson, Anders; Pihlsgård, Mats; Elmståhl, Sölve

    2017-12-04

    Differences in cystatin C and creatinine-based estimated glomerular filtration rate (eGFR) can lead to clinical uncertainty. Existing eGFR equations perform poorly in a subset of individuals. This study aims to describe the prevalence of differences between cystatin C-based (eGFR cys ) and creatinine-based (eGFR creat ) eGFR in older adults and to explore which subsets of individuals may be most affected by differing estimations. In this cross-sectional study, participants from a cohort of community-dwelling older adults were examined at a baseline visit in 2001-2004 as part of the larger "Good Aging in Skåne" study. Exposure variables were obtained from questionnaires, interviews, examinations, and medical records. Blood samples were taken during the baseline visit, cryopreserved, and analyzed at a later time for biomarkers. The CKD-EPI equations were used to estimate GFR. Initial descriptive analyses were performed on 2931 individuals. A total of 2532 participants were included in the final multiple linear regression. Nearly two-thirds of participants had eGFR differences exceeding 10%, with nearly 20 % of participants having eGFR differences exceeding 30%. Smoking, age, body mass index (BMI), C-reactive protein (CRP), glucocorticoid use, and mean eGFR were correlated with differences between eGFR creat and eGFR cys . Differences between eGFR creat and eGFR cys are common and often of large magnitude in this community-dwelling population of older adults. The finding of multiple non-GFR determinants correlated to differences in GFR estimations can help direct future research to improve eGFR equations for subgroups prone to conflicting GFR estimations or to guide choice of biomarker for GFR estimation in these subgroups.

  13. Prevalence of chronic kidney diseases in patients with chronic obstructive pulmonary disease: assessment based on glomerular filtration rate estimated from creatinine and cystatin C levels

    Directory of Open Access Journals (Sweden)

    Yoshizawa T

    2015-07-01

    Full Text Available Takayuki Yoshizawa,1,2 Kazuyoshi Okada,3 Sachiko Furuichi,1,2 Toshihiko Ishiguro,1 Akitaka Yoshizawa,1 Toshiki Akahoshi,2 Yasuhiro Gon,2 Tsuneto Akashiba,2 Yoshifumi Hosokawa,1,2 Shu Hashimoto2 1Department of Internal Medicine, Kanamecho Hospital, Toshima-ku, 2Division of Respiratory Medicine, Department of Internal Medicine, 3Division of Nephrology, Hypertension and Endocrinology, Department of Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan Background: Cardiovascular diseases, osteoporosis, and depression are identified comorbidities of chronic obstructive pulmonary disease (COPD, but there have been few reports of chronic kidney disease (CKD as a comorbidity of COPD. The objective of this study was to investigate the prevalence of CKD in COPD patients using estimated glomerular filtration rate (eGFR based on creatinine (Cr and cystatin C (Cys levels. Methods: The prevalence of CKD and the values of various CKD-related parameters were compared between 108 stable COPD outpatients (COPD group and a non-COPD control group consisting of 73 patients aged 60 years or more without a history of COPD or kidney disease. CKD was defined as an eGFR less than 60 mL/min/1.73 m2. Results: The Cr level was significantly higher in the COPD group, but eGFR based on serum Cr (eGFRCr was not significantly different between the two groups (73.3±25.3 vs 79.7±15.5 mL/min/1.73 m2. The Cys level was significantly higher and eGFR based on serum Cys (eGFRCys was significantly lower in the COPD group (60.0±19.4 vs 74.0±13.5 mL/min/1.73 m2, P<0.0001. The prevalence of CKD evaluated based on eGFRCr was 31% in the COPD group and 8% in the non-COPD group with an odds ratio of 4.91 (95% confidence interval, 1.94–12.46, P=0.0008, whereas the evaluated prevalence based on eGFRCys was 53% in the COPD group and 15% in the non-COPD group with an odds ratio of 6.30 (95% confidence interval, 2.99–13.26, P<0.0001, demonstrating a higher prevalence of

  14. Estimating trematode prevalence in snail hosts using a single-step duplex PCR: how badly does cercarial shedding underestimate infection rates?

    Czech Academy of Sciences Publication Activity Database

    Born-Torrijos, A.; Poulin, R.; Raga, J. A.; Holzer, Astrid S.

    2014-01-01

    Roč. 7, MAY 2014 (2014), s. 243 ISSN 1756-3305 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : prevalence * detection * snail host * double infection * single-steo duplex PCR Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.430, year: 2014

  15. [Orthorectic eating behaviour - nosology and prevalence rates].

    Science.gov (United States)

    Barthels, Friederike; Pietrowsky, Reinhard

    2012-12-01

    Orthorectic eating behaviour is characterised by a fixation on a healthy diet and rigidity regarding self-imposed nutrition standards. Besides malnutrition, subjective distress and social isolation might be consequences of clinical relevance. So far there are few reliable data about nosology and prevalence rates, so that it is not yet possible to evaluate the clinical significance of orthorectic eating behaviour. This article discusses nosological classifications of orthorexia and presents prevalence rates of extremely healthy eating behaviour in general population as well as in several specific subgroups. To summarise, orthorectic eating behaviour seems to be most likely an eating disorder with healthy dieting as an overvalued idea. Data on prevelance of orthorectic eating behaviour, assessed with the recently developed Düsseldorfer Orthorexie Skala, suggest a rate of 1 to 2% in general population. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Differences in pathological gambling prevalence estimates: facts or artefacts?

    Science.gov (United States)

    Sassen, Monika; Kraus, Ludwig; Bühringer, Gerhard

    2011-12-01

    The paper aims at investigating whether survey methodology has recently converged to justify the common practice of comparing prevalence estimates and interpreting differences within and between countries. To this end, prevalence studies of problem (PrG) and pathological gambling (PG) published in peer-reviewed journals between 2000 and 2010 were critically reviewed. A systematic computer-based literature search was conducted within various databases and major gambling journals. In a two-step search process, a total of 39 studies reporting current prevalence data of non-clinical national samples from different countries were identified. Analyses revealed wide ranges in estimated PrG/PG rates for adults, adolescents, and college students, whereas similar estimates were reported in two studies on PrG/PG in seniors. Despite the discussion on methodological consistency in the field of gambling research, comparability of the reported estimates was found to be still highly limited by major variation between studies with regard to survey description, administration format, exclusion criteria, assessment instrument, cut-off scores, sample frame, and reference period. The interpretation of differences in PrG and PG prevalence estimates within and between countries may be improved by using valid and reliable instruments and by applying comparable survey methodology in well-defined populations. Copyright © 2011 John Wiley & Sons, Ltd.

  17. Prevalence of decreased glomerular filtration rate in patients seeking non-nephrological medical care--an evaluation using IDMS-traceable creatinine based MDRD as well as Mayo Clinic quadratic equation estimates.

    Science.gov (United States)

    Risch, Lorenz; Saely, Christoph H; Neyer, Ulrich; Hoefle, Guenter; Gouya, Ghazaleh; Zerlauth, Manfred; Risch, Gerhard M; Risch, Martin; Drexel, Heinz

    2007-03-01

    Data on the prevalence of decreased glomerular filtration rate in Europe are limited. Most of the available studies did not employ laboratory methods providing creatinine concentrations traceable to the reference method, i.e. isotope dilution mass spectrometry (IDMS). We therefore conducted a cross-sectional study in the principality of Liechtenstein consecutively enrolling adult patients seeking non-nephrological medical care from whom serum samples were referred for renal function assessment. All measurements were done in one central laboratory. The estimated glomerular filtration rate (eGFR) was calculated based on the determination of IDMS-traceable creatinine by a kinetic Jaffe method (Roche Diagnostics, Switzerland) by means of the MDRD and Mayo Clinic quadratic equations. We further estimated the incidence of end stage renal disease during the next 5 years. For 43% (n=9378) of the entire population>or=25 years renal function assessment was available. An eGFR indicating chronic kidney disease (CKD) stages 3-5 was found in 4.93% when using the MDRD equation and in 3.98 % when using the Mayo Clinic quadratic equation. The two equations had a very good agreement in classifying patients to have an eGFR consistent with CKD stages 3-5 (Cohen's kappa 0.887). Further calculations suggested that among patients aged 80 or younger, annually 42 per 100,000 are going to develop an eGFR<15 ml/min/1.73 m2 over the next 5 years. 4-5% of patients seeking non-nephrological medical advice have an eGFR consistent with CKD stages 3-5, and a considerable number of subjects is expected to develop end stage renal disease over a 5 year period. In order to obtain comparable kidney function estimates among different institutions it is not only important to use standardized methods to measure creatinine but rather to employ standardized methods to calculate a GFR estimate.

  18. Estimated prevalence of compulsive buying behavior in the United States.

    Science.gov (United States)

    Koran, Lorrin M; Faber, Ronald J; Aboujaoude, Elias; Large, Michael D; Serpe, Richard T

    2006-10-01

    Compulsive buying (uncontrolled urges to buy, with resulting significant adverse consequences) has been estimated to affect from 1.8% to 16% of the adult U.S. population. To the authors' knowledge, no study has used a large general population sample to estimate its prevalence. The authors conducted a random sample, national household telephone survey in the spring and summer of 2004 and interviewed 2,513 adults. The interviews addressed buying attitudes and behaviors, their consequences, and the respondents' financial and demographic data. The authors used a clinically validated screening instrument, the Compulsive Buying Scale, to classify respondents as either compulsive buyers or not. The rate of response was 56.3%, which compares favorably with rates in federal national health surveys. The cooperation rate was 97.6%. Respondents included a higher percentage of women and people ages 55 and older than the U.S. adult population. The estimated point prevalence of compulsive buying among respondents was 5.8% (by gender: 6.0% for women, 5.5% for men). The gender-adjusted prevalence rate was 5.8%. Compared with other respondents, compulsive buyers were younger, and a greater proportion reported incomes under 50,000 US dollars. They exhibited more maladaptive responses on most consumer behavior measures and were more than four times less likely to pay off credit card balances in full. A study using clinically valid interviews is needed to evaluate these results. The emotional and functional toll of compulsive buying and the frequency of comorbid psychiatric disorders suggests that studies of treatments and social interventions are warranted.

  19. HIV infection among tuberculosis patients in Vietnam: prevalence and impact on tuberculosis notification rates

    NARCIS (Netherlands)

    Thanh, D. H.; Sy, D. N.; Linh, N. D.; Hoan, T. M.; Dien, H. T.; Thuy, T. B.; Hoa, N. P.; Tung, L. B.; Cobelens, F.

    2010-01-01

    Vietnam has an emerging human immunodeficiency virus (HIV) epidemic (estimated population prevalence 0.5%), but valid data on HIV prevalence among tuberculosis (TB) patients are limited. Recent increases in TB notification rates among young adults may be related to HIV. To assess the prevalence of

  20. Uma metodologia para estimar a incidência a partir de prevalências obtidas em Pesquisas Nacionais por Amostra de Domicílios: o exemplo da alfabetização A methodology to estimate incidence from prevalence rates in household surveys: the example of literacy

    Directory of Open Access Journals (Sweden)

    Greice Maria Silva da Conceição

    2008-06-01

    Full Text Available Conhecer a incidência de algum evento por idade e tempo é sem dúvida um dos maiores interesses da epidemiologia. Devido à relação matemática que existe entre as medidas de incidência e prevalência, alguns métodos foram desenvolvidos com o objetivo de obter a incidência a partir da prevalência. Este estudo descreve, de forma tutorial, um método que fornece estimativas de incidências por idade e tempo desde que existam prevalências repetidas de um evento, que a ocorrência do mesmo esteja relacionada à idade do indivíduo e que este possua características de uma doença crônica. O estudo foi realizado para a alfabetização da população brasileira, utilizando as prevalências por idade obtidas na Pesquisa Nacional por Amostra de Domicílios (PNAD 1981, 1985, 1989, 1992, 1995 e 2001, e permitiu recuperar as estimativas da incidência de alfabetização nas idades entre 5 e 20 anos entre os anos de 1960 a 2000. O método ajusta os parâmetros de incidência para idade e tempo com o auxílio de um modelo linear generalizado para dados categóricos e utiliza o algoritmo EM para obter os dados não observados.Age and time-specific incidence rates are highly relevant to epidemiologists. Due to the mathematical relationship between incidence and prevalence, several methods have been developed to obtain incidence based on prevalence. The present study didactically describes a method to estimate age and time incidence, based on: repeated measurements of prevalence for an event; events related to the individual's age; and events with the characteristics of a chronic disease. The method was used to analyze literacy in the Brazilian population, using prevalence by age obtained from the National Household Sample Survey (PNAD for 1981, 1985, 1989, 1992, 1995, and 2001, and allowed obtaining literacy incidence estimates for ages 5 to 20 years, for the years 1960 through 2001. The method adjusts incidence parameters for age and time with the

  1. Prevalence rate of chronic overuse pain in taekwondo athletes.

    Science.gov (United States)

    Koh, Jae-Ok

    2017-10-01

    The aim of this study was to estimate the prevalence of chronic overuse pain (COP) and to identify possible risk factors of COP in sport poomsae taekwondo. This is a cross-sectional survey. A total of 263 sport-poomsae competitors (112 females; 151 males; aged between 12-44 years), who competed at the 2014 sport poomsae taekwondo competition, participated in this study. The prevalence rate of COP and possible risk factors associated with COP were analyzed by using Chi-square tests and independent t-tests. A total of 173 athletes reported that they experienced COP (65.8%; 95% confidence interval [CI]: 60.5-71.5). Female athletes showed a higher prevalence rate than their male counterparts (75.9% vs. 58.3%). Lower body (61.5%) and knee joints (26.4%) were the two primarily injured body part. A total of 101 athletes reported that they injured in the previous year. Among those, 81.2% were suffered from COP. The technique that caused pain most frequently was side-kick among females and front-kick among males. Prevalence rates of COP were significantly different by sex, education level, training hour, and a history of injury. The prevalence of COP is high among sport poomsae taekwondo athletes. Competitors who are female, have a history of injury, and train for extended hours were more likely to experience COP. To identify other potential risk factors of COP in sport poomsae taekwondo, more research is needed to build upon the findings.

  2. Can extinction rates be estimated without fossils?

    Science.gov (United States)

    Paradis, Emmanuel

    2004-07-07

    There is considerable interest in the possibility of using molecular phylogenies to estimate extinction rates. The present study aims at assessing the statistical performance of the birth-death model fitting approach to estimate speciation and extinction rates by comparison to the approach considering fossil data. A simulation-based approach was used. The diversification of a large number of lineages was simulated under a wide range of speciation and extinction rate values. The estimators obtained with fossils performed better than those without fossils. In the absence of fossils (e.g. with a molecular phylogeny), the speciation rate was correctly estimated in a wide range of situations; the bias of the corresponding estimator was close to zero for the largest trees. However, this estimator was substantially biased when the simulated extinction rate was high. On the other hand the estimator of extinction rate was biased in a wide range of situations. Surprisingly, this bias was lesser with medium-sized trees. Some recommendations for interpreting results from a diversification analysis are given. Copyright 2003 Elsevier Ltd.

  3. Refusal bias in the estimation of HIV prevalence

    NARCIS (Netherlands)

    Janssens, Wendy; van der Gaag, Jacques; Rinke de Wit, Tobias F.; Tanović, Zlata

    2014-01-01

    In 2007, UNAIDS corrected estimates of global HIV prevalence downward from 40 million to 33 million based on a methodological shift from sentinel surveillance to population-based surveys. Since then, population-based surveys are considered the gold standard for estimating HIV prevalence. However,

  4. Adaptive Algorithm for Chirp-Rate Estimation

    Directory of Open Access Journals (Sweden)

    Igor Djurović

    2009-01-01

    Full Text Available Chirp-rate, as a second derivative of signal phase, is an important feature of nonstationary signals in numerous applications such as radar, sonar, and communications. In this paper, an adaptive algorithm for the chirp-rate estimation is proposed. It is based on the confidence intervals rule and the cubic-phase function. The window width is adaptively selected to achieve good tradeoff between bias and variance of the chirp-rate estimate. The proposed algorithm is verified by simulations and the results show that it outperforms the standard algorithm with fixed window width.

  5. Smoking rate and periodontal disease prevalence: 40-year trends in Sweden 1970-2010.

    Science.gov (United States)

    Bergstrom, Jan

    2014-10-01

    To investigate the relationship between smoking rate and periodontal disease prevalence in Sweden. National smoking rates were found from Swedish National Statistics on smoking habits. Based on smoking rates for the years 1970-2010, periodontal disease prevalence estimates were calculated for the age bracket 40-70 years and smoking-associated relative risks between 2.0 and 20.0. The impact of smoking on the population was estimated according to the concept of population attributable fraction. The age-standardized smoking rate in Sweden declined from 44% in 1970 to 15% in 2010. In parallel with the smoking decline the calculated prevalence estimate of periodontal disease dropped from 26% to 12% assuming a 10-fold smoking-associated relative risk. Even at more moderate magnitudes of the relative risk, e.g. 2-fold or 5-fold, the prevalence decrease was quite tangible, suggesting that the current prevalence in Sweden is about 20-50% of the level 40 years ago. The population attributable fraction, estimating the portion of the disease that would have been avoided in the absence of smoking, was 80% in 1970 and 58% in 2010 at a ten-fold relative risk. Calculated estimates of periodontal disease prevalence are closely related to real changes in smoking rate. As smoking rate drops periodontal disease prevalence will drop. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. [Using log-binomial model for estimating the prevalence ratio].

    Science.gov (United States)

    Ye, Rong; Gao, Yan-hui; Yang, Yi; Chen, Yue

    2010-05-01

    To estimate the prevalence ratios, using a log-binomial model with or without continuous covariates. Prevalence ratios for individuals' attitude towards smoking-ban legislation associated with smoking status, estimated by using a log-binomial model were compared with odds ratios estimated by logistic regression model. In the log-binomial modeling, maximum likelihood method was used when there were no continuous covariates and COPY approach was used if the model did not converge, for example due to the existence of continuous covariates. We examined the association between individuals' attitude towards smoking-ban legislation and smoking status in men and women. Prevalence ratio and odds ratio estimation provided similar results for the association in women since smoking was not common. In men however, the odds ratio estimates were markedly larger than the prevalence ratios due to a higher prevalence of outcome. The log-binomial model did not converge when age was included as a continuous covariate and COPY method was used to deal with the situation. All analysis was performed by SAS. Prevalence ratio seemed to better measure the association than odds ratio when prevalence is high. SAS programs were provided to calculate the prevalence ratios with or without continuous covariates in the log-binomial regression analysis.

  7. ORIGINAL ARTICLE Soil Contamination Rate, Prevalence, Intensity ...

    African Journals Online (AJOL)

    2017-11-01

    Nov 1, 2017 ... January 2018. DOI: http://dx.doi.org/10.4314/ejhs.v28i1.8. 64. INTRODUCTION. Soil contamination with parasite eggs, infective larvae, cysts and oocysts constitutes the most important risk factor for some human parasitic .... 0.05 since no report was recorded for infection prevalence of intestinal parasitic ...

  8. Epistemic uncertainties when estimating component failure rate

    International Nuclear Information System (INIS)

    Jordan Cizelj, R.; Mavko, B.; Kljenak, I.

    2000-01-01

    A method for specific estimation of a component failure rate, based on specific quantitative and qualitative data other than component failures, was developed and is described in the proposed paper. The basis of the method is the Bayesian updating procedure. A prior distribution is selected from a generic database, whereas likelihood is built using fuzzy logic theory. With the proposed method, the component failure rate estimation is based on a much larger quantity of information compared to the presently used classical methods. Consequently, epistemic uncertainties, which are caused by lack of knowledge about a component or phenomenon are reduced. (author)

  9. Analysis of self-reported versus biomarker based smoking prevalence: methodology to compute corrected smoking prevalence rates.

    Science.gov (United States)

    Jain, Ram B

    2017-07-01

    Prevalence of smoking is needed to estimate the need for future public health resources. To compute and compare smoking prevalence rates by using self-reported smoking statuses, two serum cotinine (SCOT) based biomarker methods, and one urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) based biomarker method. These estimates were then used to develop correction factors to be applicable to self-reported prevalences to arrive at corrected smoking prevalence rates. Data from National Health and Nutrition Examination Survey (NHANES) for 2007-2012 for those aged ≥20 years (N = 16826) were used. Self-reported prevalence rate for the total population computed as the weighted number of self-reported smokers divided by weighted number of all participants was 21.6% and 24% when computed by weighted number of self-reported smokers divided by the weighted number of self-reported smokers and nonsmokers. The corrected prevalence rate was found to be 25.8%. A 1% underestimate in smoking prevalence is equivalent to not being able to identify 2.2 million smokers in US in a given year. This underestimation, if not corrected, could lead to serious gap in the public health services available and needed to provide adequate preventive and corrective treatment to smokers.

  10. Estimating multimorbidity prevalence with the Canadian Chronic Disease Surveillance System

    Directory of Open Access Journals (Sweden)

    Allison Feely

    2017-07-01

    Full Text Available Introduction: The Public Health Agency of Canada’s Canadian Chronic Disease Surveillance System (CCDSS uses a validated, standardized methodology to estimate prevalence of individual chronic diseases, such as diabetes. Expansion of the CCDSS for surveillance of multimorbidity, the co-occurrence of two or more chronic diseases, could better inform health promotion and disease prevention. The objective of this study was to assess the feasibility of using the CCDSS to estimate multimorbidity prevalence. Methods: We used administrative health data from seven provinces and three territories and five validated chronic conditions (i.e. cardiovascular disease, respiratory disease, mental illness, hypertension and diabetes to estimate multimorbidity prevalence. We produced age-standardized (using Canada’s 1991 population and age-specific estimates for two multimorbidity definitions: (1 two or more conditions, and (2 three or more conditions from the five validated conditions, by sex, fiscal year and geography. Results: Among Canadians aged 40 years and over in the fiscal year 2011/12, the prevalence of two or more and three or more chronic conditions was 26.5% and 10.2%, respectively, which is comparable to other estimates based on administrative health data. The increase in multimorbidity prevalence with increasing age was similar across provinces. The difference in prevalence for males and females varied by province and territory. We observed substantial variation in estimates over time. Results were consistent for the two definitions of multimorbidity. Conclusion: The CCDSS methodology can produce comparative estimates of multimorbidity prevalence across provinces and territories, but there are challenges in using it to estimate temporal trends. Further expansion of the CCDSS in the number and breadth of validated case definitions will improve the accuracy of multimorbidity surveillance for the Canadian population.

  11. Estimating the prevalence of female genital mutilation in Portugal.

    Science.gov (United States)

    Teixeira, A L; Lisboa, M

    2016-10-01

    Due to globalized migratory processes, female genital mutilation/cutting (FGM/C) has spread to other countries, including countries in Europe, where, with a few exceptions, it remains a concealed problem. To the authors' knowledge, this is the first national extensive study to estimate the prevalence of FGM/C in Portugal. Prevalence estimation. Using extrapolation of country-of-origin prevalence data and the 2011 Census data, this study estimated: the prevalence of FGM/C in Portugal among women of reproductive age (15-49 years) and among all women aged ≥15 years; and the number of girls aged females who have undergone or are at risk of undergoing FGM/C. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  12. Estimating Relative Uncertainty of Radiative Transition Rates

    Directory of Open Access Journals (Sweden)

    Daniel E. Kelleher

    2014-11-01

    Full Text Available We consider a method to estimate relative uncertainties of radiative transition rates in an atomic spectrum. Few of these many transitions have had their rates determined by more than two reference-quality sources. One could estimate uncertainties for each transition, but analyses with only one degree of freedom are generally fraught with difficulties. We pursue a way to empirically combine the limited uncertainty information in each of the many transitions. We “pool” a dimensionless measure of relative dispersion, the “Coefficient of Variation of the mean,” \\(C_{V}^{n} \\equiv s/(\\bar{x}\\sqrt{n}\\. Here, for each transition rate, “s” is the standard deviation, and “\\(\\bar{x}\\” is the mean of “n” independent data sources. \\(C_{V}^{n}\\ is bounded by zero and one whenever the determined quantity is intrinsically positive. We scatter-plot the \\(C_{V}^{n} \\as a function of the “line strength” (here a more useful radiative transition rate than transition probability. We find a curve through comparable \\(C_{V}^{n} \\as that envelops a specified percentage of the \\(C_{V}^{n} \\s (e.g. 95%. We take this curve to represent the expanded relative uncertainty of the mean. The method is most advantageous when the number of determined transition rates is large while the number of independent determinations per transition is small. The transition rate data of Na III serves as an example.

  13. Prevalence Rates of Mental Disorders in Chilean Prisons

    Science.gov (United States)

    Mundt, Adrian P.; Alvarado, Rubén; Fritsch, Rosemarie; Poblete, Catalina; Villagra, Carolina; Kastner, Sinja; Priebe, Stefan

    2013-01-01

    Objective High rates of mental disorders have been reported for prison populations worldwide, particularly in low- and middle-income countries (LMICs). The present study aimed to establish prevalence rates of mental disorders in Chilean prisoners. Method A nationwide random sample of 1008 prisoners was assessed in 7 penal institutions throughout Chile. Twelve-month prevalence rates were established using the Composite International Diagnostic Interview (CIDI) and compared to the prevalence rates previously published for the general population. Results Prevalence rates were 12.2% (95% CI, 10.2-14.1) for any substance use disorder, 8.3% (6.6-10.0) for anxiety disorders, 8.1% (6.5-9.8) for affective disorders, 5.7% (4.4-7.1) for intermittent explosive disorders, 2.2% (1.4-3.2) for ADHD of the adult, and 0.8% (0.3-1.3) for non-affective psychoses. Significantly higher prevalence rates among prisoners as compared to the general population in Chile were seen for major depression (6.1% vs. 3.7% males, Z=2.58, pprison population than in the general population. One-year prevalence rates of alcohol abuse (2.3% vs. 3.9%; Z=-2.04; pprison population than in the general population. Conclusions Service provision for prison populations in Chile should acknowledge high rates of depression and illicit drug use. Overall prevalence rates are lower than reported in other LMICs. Previous research in prison populations in LMICs might have overestimated prevalence rates of mental disorders. PMID:23894415

  14. Estimating Glomerular Filtration Rate in Older People

    Directory of Open Access Journals (Sweden)

    Sabrina Garasto

    2014-01-01

    Full Text Available We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting.

  15. Prevalence of estimated GFR reporting among US clinical laboratories.

    Science.gov (United States)

    Accetta, Nancy A; Gladstone, Elisa H; DiSogra, Charles; Wright, Elizabeth C; Briggs, Michael; Narva, Andrew S

    2008-10-01

    Routine laboratory reporting of estimated glomerular filtration rate (eGFR) may help clinicians detect kidney disease. The current national prevalence of eGFR reporting in clinical laboratories is unknown; thus, the extent of the situation of laboratories not routinely reporting eGFR with serum creatinine results is not quantified. Observational analysis. National Kidney Disease Education Program survey of clinical laboratories conducted in 2006 to 2007 by mail, web, and telephone follow-up. A national random sample, 6,350 clinical laboratories, drawn from the Federal Clinical Laboratory Improvement Amendments database and stratified by 6 major laboratory types/groupings. Laboratory reports serum creatinine results. Reporting eGFR values with serum creatinine results. Percentage of laboratories reporting eGFR along with reporting serum creatinine values, reporting protocol, eGFR formula used, and style of reporting cutoff values. Of laboratories reporting serum creatinine values, 38.4% report eGFR (physician offices, 25.8%; hospitals, 43.6%; independents, 38.9%; community clinics, 47.2%; health fair/insurance/public health, 45.5%; and others, 43.2%). Physician office laboratories have a reporting prevalence lower than other laboratory types (P laboratories reporting eGFR, 66.7% do so routinely with all adult serum creatinine determinations; 71.6% use the 4-variable Modification of Diet in Renal Disease Study equation; and 45.3% use the ">60 mL/min/1.73 m(2)" reporting convention. Independent laboratories are least likely to routinely report eGFR (50.6%; P laboratories across all strata are more likely to report eGFR (P laboratories, federal database did not have names of laboratory directors/managers (intended respondents), assumed accuracy of federal database for sample purposes. Routine eGFR reporting with serum creatinine values is not yet universal, and laboratories vary in their reporting practices.

  16. BAYESIAN ESTIMATION OF THERMONUCLEAR REACTION RATES

    Energy Technology Data Exchange (ETDEWEB)

    Iliadis, C.; Anderson, K. S. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Coc, A. [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS/IN2P3, Univ. Paris-Sud, Université Paris–Saclay, Bâtiment 104, F-91405 Orsay Campus (France); Timmes, F. X.; Starrfield, S., E-mail: iliadis@unc.edu [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1504 (United States)

    2016-11-01

    The problem of estimating non-resonant astrophysical S -factors and thermonuclear reaction rates, based on measured nuclear cross sections, is of major interest for nuclear energy generation, neutrino physics, and element synthesis. Many different methods have been applied to this problem in the past, almost all of them based on traditional statistics. Bayesian methods, on the other hand, are now in widespread use in the physical sciences. In astronomy, for example, Bayesian statistics is applied to the observation of extrasolar planets, gravitational waves, and Type Ia supernovae. However, nuclear physics, in particular, has been slow to adopt Bayesian methods. We present astrophysical S -factors and reaction rates based on Bayesian statistics. We develop a framework that incorporates robust parameter estimation, systematic effects, and non-Gaussian uncertainties in a consistent manner. The method is applied to the reactions d(p, γ ){sup 3}He, {sup 3}He({sup 3}He,2p){sup 4}He, and {sup 3}He( α , γ ){sup 7}Be, important for deuterium burning, solar neutrinos, and Big Bang nucleosynthesis.

  17. A prospective longitudinal study to estimate the prevalence of ...

    African Journals Online (AJOL)

    A prospective longitudinal study to estimate the prevalence of obesity in Egyptian children with nocturnal enuresis and the association between body mass index and ... Egyptian Journal of Medical Human Genetics ... Response to the treatment was evaluated statistically and correlated with body mass index percentile.

  18. Prevalence rates of mental disorders in Chilean prisons.

    Directory of Open Access Journals (Sweden)

    Adrian P Mundt

    Full Text Available OBJECTIVE: High rates of mental disorders have been reported for prison populations worldwide, particularly in low- and middle-income countries (LMICs. The present study aimed to establish prevalence rates of mental disorders in Chilean prisoners. METHOD: A nationwide random sample of 1008 prisoners was assessed in 7 penal institutions throughout Chile. Twelve-month prevalence rates were established using the Composite International Diagnostic Interview (CIDI and compared to the prevalence rates previously published for the general population. RESULTS: Prevalence rates were 12.2% (95% CI, 10.2-14.1 for any substance use disorder, 8.3% (6.6-10.0 for anxiety disorders, 8.1% (6.5-9.8 for affective disorders, 5.7% (4.4-7.1 for intermittent explosive disorders, 2.2% (1.4-3.2 for ADHD of the adult, and 0.8% (0.3-1.3 for non-affective psychoses. Significantly higher prevalence rates among prisoners as compared to the general population in Chile were seen for major depression (6.1% vs. 3.7% males, Z=2.58, p<0.05 and illicit drug use (3.3% vs. 0.6% males with drug abuse, Z=2.04, p<0.05; 2.6% vs. 0.1% females with drug abuse, Z=5.36, p<0.001; 3.4% vs. 1.1% males with drug dependence, Z=3.70; p<0.001. Dysthymia (6.5% vs. 15.6%, Z=-2.39, p<0.05, simple (3.3% vs. 11.5%, Z=-3.13, p<0.001 and social phobias (3.9% vs. 9.7%, Z=2.38, p<0.05 were significantly less frequent in the female prison population than in the general population. One-year prevalence rates of alcohol abuse (2.3% vs. 3.9%; Z=-2.04; p<0.05 and dependence (2.7% vs. 8.2%; Z=-5.24; p<0.001 were less prevalent in the male prison population than in the general population. CONCLUSIONS: Service provision for prison populations in Chile should acknowledge high rates of depression and illicit drug use. Overall prevalence rates are lower than reported in other LMICs. Previous research in prison populations in LMICs might have overestimated prevalence rates of mental disorders.

  19. Estimating Contraceptive Prevalence Using Logistics Data for Short-Acting Methods: Analysis Across 30 Countries.

    Science.gov (United States)

    Cunningham, Marc; Bock, Ariella; Brown, Niquelle; Sacher, Suzy; Hatch, Benjamin; Inglis, Andrew; Aronovich, Dana

    2015-09-01

    Contraceptive prevalence rate (CPR) is a vital indicator used by country governments, international donors, and other stakeholders for measuring progress in family planning programs against country targets and global initiatives as well as for estimating health outcomes. Because of the need for more frequent CPR estimates than population-based surveys currently provide, alternative approaches for estimating CPRs are being explored, including using contraceptive logistics data. Using data from the Demographic and Health Surveys (DHS) in 30 countries, population data from the United States Census Bureau International Database, and logistics data from the Procurement Planning and Monitoring Report (PPMR) and the Pipeline Monitoring and Procurement Planning System (PipeLine), we developed and evaluated 3 models to generate country-level, public-sector contraceptive prevalence estimates for injectable contraceptives, oral contraceptives, and male condoms. Models included: direct estimation through existing couple-years of protection (CYP) conversion factors, bivariate linear regression, and multivariate linear regression. Model evaluation consisted of comparing the referent DHS prevalence rates for each short-acting method with the model-generated prevalence rate using multiple metrics, including mean absolute error and proportion of countries where the modeled prevalence rate for each method was within 1, 2, or 5 percentage points of the DHS referent value. For the methods studied, family planning use estimates from public-sector logistics data were correlated with those from the DHS, validating the quality and accuracy of current public-sector logistics data. Logistics data for oral and injectable contraceptives were significantly associated (Pcontraceptive logistics data are strongly correlated with public-sector prevalence rates for short-acting methods, demonstrating the quality of current logistics data and their ability to provide relatively accurate prevalence

  20. Accidental Turbulent Discharge Rate Estimation from Videos

    Science.gov (United States)

    Ibarra, Eric; Shaffer, Franklin; Savaş, Ömer

    2015-11-01

    A technique to estimate the volumetric discharge rate in accidental oil releases using high speed video streams is described. The essence of the method is similar to PIV processing, however the cross correlation is carried out on the visible features of the efflux, which are usually turbulent, opaque and immiscible. The key step in the process is to perform a pixelwise time filtering on the video stream, in which the parameters are commensurate with the scales of the large eddies. The velocity field extracted from the shell of visible features is then used to construct an approximate velocity profile within the discharge. The technique has been tested on laboratory experiments using both water and oil jets at Re ~105 . The technique is accurate to 20%, which is sufficient for initial responders to deploy adequate resources for containment. The software package requires minimal user input and is intended for deployment on an ROV in the field. Supported by DOI via NETL.

  1. Estimation of social discount rate for Lithuania

    Directory of Open Access Journals (Sweden)

    Vilma Kazlauskiene

    2016-09-01

    Full Text Available Purpose of the article: The paper seeks to analyse the problematics of estimation of the social discount rate (SDR. The SDR is the critical parameter of cost-benefit analysis, which allows calculating the present value of cost and the benefit of public sector investment projects. Incorrect choice of the SDR can lead to the realisation of ineffective public project or conversely, cost-effective project will be rejected. The relevance of this problem analysis is determined by discussions and different viewpoints of scientists on the choice of the most appropriate approach to determine the SDR and absence of methodically based the SDR on the national level of Lithuania. Methodology/methods: The research is performed by the scientific and methodical literature analysis, systematization, time series and regression analysis. Scientific aim: The aim of the article is to calculate the SDR based on the statistical data of Lithuania. Findings: The analysis of methods of SDR determination, as well as the researches performed by foreign researchers, allows stating that the social rate of time preference (SRTP approach is the most appropriate. The SDR, calculated by the SRTP approach, reflects the main purpose of public investment projects, i.e. to enhance social benefit for society, the best. The analyses of SDR determination practice of the foreign countries shows that the SDR level should not be universal for all states. Each country should calculate the SDR based on its own data and apply it for the assessment of public projects. Conclusions: The calculated SDR for Lithuania using the SRTP approach varies between 3.5% and 4.3%. Although it is lower than 5% that is offered by European Commission, this rate is based on the statistical data of Lithuania and should be used for the assessment of the national public projects. Applicatio

  2. Estimating the geographical distribution of the prevalence of the metabolic syndrome in young Mexicans

    Directory of Open Access Journals (Sweden)

    Miguel Murguía-Romero

    2012-09-01

    Full Text Available The geographical distribution of the metabolic syndrome (MetS prevalence in young Mexicans (aged 17-24 years was estimated stepwise starting from its prevalence based on the body mass index (BMI in a study of 3,176 undergraduate students of this age group from Mexico City. To estimate the number of people with MetS by state, we multiplied its prevalence derived from the BMI range found in the Mexico City sample by the BMI proportions (range and state obtained from the Mexico 2006 national survey on health and nutrition. Finally, to estimate the total number of young people with MetS in Mexico, its prevalence by state was multiplied by the share of young population in each state according to the National Population and Housing Census 2010. Based on these figures, we estimated the national prevalence of MetS at 15.8%, the average BMI at 24.1 (standard deviation = 4.2, and the prevalence of overweight people (BMI ≥25 of that age group at 39.0%. These results imply that 2,588,414 young Mexicans suffered from MetS in 2010. The Yucatan peninsula in the south and the Sonora state in the north showed the highest rates of MetS prevalence. The calculation of the MetS prevalence by BMI range in a sample of the population, and extrapolating it using the BMI proportions by range of the total population, was found to be a useful approach. We conclude that the BMI is a valuable public health tool to estimate MetS prevalence in the whole country, including its geographical distribution.

  3. The obsessive compulsive spectrum in schizophrenia, a meta-analysis and meta-regression exploring prevalence rates

    NARCIS (Netherlands)

    Swets, Marije; Dekker, Jack; van Emmerik-van Oortmerssen, Katelijne; Smid, Geert E.; Smit, Filip; de Haan, Lieuwe; Schoevers, Robert A.

    2014-01-01

    The aims of this study were to conduct a meta-analysis and meta-regression to estimate the prevalence rates for obsessive compulsive symptoms (OCS) and obsessive compulsive disorder (OCD) in schizophrenia, and to investigate what influences these prevalence rates. Studies were identified via an

  4. Prevalence estimates of chronic kidney disease in Canada: results of a nationally representative survey

    Science.gov (United States)

    Arora, Paul; Vasa, Priya; Brenner, Darren; Iglar, Karl; McFarlane, Phil; Morrison, Howard; Badawi, Alaa

    2013-01-01

    Background: Chronic kidney disease is an important risk factor for death and cardiovascular-related morbidity, but estimates to date of its prevalence in Canada have generally been extrapolated from the prevalence of end-stage renal disease. We used direct measures of kidney function collected from a nationally representative survey population to estimate the prevalence of chronic kidney disease among Canadian adults. Methods: We examined data for 3689 adult participants of cycle 1 of the Canadian Health Measures Survey (2007–2009) for the presence of chronic kidney disease. We also calculated the age-standardized prevalence of cardiovascular risk factors by chronic kidney disease group. We cross-tabulated the estimated glomerular filtration rate (eGFR) with albuminuria status. Results: The prevalence of chronic kidney disease during the period 2007–2009 was 12.5%, representing about 3 million Canadian adults. The estimated prevalence of stage 3–5 disease was 3.1% (0.73 million adults) and albuminuria 10.3% (2.4 million adults). The prevalence of diabetes, hypertension and hypertriglyceridemia were all significantly higher among adults with chronic kidney disease than among those without it. The prevalence of albuminuria was high, even among those whose eGFR was 90 mL/min per 1.73 m2 or greater (10.1%) and those without diabetes or hypertension (9.3%). Awareness of kidney dysfunction among adults with stage 3–5 chronic kidney disease was low (12.0%). Interpretation: The prevalence of kidney dysfunction was substantial in the survey population, including individuals without hypertension or diabetes, conditions most likely to prompt screening for kidney dysfunction. These findings highlight the potential for missed opportunities for early intervention and secondary prevention of chronic kidney disease. PMID:23649413

  5. The role of sex in the prevalence rates and psychological ...

    African Journals Online (AJOL)

    The study recorded the prevalence rates of cyberbullying and investigated its psychological outcomes among 324 secondary school learners in the Kgakotlou school circuit, Limpopo Province, South Africa. Learners completed an instrument consisting of objective questionnaires on cyberbullying, psychological distress and ...

  6. Epidemiology of Eating Disorders : Incidence, Prevalence and Mortality Rates

    NARCIS (Netherlands)

    Smink, Frederique R. E.; van Hoeken, Daphne; Hoek, Hans W.

    Eating disorders are relatively rare among the general population. This review discusses the literature on the incidence, prevalence and mortality rates of eating disorders. We searched online Medline/Pubmed, Embase and PsycINFO databases for articles published in English using several keyterms

  7. Prevalence of HIV and discordant rate and their associated factors ...

    African Journals Online (AJOL)

    Background: Understanding and monitoring the prevalence of Human Immunodeficiency Virus (HIV) infection among premarital clients and determining discordant rate and applying specific interventions targeted at this group could bring dual benefits as it prevents both heterosexual and vertical transmission of the disease.

  8. College Students' Perceived Disease Risk versus Actual Prevalence Rates

    Science.gov (United States)

    Smith, Matthew Lee; Dickerson, Justin B.; Sosa, Erica T.; McKyer, E. Lisako J.; Ory, Marcia G.

    2012-01-01

    Objective: To compare college students' perceived disease risk with disease prevalence rates. Methods: Data were analyzed from 625 college students collected with an Internet-based survey. Paired t-tests were used to separately compare participants' perceived 10-year and lifetime disease risk for 4 diseases: heart disease, cancer, diabetes, and…

  9. Soil contamination rate, prevalence, intensity of infection of ...

    African Journals Online (AJOL)

    Background: Soil-transmitted helminths (STH) infections remain an important public health problem in the tropics. This study aimed to evaluate the soil contamination rate and prevalence of infestations of geohelminth among residents in Bazou. Methods: Four hundred (400) soil samples and 182 stool specimens were ...

  10. Epidemiology of Eating Disorders: Incidence, Prevalence and Mortality Rates

    OpenAIRE

    Smink, Frédérique R. E.; van Hoeken, Daphne; Hoek, Hans W.

    2012-01-01

    Eating disorders are relatively rare among the general population. This review discusses the literature on the incidence, prevalence and mortality rates of eating disorders. We searched online Medline/Pubmed, Embase and PsycINFO databases for articles published in English using several keyterms relating to eating disorders and epidemiology. Anorexia nervosa is relatively common among young women. While the overall incidence rate remained stable over the past decades, there has been an increas...

  11. Estimating the global production rate of TGFs

    Science.gov (United States)

    Albrechtsen, K. H.; Østgaard, N.; Marisaldi, M.; Gjesteland, T.; Berge, N.

    2017-12-01

    Terrestrial gamma-ray flashes (TGFs) are short sub-millisecond bursts of high energy gamma radiation, bremsstrahlung from the negative charges brought upwards from positive intracloud lightning. They were first detected by the Burst and Transient Source Experiment (BATSE) in 1991 and were thought to be a rare phenomena. However with new and improved satellites and more sophisticated data search algorithms, they have been found to be more and more common. This begs the question; how common are TGFs? We have previously used the World Wide Lightning Location Network (WWLLN) in addition to RHESSI to extract 100ms interval of RHESSI data centred at the time of each lightning flash. By superposing the RHESSI intervals of data (excluding already identified TGFs) between August 2002 and December 2015, we found a 9.39σ increase in gamma-rays at the time of lightning. This indicates that there exists a population of observationally faint TGFs that cannot be identified by current RHESSI search algorithms. Comparing the detected counts at the time of lightning to the background over all events, we find a significant and continuous signal down to 3 counts in the detector. We do not see a clear cutoff in the signal, as has been suggested by others. This could indicate that a potential signal cutoff happens below this level in RHESSI. In this work we will deadtime correct the faint TGF-WWLLN events so that we can fit a power law function to their fluence. Comparing this with the fluence distribution of TGFs without WWLLN matches should enable us to estimate the global production rate of TGFs.

  12. National and subnational hypertension prevalence estimates for the Republic of Ireland: better outcome and risk factor data are needed to produce better prevalence estimates.

    LENUS (Irish Health Repository)

    Barron, Steve

    2014-01-10

    Hypertension is a global public health challenge. National prevalence estimates can conceal important differences in prevalence in subnational areas. This paper aims to develop a consistent set of national and subnational estimates of the prevalence of hypertension in a country with limited data for subnational areas.

  13. Global Prevalence of Past-year Violence Against Children: A Systematic Review and Minimum Estimates.

    Science.gov (United States)

    Hillis, Susan; Mercy, James; Amobi, Adaugo; Kress, Howard

    2016-03-01

    Evidence confirms associations between childhood violence and major causes of mortality in adulthood. A synthesis of data on past-year prevalence of violence against children will help advance the United Nations' call to end all violence against children. Investigators systematically reviewed population-based surveys on the prevalence of past-year violence against children and synthesized the best available evidence to generate minimum regional and global estimates. We searched Medline, PubMed, Global Health, NBASE, CINAHL, and the World Wide Web for reports of representative surveys estimating prevalences of violence against children. Two investigators independently assessed surveys against inclusion criteria and rated those included on indicators of quality. Investigators extracted data on past-year prevalences of violent victimization by country, age group, and type (physical, sexual, emotional, or multiple types). We used a triangulation approach which synthesized data to generate minimum regional prevalences, derived from population-weighted averages of the country-specific prevalences. Thirty-eight reports provided quality data for 96 countries on past-year prevalences of violence against children. Base case estimates showed a minimum of 50% or more of children in Asia, Africa, and Northern America experienced past-year violence, and that globally over half of all children-1 billion children, ages 2-17 years-experienced such violence. Due to variations in timing and types of violence reported, triangulation could only be used to generate minimum prevalence estimates. Expanded population-based surveillance of violence against children is essential to target prevention and drive the urgent investment in action endorsed in the United Nations 2030 Sustainable Development Agenda. Copyright © 2016 by the American Academy of Pediatrics.

  14. A population-based approach to the estimation of diabetes prevalence and health resource utilisation.

    Science.gov (United States)

    Smith, James; Jackson, Gary; Orr-Walker, Brandon; Jackson, Rod; Sinclair, Siniva; Thornley, Simon; Riddell, Tania; Chan, Wing Cheuk

    2010-03-05

    This study estimated diabetes prevalence and utilisation of healthcare services in Counties Manukau using routinely collected administrative data and compared estimates with findings for three other district health boards (DHBs) in close geographic proximity. Records of subsidy claims for pharmaceuticals and laboratory investigations were linked to records in a national hospital admissions database to 'reconstruct' populations of four DHBs--Counties Manukau, Northland, Waitemata and Auckland. Individuals were included in reconstructed populations if they had health events recorded between January 2006 and December 2007. Diabetes cases were identified using an algorithm based on claims for monitoring tests and pharmaceuticals, as well as clinical codes for diabetes in hospital admissions. Reconstructed populations were only 6% lower than census population counts indicating that the vast majority of the population use health services in a two year period. The age- and sex-standardised prevalence of diabetes was 7.1% in Counties Manukau and 5.2% in the other three DHBs combined. Prevalence of diabetes was highest amongst Māori (10.6% in women and 12.2% in men) and Pacific peoples (15.0% for women and 13.5% for men). Maori diabetes cases had the highest hospital discharge rate of any ethnic group. Community pharmaceutical prescribing patterns and laboratory test frequency were similar between diabetes cases by ethnicity and deprivation. Estimates of diabetes prevalence using linkage of routinely collected administrative data were consistent with epidemiological surveys, suggesting that linkage of pharmaceutical and laboratory subsidy databases with hospital admissions data can be used as an alternative to traditional surveys for estimating the prevalence of some long-term conditions. This study demonstrated substantial differences in the prevalence of diabetes and in hospitalisation rates by ethnicity, but measures of community diabetes care were similar by ethnicity

  15. Sibling rivalry : Estimating cannibalization rates for innovations

    NARCIS (Netherlands)

    van Heerde, H.J.; Srinivasan, S.; Dekimpe, M.G.

    2012-01-01

    To evaluate the success of a new product, managers need to determine how much of its new demand is due to cannibalizing the company’s other products, rather than drawing from competition or generating primary demand. A new model allows managers to estimate cannibalization effects and to calculate

  16. Burden of type 2 diabetes in Mexico: past, current and future prevalence and incidence rates.

    Science.gov (United States)

    Meza, Rafael; Barrientos-Gutierrez, Tonatiuh; Rojas-Martinez, Rosalba; Reynoso-Noverón, Nancy; Palacio-Mejia, Lina Sofia; Lazcano-Ponce, Eduardo; Hernández-Ávila, Mauricio

    2015-12-01

    Mexico diabetes prevalence has increased dramatically in recent years. However, no national incidence estimates exist, hampering the assessment of diabetes trends and precluding the development of burden of disease analyses to inform public health policy decision-making. Here we provide evidence regarding current magnitude of diabetes in Mexico and its future trends. We used data from the Mexico National Health and Nutrition Survey, and age-period-cohort models to estimate prevalence and incidence of self-reported diagnosed diabetes by age, sex, calendar-year (1960-2012), and birth-cohort (1920-1980). We project future rates under three alternative incidence scenarios using demographic projections of the Mexican population from 2010-2050 and a Multi-cohort Diabetes Markov Model. Adult (ages 20+) diagnosed diabetes prevalence in Mexico increased from 7% to 8.9% from 2006 to 2012. Diabetes prevalence increases with age, peaking around ages 65-68 to then decrease. Age-specific incidence follows similar patterns, but peaks around ages 57-59. We estimate that diagnosed diabetes incidence increased exponentially during 1960-2012, roughly doubling every 10 years. Projected rates under three age-specific incidence scenarios suggest diabetes prevalence among adults (ages 20+) may reach 13.7-22.5% by 2050, affecting 15-25 million individuals, with a lifetime risk of 1 in 3 to 1 in 2. Diabetes prevalence in Mexico will continue to increase even if current incidence rates remain unchanged. Continued implementation of policies to reduce obesity rates, increase physical activity, and improve population diet, in tandem with diabetes surveillance and other risk control measures is paramount to substantially reduce the burden of diabetes in Mexico. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Burden of Type 2 Diabetes in Mexico: Past, Current and Future Prevalence and Incidence Rates

    Science.gov (United States)

    Meza, Rafael; Barrientos-Gutierrez, Tonatiuh; Rojas-Martinez, Rosalba; Reynoso-Noverón, Nancy; Palacio-Mejia, Lina Sofia; Lazcano-Ponce, Eduardo; Hernández-Ávila, Mauricio

    2015-01-01

    Introduction Mexico diabetes prevalence has increased dramatically in recent years. However, no national incidence estimates exist, hampering the assessment of diabetes trends and precluding the development of burden of disease analyses to inform public health policy decision-making. Here we provide evidence regarding current magnitude of diabetes in Mexico and its future trends. Methods We used data from the Mexico National Health and Nutrition Survey, and age-period-cohort models to estimate prevalence and incidence of self-reported diagnosed diabetes by age, sex, calendar-year (1960–2012), and birth-cohort (1920–1980). We project future rates under three alternative incidence scenarios using demographic projections of the Mexican population from 2010–2050 and a Multi-cohort Diabetes Markov Model. Results Adult (ages 20+) diagnosed diabetes prevalence in Mexico increased from 7% to 8.9% from 2006 to 2012. Diabetes prevalence increases with age, peaking around ages 65–68 to then decrease. Age-specific incidence follows similar patterns, but peaks around ages 57–59. We estimate that diagnosed diabetes incidence increased exponentially during 1960–2012, roughly doubling every 10 years. Projected rates under three age-specific incidence scenarios suggest diabetes prevalence among adults (ages 20+) may reach 13.7–22.5% by 2050, affecting 15–25 million individuals, with a lifetime risk of 1 in 3 to 1 in 2. Conclusions Diabetes prevalence in Mexico will continue to increase even if current incidence rates remain unchanged. Continued implementation of policies to reduce obesity rates, increase physical activity, and improve population diet, in tandem with diabetes surveillance and other risk control measures is paramount to substantially reduce the burden of diabetes in Mexico. PMID:26546108

  18. [Estimated prevalence of autism spectrum disorders in the Canary Islands].

    Science.gov (United States)

    Fortea Sevilla, M S; Escandell Bermúdez, M O; Castro Sánchez, J J

    2013-12-01

    To make an initial estimate of the prevalence of autism spectrum disorders (ASDs) among children in the province of Las Palmas (Spain). Descriptive study was conducted on 1,796 children between the ages of 18 and 30 months of age, all part of the Child Health Surveillance of the Canary Islands, more specifically the province of Las Palmas, with a population of 1,090,605. The parents of children involved completed the Spanish version of the Modified Checklist for Autism in Toddlers (M-CHAT/ES) in the paediatric clinic. The positive cases were then diagnosed by experts by means of the Autism Diagnostic Interview-Revised (ADIR) and the Autism Diagnostic Observation Schedule (ADOS). A 0.61% prevalence of ASDs was determined, similar to that reported in previous studies using the same tools. The ratio was six girls for every five boys. This was contrary to the results of previous studies which suggested more boys than girls were affected. This may have been due to the sample size, which will have to be increased in future studies to confirm this outcome. An increased sample size and also spread to other age ranges should be used in order to obtain a more reliable estimate of prevalence. As regards the gender ratio, this could be a result of the small size of the sample researched, and should therefore be confirmed by further studies. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  19. An estimate of the prevalence of dementia in Africa: a systematic analysis

    Directory of Open Access Journals (Sweden)

    Rhiannon George-Carey

    2012-12-01

    Full Text Available The burden of non–communicable diseases is growing, particularly in developing countries. The greatest economic burden is due to dementia, the prevalence of which is rising with increasing longevity. In Africa, where the rate of increase of elderly persons is the fastest in the world, dementia is normally dismissed as a part of normal ageing. The lack of awareness means that many patients are suffering undiagnosed. This review aims to assess the information on the prevalence of dementia in Africa in order to estimate the current burden.

  20. Estimation of transition probabilities of credit ratings

    Science.gov (United States)

    Peng, Gan Chew; Hin, Pooi Ah

    2015-12-01

    The present research is based on the quarterly credit ratings of ten companies over 15 years taken from the database of the Taiwan Economic Journal. The components in the vector mi (mi1, mi2,⋯, mi10) may first be used to denote the credit ratings of the ten companies in the i-th quarter. The vector mi+1 in the next quarter is modelled to be dependent on the vector mi via a conditional distribution which is derived from a 20-dimensional power-normal mixture distribution. The transition probability Pkl (i ,j ) for getting mi+1,j = l given that mi, j = k is then computed from the conditional distribution. It is found that the variation of the transition probability Pkl (i ,j ) as i varies is able to give indication for the possible transition of the credit rating of the j-th company in the near future.

  1. Lifetime prevalence rates of sleep paralysis: a systematic review.

    Science.gov (United States)

    Sharpless, Brian A; Barber, Jacques P

    2011-10-01

    To determine lifetime prevalence rates of sleep paralysis. Keyword term searches using "sleep paralysis", "isolated sleep paralysis", or "parasomnia not otherwise specified" were conducted using MEDLINE (1950-present) and PsychINFO (1872-present). English and Spanish language abstracts were reviewed, as were reference lists of identified articles. Thirty five studies that reported lifetime sleep paralysis rates and described both the assessment procedures and sample utilized were selected. Weighted percentages were calculated for each study and, when possible, for each reported subsample. Aggregating across studies (total N=36,533), 7.6% of the general population, 28.3% of students, and 31.9% of psychiatric patients experienced at least one episode of sleep paralysis. Of the psychiatric patients with panic disorder, 34.6% reported lifetime sleep paralysis. Results also suggested that minorities experience lifetime sleep paralysis at higher rates than Caucasians. Sleep paralysis is relatively common in the general population and more frequent in students and psychiatric patients. Given these prevalence rates, sleep paralysis should be assessed more regularly and uniformly in order to determine its impact on individual functioning and better articulate its relation to psychiatric and other medical conditions. Copyright © 2011. Published by Elsevier Ltd.

  2. Estimation of restaurant solid waste generation rates

    International Nuclear Information System (INIS)

    Heck, H.H.; Major, I.

    2002-01-01

    Most solid waste utilities try to create a billing schedule that is proportional to solid waste generation rates. This research was trying to determine if the current billing rate structure was appropriate or if a different rate structure should be implemented. A multiple regression model with forward stepwise addition was developed which accurately predicts weekly solid waste generation rates for restaurants. The model was based on a study of daily solid waste generation at twenty-one different businesses. The weight and volume of solid waste generated was measure daily for two weeks during the winter and two weeks during the summer. Researchers followed the collection truck and measured the volume and weight of the container contents. Data was collected on the following independent variables describing each establishment; weight of waste per collection, volume per collection, container utilization factor, building area, contract haulers bill, yearly property tax, yearly solid waste tax, average number of collections per week, type of restaurant, modal number of collections per week, storage container size, waste density, number of employees, number of hours open per week, and weekly collection capacity (collections per week times storage container size). Independent variables were added to the regression equation based on their partial correlation coefficient and confidence level. The regression equations developed had correlation coefficients of 0.87 to 1.00, which was much better than the correlation coefficient (0.84) of an existing model DeGeare and Ongerth (1971) and a correlation coefficient of 0.54 based on the current solid waste disposal tax. (author)

  3. Estimates of Incidence and Prevalence of Visual Impairment, Low Vision, and Blindness in the United States.

    Science.gov (United States)

    Chan, Tiffany; Friedman, David S; Bradley, Chris; Massof, Robert

    2018-01-01

    Updated estimates of the prevalence and incidence rates of low vision and blindness are needed to inform policy makers and develop plans to meet the future demands for low vision rehabilitation services. To provide updated estimates of the incidence and prevalence of low vision and blindness in the United States. Visual acuity measurements as a function of age from the 2007-2008 National Health and Nutrition Examination Survey, with representation of racial and ethnic groups, were used to estimate the prevalence and incidence of visual impairments. Data from 6016 survey participants, ranging in age from younger than 18 years to older than 45 years, were obtained to estimate prevalence rates for different age groups. Incidence and prevalence rates of low vision (best-corrected visual acuity [BCVA] in the better-seeing eye of United States were estimated, using the 2010 US census data by age, from the rate models applied to the census projections for 2017, 2030, and 2050. Data were collected from November 1, 2007, to October 31, 2008. Data analysis took place from March 31, 2016, to March 19, 2017. Prevalence and incidence rates of low vision and blindness in the United States. Of the 6016 people in the study, 1714 (28.4%) were younger than 18 years of age, 2358 (39.1%) were 18 to 44 years of age, and 1944 (32.3%) were 45 years of age or older. There were 2888 male (48%) and 3128 female (52%) participants. The prevalence of low vision and blindness for older adults (≥45 years) in the United States in 2017 is estimated to be 3 894 406 persons (95% CI, 3 034 442-4 862 549 persons) with a BCVA less than 20/40, 1 483 703 persons (95% CI, 968 656-2 370 513 persons) with a BCVA less than 20/60, and 1 082 790 persons (95% CI, 637 771-1 741 864 persons) with a BCVA of 20/200 or less. The estimated 2017 annual incidence (projected from 2010 census data) of low vision and blindness among older adults (≥45 years) in the United States is 481

  4. HAZARD RATE ESTIMATION OF TEMPORAL POINT PROCESS CASE STUDY: EARTHQUAKE HAZARD RATE IN NUSATENGGARA REGION

    OpenAIRE

    Sunusi, Nurtiti

    2008-01-01

    Hazard rate estimation is one of the important topics in forecasting earthquake occurrence. Forecasting earthquake occurrence is a part of the statistical seismology where the main subject is the point process. Generally, earthquake hazard rate is estimated based on the point process likelihood equation called the Hazard Rate Likelihood of Point Process (HRLPP). In this research, we have developed estimation method, that is hazard rate single decrement HRSD. This method was adapted from estim...

  5. Estimating incidence from prevalence in generalised HIV epidemics: methods and validation.

    Directory of Open Access Journals (Sweden)

    Timothy B Hallett

    2008-04-01

    Full Text Available HIV surveillance of generalised epidemics in Africa primarily relies on prevalence at antenatal clinics, but estimates of incidence in the general population would be more useful. Repeated cross-sectional measures of HIV prevalence are now becoming available for general populations in many countries, and we aim to develop and validate methods that use these data to estimate HIV incidence.Two methods were developed that decompose observed changes in prevalence between two serosurveys into the contributions of new infections and mortality. Method 1 uses cohort mortality rates, and method 2 uses information on survival after infection. The performance of these two methods was assessed using simulated data from a mathematical model and actual data from three community-based cohort studies in Africa. Comparison with simulated data indicated that these methods can accurately estimates incidence rates and changes in incidence in a variety of epidemic conditions. Method 1 is simple to implement but relies on locally appropriate mortality data, whilst method 2 can make use of the same survival distribution in a wide range of scenarios. The estimates from both methods are within the 95% confidence intervals of almost all actual measurements of HIV incidence in adults and young people, and the patterns of incidence over age are correctly captured.It is possible to estimate incidence from cross-sectional prevalence data with sufficient accuracy to monitor the HIV epidemic. Although these methods will theoretically work in any context, we have able to test them only in southern and eastern Africa, where HIV epidemics are mature and generalised. The choice of method will depend on the local availability of HIV mortality data.

  6. Epidemiology of eating disorders: incidence, prevalence and mortality rates.

    Science.gov (United States)

    Smink, Frédérique R E; van Hoeken, Daphne; Hoek, Hans W

    2012-08-01

    Eating disorders are relatively rare among the general population. This review discusses the literature on the incidence, prevalence and mortality rates of eating disorders. We searched online Medline/Pubmed, Embase and PsycINFO databases for articles published in English using several keyterms relating to eating disorders and epidemiology. Anorexia nervosa is relatively common among young women. While the overall incidence rate remained stable over the past decades, there has been an increase in the high risk-group of 15-19 year old girls. It is unclear whether this reflects earlier detection of anorexia nervosa cases or an earlier age at onset. The occurrence of bulimia nervosa might have decreased since the early nineties of the last century. All eating disorders have an elevated mortality risk; anorexia nervosa the most striking. Compared with the other eating disorders, binge eating disorder is more common among males and older individuals.

  7. Validation of a model for estimating state and local prevalence of serious mental illness.

    Science.gov (United States)

    Hudson, Christopher G

    2009-12-01

    This study addresses an ongoing problem in mental health needs assessment. This involves estimating the prevalence of an identified problem, specifically serious mental illness (SMI), for local areas in a reliable, valid, and cost-effective manner. The aim of the study is the application and testing of a recently introduced methodology from the field of small area estimation to determining SMI rates in the 48 contiguous US states, and in local areas of Massachusetts. It uses 'regression synthetic estimation fitted using area-level covariates', to estimate a model using data from the 2001-2002 replication of the National Comorbidity Study (n = 5593) and apply it, using 2000 STF-3C Census data, to various state and local areas in the United States. The estimates are then compared with independently collected SMI indicators. The estimates show not only face validity and internal consistency, but also predictive validity. The multiple logistic model has a sensitivity of 21.1% and a specificity of 95.1%, based largely on socio-economic disparities. Pearson r validity coefficients for the area estimates range from 0.43 to 0.75. The model generates a national estimate of SMI adults of 5.5%; for the 48 states, rates ranging from 4.7% to 7.0%; and for Massachusetts towns and cities, 1.1% to 7.5%.

  8. Analyse of the prevalence rate and risk factors of pulmonary embolism in the patients with dyspnea

    International Nuclear Information System (INIS)

    Cao Yanxia; Su Jian; Wang Bingsheng; Wu Songhong; Dai Ruiting; Cao Caixia

    2005-01-01

    Objective: To analyse the prevalence rate and risk factors of pulmonary embolism (PE) in patients with dyspnea and to explore the predisposing causes and its early clinical manifestations. Methods: Retrospective analysis was done in 461 patients with dyspnea performed 99 Tc m -macroaggregated albumin (MAA) lung perfusion imaging and 99 Tc m -DTPA ventilation imaging or 99 Tc m -MAA perfusion imaging and chest X-ray examination. Among them, 48 cases without apparent disease were considered as control group, whereas the remaining patients with other underlying illnesses as patients group. PEMS statistics software package was used for estimation of prevalence rate, χ 2 test and PE risk factor analysis. Results: There were 251 PE patients among 461 patients, the prevalence rate [ (π)=95% confidence interval (CI) ] was: lower extremity thrombosis and varicosity (80.79-95.47 ), post cesarean section (55.64-87.12), lower extremity bone surgery or fracture (52.76-87.27 ), cancer operation (52.19-78.19), atrial fibrillation or heart failure (53.30-74.88), obesity (23.14-50.20), post abdominal surgery (20.23-59.43), diabetes (19.12-63.95), chronic bronchitis (1.80-23.06), normal control group (3.47-22.66). Except chronic bronchitis, PE prevalence rate between patients group and control group had significant difference (P 99 Tc m -MAA and DTPA lung imaging should be done as early as possible. (authors)

  9. Prevalence Rates of the Incubus Phenomenon: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Marc L. Molendijk

    2017-11-01

    Full Text Available BackgroundThe incubus phenomenon is a paroxysmal sleep-related disorder characterized by compound hallucinations experienced during brief phases of (apparent wakefulness. The condition has an almost stereotypical presentation, characterized by a hallucinated being that exerts pressure on the thorax, meanwhile carrying out aggressive and/or sexual acts. It tends to be accompanied by sleep paralysis, anxiety, vegetative symptoms, and feelings of suffocation. Its prevalence rate is unknown since, in prior analyses, cases of recurrent isolated sleep paralysis with/without an incubus phenomenon have been pooled together. This is unfortunate, since the incubus phenomenon has a much greater clinical relevance than isolated sleep paralysis.MethodsPubMed, Embase, and PsycINFO were searched for prevalence studies of the incubus phenomenon, and a meta-analysis was performed.ResultsOf the 1,437 unique records, 13 met the inclusion criteria, reporting on 14 (k independent prevalence estimates (total N = 6,079. The pooled lifetime prevalence rate of the incubus phenomenon was 0.19 [95% confidence interval (CI = 0.14–0.25, k = 14, N = 6,079] with heterogeneous estimates over different samples. In selected samples (e.g., patients with a psychiatric disorder, refugees, and students, prevalence rates were nearly four times higher (0.41, 95% CI = 0.25–0.56, k = 4, n = 1,275 than in the random samples (0.11, 95% CI = 0.08–0.14, k = 10, n = 4,804. This difference was significant (P < 0.001.ConclusionThis review and meta-analysis yielded a lifetime prevalence of the incubus phenomenon in the general population of 0.11 and, in selected samples, of 0.41. This is slightly higher than the prevalence rates in previous analyses that included cases of recurrent isolated sleep paralysis without an incubus phenomenon. Based on the condition’s robust clinical presentation and the relatively high prevalence rates, we advocate

  10. Calculation of prevalence estimates through differential equations: application to stroke-related disability.

    Science.gov (United States)

    Mar, Javier; Sainz-Ezkerra, María; Moler-Cuiral, Jose Antonio

    2008-01-01

    Neurological diseases now make up 6.3% of the global burden of disease mainly because they cause disability. To assess disability, prevalence estimates are needed. The objective of this study is to apply a method based on differential equations to calculate the prevalence of stroke-related disability. On the basis of a flow diagram, a set of differential equations for each age group was constructed. The linear system was solved analytically and numerically. The parameters of the system were obtained from the literature. The model was validated and calibrated by comparison with previous results. The stroke prevalence rate per 100,000 men was 828, and the rate for stroke-related disability was 331. The rates steadily rose with age, but the group between the ages of 65 and 74 years had the highest total number of individuals. Differential equations are useful to represent the natural history of neurological diseases and to make possible the calculation of the prevalence for the various states of disability. In our experience, when compared with the results obtained by Markov models, the benefit of the continuous use of time outweighs the mathematical requirements of our model. (c) 2008 S. Karger AG, Basel.

  11. Estimating progression rates for human papillomavirus infection from epidemiological data.

    Science.gov (United States)

    Jit, Mark; Gay, Nigel; Soldan, Kate; Hong Choi, Yoon; Edmunds, William John

    2010-01-01

    A Markov model was constructed in order to estimate type-specific rates of cervical lesion progression and regression in women with high-risk human papillomavirus (HPV). The model was fitted to age- and type-specific data regarding the HPV DNA and cytological status of women undergoing cervical screening in a recent screening trial, as well as cervical cancer incidence. It incorporates different assumptions about the way lesions regress, the accuracy of cytological screening, the specificity of HPV DNA testing, and the age-specific prevalence of HPV infection. Combinations of assumptions generate 162 scenarios for squamous cell carcinomas and 54 scenarios for adenocarcinomas. Simulating an unscreened cohort of women infected with high-risk HPV indicates that the probability of an infection continuing to persist and to develop into invasive cancer depends on the length of time it has already persisted. The scenarios and parameter sets that produce the best fit to available epidemiological data provide a basis for modeling the natural history of HPV infection and disease.

  12. A multilevel model for cardiovascular disease prevalence in the US and its application to micro area prevalence estimates

    Directory of Open Access Journals (Sweden)

    Congdon Peter

    2009-01-01

    Full Text Available Abstract Background Estimates of disease prevalence for small areas are increasingly required for the allocation of health funds according to local need. Both individual level and geographic risk factors are likely to be relevant to explaining prevalence variations, and in turn relevant to the procedure for small area prevalence estimation. Prevalence estimates are of particular importance for major chronic illnesses such as cardiovascular disease. Methods A multilevel prevalence model for cardiovascular outcomes is proposed that incorporates both survey information on patient risk factors and the effects of geographic location. The model is applied to derive micro area prevalence estimates, specifically estimates of cardiovascular disease for Zip Code Tabulation Areas in the USA. The model incorporates prevalence differentials by age, sex, ethnicity and educational attainment from the 2005 Behavioral Risk Factor Surveillance System survey. Influences of geographic context are modelled at both county and state level, with the county effects relating to poverty and urbanity. State level influences are modelled using a random effects approach that allows both for spatial correlation and spatial isolates. Results To assess the importance of geographic variables, three types of model are compared: a model with person level variables only; a model with geographic effects that do not interact with person attributes; and a full model, allowing for state level random effects that differ by ethnicity. There is clear evidence that geographic effects improve statistical fit. Conclusion Geographic variations in disease prevalence partly reflect the demographic composition of area populations. However, prevalence variations may also show distinct geographic 'contextual' effects. The present study demonstrates by formal modelling methods that improved explanation is obtained by allowing for distinct geographic effects (for counties and states and for

  13. Prolonged decay of molecular rate estimates for metazoan mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Martyna Molak

    2015-03-01

    Full Text Available Evolutionary timescales can be estimated from genetic data using the molecular clock, often calibrated by fossil or geological evidence. However, estimates of molecular rates in mitochondrial DNA appear to scale negatively with the age of the clock calibration. Although such a pattern has been observed in a limited range of data sets, it has not been studied on a large scale in metazoans. In addition, there is uncertainty over the temporal extent of the time-dependent pattern in rate estimates. Here we present a meta-analysis of 239 rate estimates from metazoans, representing a range of timescales and taxonomic groups. We found evidence of time-dependent rates in both coding and non-coding mitochondrial markers, in every group of animals that we studied. The negative relationship between the estimated rate and time persisted across a much wider range of calibration times than previously suggested. This indicates that, over long time frames, purifying selection gives way to mutational saturation as the main driver of time-dependent biases in rate estimates. The results of our study stress the importance of accounting for time-dependent biases in estimating mitochondrial rates regardless of the timescale over which they are inferred.

  14. Reliability of Nationwide Prevalence Estimates of Dementia: A Critical Appraisal Based on Brazilian Surveys.

    Directory of Open Access Journals (Sweden)

    Flávio Chaimowicz

    Full Text Available The nationwide dementia prevalence is usually calculated by applying the results of local surveys to countries' populations. To evaluate the reliability of such estimations in developing countries, we chose Brazil as an example. We carried out a systematic review of dementia surveys, ascertained their risk of bias, and present the best estimate of occurrence of dementia in Brazil.We carried out an electronic search of PubMed, Latin-American databases, and a Brazilian thesis database for surveys focusing on dementia prevalence in Brazil. The systematic review was registered at PROSPERO (CRD42014008815. Among the 35 studies found, 15 analyzed population-based random samples. However, most of them utilized inadequate criteria for diagnostics. Six studies without these limitations were further analyzed to assess the risk of selection, attrition, outcome and population bias as well as several statistical issues. All the studies presented moderate or high risk of bias in at least two domains due to the following features: high non-response, inaccurate cut-offs, and doubtful accuracy of the examiners. Two studies had limited external validity due to high rates of illiteracy or low income. The three studies with adequate generalizability and the lowest risk of bias presented a prevalence of dementia between 7.1% and 8.3% among subjects aged 65 years and older. However, after adjustment for accuracy of screening, the best available evidence points towards a figure between 15.2% and 16.3%.The risk of bias may strongly limit the generalizability of dementia prevalence estimates in developing countries. Extrapolations that have already been made for Brazil and Latin America were based on a prevalence that should have been adjusted for screening accuracy or not used at all due to severe bias. Similar evaluations regarding other developing countries are needed in order to verify the scope of these limitations.

  15. Estimating monotonic rates from biological data using local linear regression.

    Science.gov (United States)

    Olito, Colin; White, Craig R; Marshall, Dustin J; Barneche, Diego R

    2017-03-01

    Accessing many fundamental questions in biology begins with empirical estimation of simple monotonic rates of underlying biological processes. Across a variety of disciplines, ranging from physiology to biogeochemistry, these rates are routinely estimated from non-linear and noisy time series data using linear regression and ad hoc manual truncation of non-linearities. Here, we introduce the R package LoLinR, a flexible toolkit to implement local linear regression techniques to objectively and reproducibly estimate monotonic biological rates from non-linear time series data, and demonstrate possible applications using metabolic rate data. LoLinR provides methods to easily and reliably estimate monotonic rates from time series data in a way that is statistically robust, facilitates reproducible research and is applicable to a wide variety of research disciplines in the biological sciences. © 2017. Published by The Company of Biologists Ltd.

  16. Estimates of Non-Heterosexual Prevalence: The Roles of Anonymity and Privacy in Survey Methodology.

    Science.gov (United States)

    Robertson, Ronald E; Tran, Felix W; Lewark, Lauren N; Epstein, Robert

    2017-08-07

    When do people feel comfortable enough to provide honest answers to sensitive questions? Focusing specifically on sexual orientation prevalence-a measure that is sensitive to the pressures of heteronormativity-the present study was conducted to examine the variability in U.S. estimates of non-heterosexual identity prevalence and to determine how comfortable people are with answering questions about their sexual orientation when asked through commonly used survey modes. We found that estimates of non-heterosexual prevalence in the U.S. increased as the privacy and anonymity of the survey increased. Utilizing an online questionnaire, we rank-ordered 16 survey modes by asking people to rate their level of comfort with each mode in the context of being asked questions about their sexual orientation. A demographically diverse sample of 652 individuals in the U.S. rated each mode on a scale from -5 (very uncomfortable) to +5 (very comfortable). Modes included anonymous (name not required) and non-anonymous (name required) versions of questions, as well as self-administered and interviewer-administered versions. Subjects reported significantly higher mean comfort levels with anonymous modes than with non-anonymous modes and significantly higher mean comfort levels with self-administered modes than with interviewer-administered modes. Subjects reported the highest mean comfort level with anonymous online surveys and the lowest with non-anonymous personal interviews that included a video recording. Compared with the estimate produced by an online survey with a nationally representative sample, surveys utilizing more intrusive methodologies may have underestimated non-heterosexual prevalence in the U.S. by between 50 and 414%. Implications for public policy are discussed.

  17. Angular Rate Estimation Using a Distributed Set of Accelerometers

    Directory of Open Access Journals (Sweden)

    Sung Kyung Hong

    2011-11-01

    Full Text Available A distributed set of accelerometers based on the minimum number of 12 accelerometers allows for computation of the magnitude of angular rate without using the integration operation. However, it is not easy to extract the magnitude of angular rate in the presence of the accelerometer noises, and even worse, it is difficult to determine the direction of a rotation because the angular rate is present in its quadratic form within the inertial measurement system equations. In this paper, an extended Kalman filter scheme to correctly estimate both the direction and magnitude of the angular rate through fusion of the angular acceleration and quadratic form of the angular rate is proposed. We also provide observability analysis for the general distributed accelerometers-based inertial measurement unit, and show that the angular rate can be correctly estimated by general nonlinear state estimators such as an extended Kalman filter, except under certain extreme conditions.

  18. The Estimation of the Equilibrium Real Exchange Rate for Romania

    OpenAIRE

    Bogdan Andrei Dumitrescu; Vasile Dedu

    2009-01-01

    This paper aims to estimate the equilibrium real exchange rate for Romania, respectively the real exchange rate consistent with the macroeconomic balance, which is achieved when the economy is operating at full employment and low inflation (internal balance) and has a current account that is sustainable (external balance). This equilibrium real exchange rate is very important for an economy because deviations of the real exchange rate from its equilibrium value can affect the competitiveness ...

  19. Estimating the exceedance probability of rain rate by logistic regression

    Science.gov (United States)

    Chiu, Long S.; Kedem, Benjamin

    1990-01-01

    Recent studies have shown that the fraction of an area with rain intensity above a fixed threshold is highly correlated with the area-averaged rain rate. To estimate the fractional rainy area, a logistic regression model, which estimates the conditional probability that rain rate over an area exceeds a fixed threshold given the values of related covariates, is developed. The problem of dependency in the data in the estimation procedure is bypassed by the method of partial likelihood. Analyses of simulated scanning multichannel microwave radiometer and observed electrically scanning microwave radiometer data during the Global Atlantic Tropical Experiment period show that the use of logistic regression in pixel classification is superior to multiple regression in predicting whether rain rate at each pixel exceeds a given threshold, even in the presence of noisy data. The potential of the logistic regression technique in satellite rain rate estimation is discussed.

  20. Equations to Estimate Creatinine Excretion Rate : The CKD Epidemiology Collaboration

    NARCIS (Netherlands)

    Ix, Joachim H.; Wassel, Christina L.; Stevens, Lesley A.; Beck, Gerald J.; Froissart, Marc; Navis, Gerjan; Rodby, Roger; Torres, Vicente E.; Zhang, Yaping (Lucy); Greene, Tom; Levey, Andrew S.

    Background and objectives Creatinine excretion rate (CER) indicates timed urine collection accuracy. Although equations to estimate CER exist, their bias and precision are untested and none simultaneously include age, sex, race, and weight. Design, setting, participants, & measurements Participants

  1. Updated estimates of carbon accumulation rates in coastal marsh sediments

    OpenAIRE

    Ouyang, X.; Lee, S. Y.

    2014-01-01

    Studies on carbon stock in salt marsh sediments have increased since the review by Chmura et al. (2003). However, uncertainties exist in estimating global carbon storage in these vulnerable coastal habitats, thus hindering the assessment of their importance. Combining direct data and indirect estimation, this study compiled studies involving 143 sites across the Southern and Northern hemispheres, and provides an updated estimate of the global average carbon accumulation rate...

  2. Simplifying cardiovascular risk estimation using resting heart rate.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2010-09-01

    Elevated resting heart rate (RHR) is a known, independent cardiovascular (CV) risk factor, but is not included in risk estimation systems, including Systematic COronary Risk Evaluation (SCORE). We aimed to derive risk estimation systems including RHR as an extra variable and assess the value of this addition.

  3. Estimating individual rates of discount: A meta-analysis

    NARCIS (Netherlands)

    Percoco, M.; Nijkamp, P.

    2009-01-01

    In this article, we present the results from a meta-analysis conducted over 44 experimental and field studies, which report individual discount rate estimates. We find in our research that the experimental design of a study has a decisive impact on these estimates, and conclude that meta-analysis,

  4. Preliminary estimates of population size and capture rates of mature ...

    African Journals Online (AJOL)

    Population size estimates and capture rates by various fishing techniques of mature estuarine bream, Acanthopagrus berda, were determined in the Kosi lakes system using mark-recapture methods. The total population size of mature A. berda was estimated to be 45257 (95% confidence interval: 31 589-74429) based on ...

  5. Multiresolution Motion Estimation for Low-Rate Video Frame Interpolation

    Directory of Open Access Journals (Sweden)

    Hezerul Abdul Karim

    2004-09-01

    Full Text Available Interpolation of video frames with the purpose of increasing the frame rate requires the estimation of motion in the image so as to interpolate pixels along the path of the objects. In this paper, the specific challenges of low-rate video frame interpolation are illustrated by choosing one well-performing algorithm for high-frame-rate interpolation (Castango 1996 and applying it to low frame rates. The degradation of performance is illustrated by comparing the original algorithm, the algorithm adapted to low frame rate, and simple averaging. To overcome the particular challenges of low-frame-rate interpolation, two algorithms based on multiresolution motion estimation are developed and compared on objective and subjective basis and shown to provide an elegant solution to the specific challenges of low-frame-rate video interpolation.

  6. Estimating the normal background rate of species extinction.

    Science.gov (United States)

    De Vos, Jurriaan M; Joppa, Lucas N; Gittleman, John L; Stephens, Patrick R; Pimm, Stuart L

    2015-04-01

    A key measure of humanity's global impact is by how much it has increased species extinction rates. Familiar statements are that these are 100-1000 times pre-human or background extinction levels. Estimating recent rates is straightforward, but establishing a background rate for comparison is not. Previous researchers chose an approximate benchmark of 1 extinction per million species per year (E/MSY). We explored disparate lines of evidence that suggest a substantially lower estimate. Fossil data yield direct estimates of extinction rates, but they are temporally coarse, mostly limited to marine hard-bodied taxa, and generally involve genera not species. Based on these data, typical background loss is 0.01 genera per million genera per year. Molecular phylogenies are available for more taxa and ecosystems, but it is debated whether they can be used to estimate separately speciation and extinction rates. We selected data to address known concerns and used them to determine median extinction estimates from statistical distributions of probable values for terrestrial plants and animals. We then created simulations to explore effects of violating model assumptions. Finally, we compiled estimates of diversification-the difference between speciation and extinction rates for different taxa. Median estimates of extinction rates ranged from 0.023 to 0.135 E/MSY. Simulation results suggested over- and under-estimation of extinction from individual phylogenies partially canceled each other out when large sets of phylogenies were analyzed. There was no evidence for recent and widespread pre-human overall declines in diversity. This implies that average extinction rates are less than average diversification rates. Median diversification rates were 0.05-0.2 new species per million species per year. On the basis of these results, we concluded that typical rates of background extinction may be closer to 0.1 E/MSY. Thus, current extinction rates are 1,000 times higher than natural

  7. A new approach for estimation of component failure rate

    International Nuclear Information System (INIS)

    Jordan Cizelj, R.; Kljenak, I.

    1999-01-01

    In the paper, a formal method for component failure rate estimation is described, which is proposed to be used for components, for which no specific numerical data necessary for probabilistic estimation exist. The framework of the method is the Bayesian updating procedure. A prior distribution is selected from a generic database, whereas the likelihood distribution is assessed from specific data on component state using principles of fuzzy logic theory. With the proposed method the component failure rate estimation is based on a much larger quantity of information compared to presently used classical methods.(author)

  8. Indicadores básicos de saúde infantil em área urbana no extremo sul do Brasil: estimando prevalências e avaliando diferenciais Basic indicators of child health in an urban area in southern Brazil: estimating prevalence rates and evaluating differentials

    Directory of Open Access Journals (Sweden)

    Juraci A. Cesar

    2006-12-01

    -sectional population studies were carried out in the city. Interviewers were previously trained and applied standardized questionnaires during visits to families with children under 5 years old. The following variables were investigated: family income, maternal education, type of construction of home (wooden/masonry etc., availability of toilet, running water, sewage system and domestic appliances. Data collected on the children themselves included number of antenatal consultations and age at first antenatal, type of delivery and medical care received during delivery, breastfeeding and dietary patterns, morbidity and health services utilization. Children were weighed and measured for height/length. Comparisons of frequencies between the two datasets were made using the chi-square test. RESULTS: In 1995, 395 children were studied and in 2004 there were 384. During the intervening period improvements had taken place in type of construction, number of homes with flush toilet, the availability of running water and in breastfeeding pattern and duration. The frequency of diarrhea reduced, while rates of basic vaccination coverage, growth monitoring, patients in possession of their own medical cards and reporting of birth weights all increased. There was a deterioration in families' purchasing power and in the mean number of antenatal consultations. The prevalence of childhood obesity increased by 92%, while the incidence of malnutrition remained practically unchanged. CONCLUSIONS: Comparing health indicators from the two periods revealed that, in addition to improvements in the majority of the indicators assessed, there had been a substantial increase in the prevalence of childhood obesity.

  9. Haldane and the first estimates of the human mutation rate

    Indian Academy of Sciences (India)

    Unknown

    3, December 2004. 231. Haldane and the first estimates of the human mutation rate ... in this issue, pages 235–244) was the first to provide a ... population. This provided a straightforward way to esti- mate the mutation rate for deleterious alleles: if the fre- quency of an allele could be measured and if the strength of selection ...

  10. Estimating stutter rates for Y-STR alleles

    DEFF Research Database (Denmark)

    Andersen, Mikkel Meyer; Olofsson, Jill Katharina; Mogensen, Helle Smidt

    2011-01-01

    Stutter peaks are artefacts that arise during PCR amplification of short tandem repeats. Stutter peaks are especially important in forensic case work with DNA mixtures. The aim of the study was primarily to estimate the stutter rates of the AmpFlSTR Yfiler kit. We found that the stutter rates...

  11. Estimated Interest Rate Rules: Do they Determine Determinacy Properties?

    DEFF Research Database (Denmark)

    Jensen, Henrik

    2011-01-01

    I demonstrate that econometric estimations of nominal interest rate rules may tell little, if anything, about an economy's determinacy properties. In particular, correct inference about the interest-rate response to inflation provides no information about determinacy. Instead, it could reveal...

  12. Moment estimation of customer loss rates from transactional data

    Directory of Open Access Journals (Sweden)

    D. J. Daley

    1998-01-01

    Full Text Available Moment estimators are proposed for the arrival and customer loss rates of a many-server queueing system with a Poisson arrival process with customer loss via balking or reneging. These estimators are based on the lengths {Sj1} of the initial inter-departure intervals of the busy periods j=1,…,M observed in a dataset consisting of service starting and finishing times and encompassing both busy and idle periods of the process, and whether those busy periods are of length 1 or >1. The estimators are compared with maximum likelihood and parametric model-based estimators found previously.

  13. Comparison of Prevalence- and Smoking Impact Ratio-Based Methods of Estimating Smoking-Attributable Fractions of Deaths

    Directory of Open Access Journals (Sweden)

    Kyoung Ae Kong

    2016-04-01

    Full Text Available Background: Smoking is a major modifiable risk factor for premature mortality. Estimating the smoking-attributable burden is important for public health policy. Typically, prevalence- or smoking impact ratio (SIR-based methods are used to derive estimates, but there is controversy over which method is more appropriate for country-specific estimates. We compared smoking-attributable fractions (SAFs of deaths estimated by these two methods. Methods: To estimate SAFs in 2012, we used several different prevalence-based approaches using no lag and 10- and 20-year lags. For the SIR-based method, we obtained lung cancer mortality rates from the Korean Cancer Prevention Study (KCPS and from the United States-based Cancer Prevention Study-II (CPS-II. The relative risks for the diseases associated with smoking were also obtained from these cohort studies. Results: For males, SAFs obtained using KCPS-derived SIRs were similar to those obtained using prevalence-based methods. For females, SAFs obtained using KCPS-derived SIRs were markedly greater than all prevalence-based SAFs. Differences in prevalence-based SAFs by time-lag period were minimal among males, but SAFs obtained using longer-lagged prevalence periods were significantly larger among females. SAFs obtained using CPS-II-based SIRs were lower than KCPS-based SAFs by >15 percentage points for most diseases, with the exceptions of lung cancer and chronic obstructive pulmonary disease. Conclusions: SAFs obtained using prevalence- and SIR-based methods were similar for males. However, neither prevalence-based nor SIR-based methods resulted in precise SAFs among females. The characteristics of the study population should be carefully considered when choosing a method to estimate SAF.

  14. Underreporting of BMI in adults and its effect on obesity prevalence estimations in the period 1998 to 2001

    NARCIS (Netherlands)

    Visscher, Tommy L S; Viet, A Lucie; Kroesbergen, Ike H T; Seidell, Jacob C

    2006-01-01

    OBJECTIVE: To identify the determinants of underreporting BMI and to evaluate the possibilities of using self-reported data for valid obesity prevalence rate estimations. RESEARCH METHODS AND PROCEDURES: A cross-sectional monitoring health survey was carried out between 1998 and 2002, and a review

  15. Estimation of the Prevalence of Autism Spectrum Disorder in South Korea, Revisited

    Science.gov (United States)

    Pantelis, Peter C.; Kennedy, Daniel P.

    2016-01-01

    Two-phase designs in epidemiological studies of autism prevalence introduce methodological complications that can severely limit the precision of resulting estimates. If the assumptions used to derive the prevalence estimate are invalid or if the uncertainty surrounding these assumptions is not properly accounted for in the statistical inference…

  16. Period prevalence and reporting rate of medication errors among nurses in Iran: A systematic review and meta-analysis.

    Science.gov (United States)

    Matin, Behzad Karami; Hajizadeh, Mohammad; Nouri, Bijan; Rezaeian, Shahab; Mohammadi, Masoud; Rezaei, Satar

    2018-01-22

    To estimate the 1-year period prevalence of medication errors and the reporting rate to nurse managers among nurses working in hospitals in Iran. Medication errors are one of the main factors affecting the quality of hospital services and reducing patient safety in health care systems. A literature search from Iranian and international scientific databases was developed to find relevant studies. Meta-regression was used to identify which characteristics may have a confounding effect on the pooled prevalence estimates. Based on the final 22 studies with 3556 samples, the overall estimated 1-year period prevalence of medication errors and its reporting rate to nurse managers among nurses were 53% (95% confidence interval, 41%-60%) and 36% (95% confidence interval, 23%-50%), respectively. The meta-regression analyses indicated that the sex (female/male) ratio was a statistically significant predictor of the prevalence of medication errors (p medication errors to nurse managers. The period prevalence of medication errors among nurses working in hospitals was high in Iran, whereas its reporting rate to nurse managers was low. Continuous training programmes are required to reduce and prevent medication errors among nursing staff and to improve the reporting rate to nurse managers in in Iran. © 2018 John Wiley & Sons Ltd.

  17. Improving estimates of tree mortality probability using potential growth rate

    Science.gov (United States)

    Das, Adrian J.; Stephenson, Nathan L.

    2015-01-01

    Tree growth rate is frequently used to estimate mortality probability. Yet, growth metrics can vary in form, and the justification for using one over another is rarely clear. We tested whether a growth index (GI) that scales the realized diameter growth rate against the potential diameter growth rate (PDGR) would give better estimates of mortality probability than other measures. We also tested whether PDGR, being a function of tree size, might better correlate with the baseline mortality probability than direct measurements of size such as diameter or basal area. Using a long-term dataset from the Sierra Nevada, California, U.S.A., as well as existing species-specific estimates of PDGR, we developed growth–mortality models for four common species. For three of the four species, models that included GI, PDGR, or a combination of GI and PDGR were substantially better than models without them. For the fourth species, the models including GI and PDGR performed roughly as well as a model that included only the diameter growth rate. Our results suggest that using PDGR can improve our ability to estimate tree survival probability. However, in the absence of PDGR estimates, the diameter growth rate was the best empirical predictor of mortality, in contrast to assumptions often made in the literature.

  18. A Bayesian approach to estimating the prehepatic insulin secretion rate

    DEFF Research Database (Denmark)

    Andersen, Kim Emil; Højbjerre, Malene

    The prehepatic insulin secretion rate of the pancreatic $beta$-cells is not directly measurable, since part of the secreted insulin is absorbed by the liver prior to entering the blood stream. However, C-peptide is co-secreted equimolarly and is not absorbed by the liver, allowing...... for the estimation of the prehepatic insulin secretion rate. We consider a stochastic differential equation model that combines both insulin and C-peptide concentrations in plasma to estimate the prehepatic insulin secretion rate. Previously this model has been analysed in an iterative deterministic set-up, where...... the time courses of insulin and C-peptide subsequently are used as known forcing functions. In this work we adopt a Bayesian graphical model to describe the unied model simultaneously. We develop a model that also accounts for both measurement error and process variability. The parameters are estimated...

  19. Estimation of Cessation Rates among Danish Users of Benzodiazepines

    DEFF Research Database (Denmark)

    Støvring, Henrik; Gasse, Christiane

    Background: Widespread and longterm use of benzodiazepines constitute a public health problem. Health care authorities hence advice that use should not exceed three months, in particular for the elderly and patients with a past diagnosis of drug addiction. Objectives: Estimate the shape of cessat......Background: Widespread and longterm use of benzodiazepines constitute a public health problem. Health care authorities hence advice that use should not exceed three months, in particular for the elderly and patients with a past diagnosis of drug addiction. Objectives: Estimate the shape......: While cessation rates increased significantly over time (HR: 1.104 (95% CI: 1.103; 1.105), p work in progress) Conclusions: Estimates...

  20. Estimating average glandular dose by measuring glandular rate in mammograms

    International Nuclear Information System (INIS)

    Goto, Sachiko; Azuma, Yoshiharu; Sumimoto, Tetsuhiro; Eiho, Shigeru

    2003-01-01

    The glandular rate of the breast was objectively measured in order to calculate individual patient exposure dose (average glandular dose) in mammography. By employing image processing techniques and breast-equivalent phantoms with various glandular rate values, a conversion curve for pixel value to glandular rate can be determined by a neural network. Accordingly, the pixel values in clinical mammograms can be converted to the glandular rate value for each pixel. The individual average glandular dose can therefore be calculated using the individual glandular rates on the basis of the dosimetry method employed for quality control in mammography. In the present study, a data set of 100 craniocaudal mammograms from 50 patients was used to evaluate our method. The average glandular rate and average glandular dose of the data set were 41.2% and 1.79 mGy, respectively. The error in calculating the individual glandular rate can be estimated to be less than ±3%. When the calculation error of the glandular rate is taken into consideration, the error in the individual average glandular dose can be estimated to be 13% or less. We feel that our method for determining the glandular rate from mammograms is useful for minimizing subjectivity in the evaluation of patient breast composition. (author)

  1. Distributions of component failure rates estimated from LER data

    International Nuclear Information System (INIS)

    Atwood, C.L.

    1985-01-01

    Past analyses of Licensee Event Report (LER) data have noted that component failure rates vary from plant to plant, and have estimated the distributions by two-parameter gamma distributions. In this study, a more complicated distributional form is considered, a mixture of gammas. This could arise if the plants' failure rates cluster into distinct groups. The method was applied to selected published LER data for diesel generators, pumps, valves, and instrumentation and control assemblies. The improved fits from using a mixture rather than a single gamma distribution were minimal, and not statistically significant. There seem to be two possibilities: either explanatory variables affect the failure rates only in a gradual way, not a qualitative way; or, for estimating individual component failure rates, the published LER data have been analyzed to the limit of resolution. 9 refs

  2. Distributions of component failure rates, estimated from LER data

    International Nuclear Information System (INIS)

    Atwood, C.L.

    1985-01-01

    Past analyses of Licensee Event Report (LER) data have noted that component failure rates vary from plant to plant, and have estimated the distributions by two-parameter γ distributions. In this study, a more complicated distributional form is considered, a mixture of γs. This could arise if the plants' failure rates cluster into distinct groups. The method was applied to selected published LER data for diesel generators, pumps, valves, and instrumentation and control assemblies. The improved fits from using a mixture rather than a single γ distribution were minimal, and not statistically significant. There seem to be two possibilities: either explanatory variables affect the failure rates only in a gradual way, not a qualitative way; or, for estimating individual component failure rates, the published LER data have been analyzed to the limit of resolution

  3. Prevalence of HIV in the Mthatha area of South Africa, as estimated from the testing of rape victims.

    Science.gov (United States)

    Meel, Banwari; Kwizera, Enoch

    2011-04-01

    Tremendous challenges remain in the field of HIV education, prevention and care in South Africa. There is conflicting data on the prevalence of HIV in South Africa from two major studies. Antenatal surveillance showed 29.5% prevalence whereas a household HIV survey showed a prevalence nearly half of that, at 16.2%. There is therefore a need for a third estimate in this situation. To estimate HIV prevalence in the Mthatha area of South Africa. Retrospective review of HIV testing results among victims of sexual assault who presented for the first time to the Sinawe Referral Centre, Mthatha General Hospital, for the period 2001-2005 (inclusive). Between 2001 and 2005, 1691 victims of sexual assault presented to the Sinawe Referral Centre. Of these 1435 (84.8%) were tested for HIV at the time of first consultation. One hundred and ninety-seven were found to be HIV positive on the screening test. In a space of five years (2001-2005), there was an increase in HIV prevalence from 0.9% to 6.4%. The highest HIV positive rate (3.7%) was found in the 16-20 year age group. The HIV prevalence rate is 13.7% in the Mthatha area, and just over a half (7%) of HIV-positive rape survivors were aged 16-25 years.

  4. Penetrometry and estimation of the flow rate of powder excipients.

    Science.gov (United States)

    Zatloukal, Z; Sklubalová, Z

    2007-03-01

    In this work, penetrometry with a sphere was employed to study the flow properties of non-consolidated pharmaceutical powder excipients: sodium chloride, sodium citrate, boric acid, and sorbitol. In order to estimate flow rate, the pressure of penetration in Pascals was used. Penetrometry measurement with a sphere requires modification of the measurement container, in particular by decreasing the diameter of the container, to prevent undesirable movement of material in a direction opposite to that in which the sphere penetrates. Thus penetrometry by a sphere seems to be similar to indentation by the Brinell hardness tester. The pressure of penetration was determined from the depth of penetration by analogy with the Brinell hardness number and an equation for the inter conversion of the two variables is presented. The penetration pressure allowed direct estimation of the flow rate only for those powder excipients with a size fraction in the range of 0.250-0.630 mm. Using the ratio of penetration pressure to bulk density, a polynomial quadratic equation was generated from which the flow rates for the group of all tested powders could be estimated. Finally, if the inverse ratio of bulk density and penetration pressure was used as an independent variable, the flow rate could be estimated by linear regression with the coefficient of determination r2 = 0.9941. In conclusion, using sphere penetrometry, the flow properties of non-consolidated powder samples could be investigated by indentation. As a result, a linear regression in which the flow rate was directly proportional to the powder bulk density and inversely proportional to the penetration pressure could be best recommended for the estimation of the flow rate of powder excipients.

  5. METHODICAL BASES OF ESTIMATION GLOMERULAR FILTRATION RATE IN UROLOGICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    M. M. Batiushin

    2017-01-01

    Full Text Available The article presents a review of methodological issues of estimation of glomerular filtration rate in urologic practice. Author examine the current international and national recommendations, in particular by KDIGO, the recommendations of the scientific society of nephrologists of Russia, Association of urologists of Russia, the results of comparative analysis of different methods of assessing glomerular filtration rate. It is shown that the currently calculated methods of assessment of glomerular filtration rate have advantages over technique of clearance. The advantages and disadvantages of methods for calculating glomerular filtration rate by the formula of Cockcroft-Gault and MDRD. The author lists the pathological conditions in urological practice, in which there is a need to assess glomerular filtration rate, given nomograms and links to online calculators for quick and easy calculation of glomerular filtration rate.

  6. Bayes estimation of the general hazard rate model

    International Nuclear Information System (INIS)

    Sarhan, A.

    1999-01-01

    In reliability theory and life testing models, the life time distributions are often specified by choosing a relevant hazard rate function. Here a general hazard rate function h(t)=a+bt c-1 , where c, a, b are constants greater than zero, is considered. The parameter c is assumed to be known. The Bayes estimators of (a,b) based on the data of type II/item-censored testing without replacement are obtained. A large simulation study using Monte Carlo Method is done to compare the performance of Bayes with regression estimators of (a,b). The criterion for comparison is made based on the Bayes risk associated with the respective estimator. Also, the influence of the number of failed items on the accuracy of the estimators (Bayes and regression) is investigated. Estimations for the parameters (a,b) of the linearly increasing hazard rate model h(t)=a+bt, where a, b are greater than zero, can be obtained as the special case, letting c=2

  7. Estimated Glomerular Filtration Rate and Risk of Survival in Acute ...

    African Journals Online (AJOL)

    Objective: To assess the risk of survival in acute stroke using the MDRD equation derived estimated glomerular filtration rate. Design: A prospective observational cross-sectional study. Setting: Medical wards of a tertiary care hospital. Subjects: Eighty three acute stroke patients had GFR calculated within 48 hours of ...

  8. Anthropogenic radioisotopes to estimate rates of soil redistribution by wind

    Science.gov (United States)

    Erosion of soil by wind and water is a degrading process that affects millions of hectares worldwide. Atmospheric testing of nuclear weapons and the resulting fallout of anthropogenic radioisotopes, particularly Cesium 137, has made possible the estimation of mean soil redistribution rates. The pe...

  9. Estimates of outcrossing rates in Moringa oleifera using Amplified ...

    African Journals Online (AJOL)

    The mating system in plant populations is influenced by genetic and environmental factors. Proper estimates of the outcrosing rates are often required for planning breeding programmes, conservation and management of tropical trees. However, although Moringa oleifera is adapted to a mixed mating system, the proportion ...

  10. Lidar method to estimate emission rates from extended sources

    Science.gov (United States)

    Currently, point measurements, often combined with models, are the primary means by which atmospheric emission rates are estimated from extended sources. However, these methods often fall short in their spatial and temporal resolution and accuracy. In recent years, lidar has emerged as a suitable to...

  11. Estimates of saltation threshold and erosion rates on Mars

    Science.gov (United States)

    Iversen, J. D.; White, B. R.; Greeley, R.; Pollack, J. B.

    1975-01-01

    The Mariner 9 photographs of the Martian surface include many which show crater-associated streaks caused by atmospheric winds. Due to the low density atmosphere of Mars, the wind speeds necessary to move surface particles and thus cause the streaks are apparently very high. The atmospheric-boundary-layer wind tunnel has been used to determine threshold speeds for particles of varying density and diameter and the results for small particles have been extrapolated to estimate somewhat lower threshold speeds on Mars than previous estimates. A series of streak modeling tests is used to derive an erosion-rate correlation function, which is in turn used to estimate erosion rates to the lee of some of the craters on Mars which exhibited time-dependent streak behavior during the mission.

  12. Estimating Ads’ Click through Rate with Recurrent Neural Network

    Directory of Open Access Journals (Sweden)

    Chen Qiao-Hong

    2016-01-01

    Full Text Available With the development of the Internet, online advertising spreads across every corner of the world, the ads' click through rate (CTR estimation is an important method to improve the online advertising revenue. Compared with the linear model, the nonlinear models can study much more complex relationships between a large number of nonlinear characteristics, so as to improve the accuracy of the estimation of the ads’ CTR. The recurrent neural network (RNN based on Long-Short Term Memory (LSTM is an improved model of the feedback neural network with ring structure. The model overcomes the problem of the gradient of the general RNN. Experiments show that the RNN based on LSTM exceeds the linear models, and it can effectively improve the estimation effect of the ads’ click through rate.

  13. Estimating the prevalence of chronic hepatitis B virus infection--New York City, 2008.

    Science.gov (United States)

    France, Anne Marie; Bornschlegel, Katherine; Lazaroff, Julie; Kennedy, Joseph; Balter, Sharon

    2012-04-01

    Chronic hepatitis B virus (HBV) infection is a preventable cause of liver failure, cirrhosis, and liver cancer; estimated chronic HBV infection prevalence is 0.3-0.5% in the U.S.A. Prevalence in New York City (NYC) is likely higher because foreign-born persons, who represent 36% of NYC's population versus 11% nationwide, bear a disproportionate burden of chronic HBV infection. However, because no comprehensive, population-based survey of chronic HBV infection has been conducted in NYC, a reliable prevalence estimate is unavailable. We used two approaches to estimate chronic HBV infection prevalence in NYC: (1) a census-based estimate, combining local and national prevalence data for specific populations, and (2) a surveillance-based estimate, using data from NYC's Department of Health and Mental Hygiene Hepatitis B Surveillance Registry and adjusting for out-migration and deaths. Results from both the census-based estimate and the surveillance-based estimate were similar, with an estimated prevalence of chronic HBV in NYC of 1.2%. This estimate is two to four times the estimated prevalence for the U.S.A. as a whole. According to the census-based estimate, >93% of all cases in NYC are among persons who are foreign-born, and approximately half of those are among persons born in China. These findings underscore the importance of local data for tailoring programmatic efforts to specific foreign-born populations in NYC. In particular, Chinese-language programs and health education materials are critical. Reliable estimates are important for policymakers in local jurisdictions to better understand their own population's needs and can help target primary care services, prevention materials, and education.

  14. Improving estimates of the prevalence of Female Genital Mutilation/Cutting among migrants in Western countries

    Directory of Open Access Journals (Sweden)

    Livia Elisa Ortensi

    2015-02-01

    Full Text Available Background: Female Genital Mutilation/Cutting (FGM/C is an emerging topic in immigrant countries as a consequence of the increasing proportion of African women in overseas communities. Objective: While the prevalence of FGM/C is routinely measured in practicing countries, the prevalence of the phenomenon in western countries is substantially unknown, as no standardized methods exist yet for immigrant countries. The aim of this paper is to present an improved method of indirect estimation of the prevalence of FGM/C among first generation migrants based on a migrant selection hypothesis. A criterion to assess reliability of indirect estimates is also provided. Methods: The method is based on data from Demographic Health Surveys (DHS and Multiple Indicator Cluster Surveys (MICS. Migrants' Selection Hypothesis is used to correct national prevalence estimates and obtain an improved estimation of prevalence among overseas communities. Results: The application of the selection hypothesis modifies national estimates, usually predicting a lower occurrence of FGM/C among immigrants than in their respective practicing countries. A comparison of direct and indirect estimations confirms that the method correctly predicts the direction of the variation in the expected prevalence and satisfactorily approximates direct estimates. Conclusions: Given its wide applicability, this method would be a useful instrument to estimate FGM/C occurrence among first generation immigrants and provide corresponding support for policies in countries where information from ad hoc surveys is unavailable.

  15. The effect of osteoarthritis definition on prevalence and incidence estimates: a systematic review.

    Science.gov (United States)

    Pereira, D; Peleteiro, B; Araújo, J; Branco, J; Santos, R A; Ramos, E

    2011-11-01

    To understand the differences in prevalence and incidence estimates of osteoarthritis (OA), according to case definition, in knee, hip and hand joints. A systematic review was carried out in PUBMED and SCOPUS databases comprising the date of publication period from January 1995 to February 2011. We attempted to summarise data on the incidence and prevalence of OA according to different methods of assessment: self-reported, radiographic and symptomatic OA (clinical plus radiographic). Prevalence estimates were combined through meta-analysis and between-study heterogeneity was quantified. Seventy-two papers were reviewed (nine on incidence and 63 on prevalence). Higher OA prevalences are seen when radiographic OA definition was used for all age groups. Prevalence meta-analysis showed high heterogeneity between studies even in each specific joint and using the same OA definition. Although the knee is the most studied joint, the highest OA prevalence estimates were found in hand joints. OA of the knee tends to be more prevalent in women than in men independently of the OA definition used, but no gender differences were found in hip and hand OA. Insufficient data for incidence studies didn't allow us to make any comparison according to joint site or OA definition. Radiographic case definition of OA presented the highest prevalences. Within each joint site, self-reported and symptomatic OA definitions appear to present similar estimates. The high heterogeneity found in the studies limited further conclusions. Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  16. Estimated erosion rate at the SRP burial ground

    International Nuclear Information System (INIS)

    Horton, J.H.; Wilhite, E.L.

    1978-04-01

    The rate of soil erosion at the Savannah River Plant (SRP) burial ground can be calculated by means of the universal soil loss equation. Erosion rates estimated by the equation are more suitable for long-term prediction than those which could be measured with a reasonable effort in field studies. The predicted erosion rate at the SRP burial ground ranges from 0.0007 cm/year under stable forest cover to 0.38 cm/year if farmed with cultivated crops. These values correspond to 170,000 and 320 years, respectively, to expose waste buried 4 ft deep

  17. Estimation of Eruption Source Parameters from Plume Growth Rate

    Science.gov (United States)

    Pouget, Solene; Bursik, Marcus; Webley, Peter; Dehn, Jon; Pavalonis, Michael; Singh, Tarunraj; Singla, Puneet; Patra, Abani; Pitman, Bruce; Stefanescu, Ramona; Madankan, Reza; Morton, Donald; Jones, Matthew

    2013-04-01

    The eruption of Eyjafjallajokull, Iceland in April and May, 2010, brought to light the hazards of airborne volcanic ash and the importance of Volcanic Ash Transport and Dispersion models (VATD) to estimate the concentration of ash with time. These models require Eruption Source Parameters (ESP) as input, which typically include information about the plume height, the mass eruption rate, the duration of the eruption and the particle size distribution. However much of the time these ESP are unknown or poorly known a priori. We show that the mass eruption rate can be estimated from the downwind plume or umbrella cloud growth rate. A simple version of the continuity equation can be applied to the growth of either an umbrella cloud or the downwind plume. The continuity equation coupled with the momentum equation using only inertial and gravitational terms provides another model. Numerical modeling or scaling relationships can be used, as necessary, to provide values for unknown or unavailable parameters. Use of these models applied to data on plume geometry provided by satellite imagery allows for direct estimation of plume volumetric and mass growth with time. To test our methodology, we compared our results with five well-studied and well-characterized historical eruptions: Mount St. Helens, 1980; Pinatubo, 1991, Redoubt, 1990; Hekla, 2000 and Eyjafjallajokull, 2010. These tests show that the methodologies yield results comparable to or better than currently accepted methodologies of ESP estimation. We then applied the methodology to umbrella clouds produced by the eruptions of Okmok, 12 July 2008, and Sarychev Peak, 12 June 2009, and to the downwind plume produced by the eruptions of Hekla, 2000; Kliuchevsko'i, 1 October 1994; Kasatochi 7-8 August 2008 and Bezymianny, 1 September 2012. The new methods allow a fast, remote assessment of the mass eruption rate, even for remote volcanoes. They thus provide an additional path to estimation of the ESP and the forecasting

  18. Estimation of the rate of volcanism on Venus from reaction rate measurements

    Science.gov (United States)

    Fegley, Bruce, Jr.; Prinn, Ronald G.

    1989-01-01

    Laboratory rate data for the reaction between SO2 and calcite to form anhydrite are presented. If this reaction rate represents the SO2 reaction rate on Venus, then all SO2 in the Venusian atmosphere will disappear in 1.9 Myr unless volcanism replenishes the lost SO2. The required volcanism rate, which depends on the sulfur content of the erupted material, is in the range 0.4-11 cu km of magma erupted per year. The Venus surface composition at the Venera 13, 14, and Vega 2 landing sites implies a volcanism rate of about 1 cu km/yr. This geochemically estimated rate can be used to determine if either (or neither) of two discordant geophysically estimated rates is correct. It also suggests that Venus may be less volcanically active than the earth.

  19. Estimation and Projection of Prevalence of Colorectal Cancer in Iran, 2015–2020

    Directory of Open Access Journals (Sweden)

    Hossein Molavi Vardanjani

    2018-01-01

    Full Text Available Background: Population aging and more prevalent westernized lifestyle would be expected to result in a markedly rising burden of colorectal cancer (CRC in the future years. The aim of this study is to estimate the limited-time prevalence of CRC in Iran between 2015 and 2020. Materials and Methods: Aggregated CRC incidence data were extracted from the Iranian national cancer registry (IR.NCR reports for 2003–2009 and from GLOBOCAN-2012 database for 2012. Incidence trends were analyzed by age groups, genders, histopathologic, and topographic subtypes to estimate annual percentage changes. Incidence was projected for 2020. The prevalence was estimated applying an adopted version of a previously introduced equation to estimate limited–time prevalence based on the incidence and survival data. Monte Carlo sensitivity analyses were applied to estimate 95% uncertainty levels (ULs. In each scenario, incidence, survival, annual percentage changes, and completeness of case ascertainment at IR.NCR were replaced under pre-assumed distributions. Results: Number of estimated within 1, 2-3 and 4-5-year CRC patients in 2015 were 13676 (95% UL: 10051–18807, 20964 (15835–28268, and 14485 (11188–19293, respectively. Estimated 5-year prevalence for 2020 (99463; 75150–134744 was 2.03 times of that for 2015. Highest 5-year prevalence was estimated in ages 55–59 for females and 75 + for males. Adenocarcinoma (41376; 31227 55898 was the most prevalent histologic subtype. The most prevalent tumor location was colon (30822, 23262–41638. Conclusion: A substantial growth in the prevalence of CRC survivors is highly expected for future years in Iran. Establishment of specialized institutes is highly recommended to provide medical and especially social supports for Iranian CRC survivors.

  20. Estimation and Projection of Prevalence of Colorectal Cancer in Iran, 2015-2020.

    Science.gov (United States)

    Vardanjani, Hossein Molavi; Haghdoost, AliAkbar; Bagheri-Lankarani, Kamran; Hadipour, Maryam

    2018-01-01

    Population aging and more prevalent westernized lifestyle would be expected to result in a markedly rising burden of colorectal cancer (CRC) in the future years. The aim of this study is to estimate the limited-time prevalence of CRC in Iran between 2015 and 2020. Aggregated CRC incidence data were extracted from the Iranian national cancer registry (IR.NCR) reports for 2003-2009 and from GLOBOCAN-2012 database for 2012. Incidence trends were analyzed by age groups, genders, histopathologic, and topographic subtypes to estimate annual percentage changes. Incidence was projected for 2020. The prevalence was estimated applying an adopted version of a previously introduced equation to estimate limited-time prevalence based on the incidence and survival data. Monte Carlo sensitivity analyses were applied to estimate 95% uncertainty levels (ULs). In each scenario, incidence, survival, annual percentage changes, and completeness of case ascertainment at IR.NCR were replaced under pre-assumed distributions. Number of estimated within 1, 2-3 and 4-5-year CRC patients in 2015 were 13676 (95% UL: 10051-18807), 20964 (15835-28268), and 14485 (11188-19293), respectively. Estimated 5-year prevalence for 2020 (99463; 75150-134744) was 2.03 times of that for 2015. Highest 5-year prevalence was estimated in ages 55-59 for females and 75 + for males. Adenocarcinoma (41376; 31227 55898) was the most prevalent histologic subtype. The most prevalent tumor location was colon (30822, 23262-41638). A substantial growth in the prevalence of CRC survivors is highly expected for future years in Iran. Establishment of specialized institutes is highly recommended to provide medical and especially social supports for Iranian CRC survivors.

  1. Estimation and Projection of Prevalence of Colorectal Cancer in Iran, 2015–2020

    Science.gov (United States)

    Vardanjani, Hossein Molavi; Haghdoost, AliAkbar; Bagheri-Lankarani, Kamran; Hadipour, Maryam

    2018-01-01

    Background: Population aging and more prevalent westernized lifestyle would be expected to result in a markedly rising burden of colorectal cancer (CRC) in the future years. The aim of this study is to estimate the limited-time prevalence of CRC in Iran between 2015 and 2020. Materials and Methods: Aggregated CRC incidence data were extracted from the Iranian national cancer registry (IR.NCR) reports for 2003–2009 and from GLOBOCAN-2012 database for 2012. Incidence trends were analyzed by age groups, genders, histopathologic, and topographic subtypes to estimate annual percentage changes. Incidence was projected for 2020. The prevalence was estimated applying an adopted version of a previously introduced equation to estimate limited–time prevalence based on the incidence and survival data. Monte Carlo sensitivity analyses were applied to estimate 95% uncertainty levels (ULs). In each scenario, incidence, survival, annual percentage changes, and completeness of case ascertainment at IR.NCR were replaced under pre-assumed distributions. Results: Number of estimated within 1, 2-3 and 4-5-year CRC patients in 2015 were 13676 (95% UL: 10051–18807), 20964 (15835–28268), and 14485 (11188–19293), respectively. Estimated 5-year prevalence for 2020 (99463; 75150–134744) was 2.03 times of that for 2015. Highest 5-year prevalence was estimated in ages 55–59 for females and 75 + for males. Adenocarcinoma (41376; 31227 55898) was the most prevalent histologic subtype. The most prevalent tumor location was colon (30822, 23262–41638). Conclusion: A substantial growth in the prevalence of CRC survivors is highly expected for future years in Iran. Establishment of specialized institutes is highly recommended to provide medical and especially social supports for Iranian CRC survivors. PMID:29456991

  2. High prevalence rate of left superior vena cava determined by ...

    African Journals Online (AJOL)

    2013-10-08

    Oct 8, 2013 ... persistent LSVC (6). There was a similar high prevalence, in the current study, of persistent LSVC in patients with tetralogy of. Fallot and coarctation of the aorta when compared to other studies (6, 8). This can be explained by the fact that the patient sample in the current study with these lesions was small.

  3. High prevalence rate of left superior vena cava determined by ...

    African Journals Online (AJOL)

    Background: Persistent left superior vena cava (LSVC) is one of the common anomalies of the systemic veins. Its prevalence is 0.10.3% in the general population and is more common with congenital heart disease (CHD). The importance of detecting persistent LSVC prior to cardiac surgery is paramount for systemic veins ...

  4. Likelihood of Tree Topologies with Fossils and Diversification Rate Estimation.

    Science.gov (United States)

    Didier, Gilles; Fau, Marine; Laurin, Michel

    2017-11-01

    Since the diversification process cannot be directly observed at the human scale, it has to be studied from the information available, namely the extant taxa and the fossil record. In this sense, phylogenetic trees including both extant taxa and fossils are the most complete representations of the diversification process that one can get. Such phylogenetic trees can be reconstructed from molecular and morphological data, to some extent. Among the temporal information of such phylogenetic trees, fossil ages are by far the most precisely known (divergence times are inferences calibrated mostly with fossils). We propose here a method to compute the likelihood of a phylogenetic tree with fossils in which the only considered time information is the fossil ages, and apply it to the estimation of the diversification rates from such data. Since it is required in our computation, we provide a method for determining the probability of a tree topology under the standard diversification model. Testing our approach on simulated data shows that the maximum likelihood rate estimates from the phylogenetic tree topology and the fossil dates are almost as accurate as those obtained by taking into account all the data, including the divergence times. Moreover, they are substantially more accurate than the estimates obtained only from the exact divergence times (without taking into account the fossil record). We also provide an empirical example composed of 50 Permo-Carboniferous eupelycosaur (early synapsid) taxa ranging in age from about 315 Ma (Late Carboniferous) to 270 Ma (shortly after the end of the Early Permian). Our analyses suggest a speciation (cladogenesis, or birth) rate of about 0.1 per lineage and per myr, a marginally lower extinction rate, and a considerable hidden paleobiodiversity of early synapsids. [Extinction rate; fossil ages; maximum likelihood estimation; speciation rate.]. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society

  5. Induced abortion in Tehran, Iran: estimated rates and correlates.

    Science.gov (United States)

    Erfani, Amir

    2011-09-01

    Abortion is severely restricted in Iran, and many women with an unwanted pregnancy resort to clandes-tine, unsafe abortions. Accurate information on abortion incidence is needed to assess the extent to which women ?experience unwanted pregnancies and to allocate resources for contraceptive services. Data for analysis came from 2,934 married women aged 15-49 who completed the 2009 Tehran Survey of Fertility. Estimated abortion rates and proportions of known pregnancies that end in abortion were calculated for all women and for demographic and socioeconomic subgroups, and descriptive data were used to examine women's contraceptive use and reasons for having an abortion. Annually, married women in Tehran have about 11,500 abortions. In the year before the survey, the estimated total abortion rate was 0.16 abortions per woman, and the annual general abortion rate was 5.5 abortions per 1,000 women; the general abortion rate peaked at 11.7 abortions among those aged 30-34. An estimated 8.7 of every 100 known pregnancies ended in abortion. The abortion rate was elevated among women who were employed or had high levels of income or education, as well as among those who reported a low level of religiosity, had two children or wanted no more. Fertility-related and socioeconomic reasons were cited by seven in 10 women who obtained an abortion. More than two-thirds of pregnancies that were terminated resulted from method failures among women who had used withdrawal, the pill or a condom. Estimated abortion rates and their correlates can help policymakers and program planners identify subgroups of women who are in particular need of services and counseling to prevent unwanted pregnancy.

  6. Prevalence and Predictive Value of Dyspnea Ratings in Hospitalized Patients: Pilot Studies

    Science.gov (United States)

    Stevens, Jennifer P.

    2016-01-01

    Background Dyspnea (breathing discomfort) can be as powerfully aversive as pain, yet is not routinely assessed and documented in the clinical environment. Routine identification and documentation of dyspnea is the first step to improved symptom management and it may also identify patients at risk of negative clinical outcomes. Objective To estimate the prevalence of dyspnea and of dyspnea-associated risk among hospitalized patients. Design Two pilot prospective cohort studies. Setting Single academic medical center. Patients Consecutive patients admitted to four inpatient units: cardiology, hematology/oncology, medicine, and bariatric surgery. Measurements In Study 1, nurses documented current and recent patient-reported dyspnea at the time of the Initial Patient Assessment in 581 inpatients. In Study 2, nurses documented current dyspnea at least once every nursing shift in 367 patients. We describe the prevalence of burdensome dyspnea, and compare it to pain. We also compared dyspnea ratings with a composite of adverse outcomes: 1) receipt of care from the hospital’s rapid response system, 2) transfer to the intensive care unit, or 3) death in hospital. We defined burdensome dyspnea as a rating of 4 or more on a 10-point scale. Results Prevalence of burdensome current dyspnea upon admission (Study 1) was 13% (77 of 581, 95% CI 11%-16%). Prevalence of burdensome dyspnea at some time during the hospitalization (Study 2) was 16% (57 of 367, 95% CI 12%-20%). Dyspnea was associated with higher odds of a negative outcome. Conclusions In two pilot studies, we identified a significant symptom burden of dyspnea in hospitalized patients. Patients reporting dyspnea may benefit from a more careful focus on symptom management and may represent a population at greater risk for negative outcomes. PMID:27070144

  7. The prevalence of road rage: estimates from Ontario.

    Science.gov (United States)

    Smart, Reginald G; Mann, Robert E; Stoduto, Gina

    2003-01-01

    "Road rage" has increasingly generated public concern, however, the prevalence of this behaviour has not been available. We examine the prevalence and demographic correlates of road rage victimization and perpetration based on a population survey of adults in Ontario. Data are based on the CAMH Monitor, a repeated cross-sectional telephone survey of Ontario adults (n = 1,395). The contribution of demographic factors to road rage was examined with logistic regression analysis. About half of respondents (46.6%) were shouted at, cursed at or had rude gestures directed at them in the past year, and 7.2% were threatened with damage to their vehicle or personal injury. Nearly a third of respondents (31.7%) admitted to shouting, cursing, etc. at someone, and 2.1% threatened to hurt someone or damage their vehicle. Being a Toronto resident, being younger, and earning a higher income were associated with greater likelihood of being a victim of shouting, cursing and rude gestures; however, income was not associated with being threatened with vehicle damage or injury. The likelihood of admitting to shouting, etc. at someone was greater for males, younger respondents, Toronto residents, higher income earners, and never married respondents; however, threatening someone was associated with younger age and lower education level. These results provide a first indication of the prevalence of road rage in Ontario. Road rage, in its milder forms, appears to be common, involving between a third and a half of respondents as either a victim or a perpetrator. Nearly 1 in 10 Ontario residents were threatened with damage or personal injury.

  8. Estimating contaminant discharge rates from stabilized uranium tailings embankments

    International Nuclear Information System (INIS)

    Weber, M.F.

    1986-01-01

    Estimates of contaminant discharge rates from stabilized uranium tailings embankments are essential in evaluating long-term impacts of tailings disposal on groundwater resources. Contaminant discharge rates are a function of water flux through tailings covers, the mass and distribution of tailings, and the concentrations of contaminants in percolating pore fluids. Simple calculations, laboratory and field testing, and analytical and numerical modeling may be used to estimate water flux through variably-saturated tailings under steady-state conditions, which develop after consolidation and dewatering have essentially ceased. Contaminant concentrations in water discharging from the tailings depend on tailings composition, leachability and solubility of contaminants, geochemical conditions within the embankment, tailings-water interactions, and flux of water through the embankment. These concentrations may be estimated based on maximum reported concentrations, pore water concentrations, extrapolations of column leaching data, or geochemical equilibria and reaction pathway modeling. Attempts to estimate contaminant discharge rates should begin with simple, conservative calculations and progress to more-complicated approaches, as necessary

  9. Rating curve estimation of nutrient loads in Iowa rivers

    Science.gov (United States)

    Stenback, G.A.; Crumpton, W.G.; Schilling, K.E.; Helmers, M.J.

    2011-01-01

    Accurate estimation of nutrient loads in rivers and streams is critical for many applications including determination of sources of nutrient loads in watersheds, evaluating long-term trends in loads, and estimating loading to downstream waterbodies. Since in many cases nutrient concentrations are measured on a weekly or monthly frequency, there is a need to estimate concentration and loads during periods when no data is available. The objectives of this study were to: (i) document the performance of a multiple regression model to predict loads of nitrate and total phosphorus (TP) in Iowa rivers and streams; (ii) determine whether there is any systematic bias in the load prediction estimates for nitrate and TP; and (iii) evaluate streamflow and concentration factors that could affect the load prediction efficiency. A commonly cited rating curve regression is utilized to estimate riverine nitrate and TP loads for rivers in Iowa with watershed areas ranging from 17.4 to over 34,600km2. Forty-nine nitrate and 44 TP datasets each comprising 5-22years of approximately weekly to monthly concentrations were examined. Three nitrate data sets had sample collection frequencies averaging about three samples per week. The accuracy and precision of annual and long term riverine load prediction was assessed by direct comparison of rating curve load predictions with observed daily loads. Significant positive bias of annual and long term nitrate loads was detected. Long term rating curve nitrate load predictions exceeded observed loads by 25% or more at 33% of the 49 measurement sites. No bias was found for TP load prediction although 15% of the 44 cases either underestimated or overestimate observed long-term loads by more than 25%. The rating curve was found to poorly characterize nitrate and phosphorus variation in some rivers. ?? 2010 .

  10. Application of a conversion factor to estimate the adenoma detection rate from the polyp detection rate.

    LENUS (Irish Health Repository)

    Francis, Dawn L

    2011-03-01

    The adenoma detection rate (ADR) is a quality benchmark for colonoscopy. Many practices find it difficult to determine the ADR because it requires a combination of endoscopic and histologic findings. It may be possible to apply a conversion factor to estimate the ADR from the polyp detection rate (PDR).

  11. Pooling overdispersed binomial data to estimate event rate.

    Science.gov (United States)

    Young-Xu, Yinong; Chan, K Arnold

    2008-08-19

    The beta-binomial model is one of the methods that can be used to validly combine event rates from overdispersed binomial data. Our objective is to provide a full description of this method and to update and broaden its applications in clinical and public health research. We describe the statistical theories behind the beta-binomial model and the associated estimation methods. We supply information about statistical software that can provide beta-binomial estimations. Using a published example, we illustrate the application of the beta-binomial model when pooling overdispersed binomial data. In an example regarding the safety of oral antifungal treatments, we had 41 treatment arms with event rates varying from 0% to 13.89%. Using the beta-binomial model, we obtained a summary event rate of 3.44% with a standard error of 0.59%. The parameters of the beta-binomial model took the values of 1.24 for alpha and 34.73 for beta. The beta-binomial model can provide a robust estimate for the summary event rate by pooling overdispersed binomial data from different studies. The explanation of the method and the demonstration of its applications should help researchers incorporate the beta-binomial method as they aggregate probabilities of events from heterogeneous studies.

  12. Pooling overdispersed binomial data to estimate event rate

    Directory of Open Access Journals (Sweden)

    Chan K Arnold

    2008-08-01

    Full Text Available Abstract Background The beta-binomial model is one of the methods that can be used to validly combine event rates from overdispersed binomial data. Our objective is to provide a full description of this method and to update and broaden its applications in clinical and public health research. Methods We describe the statistical theories behind the beta-binomial model and the associated estimation methods. We supply information about statistical software that can provide beta-binomial estimations. Using a published example, we illustrate the application of the beta-binomial model when pooling overdispersed binomial data. Results In an example regarding the safety of oral antifungal treatments, we had 41 treatment arms with event rates varying from 0% to 13.89%. Using the beta-binomial model, we obtained a summary event rate of 3.44% with a standard error of 0.59%. The parameters of the beta-binomial model took the values of 1.24 for alpha and 34.73 for beta. Conclusion The beta-binomial model can provide a robust estimate for the summary event rate by pooling overdispersed binomial data from different studies. The explanation of the method and the demonstration of its applications should help researchers incorporate the beta-binomial method as they aggregate probabilities of events from heterogeneous studies.

  13. Hepatitis C prevalence in Denmark -an estimate based on multiple national registers

    DEFF Research Database (Denmark)

    Christensen, Peer Brehm; Hay, Gordon; Jepsen, Peter

    2012-01-01

    A national survey for chronic hepatitis C has not been performed in Denmark and the prevalence is unknown. Our aim was to estimate the prevalence of chronic hepatitis C from public registers and the proportion of these patients who received specialized healthcare....

  14. Rate of Penetration Optimization using Moving Horizon Estimation

    Directory of Open Access Journals (Sweden)

    Dan Sui

    2016-07-01

    Full Text Available Increase of drilling safety and reduction of drilling operation costs, especially improvement of drilling efficiency, are two important considerations in the oil and gas industry. The rate of penetration (ROP, alternatively called as drilling speed is a critical drilling parameter to evaluate and improve drilling safety and efficiency. ROP estimation has an important role in drilling optimization as well as interpretation of all stages of the well life cycle. In this paper, we use a moving horizon estimation (MHE method to estimate ROP as well as other drilling parameters. In the MHE formulation the states are estimated by a forward simulation with a pre-estimating observer. Moreover, it considers the constraints of states/outputs in the MHE problem. It is shown that the estimation error is with input-to-state stability. Furthermore, the ROP optimization (to achieve minimum drilling cost/drilling energy concerning with the efficient hole cleaning condition and downhole environmental stability is presented. The performance of the methodology is demonstrated by one case study.

  15. A nonparametric mixture model for cure rate estimation.

    Science.gov (United States)

    Peng, Y; Dear, K B

    2000-03-01

    Nonparametric methods have attracted less attention than their parametric counterparts for cure rate analysis. In this paper, we study a general nonparametric mixture model. The proportional hazards assumption is employed in modeling the effect of covariates on the failure time of patients who are not cured. The EM algorithm, the marginal likelihood approach, and multiple imputations are employed to estimate parameters of interest in the model. This model extends models and improves estimation methods proposed by other researchers. It also extends Cox's proportional hazards regression model by allowing a proportion of event-free patients and investigating covariate effects on that proportion. The model and its estimation method are investigated by simulations. An application to breast cancer data, including comparisons with previous analyses using a parametric model and an existing nonparametric model by other researchers, confirms the conclusions from the parametric model but not those from the existing nonparametric model.

  16. Counting and confusion: Bayesian rate estimation with multiple populations

    Science.gov (United States)

    Farr, Will M.; Gair, Jonathan R.; Mandel, Ilya; Cutler, Curt

    2015-01-01

    We show how to obtain a Bayesian estimate of the rates or numbers of signal and background events from a set of events when the shapes of the signal and background distributions are known, can be estimated, or approximated; our method works well even if the foreground and background event distributions overlap significantly and the nature of any individual event cannot be determined with any certainty. We give examples of determining the rates of gravitational-wave events in the presence of background triggers from a template bank when noise parameters are known and/or can be fit from the trigger data. We also give an example of determining globular-cluster shape, location, and density from an observation of a stellar field that contains a nonuniform background density of stars superimposed on the cluster stars.

  17. Fast Rate Estimation for RDO Mode Decision in HEVC

    Directory of Open Access Journals (Sweden)

    Maxim P. Sharabayko

    2014-12-01

    Full Text Available The latter-day H.265/HEVC video compression standard is able to provide two-times higher compression efficiency compared to the current industrial standard, H.264/AVC. However, coding complexity also increased. The main bottleneck of the compression process is the rate-distortion optimization (RDO stage, as it involves numerous sequential syntax-based binary arithmetic coding (SBAC loops. In this paper, we present an entropy-based RDO estimation technique for H.265/HEVC compression, instead of the common approach based on the SBAC. Our RDO implementation reduces RDO complexity, providing an average bit rate overhead of 1.54%. At the same time, elimination of the SBAC from the RDO estimation reduces block interdependencies, thus providing an opportunity for the development of the compression system with parallel processing of multiple blocks of a video frame.

  18. Precise estimates of mutation rate and spectrum in yeast

    Science.gov (United States)

    Zhu, Yuan O.; Siegal, Mark L.; Hall, David W.; Petrov, Dmitri A.

    2014-01-01

    Mutation is the ultimate source of genetic variation. The most direct and unbiased method of studying spontaneous mutations is via mutation accumulation (MA) lines. Until recently, MA experiments were limited by the cost of sequencing and thus provided us with small numbers of mutational events and therefore imprecise estimates of rates and patterns of mutation. We used whole-genome sequencing to identify nearly 1,000 spontaneous mutation events accumulated over ∼311,000 generations in 145 diploid MA lines of the budding yeast Saccharomyces cerevisiae. MA experiments are usually assumed to have negligible levels of selection, but even mild selection will remove strongly deleterious events. We take advantage of such patterns of selection and show that mutation classes such as indels and aneuploidies (especially monosomies) are proportionately much more likely to contribute mutations of large effect. We also provide conservative estimates of indel, aneuploidy, environment-dependent dominant lethal, and recessive lethal mutation rates. To our knowledge, for the first time in yeast MA data, we identified a sufficiently large number of single-nucleotide mutations to measure context-dependent mutation rates and were able to (i) confirm strong AT bias of mutation in yeast driven by high rate of mutations from C/G to T/A and (ii) detect a higher rate of mutation at C/G nucleotides in two specific contexts consistent with cytosine methylation in S. cerevisiae. PMID:24847077

  19. Robust efficient estimation of heart rate pulse from video

    Science.gov (United States)

    Xu, Shuchang; Sun, Lingyun; Rohde, Gustavo Kunde

    2014-01-01

    We describe a simple but robust algorithm for estimating the heart rate pulse from video sequences containing human skin in real time. Based on a model of light interaction with human skin, we define the change of blood concentration due to arterial pulsation as a pixel quotient in log space, and successfully use the derived signal for computing the pulse heart rate. Various experiments with different cameras, different illumination condition, and different skin locations were conducted to demonstrate the effectiveness and robustness of the proposed algorithm. Examples computed with normal illumination show the algorithm is comparable with pulse oximeter devices both in accuracy and sensitivity. PMID:24761294

  20. The estimation of recombination rates from population genetic data

    OpenAIRE

    2007-01-01

    Genetic recombination is an important process that generates new combinations of genes on which natural selection can operate. As such, an understanding of recombination in the human genome will provide insight into the evolutionary processes that have shaped our genetic history. The aim of this thesis is to use samples of population genetic data to explore the patterns of variation in the rate of recombination in the human genome. To do this I introduce a novel means of estimating recombinat...

  1. Estimating Effective Subsidy Rates of Student Aid Programs

    OpenAIRE

    Stacey H. CHEN

    2008-01-01

    Every year millions of high school students and their parents in the US are asked to fill out complicated financial aid application forms. However, few studies have estimated the responsiveness of government financial aid schemes to changes in financial needs of the students. This paper identifies the effective subsidy rate (ESR) of student aid, as defined by the coefficient of financial needs in the regression of financial aid. The ESR measures the proportion of subsidy of student aid under ...

  2. EQUILIBRIUM REAL EXCHANGE RATE IN BRAZIL ESTIMATION AND POLICY IMPLICATIONS

    OpenAIRE

    Thierry Buchs

    2005-01-01

    This paper examines the determinants of the real effective exchange rate (REER) in Brazil, from 1994 to 2003. Building on a standard theoretical model and based on the Johansen cointegration estimation, the main finding is that much of the long-run behavior of the REER can be explained by relative productivity differentials, real commodity prices, government expenditures on tradables and non-tradables, trade openness and real interest differentials. On the basis of these fundamentals, the lev...

  3. A simple method for the estimation of glomerular filtration rate

    International Nuclear Information System (INIS)

    Groth, T.; Tengstroem, B.

    1977-01-01

    A simple method is presented for indirect estimation of the glomerular filtration rate from two venous blood samples, drawn after a single injection of a small dose of [ 125 I]sodium iothalamate (10 μCi). The method does not require exact dosage, as the first sample, taken after a few minutes (t=5 min) after injection, is used to normilize the value of the second sample, which should be taken in between 2-4 h after injection. The glomerular filtration rate, as measured by standard inulin clearance, may then be predicted from the logarithm of the normalized value and linear regression formulas with a standard error of estimate of the order of 1-2 ml/min/1.73 m 2 . The slope-intercept method for direct estimation of glomerular filtration rate is also evaluated and found to significantly underestimate standard insulin clearance. The normalized 'single-point' method is concluded to be superior to the slope-intercept method and more sophisticated methods using curve fitting technique, with regard to predictive force and clinical applicability. (Auth.)

  4. Phylogenetic estimates of diversification rate are affected by molecular rate variation.

    Science.gov (United States)

    Duchêne, D A; Hua, X; Bromham, L

    2017-10-01

    Molecular phylogenies are increasingly being used to investigate the patterns and mechanisms of macroevolution. In particular, node heights in a phylogeny can be used to detect changes in rates of diversification over time. Such analyses rest on the assumption that node heights in a phylogeny represent the timing of diversification events, which in turn rests on the assumption that evolutionary time can be accurately predicted from DNA sequence divergence. But there are many influences on the rate of molecular evolution, which might also influence node heights in molecular phylogenies, and thus affect estimates of diversification rate. In particular, a growing number of studies have revealed an association between the net diversification rate estimated from phylogenies and the rate of molecular evolution. Such an association might, by influencing the relative position of node heights, systematically bias estimates of diversification time. We simulated the evolution of DNA sequences under several scenarios where rates of diversification and molecular evolution vary through time, including models where diversification and molecular evolutionary rates are linked. We show that commonly used methods, including metric-based, likelihood and Bayesian approaches, can have a low power to identify changes in diversification rate when molecular substitution rates vary. Furthermore, the association between the rates of speciation and molecular evolution rate can cause the signature of a slowdown or speedup in speciation rates to be lost or misidentified. These results suggest that the multiple sources of variation in molecular evolutionary rates need to be considered when inferring macroevolutionary processes from phylogenies. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  5. Probabilistic estimation of residential air exchange rates for ...

    Science.gov (United States)

    Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER measurements. An algorithm for probabilistically estimating AER was developed based on the Lawrence Berkley National Laboratory Infiltration model utilizing housing characteristics and meteorological data with adjustment for window opening behavior. The algorithm was evaluated by comparing modeled and measured AERs in four US cities (Los Angeles, CA; Detroit, MI; Elizabeth, NJ; and Houston, TX) inputting study-specific data. The impact on the modeled AER of using publically available housing data representative of the region for each city was also assessed. Finally, modeled AER based on region-specific inputs was compared with those estimated using literature-based distributions. While modeled AERs were similar in magnitude to the measured AER they were consistently lower for all cities except Houston. AERs estimated using region-specific inputs were lower than those using study-specific inputs due to differences in window opening probabilities. The algorithm produced more spatially and temporally variable AERs compared with literature-based distributions reflecting within- and between-city differences, helping reduce error in estimates of air pollutant exposure. Published in the Journal of

  6. A prospective longitudinal study to estimate the prevalence of ...

    African Journals Online (AJOL)

    Sally S. Zahra

    2016-05-13

    May 13, 2016 ... Abstract Purpose: Nocturnal enuresis is defined as the involuntary voiding of urine in bed beyond the age at which bladder control is normally obtained. Previous studies have suggested a high rate of obesity in children with nocturnal enuresis. We evaluated this hypothesis and investi- gated the correlation ...

  7. Estimation of the prevalence of adverse drug reactions from social media.

    Science.gov (United States)

    Nguyen, Thin; Larsen, Mark E; O'Dea, Bridianne; Phung, Dinh; Venkatesh, Svetha; Christensen, Helen

    2017-06-01

    This work aims to estimate the degree of adverse drug reactions (ADR) for psychiatric medications from social media, including Twitter, Reddit, and LiveJournal. Advances in lightning-fast cluster computing was employed to process large scale data, consisting of 6.4 terabytes of data containing 3.8 billion records from all the media. Rates of ADR were quantified using the SIDER database of drugs and side-effects, and an estimated ADR rate was based on the prevalence of discussion in the social media corpora. Agreement between these measures for a sample of ten popular psychiatric drugs was evaluated using the Pearson correlation coefficient, r, with values between 0.08 and 0.50. Word2vec, a novel neural learning framework, was utilized to improve the coverage of variants of ADR terms in the unstructured text by identifying syntactically or semantically similar terms. Improved correlation coefficients, between 0.29 and 0.59, demonstrates the capability of advanced techniques in machine learning to aid in the discovery of meaningful patterns from medical data, and social media data, at scale. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Spatially Interpolated Disease Prevalence Estimation Using Collateral Indicators of Morbidity and Ecological Risk

    Directory of Open Access Journals (Sweden)

    Peter Congdon

    2013-10-01

    Full Text Available This paper considers estimation of disease prevalence for small areas (neighbourhoods when the available observations on prevalence are for an alternative partition of a region, such as service areas. Interpolation to neighbourhoods uses a kernel method extended to take account of two types of collateral information. The first is morbidity and service use data, such as hospital admissions, observed for neighbourhoods. Variations in morbidity and service use are expected to reflect prevalence. The second type of collateral information is ecological risk factors (e.g., pollution indices that are expected to explain variability in prevalence in service areas, but are typically observed only for neighbourhoods. An application involves estimating neighbourhood asthma prevalence in a London health region involving 562 neighbourhoods and 189 service (primary care areas.

  9. Spatially interpolated disease prevalence estimation using collateral indicators of morbidity and ecological risk.

    Science.gov (United States)

    Congdon, Peter

    2013-10-14

    This paper considers estimation of disease prevalence for small areas (neighbourhoods) when the available observations on prevalence are for an alternative partition of a region, such as service areas. Interpolation to neighbourhoods uses a kernel method extended to take account of two types of collateral information. The first is morbidity and service use data, such as hospital admissions, observed for neighbourhoods. Variations in morbidity and service use are expected to reflect prevalence. The second type of collateral information is ecological risk factors (e.g., pollution indices) that are expected to explain variability in prevalence in service areas, but are typically observed only for neighbourhoods. An application involves estimating neighbourhood asthma prevalence in a London health region involving 562 neighbourhoods and 189 service (primary care) areas.

  10. Estimating marginal CO2 emissions rates for national electricity systems

    International Nuclear Information System (INIS)

    Hawkes, A.D.

    2010-01-01

    The carbon dioxide (CO 2 ) emissions reduction afforded by a demand-side intervention in the electricity system is typically assessed by means of an assumed grid emissions rate, which measures the CO 2 intensity of electricity not used as a result of the intervention. This emissions rate is called the 'marginal emissions factor' (MEF). Accurate estimation of MEFs is crucial for performance assessment because their application leads to decisions regarding the relative merits of CO 2 reduction strategies. This article contributes to formulating the principles by which MEFs are estimated, highlighting the strengths and weaknesses in existing approaches, and presenting an alternative based on the observed behaviour of power stations. The case of Great Britain is considered, demonstrating an MEF of 0.69 kgCO 2 /kW h for 2002-2009, with error bars at +/-10%. This value could reduce to 0.6 kgCO 2 /kW h over the next decade under planned changes to the underlying generation mix, and could further reduce to approximately 0.51 kgCO 2 /kW h before 2025 if all power stations commissioned pre-1970 are replaced by their modern counterparts. Given that these rates are higher than commonly applied system-average or assumed 'long term marginal' emissions rates, it is concluded that maintenance of an improved understanding of MEFs is valuable to better inform policy decisions.

  11. Molecular prevalence and estimated risk of cutaneous leishmaniasis in Libya.

    Science.gov (United States)

    El-Badry, Ayman A; El-Dwibe, Hamida; Basyoni, Maha M A; Al-Antably, Abeer S A; Al-Bashier, Wafaa A

    2017-12-01

    Cutanoeus leishmaniasis (CL) is an endemic disease in the Mediterranean area including Libya. The aim of the present study is to detect the prevalent Leishmania species obtained from smeared cutaneous lesions in addition to studying the diverse sociodemographic risk factors of the reported cases from different provinces of Libya. A total of 250 archived microscopic slides from clinically suspected cases of CL attending the leishmaniasis clinic in the Dermatology Department, Tripoli Central Hospital, Tripoli, Libya, were microscopically examined. Leishmania-DNA was amplified using combined polymerase chain reaction (PCR) targeting kinetoplast-DNA (kDNA) and ribosomal internal transcribed spacer 1 (ITS1)-DNA with restriction fragment length polymorphism analysis for direct Leishmania species identification. Using kDNA and ITS1-PCR, 22.5% and 20% of cases were positive, respectively. Only 14.4% of cases were positive using microscopy. Nominating ITS1-PCR as the reference standard, kDNA-PCR assay was highly sensitive while microscopy was 100% specific but of limited sensitivity (72%) with a substantial agreement and an overall accuracy of 94.4%. Leishmania major and Leishmania tropica were the predominant species reported from the north-western provinces including Tripoli, Zintan, and Gharyan with their related subprovinces; Asabaa, Mizdan, Alkawasem, and Alorban. CL prevailed more among men and residents of rural areas. House wives and students were the most affected professions. Children were the least affected, while the middle-aged were the most affected age group. L. major and L. tropica are the predominant species in the north-western regions of Libya. ITS1-PCR-restriction fragment length polymorphism assay offered a sensitive, specific, and faster diagnostic method especially with negative parasitologic examination. Copyright © 2016. Published by Elsevier B.V.

  12. Molecular prevalence and estimated risk of cutaneous leishmaniasis in Libya

    Directory of Open Access Journals (Sweden)

    Ayman A. El-Badry

    2017-12-01

    Full Text Available Background/Purpose: Cutanoeus leishmaniasis (CL is an endemic disease in the Mediterranean area including Libya. The aim of the present study is to detect the prevalent Leishmania species obtained from smeared cutaneous lesions in addition to studying the diverse sociodemographic risk factors of the reported cases from different provinces of Libya. Methods: A total of 250 archived microscopic slides from clinically suspected cases of CL attending the leishmaniasis clinic in the Dermatology Department, Tripoli Central Hospital, Tripoli, Libya, were microscopically examined. Leishmania-DNA was amplified using combined polymerase chain reaction (PCR targeting kinetoplast-DNA (kDNA and ribosomal internal transcribed spacer 1 (ITS1-DNA with restriction fragment length polymorphism analysis for direct Leishmania species identification. Results: Using kDNA and ITS1-PCR, 22.5% and 20% of cases were positive, respectively. Only 14.4% of cases were positive using microscopy. Nominating ITS1-PCR as the reference standard, kDNA-PCR assay was highly sensitive while microscopy was 100% specific but of limited sensitivity (72% with a substantial agreement and an overall accuracy of 94.4%. Leishmania major and Leishmania tropica were the predominant species reported from the north-western provinces including Tripoli, Zintan, and Gharyan with their related subprovinces; Asabaa, Mizdan, Alkawasem, and Alorban. CL prevailed more among men and residents of rural areas. House wives and students were the most affected professions. Children were the least affected, while the middle-aged were the most affected age group. Conclusion: L. major and L. tropica are the predominant species in the north-western regions of Libya. ITS1-PCR-restriction fragment length polymorphism assay offered a sensitive, specific, and faster diagnostic method especially with negative parasitologic examination. Keywords: Archived microscopic slides, Cutaneous leishmaniasis, ITS1-PCR, kDNA-PCR

  13. Can we estimate bacterial growth rates from ribosomal RNA content?

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, P.F.

    1995-12-31

    Several studies have demonstrated a strong relationship between the quantity of RNA in bacterial cells and their growth rate under laboratory conditions. It may be possible to use this relationship to provide information on the activity of natural bacterial communities, and in particular on growth rate. However, if this approach is to provide reliably interpretable information, the relationship between RNA content and growth rate must be well-understood. In particular, a requisite of such applications is that the relationship must be universal among bacteria, or alternately that the relationship can be determined and measured for specific bacterial taxa. The RNA-growth rate relationship has not been used to evaluate bacterial growth in field studies, although RNA content has been measured in single cells and in bulk extracts of field samples taken from coastal environments. These measurements have been treated as probable indicators of bacterial activity, but have not yet been interpreted as estimators of growth rate. The primary obstacle to such interpretations is a lack of information on biological and environmental factors that affect the RNA-growth rate relationship. In this paper, the available data on the RNA-growth rate relationship in bacteria will be reviewed, including hypotheses regarding the regulation of RNA synthesis and degradation as a function of growth rate and environmental factors; i.e. the basic mechanisms for maintaining RNA content in proportion to growth rate. An assessment of the published laboratory and field data, the current status of this research area, and some of the remaining questions will be presented.

  14. Redefinition and global estimation of basal ecosystem respiration rate

    Science.gov (United States)

    Yuan, W.; Luo, Y.; Li, X.; Liu, S.; Yu, G.; Zhou, T.; Bahn, M.; Black, A.; Desai, A.R.; Cescatti, A.; Marcolla, B.; Jacobs, C.; Chen, J.; Aurela, M.; Bernhofer, C.; Gielen, B.; Bohrer, G.; Cook, D.R.; Dragoni, D.; Dunn, A.L.; Gianelle, D.; Grnwald, T.; Ibrom, A.; Leclerc, M.Y.; Lindroth, A.; Liu, H.; Marchesini, L.B.; Montagnani, L.; Pita, G.; Rodeghiero, M.; Rodrigues, A.; Starr, G.; Stoy, Paul C.

    2011-01-01

    Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still use a global constant BR largely due to the lack of a functional description for BR. In this study, we redefined BR to be ecosystem respiration rate at the mean annual temperature. To test the validity of this concept, we conducted a synthesis analysis using 276 site-years of eddy covariance data, from 79 research sites located at latitudes ranging from ∼3°S to ∼70°N. Results showed that mean annual ER rate closely matches ER rate at mean annual temperature. Incorporation of site-specific BR into global ER model substantially improved simulated ER compared to an invariant BR at all sites. These results confirm that ER at the mean annual temperature can be considered as BR in empirical models. A strong correlation was found between the mean annual ER and mean annual gross primary production (GPP). Consequently, GPP, which is typically more accurately modeled, can be used to estimate BR. A light use efficiency GPP model (i.e., EC-LUE) was applied to estimate global GPP, BR and ER with input data from MERRA (Modern Era Retrospective-Analysis for Research and Applications) and MODIS (Moderate resolution Imaging Spectroradiometer). The global ER was 103 Pg C yr −1, with the highest respiration rate over tropical forests and the lowest value in dry and high-latitude areas.

  15. Estimation of evapotranspiration rate in irrigated lands using stable isotopes

    Science.gov (United States)

    Umirzakov, Gulomjon; Windhorst, David; Forkutsa, Irina; Brauer, Lutz; Frede, Hans-Georg

    2013-04-01

    Agriculture in the Aral Sea basin is the main consumer of water resources and due to the current agricultural management practices inefficient water usage causes huge losses of freshwater resources. There is huge potential to save water resources in order to reach a more efficient water use in irrigated areas. Therefore, research is required to reveal the mechanisms of hydrological fluxes in irrigated areas. This paper focuses on estimation of evapotranspiration which is one of the crucial components in the water balance of irrigated lands. Our main objective is to estimate the rate of evapotranspiration on irrigated lands and partitioning of evaporation into transpiration using stable isotopes measurements. Experiments has done in 2 different soil types (sandy and sandy loam) irrigated areas in Ferghana Valley (Uzbekistan). Soil samples were collected during the vegetation period. The soil water from these samples was extracted via a cryogenic extraction method and analyzed for the isotopic ratio of the water isotopes (2H and 18O) based on a laser spectroscopy method (DLT 100, Los Gatos USA). Evapotranspiration rates were estimated with Isotope Mass Balance method. The results of evapotranspiration obtained using isotope mass balance method is compared with the results of Catchment Modeling Framework -1D model results which has done in the same area and the same time.

  16. Estimating prevalence of accumulated HIV-1 drug resistance in a cohort of patients on antiretroviral therapy

    DEFF Research Database (Denmark)

    Bannister, Wendy P; Cozzi-Lepri, Alessandro; Kjær, Jesper

    2011-01-01

    Estimating the prevalence of accumulated HIV drug resistance in patients receiving antiretroviral therapy (ART) is difficult due to lack of resistance testing at all occasions of virological failure and in patients with undetectable viral load. A method to estimate this for 6498 EuroSIDA patients...

  17. The SOGS-RA vs. the MAGS-7: prevalence estimates and classification congruence.

    Science.gov (United States)

    Langhinrichsen-Rohling, Jennifer; Rohling, Martin L; Rohde, Paul; Seeley, John R

    2004-01-01

    The purpose of this study was to compare the prevalence rate estimates and congruence in classification status derived from two popular measures of adolescent gambling (SOGS-RA and MAGS-7). Adolescents from three states (Alabama, Mississippi, and Oregon) completed an anonymous questionnaire ( n =1846 high school students total). Results indicate that the prevalence of probable adolescent pathological gambling varied both as a function of instrument and cut-off point utilized for classification (range 1.7%-8.2%). Classification groups (non-problem, at-risk, and problem gamblers) generated by both instruments were found to be associated with reports of gambling frequency, amount of money lost in one gambling occasion, and parental gambling problems. However, concern was raised because the MAGS-7 and the SOGS-RA had little congruence in their three-group classification decisions for specific individuals (e.g., only 20.5% agreement for problem gamblers). To improve clinical utility, an empirical case was made for using the SOGS-RA to generate a fourth group of adolescent gamblers, which we labeled "probable pathological gamblers" (SOGS-RA > or = 6). This group was differentiated from the remaining gambling groups on all the validity indices. The implications and limitations of these findings, as well as future directions, are discussed.

  18. Estimating the prevalence of hepatitis C infection in New York City using surveillance data.

    Science.gov (United States)

    Balter, S; Stark, J H; Kennedy, J; Bornschlegel, K; Konty, K

    2014-02-01

    Hepatitis C virus is the most common chronic blood-borne infection in the USA. Based on results of a serosurvey, national prevalence is estimated to be 1·3% or 3·2 million people. Sub-national estimates are not available for most jurisdictions. Hepatitis C surveillance data was adjusted for death, out-migration, under-diagnosis, and undetectable blood RNA, to estimate prevalence in New York City (NYC). The prevalence of hepatitis C infection in adults aged ⩾20 years in NYC is 2·37% (range 1·53-4·90%) or 146 500 cases of hepatitis C. This analysis presents a mechanism for generating prevalence estimates using local surveillance data accounting for biases and difficulty in accessing hard to reach populations. As the cohort of patients with hepatitis C age and require additional medical care, local public health officials will need a method to generate prevalence estimates to allocate resources. This approach can serve as a guideline for generating local estimates using surveillance data that is less resource prohibitive.

  19. Equations to estimate creatinine excretion rate: the CKD epidemiology collaboration.

    Science.gov (United States)

    Ix, Joachim H; Wassel, Christina L; Stevens, Lesley A; Beck, Gerald J; Froissart, Marc; Navis, Gerjan; Rodby, Roger; Torres, Vicente E; Zhang, Yaping Lucy; Greene, Tom; Levey, Andrew S

    2011-01-01

    Creatinine excretion rate (CER) indicates timed urine collection accuracy. Although equations to estimate CER exist, their bias and precision are untested and none simultaneously include age, sex, race, and weight. Participants (n = 2466) from three kidney disease trials were randomly allocated into equation development (2/3) and internal validation (1/3) data sets. CER served as the dependent variable in linear regression to develop new equations. Their stability was assessed within the internal validation data set. Among 987 individuals from three additional studies the equations were externally validated and compared with existing equations. Mean age was 46 years, 42% were women, and 9% were black. Age, sex, race, weight, and serum phosphorus improved model fit. Two equations were developed, with or without serum phosphorus. In external validation, the new equations showed little bias (mean difference [measured - estimated CER] -0.7% [95% confidence interval -2.5% to 1.0%] and 0.3% [95% confidence interval -2.6% to 3.1%], respectively) and moderate precision (estimated CER within 30% of measured CER among 79% [76% to 81%] and 81% [77% to 85%], respectively). Corresponding numbers within 15% were 51% [48% to 54%] and 54% [50% to 59%]). Compared with existing equations, the new equations had similar accuracy but showed less bias in individuals with high measured CER. CER can be estimated with commonly available variables with little bias and moderate precision, which may facilitate assessment of accuracy of timed urine collections.

  20. An estimate of the prevalence of biocompatible and habitable planets.

    Science.gov (United States)

    Fogg, M J

    1992-01-01

    A Monte Carlo computer model of extra-solar planetary formation and evolution, which includes the planetary geochemical carbon cycle, is presented. The results of a run of one million galactic disc stars are shown where the aim was to assess the possible abundance of both biocompatible and habitable planets. (Biocompatible planets are defined as worlds where the long-term presence of surface liquid water provides environmental conditions suitable for the origin and evolution of life. Habitable planets are those worlds with more specifically Earthlike conditions). The model gives an estimate of 1 biocompatible planet per 39 stars, with the subset of habitable planets being much rarer at 1 such planet per 413 stars. The nearest biocompatible planet may thus lie approximately 14 LY distant and the nearest habitable planet approximately 31 LY away. If planets form in multiple star systems then the above planet/star ratios may be more than doubled. By applying the results to stars in the solar neighbourhood, it is possible to identify 28 stars at distances of < 22 LY with a non-zero probability of possessing a biocompatible planet.

  1. [Estimating glomerular filtration rate in 2012: which adding value for the CKD-EPI equation?].

    Science.gov (United States)

    Delanaye, Pierre; Mariat, Christophe; Moranne, Olivier; Cavalier, Etienne; Flamant, Martin

    2012-07-01

    Measuring or estimating glomerular filtration rate (GFR) is still considered as the best way to apprehend global renal function. In 2009, the new Chronic Kidney Disease Epidemiology (CKD-EPI) equation has been proposed as a better estimator of GFR than the Modification of Diet in Renal Disease (MDRD) study equation. This new equation is supposed to underestimate GFR to a lesser degree in higher GFR levels. In this review, we will present and deeply discuss the performances of this equation. Based on articles published between 2009 and 2012, this review will underline advantages, notably the better knowledge of chronic kidney disease prevalence, but also limitations of this new equation, especially in some specific populations. We eventually insist on the fact that all these equations are estimations and nephrologists should remain cautious in their interpretation. Copyright © 2012 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  2. The Prevalence of Age-Related Eye Diseases and Visual Impairment in Aging: Current Estimates

    Science.gov (United States)

    Klein, Ronald; Klein, Barbara E. K.

    2013-01-01

    Purpose. To examine prevalence of five age-related eye conditions (age-related cataract, AMD, open-angle glaucoma, diabetic retinopathy [DR], and visual impairment) in the United States. Methods. Review of published scientific articles and unpublished research findings. Results. Cataract, AMD, open-angle glaucoma, DR, and visual impairment prevalences are high in four different studies of these conditions, especially in people over 75 years of age. There are disparities among racial/ethnic groups with higher age-specific prevalence of DR, open-angle glaucoma, and visual impairment in Hispanics and blacks compared with whites, higher prevalence of age-related cataract in whites compared with blacks, and higher prevalence of late AMD in whites compared with Hispanics and blacks. The estimates are based on old data and do not reflect recent changes in the distribution of age and race/ethnicity in the United States population. There are no epidemiologic estimates of prevalence for many visually-impairing conditions. Conclusions. Ongoing prevalence surveys designed to provide reliable estimates of visual impairment, AMD, age-related cataract, open-angle glaucoma, and DR are needed. It is important to collect objective data on these and other conditions that affect vision and quality of life in order to plan for health care needs and identify areas for further research. PMID:24335069

  3. Estimating Prevalence of Coronary Heart Disease for Small Areas Using Collateral Indicators of Morbidity

    Directory of Open Access Journals (Sweden)

    Peter Congdon

    2010-01-01

    Full Text Available Different indicators of morbidity for chronic disease may not necessarily be available at a disaggregated spatial scale (e.g., for small areas with populations under 10 thousand. Instead certain indicators may only be available at a more highly aggregated spatial scale; for example, deaths may be recorded for small areas, but disease prevalence only at a considerably higher spatial scale. Nevertheless prevalence estimates at small area level are important for assessing health need. An instance is provided by England where deaths and hospital admissions for coronary heart disease are available for small areas known as wards, but prevalence is only available for relatively large health authority areas. To estimate CHD prevalence at small area level in such a situation, a shared random effect method is proposed that pools information regarding spatial morbidity contrasts over different indicators (deaths, hospitalizations, prevalence. The shared random effect approach also incorporates differences between small areas in known risk factors (e.g., income, ethnic structure. A Poisson-multinomial equivalence may be used to ensure small area prevalence estimates sum to the known higher area total. An illustration is provided by data for London using hospital admissions and CHD deaths at ward level, together with CHD prevalence totals for considerably larger local health authority areas. The shared random effect involved a spatially correlated common factor, that accounts for clustering in latent risk factors, and also provides a summary measure of small area CHD morbidity.

  4. Effects of systematic sampling on satellite estimates of deforestation rates

    International Nuclear Information System (INIS)

    Steininger, M K; Godoy, F; Harper, G

    2009-01-01

    Options for satellite monitoring of deforestation rates over large areas include the use of sampling. Sampling may reduce the cost of monitoring but is also a source of error in estimates of areas and rates. A common sampling approach is systematic sampling, in which sample units of a constant size are distributed in some regular manner, such as a grid. The proposed approach for the 2010 Forest Resources Assessment (FRA) of the UN Food and Agriculture Organization (FAO) is a systematic sample of 10 km wide squares at every 1 deg. intersection of latitude and longitude. We assessed the outcome of this and other systematic samples for estimating deforestation at national, sub-national and continental levels. The study is based on digital data on deforestation patterns for the five Amazonian countries outside Brazil plus the Brazilian Amazon. We tested these schemes by varying sample-unit size and frequency. We calculated two estimates of sampling error. First we calculated the standard errors, based on the size, variance and covariance of the samples, and from this calculated the 95% confidence intervals (CI). Second, we calculated the actual errors, based on the difference between the sample-based estimates and the estimates from the full-coverage maps. At the continental level, the 1 deg., 10 km scheme had a CI of 21% and an actual error of 8%. At the national level, this scheme had CIs of 126% for Ecuador and up to 67% for other countries. At this level, increasing sampling density to every 0.25 deg. produced a CI of 32% for Ecuador and CIs of up to 25% for other countries, with only Brazil having a CI of less than 10%. Actual errors were within the limits of the CIs in all but two of the 56 cases. Actual errors were half or less of the CIs in all but eight of these cases. These results indicate that the FRA 2010 should have CIs of smaller than or close to 10% at the continental level. However, systematic sampling at the national level yields large CIs unless the

  5. Redefinition and global estimation of basal ecosystem respiration rate

    DEFF Research Database (Denmark)

    Yuan, Wenping; Luo, Yiqi; Li, Xianglan

    2011-01-01

    use a global constant BR largely due to the lack of a functional description for BR. In this study, we redefined BR to be ecosystem respiration rate at the mean annual temperature. To test the validity of this concept, we conducted a synthesis analysis using 276 site-years of eddy covariance data....... These results confirm that ER at the mean annual temperature can be considered as BR in empirical models. A strong correlation was found between the mean annual ER and mean annual gross primary production (GPP). Consequently, GPP, which is typically more accurately modeled, can be used to estimate BR. A light...

  6. Drug use and AIDS: estimating injection prevalence in a rural state.

    Science.gov (United States)

    Leukefeld, Carl G; Logan, T K; Farabee, David; Clayton, Richard

    2002-01-01

    This paper presents approaches used in one rural U.S. state to describe the level of injecting drug use and to estimate the number of injectors not receiving drug-user treatment. The focus is on two broad areas of estimation that were used to present the prevalence of injecting drug use in Kentucky. The first estimation approach uses available data from secondary data sources. The second approach involves three small community studies.

  7. Estimating the prevalence of illicit opioid use in New York City using multiple data sources

    Directory of Open Access Journals (Sweden)

    McNeely Jennifer

    2012-06-01

    Full Text Available Abstract Background Despite concerns about its health and social consequences, little is known about the prevalence of illicit opioid use in New York City. Individuals who misuse heroin and prescription opioids are known to bear a disproportionate burden of morbidity and mortality. Service providers and public health authorities are challenged to provide appropriate interventions in the absence of basic knowledge about the size and characteristics of this population. While illicit drug users are underrepresented in population-based surveys, they may be identified in multiple administrative data sources. Methods We analyzed large datasets tracking hospital inpatient and emergency room admissions as well as drug treatment and detoxification services utilization. These were applied in combination with findings from a large general population survey and administrative records tracking prescriptions, drug overdose deaths, and correctional health services, to estimate the prevalence of heroin and non-medical prescription opioid use among New York City residents in 2006. These data were further applied to a descriptive analysis of opioid users entering drug treatment and hospital-based medical care. Results These data sources identified 126,681 cases of opioid use among New York City residents in 2006. After applying adjustment scenarios to account for potential overlap between data sources, we estimated over 92,000 individual opioid users. By contrast, just 21,600 opioid users initiated drug treatment in 2006. Opioid users represented 4 % of all individuals hospitalized, and over 44,000 hospitalizations during the calendar year. Conclusions Our findings suggest that innovative approaches are needed to provide adequate services to this sizeable population of opioid users. Given the observed high rates of hospital services utilization, greater integration of drug services into medical settings could be one component of an effective approach to

  8. Estimates of HIV prevalence in a highly endemic area of China: Dehong Prefecture, Yunnan Province.

    Science.gov (United States)

    Jia, Yujiang; Sun, Jiangping; Fan, Lu; Song, Duan; Tian, Shuming; Yang, Yuecheng; Jia, Manhong; Lu, Lin; Sun, Xinhua; Zhang, Sanguo; Kulczycki, Andrzej; Vermund, Sten H

    2008-12-01

    Dehong Prefecture in Yunnan Province, China, borders Myanmar. Its proximity to the 'Golden Triangle', one of the world's largest illicit drug production and distribution centre, contributes to drug trafficking and ready availability of heroin. Dehong's 1.1 million people confront a serious HIV problem fuelled by injection drug use. The aim of this study is to improve the 2005 estimates of the true status of the HIV/AIDS epidemic in Dehong Prefecture. We estimated the HIV prevalence by synthesizing the results from several data sources (HIV/AIDS case reports, surveys, surveillance activities and epidemiological studies). We applied three different statistical procedures for estimations: (i) The Workbook method, adapted to meet the estimation needs in Dehong Prefecture; (ii) An estimate based on antenatal clinical data; and (iii) a dynamic model based on the local epidemic pattern. We estimated that the population prevalence for HIV infections in Dehong Prefecture is 1.3% (likely range from low/high of three estimates: 0.9-1.7%) such that 13 500 people were living with HIV/AIDS in Dehong Prefecture (likely range: 8,200-18,300) in 2005. Infections remain concentrated among injection drug users, female sex workers and their clients with an uneven geographical distribution of estimated cases. More reliable estimates of HIV prevalence can be made by synthesizing multiple data sources using several procedures. Current HIV prevention, care and treatment challenges are judged substantial in Dehong Prefecture, regardless of what modelling strategy is used.

  9. Global and Regional Estimates of Prevalent and Incident Herpes Simplex Virus Type 1 Infections in 2012.

    Directory of Open Access Journals (Sweden)

    Katharine J Looker

    Full Text Available Herpes simplex virus type 1 (HSV-1 commonly causes orolabial ulcers, while HSV-2 commonly causes genital ulcers. However, HSV-1 is an increasing cause of genital infection. Previously, the World Health Organization estimated the global burden of HSV-2 for 2003 and for 2012. The global burden of HSV-1 has not been estimated.We fitted a constant-incidence model to pooled HSV-1 prevalence data from literature searches for 6 World Health Organization regions and used 2012 population data to derive global numbers of 0-49-year-olds with prevalent and incident HSV-1 infection. To estimate genital HSV-1, we applied values for the proportion of incident infections that are genital.We estimated that 3709 million people (range: 3440-3878 million aged 0-49 years had prevalent HSV-1 infection in 2012 (67%, with highest prevalence in Africa, South-East Asia and Western Pacific. Assuming 50% of incident infections among 15-49-year-olds are genital, an estimated 140 million (range: 67-212 million people had prevalent genital HSV-1 infection, most of which occurred in the Americas, Europe and Western Pacific.The global burden of HSV-1 infection is huge. Genital HSV-1 burden can be substantial but varies widely by region. Future control efforts, including development of HSV vaccines, should consider the epidemiology of HSV-1 in addition to HSV-2, and especially the relative contribution of HSV-1 to genital infection.

  10. The impact of fecal sample processing on prevalence estimates for antibiotic-resistant Escherichia coli.

    Science.gov (United States)

    Omulo, Sylvia; Lofgren, Eric T; Mugoh, Maina; Alando, Moshe; Obiya, Joshua; Kipyegon, Korir; Kikwai, Gilbert; Gumbi, Wilson; Kariuki, Samuel; Call, Douglas R

    2017-05-01

    Investigators often rely on studies of Escherichia coli to characterize the burden of antibiotic resistance in a clinical or community setting. To determine if prevalence estimates for antibiotic resistance are sensitive to sample handling and interpretive criteria, we collected presumptive E. coli isolates (24 or 95 per stool sample) from a community in an urban informal settlement in Kenya. Isolates were tested for susceptibility to nine antibiotics using agar breakpoint assays and results were analyzed using generalized linear mixed models. We observed a 0.1). Prevalence estimates did not differ for five distinct E. coli colony morphologies on MacConkey agar plates (P>0.2). Successive re-plating of samples for up to five consecutive days had little to no impact on prevalence estimates. Finally, culturing E. coli under different conditions (with 5% CO 2 or micro-aerobic) did not affect estimates of prevalence. For the conditions tested in these experiments, minor modifications in sample processing protocols are unlikely to bias estimates of the prevalence of antibiotic-resistance for fecal E. coli. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Construct validity and prevalence rate of borderline personality disorder among Chinese adolescents.

    Science.gov (United States)

    Leung, See-Wai; Leung, Freedom

    2009-10-01

    The construct of borderline personality disorder (BPD) among adolescents is a controversial topic. No research has examined the BPD construct among Chinese adolescents because the Chinese Classification of Mental Disorders-III rejects BPD as a valid diagnostic category. The present study explored the construct validity and prevalence of BPD among Chinese adolescents in Hong Kong. A total of 4,110 high school students completed the McLean Screening Instrument for borderline personality disorder (MSI-BPD) and other measures assessing various BPD traits twice over a one-year period. DSM-IV-TR BPD criteria set as measured by the MSI-BPD demonstrated good internal consistency, concurrent validity and test-retest reliability. Confirmatory factor analysis of the MSI-BPD revealed four theoretically meaningful factors, namely affect dysregulation, impulsivity, interpersonal disturbances, and self/cognitive disturbances. Prevalence rate of BPD, according to a stringent simulated diagnostic procedure used in this study, was estimated to be 2% among Chinese adolescents in Hong Kong. Findings support that BPD is a valid clinical construct among Chinese adolescents. More research on BPD among the Chinese population is warranted.

  12. Optimized support vector regression for drilling rate of penetration estimation

    Science.gov (United States)

    Bodaghi, Asadollah; Ansari, Hamid Reza; Gholami, Mahsa

    2015-12-01

    In the petroleum industry, drilling optimization involves the selection of operating conditions for achieving the desired depth with the minimum expenditure while requirements of personal safety, environment protection, adequate information of penetrated formations and productivity are fulfilled. Since drilling optimization is highly dependent on the rate of penetration (ROP), estimation of this parameter is of great importance during well planning. In this research, a novel approach called `optimized support vector regression' is employed for making a formulation between input variables and ROP. Algorithms used for optimizing the support vector regression are the genetic algorithm (GA) and the cuckoo search algorithm (CS). Optimization implementation improved the support vector regression performance by virtue of selecting proper values for its parameters. In order to evaluate the ability of optimization algorithms in enhancing SVR performance, their results were compared to the hybrid of pattern search and grid search (HPG) which is conventionally employed for optimizing SVR. The results demonstrated that the CS algorithm achieved further improvement on prediction accuracy of SVR compared to the GA and HPG as well. Moreover, the predictive model derived from back propagation neural network (BPNN), which is the traditional approach for estimating ROP, is selected for comparisons with CSSVR. The comparative results revealed the superiority of CSSVR. This study inferred that CSSVR is a viable option for precise estimation of ROP.

  13. A Bayesian method for estimating prevalence in the presence of a hidden sub-population.

    Science.gov (United States)

    Xia, Michelle; Gustafson, Paul

    2012-09-20

    When estimating the prevalence of a binary trait in a population, the presence of a hidden sub-population that cannot be sampled will lead to nonidentifiability and potentially biased estimation. We propose a Bayesian model of trait prevalence for a weighted sample from the non-hidden portion of the population, by modeling the relationship between prevalence and sampling probability. We studied the behavior of the posterior distribution on population prevalence, with the large-sample limits of posterior distributions obtained in simple analytical forms that give intuitively expected properties. We performed MCMC simulations on finite samples to evaluate the effectiveness of statistical learning. We applied the model and the results to two illustrative datasets arising from weighted sampling. Our work confirms that sensible results can be obtained using Bayesian analysis, despite the nonidentifiability in this situation. Copyright © 2012 John Wiley & Sons, Ltd.

  14. Automatic estimation of pressure-dependent rate coefficients

    KAUST Repository

    Allen, Joshua W.

    2012-01-01

    A general framework is presented for accurately and efficiently estimating the phenomenological pressure-dependent rate coefficients for reaction networks of arbitrary size and complexity using only high-pressure-limit information. Two aspects of this framework are discussed in detail. First, two methods of estimating the density of states of the species in the network are presented, including a new method based on characteristic functional group frequencies. Second, three methods of simplifying the full master equation model of the network to a single set of phenomenological rates are discussed, including a new method based on the reservoir state and pseudo-steady state approximations. Both sets of methods are evaluated in the context of the chemically-activated reaction of acetyl with oxygen. All three simplifications of the master equation are usually accurate, but each fails in certain situations, which are discussed. The new methods usually provide good accuracy at a computational cost appropriate for automated reaction mechanism generation. This journal is © the Owner Societies.

  15. Commercial Discount Rate Estimation for Efficiency Standards Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, K. Sydny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-04-13

    Underlying each of the Department of Energy's (DOE's) federal appliance and equipment standards are a set of complex analyses of the projected costs and benefits of regulation. Any new or amended standard must be designed to achieve significant additional energy conservation, provided that it is technologically feasible and economically justified (42 U.S.C. 6295(o)(2)(A)). A proposed standard is considered economically justified when its benefits exceed its burdens, as represented by the projected net present value of costs and benefits. DOE performs multiple analyses to evaluate the balance of costs and benefits of commercial appliance and equipment e efficiency standards, at the national and individual building or business level, each framed to capture different nuances of the complex impact of standards on the commercial end user population. The Life-Cycle Cost (LCC) analysis models the combined impact of appliance first cost and operating cost changes on a representative commercial building sample in order to identify the fraction of customers achieving LCC savings or incurring net cost at the considered efficiency levels.1 Thus, the choice of commercial discount rate value(s) used to calculate the present value of energy cost savings within the Life-Cycle Cost model implicitly plays a key role in estimating the economic impact of potential standard levels.2 This report is intended to provide a more in-depth discussion of the commercial discount rate estimation process than can be readily included in standard rulemaking Technical Support Documents (TSDs).

  16. [Prevalence rate of ovine hepatic cystic echinococcosis in Quaker Wusu area of Bayinbuluke of Xinjiang, 2014].

    Science.gov (United States)

    Dong, Jian; Yang, Lingfei; Zhang, Wenbao; Li, Haitao; Jiang, Tao; Qi, Xinwei; Song, Tao

    2015-02-01

    To investigate the prevalence rate of ovine hepatic cystic echinococcosis (HCE) in sheep in Quaker Wusu area of Bayinbuluke of Xinjiang by ultrasonography and provide evidence for the prevention and control of HCE in sheep. The prevalence screening of HCE in sheep was conducted based on ultrasound images in this area in July 2014. The sheep were divided into different groups by dental age to calculate the age specific prevalence rate of HCE and analyzed the correlation between the dental age and the prevalence rate. The total prevalence rate of HCE in sheep in this area was 36.9%. The prevalence rates of none-calcified HCE and calcified HCE were 7.3% and 29.6%, respectively. The prevalence rates of none-calcified HCE in different age groups were 1.2% (1-2 years old), 1.4% (2-3 years old), 14.0% (3-4 years old), 10.0% (4-5 years old), 15.6% (5-6 years old) and 4.2% (>6 years old) respectively. The prevalence rate of calcified HCE in different age groups were 9.9% (1-2 years old), 16.2% (2-3 years old), 31.6% (3-4 years old), 47.8% (4-5 years old), 42.2% (5-6 years old) and 41.7% (>6 years old) respectively. The prevalence rate of HCE in 1-2 years old group was lower than those in other groups, the prevalence rate of HCE in age groups >3 years increased significantly. There was positive correlation between the prevalence rate of HCE and dental age (r = 0.372, R(2) = 0.107, F = 44.176, P = 0.000). HCE is highly endemic in Quaker Wusu area. The prevalence rate of HCE is low in sheep with young age and high in sheep aged 3-4 years. It is necessary to conduct early prevention of HCE in sheep in this area.

  17. The impact of height during childhood on the national prevalence rates of overweight

    NARCIS (Netherlands)

    Dommelen, P. van; Kroon, M.L.A. de; Cameron, N.; Schonbeck, Y.; Buuren, S. van

    2014-01-01

    Background It is known that height and body mass index (BMI) are correlated in childhood. However, its impact on the (trend of) national prevalence rates of overweight and obesity has never been investigated. The aim of our study is to investigate the relation between height and national prevalence

  18. Heart rate and estimated energy expenditure during ballroom dancing.

    Science.gov (United States)

    Blanksby, B A; Reidy, P W

    1988-06-01

    Ten competitive ballroom dance couples performed simulated competitive sequences of Modern and Latin American dance. Heart rate was telemetered during the dance sequences and related to direct measures of oxygen uptake and heart rate obtained while walking on a treadmill. Linear regression was employed to estimate gross and net energy expenditures of the dance sequences. A multivariate analysis of variance with repeated measures on the dance factor was applied to the data to test for interaction and main effects on the sex and dance factors. Overall mean heart rate values for the Modern dance sequence were 170 beats.min-1 and 173 beats.min-1 for males and females respectively. During the Latin American sequence mean overall heart rate for males was 168 beats.min-1 and 177 beats.min-1 for females. Predicted mean gross values of oxygen consumption for the males were 42.8 +/- 5.7 ml.kg-1 min-1 and 42.8 +/- 6.9 ml.kg-1 min-1 for the Modern and Latin American sequences respectively. Corresponding gross estimates of oxygen consumption for the females were 34.7 +/- 3.8 ml.kg-1 min-1 and 36.1 +/- 4.1 ml.kg-1 min-1. Males were estimated to expand 54.1 +/- 8.1 kJ.min-1 of energy during the Modern sequence and 54.0 +/- 9.6 kJ.min-1 during the Latin American sequence, while predicted energy expenditure for females was 34.7 +/- 3.8 kJ.min-1 and 36.1 +/- 4.1 kJ.min-1 for Modern and Latin American dance respectively. The results suggested that both males and females were dancing at greater than 80% of their maximum oxygen consumption. A significant difference between males and females was observed for predicted gross and net values of oxygen consumption (in L.min-1 and ml.kg-1 min-1).

  19. Estimated prevalence of dementia based on analysis of drug databases in the Region of Madrid (Spain).

    Science.gov (United States)

    de Hoyos-Alonso, M C; Bonis, J; Tapias-Merino, E; Castell, M V; Otero, A

    2016-01-01

    The progressive rise in dementia prevalence increases the need for rapid methods that complement population-based prevalence studies. To estimate the prevalence of dementia in the population aged 65 and older based on use of cholinesterase inhibitors and memantine. Descriptive study of use and prescription of cholinesterase inhibitors and/or memantine in 2011 according to 2 databases: Farm@drid (pharmacy billing records for the Region of Madrid) and BIFAP (database for pharmacoepidemiology research in primary care, with diagnosis and prescription records). We tested the comparability of drug use results from each database using the chi-square test and prevalence ratios. The prevalence of dementia in Madrid was estimated based on the dose per 100 inhabitants/day, adjusting the result for data obtained from BIFAP on combination treatment in the general population (0.37%) and the percentage of dementia patients undergoing treatment (41.13%). Cholinesterase inhibitors and memantine were taken by 2.08% and 0.72% of Madrid residents aged 65 and older was respectively. Both databases displayed similar results for use of these drugs. The estimated prevalence of dementia in individuals aged 65 and older is 5.91% (95% CI%, 5.85-5.95) (52 287 people), and it is higher in women (7.16%) than in men (4.00%). The estimated prevalence of dementia is similar to that found in population-based studies. Analysing consumption of specific dementia drugs can be a reliable and inexpensive means of updating prevalence data periodically and helping rationalise healthcare resources. Copyright © 2014 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  20. Improving estimates of the prevalence of Female Genital Mutilation/Cutting among migrants in Western countries

    OpenAIRE

    Livia Elisa Ortensi; Patrizia Farina; Alessio Menonna

    2015-01-01

    Background: Female Genital Mutilation/Cutting (FGM/C) is an emerging topic in immigrant countries as a consequence of the increasing proportion of African women in overseas communities. Objective: While the prevalence of FGM/C is routinely measured in practicing countries, the prevalence of the phenomenon in western countries is substantially unknown, as no standardized methods exist yet for immigrant countries. The aim of this paper is to present an improved method of indirect estimation ...

  1. Childhood sexual abuse by representatives of the Roman Catholic Church: a prevalence estimate among the Dutch population.

    Science.gov (United States)

    Langeland, Willemien; Hoogendoorn, Adriaan W; Mager, Daniel; Smit, Jan H; Draijer, Nel

    2015-08-01

    Estimates of the extent of childhood sexual abuse (CSA) within in the Roman Catholic Church (RCC) in the general population are difficult to find. The independent Commission of Inquiry into sexual abuse of minors in the RCC in the Netherlands collected population-based data to estimate its prevalence. A large random online population sample was surveyed using a two-phase stratified sampling procedure. In Phase 1, 34,267 subjects aged 40 years and older were screened for childhood exposure to sexual abuse by non-family members, a history of institutionalization and a Roman Catholic upbringing. In Phase 2, a stratified subset of 2,462 subjects was assessed to obtain more detailed target information about sexual abuse reports within the RCC. We employed multiple imputation for the estimation of RCC CSA in the original Phase 1 sample. The prevalence of non-familial CSA in general (14.0%) was higher among women (17.2%) than among men (10.6%). The prevalence of CSA within the Dutch RCC (1.7%) was higher among men (2.7%) than among women (0.7%). As expected, older subjects reported more often CSA in the RCC than their younger counterparts. Respondents who stayed for some time in RCC run institutions for education or child protection had a higher risk to report sexual abuse. Although sexual abuse of minors by representatives of the RCC was a structural problem during a period that the Church was highly influential in the Netherlands, the estimated prevalence of the phenomenon is only a fraction of the prevalence rate of non-familial CSA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Estimation of adjusted rate differences using additive negative binomial regression.

    Science.gov (United States)

    Donoghoe, Mark W; Marschner, Ian C

    2016-08-15

    Rate differences are an important effect measure in biostatistics and provide an alternative perspective to rate ratios. When the data are event counts observed during an exposure period, adjusted rate differences may be estimated using an identity-link Poisson generalised linear model, also known as additive Poisson regression. A problem with this approach is that the assumption of equality of mean and variance rarely holds in real data, which often show overdispersion. An additive negative binomial model is the natural alternative to account for this; however, standard model-fitting methods are often unable to cope with the constrained parameter space arising from the non-negativity restrictions of the additive model. In this paper, we propose a novel solution to this problem using a variant of the expectation-conditional maximisation-either algorithm. Our method provides a reliable way to fit an additive negative binomial regression model and also permits flexible generalisations using semi-parametric regression functions. We illustrate the method using a placebo-controlled clinical trial of fenofibrate treatment in patients with type II diabetes, where the outcome is the number of laser therapy courses administered to treat diabetic retinopathy. An R package is available that implements the proposed method. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Association between Search Behaviors and Disease Prevalence Rates at 18 U.S. Children's Hospitals.

    Science.gov (United States)

    Daniel, Dennis; Wolbrink, Traci; Logvinenko, Tanya; Harper, Marvin; Burns, Jeffrey

    2017-10-01

    Background Usage of online resources by clinicians in training and practice can provide insight into knowledge gaps and inform development of decision support tools. Although online information seeking is often driven by encountered patient problems, the relationship between disease prevalence and search rate has not been previously characterized. Objective This article aimed to (1) identify topics frequently searched by pediatric clinicians using UpToDate (http://www.uptodate.com) and (2) explore the association between disease prevalence rate and search rate using data from the Pediatric Health Information System. Methods We identified the most common search queries and resources most frequently accessed on UpToDate for a cohort of 18 children's hospitals during calendar year 2012. We selected 64 of the most frequently searched diseases and matched ICD-9 data from the PHIS database during the same time period. Using linear regression, we explored the relationship between clinician query rate and disease prevalence rate. Results The hospital cohort submitted 1,228,138 search queries across 592,454 sessions. The majority of search sessions focused on a single search topic. We identified no consistent overall association between disease prevalence and search rates. Diseases where search rate was substantially higher than prevalence rate were often infectious or immune/rheumatologic conditions, involved potentially complex diagnosis or management, and carried risk of significant morbidity or mortality. None of the examined diseases showed a decrease in search rate associated with increased disease prevalence rates. Conclusion This is one of the first medical learning needs assessments to use large-scale, multisite data to identify topics of interest to pediatric clinicians, and to examine the relationship between disease prevalence and search rate for a set of pediatric diseases. Overall, disease search rate did not appear to be associated with hospital

  4. Reconciling disparate prevalence rates of PTSD in large samples of US male Vietnam veterans and their controls

    Directory of Open Access Journals (Sweden)

    Gottesman Irving I

    2006-05-01

    Full Text Available Abstract Background Two large independent studies funded by the US government have assessed the impact of the Vietnam War on the prevalence of PTSD in US veterans. The National Vietnam Veterans Readjustment Study (NVVRS estimated the current PTSD prevalence to be 15.2% while the Vietnam Experience Study (VES estimated the prevalence to be 2.2%. We compared alternative criteria for estimating the prevalence of PTSD using the NVVRS and VES public use data sets collected more than 10 years after the United States withdrew troops from Vietnam. Methods We applied uniform diagnostic procedures to the male veterans from the NVVRS and VES to estimate PTSD prevalences based on varying criteria including one-month and lifetime prevalence estimates, combat and non-combat prevalence estimates, and prevalence estimates using both single and multiple indicator models. Results Using a narrow and specific set of criteria, we derived current prevalence estimates for combat-related PTSD of 2.5% and 2.9% for the VES and the NVVRS, respectively. Using a more broad and sensitive set of criteria, we derived current prevalence estimates for combat-related PTSD of 12.2% and 15.8% for the VES and NVVRS, respectively. Conclusion When comparable methods were applied to available data we reconciled disparate results and estimated similar current prevalences for both narrow and broad definitions of combat-related diagnoses of PTSD.

  5. SEE rate estimation based on diffusion approximation of charge collection

    Science.gov (United States)

    Sogoyan, Armen V.; Chumakov, Alexander I.; Smolin, Anatoly A.

    2018-03-01

    The integral rectangular parallelepiped (IRPP) method remains the main approach to single event rate (SER) prediction for aerospace systems, despite the growing number of issues impairing method's validity when applied to scaled technology nodes. One of such issues is uncertainty in parameters extraction in the IRPP method, which can lead to a spread of several orders of magnitude in the subsequently calculated SER. The paper presents an alternative approach to SER estimation based on diffusion approximation of the charge collection by an IC element and geometrical interpretation of SEE cross-section. In contrast to the IRPP method, the proposed model includes only two parameters which are uniquely determined from the experimental data for normal incidence irradiation at an ion accelerator. This approach eliminates the necessity of arbitrary decisions during parameter extraction and, thus, greatly simplifies calculation procedure and increases the robustness of the forecast.

  6. Estimation of mortality rates in stage-structured population

    CERN Document Server

    Wood, Simon N

    1991-01-01

    The stated aims of the Lecture Notes in Biomathematics allow for work that is "unfinished or tentative". This volume is offered in that spirit. The problem addressed is one of the classics of statistical ecology, the estimation of mortality rates from stage-frequency data, but in tackling it we found ourselves making use of ideas and techniques very different from those we expected to use, and in which we had no previous experience. Specifically we drifted towards consideration of some rather specific curve and surface fitting and smoothing techniques. We think we have made some progress (otherwise why publish?), but are acutely aware of the conceptual and statistical clumsiness of parts of the work. Readers with sufficient expertise to be offended should regard the monograph as a challenge to do better. The central theme in this book is a somewhat complex algorithm for mortality estimation (detailed at the end of Chapter 4). Because of its complexity, the job of implementing the method is intimidating. Any r...

  7. The Lifetime Prevalence of Anabolic-Androgenic Steroid Use and Dependence in Americans: Current Best Estimates

    Science.gov (United States)

    Pope, Harrison G.; Kanayama, Gen; Athey, Alison; Ryan, Erin; Hudson, James I.; Baggish, Aaron

    2013-01-01

    Background and Objectives Although various surveys have tracked the prevalence of anabolic-androgenic steroid (AAS) use in American teenagers and young adults, no recent surveys have assessed the lifetime prevalence of AAS use in Americans overall. We therefore analyzed serial youth-survey data to derive estimates of the lifetime prevalence of AAS use in the current American general population. Methods We first determined the distribution of age of onset of AAS use, based on pooled data from nine studies. Using this distribution, we then developed equations to project the eventual lifetime prevalence of AAS use among young survey respondents, once they aged and completed the period of risk for initiating AAS. We similarly calculated the denominator of lifetimes of risk for AAS use in the total American population. We next applied these equations to four independent national youth datasets to derive current American general-population estimates for lifetime AAS use. Finally, using data from 10 pooled studies, we estimated the lifetime prevalence of AAS dependence among AAS users. Results Age-of-onset studies consistently showed that AAS use begins later than most drugs, with only 22% of users (95% confidence interval: 19%–25%) starting before age 20. Applying the age-of-onset findings to national youth datasets, we estimated that among Americans currently age 13 to 50 years, 2.9–4.0 million have used AAS. Within this group, roughly 1 million may have experienced AAS dependence. Conclusions and Scientific Significance Although subject to various limitations, our estimation techniques suggest a surprisinigly high prevalence of AAS use and dependence among Americans. PMID:24112239

  8. Estimating the Impact of Raising Prices and Eliminating Discounts on Cigarette Smoking Prevalence in the United States.

    Science.gov (United States)

    Marynak, Kristy L; Xu, Xin; Wang, Xu; Holmes, Carissa Baker; Tynan, Michael A; Pechacek, Terry

    2016-01-01

    The average retail price per pack of cigarettes is less than $6, which is substantially lower than the $10 per-pack target established in 2014 by the Surgeon General to reduce the smoking rate. We estimated the impact of three cigarette pricing scenarios on smoking prevalence among teens aged 12-17 years, young adults aged 18-25 years, and adults aged ≥26 years, by state: (1) $0.94 federal tax increase on cigarettes, as proposed in the fiscal year 2017 President's budget; (2) $10 per-pack retail price, allowing discounts; and (3) $10 per-pack retail price, eliminating discounts. We conducted Monte Carlo simulations to generate point estimates of reductions in cigarette smoking prevalence by state. We found that each price scenario would substantially reduce cigarette smoking prevalence. A $10 per-pack retail price eliminating discounts could result in 637,270 fewer smokers aged 12-17 years; 4,186,954 fewer smokers aged 18-25 years; and 7,722,460 fewer smokers aged ≥26 years. Raising cigarette prices and eliminating discounts could substantially reduce cigarette smoking prevalence as well as smoking-related death and disease.

  9. Drug use in Australian nightlife settings: estimation of prevalence and validity of self-report.

    Science.gov (United States)

    Miller, Peter; Curtis, Ashlee; Jenkinson, Rebecca; Droste, Nicolas; Bowe, Steven J; Pennay, Amy

    2015-11-01

    This study aimed to (1) estimate the prevalence of illicit drug use in night-time entertainment districts across five major cities in Australia; and (2) validate self-reported drug use using biochemical marker oral swabs. Street intercept surveys and oral drug swabs conducted over a 7-month period during 2011-12. The night-time entertainment districts of three metropolitan cities (Sydney, Melbourne and Perth) and two regional cities (Wollongong and Geelong) in Australia, between the hours of 10 p.m. and 5 a.m. A total of 7581 individuals agreed to participate in the survey (93% response rate). More than half (62%) the sample was male, with a median age of 22 years (range 18-73). Patrons were approached in thoroughfares and while entering and leaving licensed venues. Data collected included demographics and current session alcohol and other substance use. Drug swabs (n = 401) were performed with a subsample of participants. Approximately 9% [95% confidence interval (CI) = 7-12%] of participants self-reported consumption of illicit or non-prescribed pharmaceutical drugs prior to interview; of those, 81% identified psychostimulants as the drug used. One in five drug swabs returned a positive result, with psychostimulants the most commonly detected drugs (15%; 95% CI = 12-19%). Kappa statistics indicate agreement between self-report of any illicit drug and a positive drug swab is in the slight range [κ = 0.12 (95% CI = 0.05-0.20) P = 0.000]. Self-report findings suggest drug use in Australian nightlife is common, although still very much a minority past-time. Drug swabs indicate a higher prevalence of use (20%) than self-report (9%), which suggests that self-reported drug use may not be reliable in this context. © 2015 Society for the Study of Addiction.

  10. Estimating the Prevalence of Toxic Waste Sites in Low- and Middle-Income Countries.

    Science.gov (United States)

    Dowling, Russell; Caravanos, Jack; Grigsby, Patrick; Rivera, Anthony; Ericson, Bret; Amoyaw-Osei, Yaw; Akuffo, Bennett; Fuller, Richard

    Exposure to heavy metals at contaminated industrial and mining sites, known also as hot spots, is a significant source of toxic exposure and adverse health outcomes in countries around the world. The Toxic Sites Identification Program (TSIP) developed by Pure Earth, a New York-based nongovernmental organization, is the only systematic effort to catalogue contaminated sites globally. To date, TSIP has identified and catalogued 3282 sites in low- and middle-income countries. The TSIP methodology is not designed to survey all contaminated sites in a country. Rather sites are prioritized based on their perceived impact on human health, and only a limited number of the most highly hazardous sites are surveyed. The total number of contaminated sites globally and the fraction of contaminated sites captured by TSIP is not known. To determine the TSIP site capture rate, the fraction of contaminated sites in a country catalogued by TSIP. Ghana was selected for this analysis because it is a rapidly industrializing lower middle income country with a heterogeneous industrial base, a highly urban population (51%), and good public records systems. To develop an estimate of the fraction of sites in Ghana captured by TSIP, assessors targeted randomly selected geographic quadrats for comprehensive assessment using area and population statistics from the Ghana Statistical Service. Investigators physically walked all accessible streets in each quadrat to visually identify all sites. Visual identification was supplemented by field-based confirmation with portable x-ray fluorescence instruments to test soils for metals. To extrapolate from survey findings to develop a range of estimates for the entire country, the investigators used 2 methodologies: a "bottom-up" approach that first estimated the number of waste sites in each region and then summed these regional subtotals to develop a total national estimate; and a "top-down" method that estimated the total number of sites in Ghana and

  11. The National and Regional Prevalence Rates of Disability, Type, of Disability and Severity in Saudi Arabia-Analysis of 2016 Demographic Survey Data.

    Science.gov (United States)

    Bindawas, Saad M; Vennu, Vishal

    2018-02-28

    The prevalence of disability varies between countries ranging from less than 1% to up to 30% in some countries, thus, the estimated global disability prevalence is about 15%. However, it is unknown what the current estimate of disability and its types and severity are in Saudi Arabia. Thus, the objective of this study is to estimate national and regional prevalence rates of any disability, types of disability, and their severity among Saudi populations. Data on disability status were extracted from the national demographic survey conducted in 2016 as reported by the General Authority for Statistics, Saudi Arabia (N = 20,064,970). Prevalence rates per a population of 100,000 of any disability, type of disability, and its severity were calculated at the national level and in all 13 regions. Out of 20,064,970 Saudi citizens surveyed, 667,280 citizens reported disabilities, accounting for a prevalence rate of 3326 per a population of 100,000 (3.3%). Individuals aged 60 years and above (11,014) and males (3818) had a higher prevalence rate of disability compared with females (2813). The Tabuk region has the highest rate of reported disability, at 4.3%. The prevalence rates of extreme disabilities in mobility and sight were higher in Madinah (57,343) and Northern border (41,236) regions, respectively. In Saudi Arabia, more than half a million Saudi citizens (1 out of every 30 individuals) reported the presence of disability during the year 2016. A higher prevalence rate of disability was seen among those aged 60 years and above, and males. Targeted efforts are required at the national and regional levels to expand and improve rehabilitation and social services for all people with disabilities.

  12. Specific and unspecific gynecological alarm symptoms -prevalence estimates in different age groups

    DEFF Research Database (Denmark)

    Balasubramaniam, Kirubakaran; Ravn, Pernille; Larsen, Pia V

    2015-01-01

    OBJECTIVE: To determine prevalence estimates of gynecological alarm symptoms in different age groups and to describe common patterns of gynecological symptoms. DESIGN: Web-based cross-sectional survey study. SETTING: Nationwide in Denmark. POPULATION: A random sample of 51 090 women aged 20 years...

  13. Reliability of nationwide prevalence estimates of dementia : A critical appraisal based on Brazilian surveys

    NARCIS (Netherlands)

    Chaimowicz, F. (Flávio); A. Burdorf (Alex)

    2015-01-01

    textabstractBackground: The nationwide dementia prevalence is usually calculated by applying the results of local surveys to countries' populations. To evaluate the reliability of such estimations in developing countries, we chose Brazil as an example. We carried out a systematic review of dementia

  14. Prevalence of family violence in adults and children : Estimates using the capture-recapture method

    NARCIS (Netherlands)

    Oosterlee, A.; Vink, R.M.; Smit, F.

    2009-01-01

    Background: Reliable prevalence estimates of family violence in adults and children are difficult to obtain. Most are based on surveys or registration counts, whose research designs and methods are often questionable, making the results difficult to compare. This article presents an alternative

  15. Prevalence of family violence in adults and children: estimates using the capture-recapture method

    NARCIS (Netherlands)

    Oosterlee, A.; Vink, R.M.; Smit, H.F.E.

    2009-01-01

    Background: Reliable prevalence estimates of family violence in adults and children are difficult to obtain. Most are based on surveys or registration counts, whose research designs and methods are often questionable, making the results difficult to compare. This article presents an alternative

  16. Prevalence of eosinophilic gastritis, gastroenteritis, and colitis: Estimates from a national administrative database

    Science.gov (United States)

    Jensen, Elizabeth T.; Martin, Christopher F.; Kappelman, Michael D.; Dellon, Evan S.

    2015-01-01

    Objectives Eosinophilic esophagitis (EoE) is becoming increasingly more common, but the prevalence of other eosinophilic gastrointestinal disorders (EGIDs) is unknown. Our objective was to estimate the prevalence of eosinophilic gastritis, gastroenteritis, and colitis in the U.S.. Methods We used the IMS Health LifeLink™, PharMetrics Plus™Claims Database, data representative of a U.S. national commercially-insured population containing medical and pharmaceutical claims for >75million individuals. We restricted our sample to patients age 0–64 with continuous enrollment between 7/1/2009–6/30/2011. We identified cases of eosinophilic gastritis, gastroenteritis, and colitis as defined by ≥1 instance of the ICD-9 codes 535.70, 558.41, and 558.42, respectively. We calculated the prevalence of the codes in the database and then standardized the estimates to the U.S. population by age and sex. Results The standardized estimated prevalences of eosinophilic gastritis, gastroenteritis, and colitis were 6.3/100,000, 8.4/100,000, and 3.3/100,000, respectively. The prevalence of eosinophilic gastroenteritis was highest among children age gastritis was more prevalent among older age groups. We observed no age differences for eosinophilic colitis. Among affected patients there was a high proportion of co-existing allergic conditions, 38.5% for eosinophilic gastritis, 45.6% for gastroenteritis, and 41.8% for colitis. Concomitant allergic disease was most commonly identified in pediatric patients. Conclusions The prevalence of non-EoE EGIDs remains rare in the U.S., with less than 50,000 total patients affected. There appears to be a female predominance, as well as a high co-occurrence of atopic comorbidities. PMID:25988554

  17. Mapping the serological prevalence rate of West Nile fever in equids, Tunisia.

    Science.gov (United States)

    Bargaoui, R; Lecollinet, S; Lancelot, R

    2015-02-01

    West Nile fever (WNF) is a viral disease of wild birds transmitted by mosquitoes. Humans and equids can also be affected and suffer from meningoencephalitis. In Tunisia, two outbreaks of WNF occurred in humans in 1997 and 2003; sporadic cases were reported on several other years. Small-scale serological surveys revealed the presence of antibodies against WN virus (WNV) in equid sera. However, clinical cases were never reported in equids, although their population is abundant in Tunisia. This study was achieved to characterize the nationwide serological status of WNV in Tunisian equids. In total, 1189 sera were collected in 2009 during a cross-sectional survey. Sera were tested for IgG antibodies, using ELISA and microneutralization tests. The estimated overall seroprevalence rate was 28%, 95% confidence interval [22; 34]. The highest rates were observed (i) in the north-eastern governorates (Jendouba, 74%), (ii) on the eastern coast (Monastir, 64%) and (iii) in the lowlands of Chott El Jerid and Chott el Gharsa (Kebili, 58%; Tozeur, 52%). Environmental risk factors were assessed, including various indicators of wetlands, wild avifauna, night temperature and chlorophyllous activity (normalized difference vegetation index: NDVI). Multimodel inference showed that lower distance to ornithological sites and wetlands, lower night-time temperature, and higher NDVI in late spring and late fall were associated with higher serological prevalence rate. The model-predicted nationwide map of WNF seroprevalence rate in Tunisian equids highlighted different areas with high seroprevalence probability. These findings are discussed in the perspective of implementing a better WNF surveillance system in Tunisia. This system might rely on (i) a longitudinal survey of sentinel birds in high-risk areas and time periods for WNV transmission, (ii) investigations of bird die-offs and (iii) syndromic surveillance of equine meningoencephalitis. © 2013 Blackwell Verlag GmbH.

  18. Base-rate estimates of criminal behavior by homeless mentally ill persons in New York City.

    Science.gov (United States)

    Martell, D A; Rosner, R; Harmon, R B

    1995-06-01

    The study aimed to estimate the prevalence of homelessness among mentally disordered offenders entering the criminal justice and forensic mental health systems, to compare base rates of arrest for violent and nonviolent criminal charges among homeless and domiciled persons with mental illness, and to examine patterns in the categories of victims chosen by these two groups. The authors analyzed data from structured psychiatric interviews and criminal and psychiatric records of 77 homeless defendants and 107 domiciled defendants referred for psychiatric examination by the criminal and supreme courts in Manhattan over a six-month period. Mentally disordered defendants had 40 times the rate of homelessness found in the general population, and 21 times the rate in the population of mentally ill persons in the city. The overall rate of criminal offenses was 35 times higher in the homeless mentally ill population than in the domiciled mentally ill population. The rate of violent crimes was 40 times higher and the rate of nonviolent crimes 27 times higher in the homeless population. Homeless defendants were significantly more likely to have been charged with victimizing strangers. Homeless mentally ill persons appear to be grossly overrepresented among mentally disordered defendants entering the criminal justice and forensic mental health systems and to have a higher base rate of arrest for both violent and nonviolent crimes than domiciled mentally ill persons.

  19. Estimating Steatosis Prevalence in Overweight and Obese Children: Comparison of Bayesian Small Area and Direct Methods

    Directory of Open Access Journals (Sweden)

    Hamid Reza Khalkhali

    2016-09-01

    Full Text Available Background Often, there is no access to sufficient sample size to estimate the prevalence using the method of direct estimator in all areas. The aim of this study was to compare small area’s Bayesian method and direct method in estimating the prevalence of steatosis in obese and overweight children. Materials and Methods: In this cross-sectional study, was conducted on 150 overweight and obese children aged 2 to 15 years referred to the Children's digestive clinic of Urmia University of Medical Sciences- Iran, in 2013. After Body mass index (BMI calculation, children with overweight and obese were assessed in terms of primary tests of obesity screening. Then children with steatosis confirmed by abdominal Ultrasonography, were referred to the laboratory for doing further tests. Steatosis prevalence was estimated by direct and Bayesian method and their efficiency were evaluated using mean-square error Jackknife method. The study data was analyzed using the open BUGS3.1.2 and R2.15.2 software. Results: The findings indicated that estimation of steatosis prevalence in children using Bayesian and direct methods were between 0.3098 to 0.493, and 0.355 to 0.560 respectively, in Health Districts; 0.3098 to 0.502, and 0.355 to 0.550 in Education Districts; 0.321 to 0.582, and 0.357 to 0.615 in age groups; 0.313 to 0.429, and 0.383 to 0.536 in sex groups. In general, according to the results, mean-square error of Bayesian estimation was smaller than direct estimation (P

  20. National South African HIV prevalence estimates robust despite substantial test non-participation

    Directory of Open Access Journals (Sweden)

    Guy Harling

    2017-07-01

    Full Text Available Background. South African (SA national HIV seroprevalence estimates are of crucial policy relevance in the country, and for the worldwide HIV response. However, the most recent nationally representative HIV test survey in 2012 had 22% test non-participation, leaving the potential for substantial bias in current seroprevalence estimates, even after controlling for selection on observed factors. Objective. To re-estimate national HIV prevalence in SA, controlling for bias due to selection on both observed and unobserved factors in the 2012 SA National HIV Prevalence, Incidence and Behaviour Survey. Methods. We jointly estimated regression models for consent to test and HIV status in a Heckman-type bivariate probit framework. As selection variable, we used assigned interviewer identity, a variable known to predict consent but highly unlikely to be associated with interviewees’ HIV status. From these models, we estimated the HIV status of interviewed participants who did not test. Results. Of 26 710 interviewed participants who were invited to test for HIV, 21.3% of females and 24.3% of males declined. Interviewer identity was strongly correlated with consent to test for HIV; declining a test was weakly associated with HIV serostatus. Our HIV prevalence estimates were not significantly different from those using standard methods to control for bias due to selection on observed factors: 15.1% (95% confidence interval (CI 12.1 - 18.6 v. 14.5% (95% CI 12.8 - 16.3 for 15 - 49-year-old males; 23.3% (95% CI 21.7 - 25.8 v. 23.2% (95% CI 21.3 - 25.1 for 15 - 49-year-old females. Conclusion. The most recent SA HIV prevalence estimates are robust under the strongest available test for selection bias due to missing data. Our findings support the reliability of inferences drawn from such data.

  1. The Relationship Between Child Mortality Rates and Prevalence of Celiac Disease.

    Science.gov (United States)

    Biagi, Federico; Raiteri, Alberto; Schiepatti, Annalisa; Klersy, Catherine; Corazza, Gino R

    2018-02-01

    Some evidence suggests that prevalence of celiac disease in the general population is increasing over time. Because the prognosis of celiac disease was a dismal one before discovering the role of gluten, our aim was to investigate a possible relationship between children under-5 mortality rates and prevalence rates of celiac disease. Thanks to a literature review, we found 27 studies performed in 17 different countries describing the prevalence of celiac disease in schoolchildren; between 1995 and 2011, 4 studies were performed in Italy. A meta-analysis of prevalence rates was performed. Prevalence was compared between specific country under-5 mortality groups, publication year, and age. In the last decades, under-5 mortality rates have been decreasing all over the world. This reduction is paralleled by an increase of the prevalence of celiac disease. The Spearman correlation coefficient was -63%, 95% confidence interval -82% to -33% (P celiac disease in the general population. In the near future, the number of patients with celiac disease will increase, thanks to the better environmental conditions that nowadays allow a better survival of children with celiac disease.

  2. Estimating cougar predation rates from GPS location clusters

    Science.gov (United States)

    Anderson, C.R.; Lindzey, F.G.

    2003-01-01

    We examined cougar (Puma concolor) predation from Global Positioning System (GPS) location clusters (???2 locations within 200 m on the same or consecutive nights) of 11 cougars during September-May, 1999-2001. Location success of GPS averaged 2.4-5.0 of 6 location attempts/night/cougar. We surveyed potential predation sites during summer-fall 2000 and summer 2001 to identify prey composition (n = 74; 3-388 days post predation) and record predation-site variables (n = 97; 3-270 days post predation). We developed a model to estimate probability that a cougar killed a large mammal from data collected at GPS location clusters where the probability of predation increased with number of nights (defined as locations at 2200, 0200, or 0500 hr) of cougar presence within a 200-m radius (P days/kill for subadult females (1-2.5 yr; n = 3, 90% CI: 6.3 to 9.9), 7.0 days/kill for adult females (n = 2, 90% CI: 5.8 to 10.8), 5.4 days/kill for family groups (females with young; n = 3, 90% CI: 4.5 to 8.4), 9.5 days/kill for a subadult male (1-2.5 yr; n = 1, 90% CI: 6.9 to 16.4), and 7.8 days/kill for adult males (n = 2, 90% CI: 6.8 to 10.7). We may have slightly overestimated cougar predation rates due to our inability to separate scavenging from predation. We detected 45 deer (Odocoileus spp.), 15 elk (Cervus elaphus), 6 pronghorn (Antilocapra americana), 2 livestock, 1 moose (Alces alces), and 6 small mammals at cougar predation sites. Comparisons between cougar sexes suggested that females selected mule deer and males selected elk (P nights on pronghorn carcasses, 3.4 nights on deer carcasses, and 6.0 nights on elk carcasses. Most cougar predation (81.7%) occurred between 1901-0500 hr and peaked from 2201-0200 hr (31.7%). Applying GPS technology to identify predation rates and prey selection will allow managers to efficiently estimate the ability of an area's prey base to sustain or be affected by cougar predation.

  3. Prevalence of hearing impairment in a rural midwestern cohort: estimates from the Keokuk county rural health study, 1994 to 1998.

    Science.gov (United States)

    Flamme, Gregory A; Mudipalli, V Ranjit; Reynolds, Stephen J; Kelly, Kevin M; Stromquist, Ann M; Zwerling, Craig; Burmeister, Leon F; Peng, Shu-Chen; Merchant, James A

    2005-06-01

    The current paper estimates the prevalence of hearing problems in a rural population, analyzes the prevalence of hearing problems across age groups, and compares the prevalence of hearing problems in this population with results obtained in other populations. Data were obtained from a random sample of the residents of a rural county, stratified by farm, rural non-farm, and town residence. Hearing test results were obtained from participants between the ages of 8 and 92 years (N = 1972; 47% male). Pure-tone thresholds were classified as normal or impaired using a number of metrics, including speech intelligibility index values. Selected comparisons of crude rates were made with previous population-based studies of hearing loss prevalence. Nearly all (99%) of the participants in this study had significant hearing impairment. Atypical hearing impairment is most prevalent at 6 kHz. In males, this excess impairment shifts to lower frequencies with age but monotonically decreases in females. Notched configurations were most common among those between 30 and 59 years old. In females, the prevalence of hearing impairments sufficient to interfere with speech understanding begins to rapidly increase in the 6th decade (4th decade in males). Comparisons with prior population-based studies in the United States and Great Britain identified few significant differences. Significant hearing impairment is common in rural populations. The high prevalence in this population is similar to that found in other population-based studies. Future studies are needed to examine (1) the risk factors for hearing impairment, (2) the natural course of hearing problems across the life span, and (3) the effect of programs for the prevention of hearing impairment and rehabilitation for persons with existing hearing impairments.

  4. Hypertension prevalence and influence of basal metabolic rate on blood pressure among adult students in Bangladesh.

    Science.gov (United States)

    Ali, Nurshad; Mahmood, Shakil; Manirujjaman, M; Perveen, Rasheda; Al Nahid, Abdullah; Ahmed, Shamim; Khanum, Farida Adib; Rahman, Mustafizur

    2017-07-25

    Hypertension is a global health issue and is currently increasing at rapid pace in South Asian countries including Bangladesh. Although, some studies on hypertension have been conducted in Bangladesh, there is a lack of scientific evidence in the adult student population that was missing from the previous and recent national cross-sectional studies. Moreover, the specific risk factors of hypertension in the Bangladeshi adults still need to be investigated. This study was conducted to estimate hypertension prevalence among adult students in Bangladesh and to test the hypothesis of Luke et al. (Hypertension 43:555-560, 2004) that basal metabolic rate (BMR) and blood pressure are positively associated independent of body size. The data was collected on 184 adult university students (118 female and 66 male) in Dhaka, Bangladesh. Anthropometric, BMR details and an average of at least two blood pressure measurements were obtained. Hypertension was defined by a systolic blood pressure (SBP) ≥ 140 mmHg and/or, diastolic blood pressure (DBP) ≥ 90 mmHg. Overall, 6.5% of participants had hypertension with significantly (p BMR was positively correlated with SBP and DBP (p BMR is associated with SBP and DBP; this is opposite the well documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMR might be an important predictor that can explain relatively high blood pressure and hypertension in humans. This study reports the prevalence and associated risk factors of hypertension in the Bangladeshi adult students. The study also showed a positive association between BMR and blood pressure among the participants. A large scale longitudinal study across the country is needed to find out the underlying causes of hypertension in the Bangladeshi adults. In addition, comprehensive and integrated intervention programs focusing on modifiable risk factors are recommended to

  5. Program CONTRAST--A general program for the analysis of several survival or recovery rate estimates

    Science.gov (United States)

    Hines, J.E.; Sauer, J.R.

    1989-01-01

    This manual describes the use of program CONTRAST, which implements a generalized procedure for the comparison of several rate estimates. This method can be used to test both simple and composite hypotheses about rate estimates, and we discuss its application to multiple comparisons of survival rate estimates. Several examples of the use of program CONTRAST are presented. Program CONTRAST will run on IBM-cimpatible computers, and requires estimates of the rates to be tested, along with associated variance and covariance estimates.

  6. Satellite-based Estimates of Ambient Air Pollution and Global Variations in Childhood Asthma Prevalence

    Science.gov (United States)

    Anderson, H. Ross; Butland, Barbara K.; Donkelaar, Aaron Matthew Van; Brauer, Michael; Strachan, David P.; Clayton, Tadd; van Dingenen, Rita; Amann, Marcus; Brunekreef, Bert; Cohen, Aaron; hide

    2012-01-01

    Background: The effect of ambient air pollution on global variations and trends in asthma prevalence is unclear. Objectives: Our goal was to investigate community-level associations between asthma prevalence data from the International Study of Asthma and Allergies in Childhood (ISAAC) and satellite-based estimates of particulate matter with aerodynamic diameter children per 10% increase in center-level PM2.5 and NO2 was -0.043 [95% confidence interval (CI): -0.139, 0.053] and 0.017 (95% CI: -0.030, 0.064) respectively. For ozone the estimated change in prevalence per parts per billion by volume was -0.116 (95% CI: -0.234, 0.001). Equivalent results for the 6- to 7-year age group (83 centers in 20 countries), though slightly different, were not significantly positive. For the 13- to 14-year age group, change in center-level asthma prevalence over time per 100 children per 10% increase in PM2.5 from Phase One to Phase Three was -0.139 (95% CI: -0.347, 0.068). The corresponding association with ozone (per ppbV) was -0.171 (95% CI: -0.275, -0.067). Conclusion: In contrast to reports from within-community studies of individuals exposed to traffic pollution, we did not find evidence of a positive association between ambient air pollution and asthma prevalence as measured at the community level.

  7. Estimation of live birth and population prevalence of Down syndrome in nine U.S. states.

    Science.gov (United States)

    de Graaf, Gert; Buckley, Frank; Dever, Jennifer; Skotko, Brian G

    2017-10-01

    For all of the U.S. states with sufficient data, we estimated live birth and population prevalences for Down syndrome (DS). As social service resources vary between states, such data are important for public policy discussions and state planning. We predicted the actual and nonselective live birth prevalence, and population prevalence, for DS in nine U.S. states based on publicly available datasets from the Centers for Disease Control and Prevention and the Integrated Public Use Microdata Series. As of 2010, we estimated a population size for people with DS of 4,554 in MA (population prevalence 1 in 1,440), 6,101 in NJ (1 in 1,443), 14,315 in NY (1 in 1,355), 9,739 in IL (1 in 1,319), 4,354 in IN (1 in 1,491), 7,295 in MI (1 in 1,354), 9,099 in FL (1 in 2,071), 3,014 in KY (1 in 1,442), and 3,596 in AZ (1 in 1,784). The number of people living with DS has steadily increased from 1950 until 2010 in these nine U.S. states. Population prevalence would have been higher absent DS-related elective terminations. Racial and ethnic groups, other than non-Hispanic whites, comprise a growing proportion within these DS communities, particularly among younger-aged persons. © 2017 Wiley Periodicals, Inc.

  8. Prevalence and incidence rate of injuries in runners at a local athletic club in Cape Town

    Directory of Open Access Journals (Sweden)

    C. Hendricks

    2013-12-01

    Full Text Available People across the world are running on a daily basis to improvetheir health status. However, running can predispose an individual to injuryto the back and lower limb. Baseline data on prevalence, incidence rate ofinjury and aetiological factors associated with running injuries are neededby physiotherapists to develop and implement effective prevention programmesto allow optimal performance in runners. Thus, the purpose of this study wasto determine the prevalence and incidence of injuries in runners at a localathletic club.Methods: A prospective, non-experimental cohort study was conductedover a 16 week period. A sample of 50 runners completed a self-administeredquestionnaire and an injury report form recording injuries sustained during the 16 week study period. Injury prevalence andcumulative incidence was calculated as a proportion rate along with 95% confidence interval.Results: The prevalence rate of injuries was 32%. The incidence rate of injuries was 0.67 per 1000km run (95% CI: 0.41- 1.08.The most common anatomical sites for new injuries were the calf (20% and the knee (18%.Conclusions: The study found a moderate prevalence and incidence rate of injury in runners, thus the need for physiotherapyledinjury surveillance and prevention programmes have been highlighted.

  9. The prevalence rates of refractive errors among children, adolescents, and adults in Germany

    OpenAIRE

    Sandra Jobke; Erich Kasten; Christian Vorwerk

    2008-01-01

    Sandra Jobke1, Erich Kasten2, Christian Vorwerk31Institute of Medical Psychology, 3Department of Ophthalmology, Otto-von Guericke-University of Magdeburg, Magdeburg, Germany; 2Institute of Medical Psychology, University Hospital Schleswig-Holstein, Luebeck, GermanyPurpose: The prevalence rates of myopia vary between 5% in Australian Aborigines to 84% in Hong Kong and Taiwan, 30% in Norwegian adults, and 49.5% in Swedish schoolchildren. The aim of this study was to determine the prevalence of ...

  10. Prevalence estimates of violence in the dating experiences of college women.

    Science.gov (United States)

    Amar, Angela Frederick

    2004-12-01

    Young women are vulnerable to experiencing psychological, physical, and sexual violence and stalking through dating experiences. This study used a correlational design to report prevalence estimates of psychological, physical, and sexual violence and stalking that occur within the dating experiences of college women. This study also compared prevalence estimates of violence between African-American and White college women. A convenience sample of 863 (N = 863) women between 18 and 25 years of age from a private, historically African-American college in the south and a private, historically primarily White college in the mid-Atlantic completed the Abuse Assessment Screen, and a background data sheet. All participants had the option of completing a narrative note. Data analysis consisted of frequencies, and chi2. Almost half of the total sample 48% (n = 412) reported the experience of violence and of these, 39% (n = 160) reported more than one form of violence. Specific prevalence was as follows: psychological violence 22% (n = 190), stalking or harassment 31% (n = 266), physical violence 12% (n = 99), and all unwanted sexual activity 9% (n = 80). Prevalence estimates were consistent for African-American and White college students in all types of violence except in reporting threats of physical violence and threats plus actual physical violence. Study findings highlight the need for nurses to routinely screen and assess all young women for psychological, physical, and sexual violence and stalking Surveillance efforts will help identify victims and potential victims so that appropriate referrals for treatment and support can be made.

  11. Low disease prevalence and inappropriate implantable cardioverter defibrillator shock rate in Brugada syndrome

    DEFF Research Database (Denmark)

    Holst, Anders Gaarsdal; Jensen, Henrik Kjærulf; Eschen, Ole

    2012-01-01

    Brugada syndrome (BrS) is an inherited channelopathy that predisposes to malignant ventricular arrhythmias and thereby syncope and sudden cardiac death. Prior studies characterizing BrS patients have used highly selected referral populations from tertiary centres and prevalence estimates have been...

  12. A portable respiratory rate estimation system with a passive single-lead electrocardiogram acquisition module.

    Science.gov (United States)

    Nayan, Nazrul Anuar; Risman, Nur Sabrina; Jaafar, Rosmina

    2016-07-27

    Among vital signs of acutely ill hospital patients, respiratory rate (RR) is a highly accurate predictor of health deterioration. This study proposes a system that consists of a passive and non-invasive single-lead electrocardiogram (ECG) acquisition module and an ECG-derived respiratory (EDR) algorithm in the working prototype of a mobile application. Before estimating RR that produces the EDR rate, ECG signals were evaluated based on the signal quality index (SQI). The SQI algorithm was validated quantitatively using the PhysioNet/Computing in Cardiology Challenge 2011 training data set. The RR extraction algorithm was validated by adopting 40 MIT PhysioNet Multiparameter Intelligent Monitoring in Intensive Care II data set. The estimated RR showed a mean absolute error (MAE) of 1.4 compared with the ``gold standard'' RR. The proposed system was used to record 20 ECGs of healthy subjects and obtained the estimated RR with MAE of 0.7 bpm. Results indicate that the proposed hardware and algorithm could replace the manual counting method, uncomfortable nasal airflow sensor, chest band, and impedance pneumotachography often used in hospitals. The system also takes advantage of the prevalence of smartphone usage and increase the monitoring frequency of the current ECG of patients with critical illnesses.

  13. Estimated prevalence of nematode parasitism among pet cats in the United States.

    Science.gov (United States)

    De Santis, Andrea C; Raghavan, Malathi; Caldanaro, Richard J; Glickman, Nita W; Moore, George E; Lewis, Hugh B; Schantz, Peter M; Glickman, Lawrence T

    2006-03-15

    To estimate prevalences of roundworm, hookworm, and whipworm infections in pet cats in the United States and identify risk factors for parasitism. Retrospective period prevalence survey. 356,086 cats examined at 359 private veterinary hospitals during 2003. Electronic medical records were searched to identify cats for which fecal flotation tests had been performed and to determine proportions of test results positive for roundworms, hookworms, and whipworms. Potential risk factors for roundworm and hookworm infection were identified by means of multivariate logistic regression analysis. A total of 80,278 tests were performed on fecal samples from 66,819 cats. Calculated prevalences of roundworm, hookworm, and whipworm infection were 2.92%, 0.63%, and 0.031%, respectively. Age, reproductive status, breed, and season were significant risk factors for roundworm infection, with cats prevalences of roundworm and hookworm infection were found. Results suggest that prevalences of nematode infections among pet cats in the United States may be lower than previously suspected on the basis of prevalences reported among cats in humane shelters and those reported in more geographically focused studies.

  14. [Ischemic heart disease prevalence estimated using a standard algorithm based on electronic health data in various areas of Italy].

    Science.gov (United States)

    Balzi, Daniela; Barchielli, Alessandro; Battistella, Giuseppe; Gnavi, Roberto; Inio, Andrea; Tessari, Roberta; Picariello, Roberta; Canova, Cristina; Simonato, Lorenzo

    2008-01-01

    to define an algorithm to estimate prevalence of ischemic heart disease from health administrative datasets. four Italian areas: Venezia, Treviso, Torino, Firenze. resident population in the four areas in the period 2002-2004 (only 2003 for Firenze) for a total of 2,350,000 inhabitants in 2003. annual crude and standardized prevalence rate (x100 inhabitants), 95% confidence intervals by area. Quality (comparability and coherence) indicators are also reported the algorithm is based on record linkage of hospital discharges (SDO), pharmacological prescriptions (PF), exemptions from health-tax exemptions (ET) and causes of mortality (CM). From SDO we extracted discharges for ICD9-CM codes 410*-414* in all diagnoses in the estimation year and during the four years immediately preceding. We selected from PF subjects with at least two prescriptions of organic nitrates (ATC = C01DA*) in the estimation year. From ET subjects with a new exemption for ischemic heart disease (002.414) or who obtained exemption in the three years preceding, were selected. We also considered all deaths in the year for ischemic heart disease (ICD9 CM 410-414). Cases were defined as ischemic heart disease prevalent cases if they were extracted at least once from one of the datasets and if they were alive on January 1 of the estimation year. estimated crude prevalence ranges from 2.5 to 4%. The standardized prevalence led to a narrower range of values (2.8-3.3%). Venezia and Firenze show a higher standardized prevalence in both sexes (men 4.7% and 4.4%; women 2.3% and 2.2% respectively); Treviso and Torino present a lower standardized prevalence (men: 3.9%; women: 1.9%). The hospital discharges are the main source to identify prevalent subjects (34-48% of subjects are solely identified by SDO), pharmacological prescriptions are a relevant source in Firenze and Torino (27-28%), while they are less relevant in Venezia and Treviso (13-15%). ET shows a different contribution to prevalent case

  15. Hypertension prevalence and influence of basal metabolic rate on blood pressure among adult students in Bangladesh

    Directory of Open Access Journals (Sweden)

    Nurshad Ali

    2017-07-01

    Full Text Available Abstract Background Hypertension is a global health issue and is currently increasing at rapid pace in South Asian countries including Bangladesh. Although, some studies on hypertension have been conducted in Bangladesh, there is a lack of scientific evidence in the adult student population that was missing from the previous and recent national cross-sectional studies. Moreover, the specific risk factors of hypertension in the Bangladeshi adults still need to be investigated. This study was conducted to estimate hypertension prevalence among adult students in Bangladesh and to test the hypothesis of Luke et al. (Hypertension 43:555–560, 2004 that basal metabolic rate (BMR and blood pressure are positively associated independent of body size. Method The data was collected on 184 adult university students (118 female and 66 male in Dhaka, Bangladesh. Anthropometric, BMR details and an average of at least two blood pressure measurements were obtained. Hypertension was defined by a systolic blood pressure (SBP ≥ 140 mmHg and/or, diastolic blood pressure (DBP ≥ 90 mmHg. Results Overall, 6.5% of participants had hypertension with significantly (p < 0.001 higher prevalence in male (12.1% than in the female (3.4% students. Age and BMI showed positive and significant correlation with hypertension among the students. When adjusted for body mass index (BMI, as well as other potentially confounding variables such as age, sex, smoking status and degree of urbanization, BMR was positively correlated with SBP and DBP (p < 0.001. Thus, higher BMR is associated with SBP and DBP; this is opposite the well documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMR might be an important predictor that can explain relatively high blood pressure and hypertension in humans. Conclusion This study reports the prevalence and associated risk factors

  16. Estimating the prevalence of generalized and partial lipodystrophy: findings and challenges

    Directory of Open Access Journals (Sweden)

    Chiquette E

    2017-09-01

    Full Text Available Elaine Chiquette,1 Elif A Oral,2 Abhimanyu Garg,3 David Araújo-Vilar,4 Praveen Dhankhar5 1Aegerion Pharmaceuticals, Cambridge, MA, USA; 2Brehm Center for Diabetes Research and Metabolism, Endocrinology and Diabetes Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA; 3Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX, USA; 4Department of Medicine, UETeM, CIMUS School of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain; 5Complete HEOR Solutions (CHEORS, North Wales, PA, USA Background: Lipodystrophy (LD; non-human immunodeficiency virus [HIV]-associated syndromes are a rare body of disorders for which true prevalence is unknown. Prevalence estimates of rare diseases are important to increase awareness and financial resources. Current qualitative and quantitative estimates of LD prevalence range from ~0.1 to 90 cases/million. We demonstrate an approach to quantitatively estimate LD prevalence (all, generalized, and partial through a search of 5 electronic medical record (EMR databases and 4 literature searches.Methods: EMR and literature searches were conducted from 2012 to 2014. For the EMR database searches (Quintiles, IMS LifeLink, General Electric Healthcare, and Humedica EMR, LD cases were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM code 272.6 (United Kingdom General Practice Research Database used other diagnostic codes to identify LD plus additional LD-associated clinical characteristics (patients with HIV or documented HIV treatment were excluded. Expert adjudication of cases was used for the Quintiles database only. Literature searches (PubMed and EMBASE were conducted for each of the 4 major LD subtypes. Prevalence estimates were determined by extrapolating the total number of cases identified for

  17. Estimating mental fatigue based on electroencephalogram and heart rate variability

    Science.gov (United States)

    Zhang, Chong; Yu, Xiaolin

    2010-01-01

    The effects of long term mental arithmetic task on psychology are investigated by subjective self-reporting measures and action performance test. Based on electroencephalogram (EEG) and heart rate variability (HRV), the impacts of prolonged cognitive activity on central nervous system and autonomic nervous system are observed and analyzed. Wavelet packet parameters of EEG and power spectral indices of HRV are combined to estimate the change of mental fatigue. Then wavelet packet parameters of EEG which change significantly are extracted as the features of brain activity in different mental fatigue state, support vector machine (SVM) algorithm is applied to differentiate two mental fatigue states. The experimental results show that long term mental arithmetic task induces the mental fatigue. The wavelet packet parameters of EEG and power spectral indices of HRV are strongly correlated with mental fatigue. The predominant activity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. Moreover, the slow waves of EEG increase, the fast waves of EEG and the degree of disorder of brain decrease compared with the pre-task. The SVM algorithm can effectively differentiate two mental fatigue states, which achieves the maximum classification accuracy (91%). The SVM algorithm could be a promising tool for the evaluation of mental fatigue. Fatigue, especially mental fatigue, is a common phenomenon in modern life, is a persistent occupational hazard for professional. Mental fatigue is usually accompanied with a sense of weariness, reduced alertness, and reduced mental performance, which would lead the accidents in life, decrease productivity in workplace and harm the health. Therefore, the evaluation of mental fatigue is important for the occupational risk protection, productivity, and occupational health.

  18. IDF Diabetes Atlas: Global estimates for the prevalence of diabetes for 2015 and 2040.

    Science.gov (United States)

    Ogurtsova, K; da Rocha Fernandes, J D; Huang, Y; Linnenkamp, U; Guariguata, L; Cho, N H; Cavan, D; Shaw, J E; Makaroff, L E

    2017-06-01

    To produce current estimates of the national, regional and global impact of diabetes for 2015 and 2040. A systematic literature review was conducted to identify data sources on the prevalence of diabetes from studies conducted in the period from 1990 to 2015. An analytic hierarchy process was used to select the most appropriate studies for each country, and estimates for countries without data were modelled using extrapolation from similar countries that had available data. A logistic regression model was used to generate smoothed age-specific estimates, which were applied to UN population estimates. 540 data sources were reviewed, of which 196 sources from 111 countries were selected. In 2015 it was estimated that there were 415 million (uncertainty interval: 340-536 million) people with diabetes aged 20-79years, 5.0 million deaths attributable to diabetes, and the total global health expenditure due to diabetes was estimated at 673 billion US dollars. Three quarters (75%) of those with diabetes were living in low- and middle-income countries. The number of people with diabetes aged 20-79years was predicted to rise to 642 million (uncertainty interval: 521-829 million) by 2040. Diabetes prevalence, deaths attributable to diabetes, and health expenditure due to diabetes continue to rise across the globe with important social, financial and health system implications. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Estimating the effects of Exchange and Interest Rates on Stock ...

    African Journals Online (AJOL)

    The study examined the effects of exchange rate and interest rate on the Nigerian Stock Market using the All-share index as a proxy for the market. The monthly closing returns of All-share index, exchange rates and interest rates were utilized for a period of thirty years beginning from January, 2009 to December, 2011.

  20. A univariate estimation of the Philippine's exchange rate | Urrutia ...

    African Journals Online (AJOL)

    This study aims to forecast the Exchange Rate of the Philippines for five years starting from 2016 to 2020, and determine which among Inflation Rate, Purchasing Power of Peso, Interest Rate, Exports, Imports, and Balance of Payments is a significant factor that can influence Exchange Rate. The researchers used the ...

  1. Oppositional Defiant Disorder: prevalence based on parent and teacher ratings of Malaysian primary school children.

    Science.gov (United States)

    Gomez, Rapson; Hafetz, Nina; Gomez, Rashika Miranjani

    2013-08-01

    This study examined the prevalence rate of Oppositional Defiant Disorder (ODD) in Malaysian primary school children. In all 934 Malaysian parents and teachers completed ratings of their children using a scale comprising DSM-IV-TR ODD symptoms. Results showed rates of 3.10%, 3.85%, 7.49% and 0.64% for parent, teacher, parent or teacher ("or-rule"), and parent and teacher ("and-rule") ratings, respectively. When the functional impairment criterion was not considered, the rate reported by parents was higher at 13.28%. The theoretical, diagnostic and cultural implications of the findings are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Estimating the global prevalence of zinc deficiency: results based on zinc availability in national food supplies and the prevalence of stunting.

    Directory of Open Access Journals (Sweden)

    K Ryan Wessells

    Full Text Available BACKGROUND: Adequate zinc nutrition is essential for adequate growth, immunocompetence and neurobehavioral development, but limited information on population zinc status hinders the expansion of interventions to control zinc deficiency. The present analyses were conducted to: (1 estimate the country-specific prevalence of inadequate zinc intake; and (2 investigate relationships between country-specific estimated prevalence of dietary zinc inadequacy and dietary patterns and stunting prevalence. METHODOLOGY AND PRINCIPAL FINDINGS: National food balance sheet data were obtained from the Food and Agriculture Organization of the United Nations. Country-specific estimated prevalence of inadequate zinc intake were calculated based on the estimated absorbable zinc content of the national food supply, International Zinc Nutrition Consultative Group estimated physiological requirements for absorbed zinc, and demographic data obtained from United Nations estimates. Stunting data were obtained from a recent systematic analysis based on World Health Organization growth standards. An estimated 17.3% of the world's population is at risk of inadequate zinc intake. Country-specific estimated prevalence of inadequate zinc intake was negatively correlated with the total energy and zinc contents of the national food supply and the percent of zinc obtained from animal source foods, and positively correlated with the phytate: zinc molar ratio of the food supply. The estimated prevalence of inadequate zinc intake was correlated with the prevalence of stunting (low height-for-age in children under five years of age (r = 0.48, P<0.001. CONCLUSIONS AND SIGNIFICANCE: These results, which indicate that inadequate dietary zinc intake may be fairly common, particularly in Sub-Saharan Africa and South Asia, allow inter-country comparisons regarding the relative likelihood of zinc deficiency as a public health problem. Data from these analyses should be used to determine

  3. [Changes in Upper Gastrointestinal Diseases according to Improvement of Helicobacter pylori Prevalence Rate in Korea].

    Science.gov (United States)

    Park, Soo Heon

    2015-04-01

    Helicobacter pylori can cause variety of upper gastrointestinal disorders such as peptic ulcer, mucosa associated lymphoid tissue (MALT)-lymphoma, and gastric cancer. The prevalence of H. pylori infection has significantly decreased in Korea since 1998 owing to active eradication of H. pylori. Along with its decrease, the prevalence of peptic ulcer has also decreased. However, the mean age of gastric ulcer increased and this is considered to be due to increase in NSAID prescription. Gastric cancer is one of the leading causes of cancer deaths in Korea and Japan, and IARC/WHO has classified H. pylori as class one carcinogen of gastric cancer. Despite the decreasing prevalence of H. pylori infection, the total number of gastric cancer in Korea has continuously increased from 2006 to 2011. Nevertheless, the 5 year survival rate of gastric cancer patients significantly increased from 42.8% in 1993 to 67% in 2010. This increase in survival rate seems to be mainly due to early detection of gastric cancer and endoscopic mucosal dissection treatment. Based on these findings, the prevalence of peptic ulcer is expected to decrease even more with H. pylori eradication therapy and NSAID will become the main cause of peptic ulcer. Although the prevalence of gastric cancer has not changed along with decreased the prevalence of H. pylori, gastric cancer is expected to decrease in the long run with the help of eradication therapy and endoscopic treatment of precancerous lesions.

  4. Reducing pressure ulcer prevalence rates in the long-term acute care setting.

    Science.gov (United States)

    Milne, Catherine T; Trigilia, Donna; Houle, Tracy L; Delong, Sandra; Rosenblum, David

    2009-04-01

    Information about pressure ulcer prevalence, prevention, and optimal management strategies in the long-term acute care hospital (LTACH) setting is sparse. Although care processes in other patient care settings have been reported to affect pressure ulcer prevalence rates, the effect of such programs in the LTACH is unknown. To reduce perceived above-average pressure ulcer prevalence rates and improve care processes, a 108-bed LTACH used a failure mode and effects analysis to identify and address high-priority areas for improvement. Areas in need of improvement included a lack of 1) wound care professionals, 2) methods to consistently document prevention and wound data, and 3) an interdisciplinary wound care team approach, as well as a faulty electronic medical record. While prevalence data were collected, policies and procedures based on several published guidelines were developed and incorporated into the pressure ulcer plan of care by the newly established wound care team. Improved assessment and documentation methods, enhanced staff education, revised electronic records, wound care product reviews, and a facility-wide commitment to improved care resulted in a reduction of facility-acquired pressure ulcer prevalence from 41% at baseline to an average of 4.2% during the following 12 months as well as fewer missing electronic record data (improves care practices and reduces pressure ulcer prevalence in the LTACH. Studies to increase knowledge about the LTACH patient population and their unique needs and risk profiles are needed.

  5. Estimates of rate of passage, intake and apparent digestibility of ...

    African Journals Online (AJOL)

    UPUSER

    alkane technique is suitable to estimate feed intake under grazing conditions. However, the proportion of dietary alkanes recovered in the faeces has to be known to obtain an accurate estimate of apparent digestibility. This would be a problem under grazing conditions when faecal grab samples are taken for measuring ...

  6. The Impact of Proposed Changes to ICD-11 on Estimates of PTSD Prevalence and Comorbidity

    Science.gov (United States)

    Wisco, Blair E.; Miller, Mark W.; Wolf, Erika J.; Kilpatrick, Dean; Resnick, Heidi S.; Badour, Christal L.; Marx, Brian P.; Keane, Terence M.; Rosen, Raymond C.; Friedman, Matthew J.

    2016-01-01

    The World Health Organization's posttraumatic stress disorder (PTSD) work group has published a proposal for the forthcoming edition of the International Classification of Diseases (ICD-11) that would yield a very different diagnosis relative to DSM-5. This study examined the impact of the proposed ICD-11 changes on PTSD prevalence relative to the ICD-10 and DSM-5 definitions and also evaluated the extent to which these changes would accomplish the stated aim of reducing the comorbidity associated with PTSD. Diagnostic prevalence estimates were compared using a U.S. national community sample and two U.S. Department of Veterans Affairs clinical samples. The ICD-11 definition yielded prevalence estimates 10 to 30 percent lower than DSM-5 and 25 and 50 percent lower than ICD-10 with no reduction in the prevalence of common comorbidities. Findings suggest that by constraining the diagnosis to a narrower set of symptoms, the proposed ICD-11 criteria set would substantially reduce the number of individuals with the disorder. These findings raise doubt about the extent to which the ICD-11 proposal would achieve the aim of reducing comorbidity associated with PTSD and highlight the public health and policy implications of such a redefinition. PMID:27124207

  7. Global trends in dietary micronutrient supplies and estimated prevalence of inadequate intakes.

    Directory of Open Access Journals (Sweden)

    Ty Beal

    Full Text Available Understanding dietary patterns is vital to reducing the number of people experiencing hunger (about 795 million, micronutrient deficiencies (2 billion, and overweight or obesity (2.1 billion. We characterize global trends in dietary quality by estimating micronutrient density of the food supply, prevalence of inadequate intake of 14 micronutrients, and average prevalence of inadequate intake of these micronutrients for all countries between 1961 and 2011. Over this 50-year period, the estimated prevalence of inadequate intakes of micronutrients has declined in all regions due to increased total production of food and/or micronutrient density. This decline has been particularly strong in East and Southeast Asia and weaker in South Asia and sub-Saharan Africa. Sub-Saharan Africa is the only region where dietary micronutrient density has declined over this 50-year period. At the global level, micronutrients with the lowest levels of adequate estimated intake are calcium, iron, vitamin A, and zinc, but there are strong differences between countries and regions. Fortification has reduced the estimated prevalence of inadequate micronutrient intakes in all low-income regions, except South Asia. The food supply in many countries is still far below energy requirements, which suggests a need to increase the availability and accessibility of nutritious foods. Countries where the food energy supply is adequate show a very large variation in dietary quality, and in many of these countries people would benefit from more diverse diets with a greater proportion of micronutrient-dense foods. Dietary quality can be improved through fortification, biofortification, and agricultural diversification, as well as efforts to improve access to and use of micronutrient-dense foods and nutritional knowledge. Reducing poverty and increasing education, especially of women, are integral to sustainably addressing malnutrition.

  8. Global trends in dietary micronutrient supplies and estimated prevalence of inadequate intakes.

    Science.gov (United States)

    Beal, Ty; Massiot, Eric; Arsenault, Joanne E; Smith, Matthew R; Hijmans, Robert J

    2017-01-01

    Understanding dietary patterns is vital to reducing the number of people experiencing hunger (about 795 million), micronutrient deficiencies (2 billion), and overweight or obesity (2.1 billion). We characterize global trends in dietary quality by estimating micronutrient density of the food supply, prevalence of inadequate intake of 14 micronutrients, and average prevalence of inadequate intake of these micronutrients for all countries between 1961 and 2011. Over this 50-year period, the estimated prevalence of inadequate intakes of micronutrients has declined in all regions due to increased total production of food and/or micronutrient density. This decline has been particularly strong in East and Southeast Asia and weaker in South Asia and sub-Saharan Africa. Sub-Saharan Africa is the only region where dietary micronutrient density has declined over this 50-year period. At the global level, micronutrients with the lowest levels of adequate estimated intake are calcium, iron, vitamin A, and zinc, but there are strong differences between countries and regions. Fortification has reduced the estimated prevalence of inadequate micronutrient intakes in all low-income regions, except South Asia. The food supply in many countries is still far below energy requirements, which suggests a need to increase the availability and accessibility of nutritious foods. Countries where the food energy supply is adequate show a very large variation in dietary quality, and in many of these countries people would benefit from more diverse diets with a greater proportion of micronutrient-dense foods. Dietary quality can be improved through fortification, biofortification, and agricultural diversification, as well as efforts to improve access to and use of micronutrient-dense foods and nutritional knowledge. Reducing poverty and increasing education, especially of women, are integral to sustainably addressing malnutrition.

  9. Retrospectively Estimating Prevalence of Peanut Allergy Genetic Markers in an Air Force Population

    Science.gov (United States)

    2018-01-25

    AFRL-SA-WP-SR-2018-0002 Retrospectively Estimating Prevalence of Peanut Allergy Genetic Markers in an Air Force Population ...an Air Force Population 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Katherine Kohnen, Summer Hughes... population of children were over- or under-represented in a U.S. Air Force population . Our results showed that for a single polymorphism, there was a

  10. An evaluation of variation in published estimates of schizophrenia prevalence from 1990─2013: a systematic literature review.

    Science.gov (United States)

    Simeone, Jason C; Ward, Alexandra J; Rotella, Philip; Collins, Jenna; Windisch, Ricarda

    2015-08-12

    There is a lack of consistency in findings across studies on the prevalence of schizophrenia, and no recent systematic review of the literature exists. The purpose of this study is to provide an updated systematic review of population-based prevalence estimates and to understand the factors that could account for this variation in prevalence estimates. MEDLINE, Embase, and PsycInfo databases were searched for observational studies describing schizophrenia prevalence in general populations from 2003-2013 and supplemented by studies from a prior review covering 1990-2002. Studies reporting prevalence estimates from specialized populations such as institutionalized, homeless, or incarcerated persons were excluded. Prevalence estimates were compared both across and within studies by factors that might contribute to variability using descriptive statistics. Sixty-five primary studies were included; thirty-one (48 %) were from Europe and 35 (54 %) were conducted in samples of ≥50,000 persons. Among 21 studies reporting 12-month prevalence, the median estimate was 0.33 % with an interquartile range (IQR) of 0.26 %-0.51 %. The median estimate of lifetime prevalence among 29 studies was 0.48 % (IQR: 0.34 %-0.85 %). Prevalence across studies appeared to vary by study design, geographic region, time of assessment, and study quality scores; associations between study sample size and prevalence were not observed. Within studies, age-adjusted estimates were higher than crude estimates by 17 %-138 %, the use of a broader definition of schizophrenia spectrum disorders compared to schizophrenia increased case identification by 18 %-90 %, identification of cases from inpatient-only settings versus any setting decreased prevalence by 60 %, and no consistent trends were noted by differing diagnostic criteria. This review provides updated information on the epidemiology of schizophrenia in general populations, which is vital information for many stakeholders. Study characteristics

  11. Validation of estimated glomerular filtration rate equations for Japanese children.

    Science.gov (United States)

    Gotoh, Yoshimitsu; Uemura, Osamu; Ishikura, Kenji; Sakai, Tomoyuki; Hamasaki, Yuko; Araki, Yoshinori; Hamda, Riku; Honda, Masataka

    2018-01-25

    The gold standard for evaluation of kidney function is renal inulin clearance (Cin). However, the methodology for Cin is complicated and difficult, especially for younger children and/or patients with bladder dysfunction. Therefore, we developed a simple and easier method for obtaining the estimated glomerular filtration rate (eGFR) using equations and values for several biomarkers, i.e., serum creatinine (Cr), serum cystatin C (cystC), serum beta-2 microglobulin (β 2 MG), and creatinine clearance (Ccr). The purpose of the present study was to validate these equations with a new data set. To validate each equation, we used data of 140 patients with CKD with clinical need for Cin, using the measured GFR (mGFR). We compared the results for each eGFR equation with the mGFR using mean error (ME), root mean square error (RMSE), P 30 , and Bland-Altman analysis. The ME of Cr, cystC, β 2 MG, and Ccr based on eGFR was 15.8 ± 13.0, 17.2 ± 16.5, 15.4 ± 14.3, and 10.6 ± 13.0 ml/min/1.73 m 2 , respectively. The RMSE was 29.5, 23.8, 20.9, and 16.7, respectively. The P 30 was 79.4, 71.1, 69.5, and 92.9%, respectively. The Bland-Altman bias analysis showed values of 4.0 ± 18.6, 5.3 ± 16.8, 12.7 ± 17.0, and 2.5 ± 17.2 ml/min/1.73 m 2 , respectively, for these parameters. The bias of each eGFR equation was not large. Therefore, each eGFR equation could be used.

  12. Hepatitis C virus infection in USA: an estimate of true prevalence.

    Science.gov (United States)

    Chak, Eric; Talal, Andrew H; Sherman, Kenneth E; Schiff, Eugene R; Saab, Sammy

    2011-09-01

    The recent National Health and Nutrition Examination Survey (NHANES) sampled only the civilian, non-institutionalized population of USA and may have underestimated the prevalence of hepatitis C virus (HCV) in this country. We searched the database MEDLINE, the Bureau of Justice Statistics, Center for Medicare and Medicaid and individual states Department of Corrections for all epidemiological studies regarding the prevalence of HCV in populations not sampled by the NHANES survey namely the incarcerated, homeless, nursing home residents, hospitalized and those on active military duty. Because of their relatively low frequency in the NHANES sample, we also expanded our search to include healthcare workers and long-term dialysis patients. Although included in the NHANES sample, we also performed searches on drug users (injection and non-injection) and veterans to confirm the findings of the NHANES study. Based on the prevalence of studies identified meeting our inclusion criteria, our most conservative estimates state that there at least 142,761 homeless persons, 372,754 incarcerated persons and 6805 persons on active military duty unaccounted for in the NHANES survey. While the NHANES estimates of drug users (both injection and non-injection) appear to be reasonable, the survey seems to have underestimated the number of HCV-positive veterans. Our most conservative estimates suggest that there are at least 5.2 million persons living with HCV in USA today, approximately 1.9 million of whom were unaccounted for in the NHANES survey. © 2011 John Wiley & Sons A/S.

  13. Estimating the prevalence, hospitalisation and mortality from type 2 diabetes mellitus in Nigeria: a systematic review and meta-analysis.

    Science.gov (United States)

    Adeloye, Davies; Ige, Janet O; Aderemi, Adewale V; Adeleye, Ngozi; Amoo, Emmanuel O; Auta, Asa; Oni, Gbolahan

    2017-05-11

    There is not yet a comprehensive evidence-based epidemiological report on type 2 diabetes mellitus (T2DM) in Nigeria. We aimed to estimate country-wide and zonal prevalence, hospitalisation and mortality rates of T2DM in Nigeria. We searched MEDLINE, EMBASE, Global Health, Africa Journals Online (AJOL) and Google Scholar for population and hospital-based studies on T2DM in Nigeria. We conducted a random-effects meta-analysis on extracted crude estimates, and applied a meta-regression epidemiological model, using the United Nations demographics for Nigeria in 1990 and 2015 to determine estimates of diabetes in Nigeria for the two years. 42 studies, with a total population of 91 320, met our selection criteria. Most of the studies selected were of medium quality (90.5%). The age-adjusted prevalence rates of T2DM in Nigeria among persons aged 20-79 years increased from 2.0% (95% CI 1.9% to 2.1%) in 1990 to 5.7% (95% CI 5.5% to 5.8%) in 2015, accounting for over 874 000 and 4.7 million cases, respectively. The pooled prevalence rate of impaired glucose tolerance was 10.0% (95% CI 4.5% to 15.6%), while impaired fasting glucose was 5.8% (95% CI 3.8% to 7.8%). Hospital admission rate for T2DM was 222.6 (95% CI 133.1 to 312.1) per 100 000 population with hyperglycaemic emergencies, diabetic foot and cardiovascular diseases being most common complications. The overall mortality rate was 30.2 (95% CI 14.6 to 45.8) per 100 000 population, with a case fatality rate of 22.0% (95% CI 8.0% to 36.0%). Our findings suggest an increasing burden of T2DM in Nigeria with many persons currently undiagnosed, and few known cases on treatment. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. [Evaluation of estimation of prevalence ratio using bayesian log-binomial regression model].

    Science.gov (United States)

    Gao, W L; Lin, H; Liu, X N; Ren, X W; Li, J S; Shen, X P; Zhu, S L

    2017-03-10

    To evaluate the estimation of prevalence ratio ( PR ) by using bayesian log-binomial regression model and its application, we estimated the PR of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea in their infants by using bayesian log-binomial regression model in Openbugs software. The results showed that caregivers' recognition of infant' s risk signs of diarrhea was associated significantly with a 13% increase of medical care-seeking. Meanwhile, we compared the differences in PR 's point estimation and its interval estimation of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea and convergence of three models (model 1: not adjusting for the covariates; model 2: adjusting for duration of caregivers' education, model 3: adjusting for distance between village and township and child month-age based on model 2) between bayesian log-binomial regression model and conventional log-binomial regression model. The results showed that all three bayesian log-binomial regression models were convergence and the estimated PRs were 1.130(95 %CI : 1.005-1.265), 1.128(95 %CI : 1.001-1.264) and 1.132(95 %CI : 1.004-1.267), respectively. Conventional log-binomial regression model 1 and model 2 were convergence and their PRs were 1.130(95 % CI : 1.055-1.206) and 1.126(95 % CI : 1.051-1.203), respectively, but the model 3 was misconvergence, so COPY method was used to estimate PR , which was 1.125 (95 %CI : 1.051-1.200). In addition, the point estimation and interval estimation of PRs from three bayesian log-binomial regression models differed slightly from those of PRs from conventional log-binomial regression model, but they had a good consistency in estimating PR . Therefore, bayesian log-binomial regression model can effectively estimate PR with less misconvergence and have more advantages in application compared with conventional log-binomial regression model.

  15. Potential Impact of DSM-5 Criteria on Autism Spectrum Disorder Prevalence Estimates

    Science.gov (United States)

    Maenner, Matthew J.; Rice, Catherine E.; Arneson, Carrie L.; Cunniff, Christopher; Schieve, Laura A.; Carpenter, Laura A.; Van Naarden Braun, Kim; Kirby, Russell S.; Bakian, Amanda V.; Durkin, Maureen S.

    2014-01-01

    IMPORTANCE The DSM-5 contains revised diagnostic criteria for autism spectrum disorder (ASD) from the DSM-IV-TR. Potential impacts of the new criteria on ASD prevalence are unclear. OBJECTIVE To assess potential effects of the DSM-5 ASD criteria on ASD prevalence estimation by retrospectively applying the new criteria to population-based surveillance data collected for previous ASD prevalence estimation. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional, population-based ASD surveillance based on clinician review of coded behaviors documented in children’s medical and educational evaluations from 14 geographically defined areas in the United States participating in the Autism and Developmental Disabilities Monitoring (ADDM) Network in 2006 and 2008. This study included 8-year-old children living in ADDM Network study areas in 2006 or 2008, including 644 883 children under surveillance, of whom 6577 met surveillance ASD case status based on the DSM-IV-TR. MAIN OUTCOMES AND MEASURES Proportion of children meeting ADDM Network ASD criteria based on the DSM-IV-TR who also met DSM-5 criteria; overall prevalence of ASD using DSM-5 criteria. RESULTS Among the 6577 children classified by the ADDM Network as having ASD based on the DSM-IV-TR, 5339 (81.2%) met DSM-5 ASD criteria. This percentage was similar for boys and girls but higher for those with than without intellectual disability (86.6% and 72.5%, respectively; P DSM-5 ASD criteria but not current ADDM Network ASD case status. Based on these findings, ASD prevalence per 1000 for 2008 would have been 10.0 (95% CI, 9.6–10.3) using DSM-5 criteria compared with the reported prevalence based on DSM-IV-TR criteria of 11.3 (95% CI, 11.0–11.7). CONCLUSIONS AND RELEVANCE Autism spectrum disorder prevalence estimates will likely be lower under DSM-5 than under DSM-IV-TR diagnostic criteria, although this effect could be tempered by future adaptation of diagnostic practices and documentation of behaviors to fit the new

  16. Back pain in the working population: Prevalence rates in Dutch trades and professions

    NARCIS (Netherlands)

    Hildebrandt, V.H.

    1995-01-01

    An analysis of three health surveys in the Dutch working population is described, aimed at the identification of Dutch trades and professions with relative high and low prevalence rates of back pain. The sample was representative of the working population in the Netherlands and consisted of 5840 men

  17. Initial-rate based method for estimating the maximum heterotrophic growth rate parameter (μHmax).

    Science.gov (United States)

    Fall, C; Hooijmans, C M; Esparza-Soto, M; Olguin, M T; Bâ, K M

    2012-07-01

    Currently, the method most used for measuring the maximum specific growth rate (μ(Hmax)) of heterotrophic biomass is by respirometry, using growth batch tests performed at high food/microorganism ratio. No other technique has been suggested, although the former approach was criticized for providing kinetic constants that could be unrepresentative of the original biomass. An alternative method (seed-increments) is proposed, which relies on measuring the initial rates of respiration (r(O2)(_ini)) at different seeding levels, in a single batch, and in the presence of excess readily biodegradable substrate (S(S)). The ASM1-based underlying equations were developed, which showed that μ(Hmax) could be estimated through the slope of the linear function of r(O2)(_ini)·(V(WW)+v(ML)) vs v(ML) (volume of mixed liquor inoculum); V(WW) represent the wastewater volume added. The procedure was tested, being easy to apply; the postulated linearity was constantly observed and the method is claimed to measure the characteristics of the biomass of interest. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Can we use the pharmacy data to estimate the prevalence of chronic conditions? a comparison of multiple data sources

    Directory of Open Access Journals (Sweden)

    Borgia Piero

    2011-09-01

    Full Text Available Abstract Background The estimate of the prevalence of the most common chronic conditions (CCs is calculated using direct methods such as prevalence surveys but also indirect methods using health administrative databases. The aim of this study is to provide estimates prevalence of CCs in Lazio region of Italy (including Rome, using the drug prescription's database and to compare these estimates with those obtained using other health administrative databases. Methods Prevalence of CCs was estimated using pharmacy data (PD using the Anathomical Therapeutic Chemical Classification System (ATC. Prevalences estimate were compared with those estimated by hospital information system (HIS using list of ICD9-CM diagnosis coding, registry of exempt patients from health care cost for pathology (REP and national health survey performed by the Italian bureau of census (ISTAT. Results From the PD we identified 20 CCs. About one fourth of the population received a drug for treating a cardiovascular disease, 9% for treating a rheumatologic conditions. The estimated prevalences using the PD were usually higher that those obtained with one of the other sources. Regarding the comparison with the ISTAT survey there was a good agreement for cardiovascular disease, diabetes and thyroid disorder whereas for rheumatologic conditions, chronic respiratory illnesses, migraine and Alzheimer's disease, the prevalence estimates were lower than those estimated by ISTAT survey. Estimates of prevalences derived by the HIS and by the REP were usually lower than those of the PD (but malignancies, chronic renal diseases. Conclusion Our study showed that PD can be used to provide reliable prevalence estimates of several CCs in the general population.

  19. The Prevalence of ADHD in Fayoum City (Egypt) Among School-Age Children: Depending on a DSM-5-Based Rating Scale.

    Science.gov (United States)

    Aboul-Ata, Mohammad A; Amin, Fatma A

    2018-01-01

    In the present study, we created a new valid rating scale to estimate the prevalence of ADHD among school-age children in Fayoum City. We conducted two consequential studies (Studies 1 and 2). In Study 1, the sample comprised 106 children. The ages of the sample participants ranged between 6 and 14 years. The purpose of that study was to validate a new Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5)-based ADHD rating scale. In Study 2, the sample consisted of 420 children with ages ranging from 6 to 14 years. We used the new rating scale to estimate the prevalence of ADHD. The first study showed that the new rating scale for ADHD was valid. The second study revealed that the prevalence of ADHD in Fayoum City was 20.5%, with 33.8% among boys and 6.8% among girls. We validated a new ADHD rating scale and estimated the prevalence of ADHD in Fayoum City for the first time in Egypt.

  20. Estimates of global and regional prevalence of neural tube defects for 2015: a systematic analysis.

    Science.gov (United States)

    Blencowe, Hannah; Kancherla, Vijaya; Moorthie, Sowmiya; Darlison, Matthew W; Modell, Bernadette

    2018-02-01

    Neural tube defects (NTDs) are associated with substantial mortality, morbidity, disability, and psychological and economic costs. Many are preventable with folic acid, and access to appropriate services for those affected can improve survival and quality of life. We used a compartmental model to estimate global and regional birth prevalence of NTDs (live births, stillbirths, and elective terminations of pregnancy) and subsequent under-5 mortality. Data were identified through web-based reviews of birth defect registry databases and systematic literature reviews. Meta-analyses were undertaken where appropriate. For 2015, our model estimated 260,100 (uncertainty interval (UI): 213,800-322,000) NTD-affected birth outcomes worldwide (prevalence 18.6 (15.3-23.0)/10,000 live births). Approximately 50% of cases were elective terminations of pregnancy for fetal anomalies (UI: 59,300 (47,900-74,500)) or stillbirths (57,800 (UI: 35,000-88,600)). Of NTD-affected live births, 117,900 (∼75%) (UI: 105,500-186,600) resulted in under-5 deaths. Our systematic review showed a paucity of high-quality data in the regions of the world with the highest burden. Despite knowledge about prevention, NTDs remain highly prevalent worldwide. Lack of surveillance and incomplete ascertainment of affected pregnancies make NTDs invisible to policy makers. Improved surveillance of all adverse outcomes is needed to improve the robustness of total NTD prevalence estimation, evaluate effectiveness of prevention through folic acid fortification, and improve outcomes through care and rehabilitation. © 2018 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of New York Academy of Sciences.

  1. The Dynamics of Type 2 Diabetes Mellitus Prevalence and Management Rates among Rural Population in Henan Province, China

    Directory of Open Access Journals (Sweden)

    Xiaotian Liu

    2017-01-01

    Full Text Available The aim of this study was to estimate the dynamics of type 2 diabetes mellitus (T2DM prevalence and management rates based on a rural cohort study in Henan Province of China. The rural prospective study was conducted for 20194 Chinese population ≥18 years in 2007-2008 and followed during 2013-2014. A total of 14009 individuals were recruited for the prospective analysis ultimately. Over 5.74 years of follow-up, the age-standardized prevalence, awareness, treatment, and control of T2DM increased from 6.18%, 44.41%, 34.39%, and 19.08% at baseline to 7.87%, 59.64%, 52.17%, and 26.52% at follow-up in total population, respectively. Similar changes were found in men and women except the age-standardized control in men. The four parameters of T2DM were higher among various factors at follow-up than those at baseline. There was no statistical difference in awareness (P=0.089 and treatment (P=0.257 in the newly diagnosed T2DM compared with the rates at baseline. The current study indicated that the prevalence, awareness, treatment, and control of T2DM displayed chronological increasing trends while the awareness, treatment, and control of T2DM were still disproportionally low in central China. More works are needed urgently to popularize public health education and improve the quality of medical care in T2DM.

  2. Standing Shocks around Black Holes and Estimation of Outflow Rates

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... One can obtain the spectral properties, quasi-periodic oscillation frequencies and the outflowrates when the inflow parameters are known. Since temperature of the CENBOL decides the spectral states of the black hole, and also the outflow rate, the outflow rate is directly related to the spectral states.

  3. Redefinition and global estimation of basal ecosystem respiration rate

    NARCIS (Netherlands)

    Jacobs, C.M.J.; Yuan, W.

    2011-01-01

    Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still

  4. Redefinition and global estimation of basal ecosystem respiration rate

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Wenping [College of Global Change and Earth System Science, Beijing Normal University, Beijing, China; Luo, Yiqi [Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma, USA; Li, Xianglan [College of Global Change and Earth System Science, Beijing Normal University, Beijing, China; Liu, Shuguang; Yu, Guirui [Key Laboratory of Ecosystem Network Observation and Modeling, Synthesis Research Center of Chinese Ecosystem Research Network, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; Zhou, Tao [State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China; Bahn, Michael [Institute of Ecology, University of Innsbruck, Innsbruck, Austria; Black, Andy [Faculty of Land and Food Systems, University of British Columbia, Vancouver, B. C., Canada; Desai, Ankur R. [Atmospheric and Oceanic Sciences Department, Center for Climatic Research, Nelson Institute for Environmental Studies, University of Wisconsin-Madison, Madison, Wisconsin, USA; Cescatti, Alessandro [Institute for Environment and Sustainability, Joint Research Centre, European Commission, Ispra, Italy; Marcolla, Barbara [Sustainable Agro-ecosystems and Bioresources Department, Fondazione Edmund Mach-IASMA Research and Innovation Centre, San Michele all' Adige, Italy; Jacobs, Cor [Alterra, Earth System Science-Climate Change, Wageningen University, Wageningen, Netherlands; Chen, Jiquan [Department of Earth, Ecological, and Environmental Sciences, University of Toledo, Toledo, Ohio, USA; Aurela, Mika [Climate and Global Change Research, Finnish Meteorological Institute, Helsinki, Finland; Bernhofer, Christian [Chair of Meteorology, Institute of Hydrology and Meteorology, Technische Universität Dresden, Dresden, Germany; Gielen, Bert [Department of Biology, University of Antwerp, Wilrijk, Belgium; Bohrer, Gil [Department of Civil, Environmental, and Geodetic Engineering, Ohio State University, Columbus, Ohio, USA; Cook, David R. [Climate Research Section, Environmental Science Division, Argonne National Laboratory, Argonne, Illinois, USA; Dragoni, Danilo [Department of Geography, Indiana University, Bloomington, Indiana, USA; Dunn, Allison L. [Department of Physical and Earth Sciences, Worcester State College, Worcester, Massachusetts, USA; Gianelle, Damiano [Sustainable Agro-ecosystems and Bioresources Department, Fondazione Edmund Mach-IASMA Research and Innovation Centre, San Michele all' Adige, Italy; Grünwald, Thomas [Chair of Meteorology, Institute of Hydrology and Meteorology, Technische Universität Dresden, Dresden, Germany; Ibrom, Andreas [Risø DTU National Laboratory for Sustainable Energy, Biosystems Division, Technical University of Denmark, Roskilde, Denmark; Leclerc, Monique Y. [Department of Crop and Soil Sciences, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, Georgia, USA; Lindroth, Anders [Geobiosphere Science Centre, Physical Geography and Ecosystems Analysis, Lund University, Lund, Sweden; Liu, Heping [Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington, USA; Marchesini, Luca Belelli [Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, Viterbo, Italy; Montagnani, Leonardo; Pita, Gabriel [Department of Mechanical Engineering, Instituto Superior Técnico, Lisbon, Portugal; Rodeghiero, Mirco [Sustainable Agro-ecosystems and Bioresources Department, Fondazione Edmund Mach-IASMA Research and Innovation Centre, San Michele all' Adige, Italy; Rodrigues, Abel [Unidade de Silvicultura e Produtos Florestais, Instituto Nacional dos Recursos Biológicos, Oeiras, Portugal; Starr, Gregory [Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA; Stoy, Paul C. [Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, USA

    2011-10-13

    Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still use a global constant BR largely due to the lack of a functional description for BR. In this study, we redefined BR to be ecosystem respiration rate at the mean annual temperature. To test the validity of this concept, we conducted a synthesis analysis using 276 site-years of eddy covariance data, from 79 research sites located at latitudes ranging from ~3°S to ~70°N. Results showed that mean annual ER rate closely matches ER rate at mean annual temperature. Incorporation of site-specific BR into global ER model substantially improved simulated ER compared to an invariant BR at all sites. These results confirm that ER at the mean annual

  5. Should physicians always rely on estimated glomerular filtration rate without knowing the equation?

    Directory of Open Access Journals (Sweden)

    Fabbian F

    2017-08-01

    Full Text Available Fabio Fabbian, Dario Priori, Alfredo De Giorgi Department of Medical Sciences, Clinica Medica Unit, University Hospital St Anna, University of Ferrara, Ferrara, ItalyWe read with interest the paper written by Deskur-Smielecka et al1 who investigated the performance of three equations for valuating renal function in 174 patients, aged 78 years, with different cancer diagnosis. They used Cockcroft–Gault (C–G, Modification of Diet in Renal Disease (MDRD, and Berlin Initiative Study1 (BIS1 equations and found that there is a considerable disagreement between renal function estimation formulas. We also performed two studies evaluating different formulas for the calculation of glomerular filtration rate (GFR in patients with eating disorders2 and in those with type 2 diabetes mellitus (DM.3Authors’ replyEwa Deskur-Smielecka1,2 Aleksandra Kotlinska-Lemieszek1,2 Jerzy Chudek3,4 Katarzyna Wieczorowska-Tobis1,2The letter from Fabbian et al, in general, supports our findings concerning the disagreement between currently used equations for the estimation of glomerular filtration rate (GFR. We agree that disagreement in the estimation of kidney function was previously found by a number of authors. However, in our paper1 we describe this aspect in very specific population – geriatric, palliative care patients – with high prevalence of cachexia and substantial muscle mass loss. Our group has shown some similarities (low creatinine generation to the group of patients with anorexia nervosa and bulimia nervosa studied by Fabbian et al.2 However, it has to be stressed that patients with anorexia nervosa and bulimia nervosa were much younger, and therefore had much better, mostly normal kidney function. The second population analyzed by Fabbian et al3 – diabetic patients – also differ from out cohort, as they were better nourished. Regardless of these differences, the conclusions concerning the disagreement of different methods in the estimation of

  6. [Prevalence estimates of problem drug users in the Czech Republic in 2006 and 2007 using the capture-recapture method].

    Science.gov (United States)

    Mravčík, Viktor; Sopko, Bruno

    2013-07-01

    An estimate of problem drug use prevalence is a substantial part of the monitoring of the epidemiological situation in drug use and its consequences and an important indicator for drug policy implementation. The capture-recapture method (CRM) is one of the most commonly used standard methods for this purpose worldwide. The CRM was used to estimate the numbers of problem drug users (PDU) and problem users of opiates/opioids (PUO) in the Czech Republic in 2006 and 2007. The following data sources were used: the General Health Insurance Company records of payments to out- and in-patient psychiatric care providers, records of admissions to psychiatric hospitals, replacement therapy register, and reports of newly diagnosed cases of viral hepatitis. Cases were defined as diagnoses F11, F15, and F19 according to the International Classification of Diseases, Tenth Revision (ICD-10) from the health insurance and admission records, the replacement therapy register covers PUO by definition, and injecting drug users were selected from reported cases of viral hepatitis. Log-linear analysis in Rcapture (R) was performed and the Akaike information criterion was used for model selection. Altogether 12,882 and 13,505 individuals entered into analysis of PDUs and 5146 and 5409 individuals entered into analysis of PUO in 2006 and 2007, respectively. The estimates of PDUs were 23,900 (95% CI: 20,700-28,500) in 2006 and 31,000 (25,500-39,400) in 2007. The estimates of PUO were 6,864 (6,641-7,113) in 2006 and 7,096 (6,871-7,346) in 2007. The male/female ratio was 2.2/1. In PDU estimates, 83% were in the age range 15-34 and 17% were aged above 34; in PUO estimates, the respective rates were 80% and 20%. The prevalence rates of PDU in the age range 15-64 were 2.28 and 2.95 per 1,000 population in 2006 and 2007, respectively. The prevalence rates of PUO in the age range 15-64 were 0.65 and 0.67 per 1,000 in 2006 and 2007, respectively. The highest prevalence of both PDUs and PUO was

  7. A Priori Estimation of Rate Constants for Unimolecular Decomposition Reactions

    Science.gov (United States)

    1979-02-01

    activation energy, Ea, which is assumed to equal the critical energy. A thermochemical argument by Batt and McCulloch estimates Ea= 25 kcal mol The...Commander US Army Tank Automotive Research SCommander and Development Command US Army Materiel Development ATTN: DRDTA-UL and Readiness Command Warren , MI

  8. Reconciling Estimates of Earnings Processes in Growth Rates and Levels

    DEFF Research Database (Denmark)

    Daly, Moira; Hryshko, Dmytro; Manovskii, Iourii

    magnitudes of the permanent and transitory innovations in earnings. When estimation is based on the earnings moments in levels, the variance of transitory shocks is found to be relatively high. When the moments in differences are used, the variance of the permanent component is relatively high instead. We...

  9. Using genetic data to estimate diffusion rates in heterogeneous landscapes.

    Science.gov (United States)

    Roques, L; Walker, E; Franck, P; Soubeyrand, S; Klein, E K

    2016-08-01

    Having a precise knowledge of the dispersal ability of a population in a heterogeneous environment is of critical importance in agroecology and conservation biology as it can provide management tools to limit the effects of pests or to increase the survival of endangered species. In this paper, we propose a mechanistic-statistical method to estimate space-dependent diffusion parameters of spatially-explicit models based on stochastic differential equations, using genetic data. Dividing the total population into subpopulations corresponding to different habitat patches with known allele frequencies, the expected proportions of individuals from each subpopulation at each position is computed by solving a system of reaction-diffusion equations. Modelling the capture and genotyping of the individuals with a statistical approach, we derive a numerically tractable formula for the likelihood function associated with the diffusion parameters. In a simulated environment made of three types of regions, each associated with a different diffusion coefficient, we successfully estimate the diffusion parameters with a maximum-likelihood approach. Although higher genetic differentiation among subpopulations leads to more accurate estimations, once a certain level of differentiation has been reached, the finite size of the genotyped population becomes the limiting factor for accurate estimation.

  10. Bayesian nonparametric estimation of hazard rate in monotone Aalen model

    Czech Academy of Sciences Publication Activity Database

    Timková, Jana

    2014-01-01

    Roč. 50, č. 6 (2014), s. 849-868 ISSN 0023-5954 Institutional support: RVO:67985556 Keywords : Aalen model * Bayesian estimation * MCMC Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.541, year: 2014 http://library.utia.cas.cz/separaty/2014/SI/timkova-0438210.pdf

  11. Mean square convergence rates for maximum quasi-likelihood estimators

    NARCIS (Netherlands)

    den Boer, A.V.; Zwart, Bert

    2014-01-01

    In this note we study the behavior of maximum quasilikelihood estimators (MQLEs) for a class of statistical models, in which only knowledge about the first two moments of the response variable is assumed. This class includes, but is not restricted to, generalized linear models with general link

  12. Combining heart rate and accelerometer data to estimate physical fitness

    NARCIS (Netherlands)

    Tönis, Thijs; Vollenbroek-Hutten, Miriam Marie Rosé; Hermens, Hermanus J.

    2012-01-01

    Monitoring changes in physical fitness is relevant in many conditions and groups of patients, but its estimation demands substantial effort from the person, personnel and equipment. Besides that, present (sub) maximal exercise tests give a momentary fitness score, which depends on many (external)

  13. Prevalence rate and dentoskeletal features associated with buccally displaced maxillary canines.

    Science.gov (United States)

    Mucedero, Manuela; Ricchiuti, Maria Rosaria; Cozza, Paola; Baccetti, Tiziano

    2013-06-01

    The aim of the study was to analyse the prevalence and distribution of buccally displaced canines (BDCs) in subjects scheduled for orthodontic treatment and to investigate the association between BDC and sagittal, vertical, and transverse dentoskeletal relationships. A study sample of 1852 subjects was examined, and it was divided randomly into two groups. A first group of 252 subjects served as control group: the 'reference' prevalence rates for the examined parameters were calculated in this group. The remaining 1600 subjects comprised the sample from which the experimental BDC group was derived. Presence of unilateral or bilateral maxillary BDC, ANB, and SN GOGn angles for sagittal and vertical skeletal relationships, intercanine and intermolar distances, and tooth crowding at the maxillary arch were recorded for each subject. The statistical significance of differences between the BDC and the control groups in transverse relations and tooth crowding at the upper arch was tested by means of independent sample t-tests. Chi-square tests were performed to compare the prevalence rates of BDC and also sagittal and vertical skeletal features in the two groups. The prevalence rate of BDC was 3.06 per cent with a male-to-female ratio of 1:1. BDC subjects exhibited a significant association with hyperdivergent skeletal relationships (38.8%), reduced maxillary intercanine width, and crowding in the upper arch. The presence of specific dentoskeletal characteristics can be considered as a risk indicator for developing a buccal displacement of upper permanent canines.

  14. Body dysmorphic disorder in different settings: A systematic review and estimated weighted prevalence.

    Science.gov (United States)

    Veale, David; Gledhill, Lucinda J; Christodoulou, Polyxeni; Hodsoll, John

    2016-09-01

    Our aim was to systematically review the prevalence of body dysmorphic disorder (BDD) in a variety of settings. Weighted prevalence estimate and 95% confidence intervals in each study were calculated. The weighted prevalence of BDD in adults in the community was estimated to be 1.9%; in adolescents 2.2%; in student populations 3.3%; in adult psychiatric inpatients 7.4%; in adolescent psychiatric inpatients 7.4%; in adult psychiatric outpatients 5.8%; in general cosmetic surgery 13.2%; in rhinoplasty surgery 20.1%; in orthognathic surgery 11.2%; in orthodontics/cosmetic dentistry settings 5.2%; in dermatology outpatients 11.3%; in cosmetic dermatology outpatients 9.2%; and in acne dermatology clinics 11.1%. Women outnumbered men in the majority of settings but not in cosmetic or dermatological settings. BDD is common in some psychiatric and cosmetic settings but is poorly identified. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Estimated prevalence of compulsive buying in Germany and its association with sociodemographic characteristics and depressive symptoms.

    Science.gov (United States)

    Mueller, Astrid; Mitchell, James E; Crosby, Ross D; Gefeller, Olaf; Faber, Ronald J; Martin, Alexandra; Bleich, Stefan; Glaesmer, Heide; Exner, Cornelia; de Zwaan, Martina

    2010-12-30

    The aim of this study was to estimate the prevalence of compulsive buying and its association with sociodemographic characteristics and depressive symptoms in a nationally representative sample of the German population using the validated German version of the Compulsive Buying Scale (CBS; Faber and O'Guinn, 1992) in order to have a direct comparison with U.S. findings. The point prevalence of compulsive buying in the weighted representative sample (N=2,350) was estimated to be 6.9%. This was somewhat higher than the percentage in the American sample assessed in 2004 (5.8%). No significant difference was found between women and men (6.9% and 6.8%, respectively). Age was inversely related to the prevalence of compulsive buying. Individuals with compulsive buying reported more depressive symptoms assessed via the German version of the Brief Patient Health Questionnaire Mood Scale (PHQ-9). Further research on this topic is needed to establish a clearer delineation of when excessive buying is clinically significant and should be treated and how it could be prevented. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  16. Prevalence, Treatment, and Control Rates of Conventional and Ambulatory Hypertension Across 10 Populations in 3 Continents

    DEFF Research Database (Denmark)

    Melgarejo, Jesus D.; Maestre, Gladys E; Thijs, Lutgarde

    2017-01-01

    Hypertension is a major global health problem, but prevalence rates vary widely among regions. To determine prevalence, treatment, and control rates of hypertension, we measured conventional blood pressure (BP) and 24-hour ambulatory BP in 6546 subjects, aged 40 to 79 years, recruited from 10...... community-dwelling cohorts on 3 continents. We determined how between-cohort differences in risk factors and socioeconomic factors influence hypertension rates. The overall prevalence was 49.3% (range between cohorts, 40.0%-86.8%) for conventional hypertension (conventional BP ≥140/90 mm Hg) and 48.7% (35.......2%-66.5%) for ambulatory hypertension (ambulatory BP ≥130/80 mm Hg). Treatment and control rates for conventional hypertension were 48.0% (33.5%-74.1%) and 38.6% (10.1%-55.3%) respectively. The corresponding rates for ambulatory hypertension were 48.6% (30.5%-71.9%) and 45.6% (18.6%-64.2%). Among 1677 untreated subjects...

  17. Estimated prevalence of polysaccharide storage myopathy among overtly healthy Quarter Horses in the United States.

    Science.gov (United States)

    McCue, Molly E; Valberg, Stephanie J

    2007-09-01

    To estimate the prevalence of polysaccharide storage myopathy (PSSM) among Quarter Horses in the United States and evaluate possible relationships between muscle glycogen concentration, turnout time, and exercise level. Cross-sectional study. 164 overtly healthy Quarter Horses > 2 years old from 5 states. Horses with a history of exertional rhabdomyolysis or any other muscular disease were excluded. Muscle biopsy specimens were examined histologically for evidence of PSSM and were submitted for determination of muscle glycogen concentration. A diagnosis of PSSM was made if amylase-resistant inclusions that stained with periodic acid-Schiff stain were detected. Prevalences of PSSM on the 2 farms with a history of PSSM were 20% (1/5) and 40.7% (11/27); mean prevalence for the other 4 farms was 6.1% (8/132). Sex was not significantly associated with a diagnosis of PSSM, and age was not significantly different between horses with and without PSSM. Total histologic score, serum creatine kinase activity, and muscle glycogen concentration were significantly higher in horses with PSSM than in horses without. Results suggested that the prevalence of PSSM among overtly healthy Quarter Horses in the United States is likely to be between 6% and 12%.

  18. Estimating the global prevalence of inadequate zinc intake from national food balance sheets: effects of methodological assumptions.

    Directory of Open Access Journals (Sweden)

    K Ryan Wessells

    Full Text Available The prevalence of inadequate zinc intake in a population can be estimated by comparing the zinc content of the food supply with the population's theoretical requirement for zinc. However, assumptions regarding the nutrient composition of foods, zinc requirements, and zinc absorption may affect prevalence estimates. These analyses were conducted to: (1 evaluate the effect of varying methodological assumptions on country-specific estimates of the prevalence of dietary zinc inadequacy and (2 generate a model considered to provide the best estimates.National food balance data were obtained from the Food and Agriculture Organization of the United Nations. Zinc and phytate contents of these foods were estimated from three nutrient composition databases. Zinc absorption was predicted using a mathematical model (Miller equation. Theoretical mean daily per capita physiological and dietary requirements for zinc were calculated using recommendations from the Food and Nutrition Board of the Institute of Medicine and the International Zinc Nutrition Consultative Group. The estimated global prevalence of inadequate zinc intake varied between 12-66%, depending on which methodological assumptions were applied. However, country-specific rank order of the estimated prevalence of inadequate intake was conserved across all models (r = 0.57-0.99, P<0.01. A "best-estimate" model, comprised of zinc and phytate data from a composite nutrient database and IZiNCG physiological requirements for absorbed zinc, estimated the global prevalence of inadequate zinc intake to be 17.3%.Given the multiple sources of uncertainty in this method, caution must be taken in the interpretation of the estimated prevalence figures. However, the results of all models indicate that inadequate zinc intake may be fairly common globally. Inferences regarding the relative likelihood of zinc deficiency as a public health problem in different countries can be drawn based on the country

  19. Prostate cancer trends in Latvia during 1990-2012: incidence, prevalence, mortality, and survival rates.

    Science.gov (United States)

    Plonis, Juris; Bokums, Kristaps; Cauce, Vinita; Miklasevics, Edvins; Vaganovs, Peteris; Irmejs, Arvids; Gardovskis, Janis; Vjaters, Egils

    2014-01-01

    Prostate cancer (PCa) is one of the most common form of cancer in males worldwide. One of the highest PCa-related mortality rates in the world is observed in Latvia. Our study included male patients diagnosed with PCa between 1990 and 2012. We analyzed incidence, prevalence and mortality trends using joinpoint analysis. Kaplan-Meier analysis was performed for 5-, 10-, 15- and 20-year overall survival and cancer-specific survival rates. A total of 14,083PCa patients with a mean age of initial PCa diagnosis being 70.1 (SD 8.6) was registered. The standardized incidence rates (per 100,000) increased from 18.9 in 1990 to 74.7 in 2012, while the standardized prevalence rates (per 100,000) increased from 69.9 in 1990 to 437.6 in 2012. Standardized PCa mortality rates (per 100,000) also rose from 13.2 in 1990 to 27.2 in 2006 followed by statistically insignificant decrease continuing up to 2012. The mean 5-year cancer-specific survival rates increased from 43.6% in 1990 to 70.7% in 2007, and the mean 10-year cancer-specific survival rates from 32.9% in 1990 to 40.5% in 2001. This study revealed that the incidence, prevalence and mortality rates increased between 1990 and 2012, and although the 5- and 10-year overall and cancer-specific survival rates improved over the reviewed period they still needed to get better. Copyright © 2014 Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  20. Estimating the market premium in short term interest rates

    OpenAIRE

    Hansen, Hans Fredrik

    2006-01-01

    Looking at the term structure in the interest rate market one can’t help notice the evident market premium above the central banks target rate. What factors might decide this premium? By using different variations of simple regression models we see that the model is constantly lagging the real time series. Acknowledging the fact that market clearings often are subject to several equations; we’re better able to develop a sensible model using a simultaneous equilibrium model. The multiple equat...

  1. Capture-recapture analysis for estimating manatee reproductive rates

    Science.gov (United States)

    Kendall, W.L.; Langtimm, C.A.; Beck, C.A.; Runge, M.C.

    2004-01-01

    Modeling the life history of the endangered Florida manatee (Trichechus manatus latirostris) is an important step toward understanding its population dynamics and predicting its response to management actions. We developed a multi-state mark-resighting model for data collected under Pollock's robust design. This model estimates breeding probability conditional on a female's breeding state in the previous year; assumes sighting probability depends on breeding state; and corrects for misclassification of a cow with first-year calf, by estimating conditional sighting probability for the calf. The model is also appropriate for estimating survival and unconditional breeding probabilities when the study area is closed to temporary emigration across years. We applied this model to photo-identification data for the Northwest and Atlantic Coast populations of manatees, for years 1982?2000. With rare exceptions, manatees do not reproduce in two consecutive years. For those without a first-year calf in the previous year, the best-fitting model included constant probabilities of producing a calf for the Northwest (0.43, SE = 0.057) and Atlantic (0.38, SE = 0.045) populations. The approach we present to adjust for misclassification of breeding state could be applicable to a large number of marine mammal populations.

  2. Prevalence, Treatment, and Control Rates of Conventional and Ambulatory Hypertension Across 10 Populations in 3 Continents.

    Science.gov (United States)

    Melgarejo, Jesus D; Maestre, Gladys E; Thijs, Lutgarde; Asayama, Kei; Boggia, José; Casiglia, Edoardo; Hansen, Tine W; Imai, Yutaka; Jacobs, Lotte; Jeppesen, Jørgen; Kawecka-Jaszcz, Kalina; Kuznetsova, Tatiana; Li, Yan; Malyutina, Sofia; Nikitin, Yuri; Ohkubo, Takayoshi; Stolarz-Skrzypek, Katarzyna; Wang, Ji-Guang; Staessen, Jan A

    2017-07-01

    Hypertension is a major global health problem, but prevalence rates vary widely among regions. To determine prevalence, treatment, and control rates of hypertension, we measured conventional blood pressure (BP) and 24-hour ambulatory BP in 6546 subjects, aged 40 to 79 years, recruited from 10 community-dwelling cohorts on 3 continents. We determined how between-cohort differences in risk factors and socioeconomic factors influence hypertension rates. The overall prevalence was 49.3% (range between cohorts, 40.0%-86.8%) for conventional hypertension (conventional BP ≥140/90 mm Hg) and 48.7% (35.2%-66.5%) for ambulatory hypertension (ambulatory BP ≥130/80 mm Hg). Treatment and control rates for conventional hypertension were 48.0% (33.5%-74.1%) and 38.6% (10.1%-55.3%) respectively. The corresponding rates for ambulatory hypertension were 48.6% (30.5%-71.9%) and 45.6% (18.6%-64.2%). Among 1677 untreated subjects with conventional hypertension, 35.7% had white coat hypertension (23.5%-56.2%). Masked hypertension (conventional BP hypertension rates. Higher social and economic development, measured by the Human Development Index, was associated with lower rates of conventional and ambulatory hypertension. In conclusion, high rates of hypertension in all cohorts examined demonstrate the need for improvements in prevention, treatment, and control. Strategies for the management of hypertension should continue to not only focus on preventable and modifiable risk factors but also consider societal issues. © 2017 American Heart Association, Inc.

  3. Curve fitting of the corporate recovery rates: the comparison of Beta distribution estimation and kernel density estimation.

    Directory of Open Access Journals (Sweden)

    Rongda Chen

    Full Text Available Recovery rate is essential to the estimation of the portfolio's loss and economic capital. Neglecting the randomness of the distribution of recovery rate may underestimate the risk. The study introduces two kinds of models of distribution, Beta distribution estimation and kernel density distribution estimation, to simulate the distribution of recovery rates of corporate loans and bonds. As is known, models based on Beta distribution are common in daily usage, such as CreditMetrics by J.P. Morgan, Portfolio Manager by KMV and Losscalc by Moody's. However, it has a fatal defect that it can't fit the bimodal or multimodal distributions such as recovery rates of corporate loans and bonds as Moody's new data show. In order to overcome this flaw, the kernel density estimation is introduced and we compare the simulation results by histogram, Beta distribution estimation and kernel density estimation to reach the conclusion that the Gaussian kernel density distribution really better imitates the distribution of the bimodal or multimodal data samples of corporate loans and bonds. Finally, a Chi-square test of the Gaussian kernel density estimation proves that it can fit the curve of recovery rates of loans and bonds. So using the kernel density distribution to precisely delineate the bimodal recovery rates of bonds is optimal in credit risk management.

  4. Curve fitting of the corporate recovery rates: the comparison of Beta distribution estimation and kernel density estimation.

    Science.gov (United States)

    Chen, Rongda; Wang, Ze

    2013-01-01

    Recovery rate is essential to the estimation of the portfolio's loss and economic capital. Neglecting the randomness of the distribution of recovery rate may underestimate the risk. The study introduces two kinds of models of distribution, Beta distribution estimation and kernel density distribution estimation, to simulate the distribution of recovery rates of corporate loans and bonds. As is known, models based on Beta distribution are common in daily usage, such as CreditMetrics by J.P. Morgan, Portfolio Manager by KMV and Losscalc by Moody's. However, it has a fatal defect that it can't fit the bimodal or multimodal distributions such as recovery rates of corporate loans and bonds as Moody's new data show. In order to overcome this flaw, the kernel density estimation is introduced and we compare the simulation results by histogram, Beta distribution estimation and kernel density estimation to reach the conclusion that the Gaussian kernel density distribution really better imitates the distribution of the bimodal or multimodal data samples of corporate loans and bonds. Finally, a Chi-square test of the Gaussian kernel density estimation proves that it can fit the curve of recovery rates of loans and bonds. So using the kernel density distribution to precisely delineate the bimodal recovery rates of bonds is optimal in credit risk management.

  5. Probabilistic estimation of entrainment rate in coarse sediment beds

    Science.gov (United States)

    Bottacin-Busolin, Andrea; Tregnaghi, Matteo; Cecchetto, Martina; Marion, Andrea; Tait, Simon

    2017-04-01

    Many problems in river and coastal engineering depend on sediment transport dynamics induced by turbulent flows over sediment beds. Given the chaotic nature of turbulence and the complex mechanics of granular beds, grain-scale interactions between fluid and sediment are better described using stochastic approaches. A probabilistic model is presented linking entrainment rate to the stochastic properties of the near-bed fluid velocity and the probability distribution of particle elevation. By using a simplified description of the mechanics of grain dislodgement, the distribution of particle waiting time is derived, which is linked to the entrainment rate. The predictive capability of the model and the associated uncertainty are analysed using near-bed flow field and grain motion data obtained from flume experiments at low transport stages. The model predictions are found to be in good agreement with the data. Experimental evidence of distinct entrainment mechanisms is discussed, and flow patterns are identified that cause significant fluctuations in the entrainment rate.

  6. Estimating spontaneous mutation rates at enzyme loci in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mukai, Terumi; Yamazaki, Tsuneyuki; Harada, Ko; Kusakabe, Shin-ichi

    1990-04-01

    Spontaneous mutations were accumulated for 1,620,826 allele-generations on chromosomes that originated from six stem second chromosomes of Drosophila melanogaster. Only null-electromorph mutations were detected. Band-electromorph mutations were not found. The average rate of null-electromorph mutations was 2.71 x 10 -5 per locus per generation. The 95% confidence interval (μ n ) was 1.97 x 10 -5 n -5 per locus per generation. The upper 95% confidence limit of the band-electromorph mutation rate (μ B ) was 2.28 x 10 -6 per locus per generation. It appeared that null mutations were induced by movable genetic elements and that the mutation rates were different from chromosome to chromosome. (author)

  7. Prevalent Rate of Nonalbuminuric Renal Insufficiency and Its Association with Cardiovascular Disease Event in Korean Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Hye Won Lee

    2016-12-01

    Full Text Available BackgroundNonalbuminuric renal insufficiency is a unique category of diabetic kidney diseases. The objectives of the study were to evaluate prevalent rate of nonalbuminuric renal insufficiency and to investigate its relationship with previous cardiovascular disease (CVD event in Korean patients with type 2 diabetes mellitus (T2DM.MethodsLaboratory and clinical data of 1,067 subjects with T2DM were obtained and reviewed. Study subjects were allocated into four subgroups according to the CKD classification. Major CVD events were included with coronary, cerebrovascular, and peripheral vascular events.ResultsNonalbuminuric stage ≥3 CKD group, when compared with albuminuric stage ≥3 CKD group, had shorter diabetic duration, lower concentrations of glycated hemoglobin, high density lipoprotein cholesterol, and high-sensitivity C-reactive protein, lower prevalent rates of retinopathy and previous CVD, and higher rate of treatment with angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Nonalbuminuric stage ≥3 CKD group showed a greater association with prior CVD events than no CKD group; however, albuminuric stage ≥3 CKD group made addition to increase prevalence of prior CVD events significantly when CKD categories were applied as covariates. Association of prior CVD events, when compared with normal estimated glomerular filtration rate (eGFR and nonalbuminuria categories, became significant for declined eGFR, which was higher for eGFR of <30 mL/min/1.73 m2, and albuminuria.ConclusionThe results show that subjects with nonalbuminuric stage ≥3 CKD is significantly interrelated with occurrence of prior CVD events than those with normal eGFR with or without albuminuria. Comparing with normal eGFR and nonalbuminuria categories, the combination of increased degree of albuminuria and declined eGFR is becoming significant for the association of prior CVD events.

  8. Estimating disability prevalence among adults by body mass index: 2003-2009 National Health Interview Survey.

    Science.gov (United States)

    Armour, Brian S; Courtney-Long, Elizabeth; Campbell, Vincent A; Wethington, Holly R

    2012-01-01

    Obesity is associated with adverse health outcomes in people with and without disabilities; however, little is known about disability prevalence among people who are obese. The purpose of this study was to determine the prevalence and type of disability among obese adults in the United States. We analyzed pooled data from sample adult modules of the 2003-2009 National Health Interview Survey (NHIS) to obtain national prevalence estimates of disability, disability type, and obesity by using 30 questions that screened for activity limitations, vision and hearing impairment, and cognitive, movement, and emotional difficulties. We stratified disability prevalence by category of body mass index (BMI, measured as kg/m(2)): underweight, less than 18.5; normal weight, 18.5 to 24.9; overweight, 25.0 to 29.9; and obese, 30.0 or higher. Among the 25.3% of adult men and 24.6% of women in our pooled sample who were obese, 35.2% and 46.9%, respectively, reported a disability. In contrast, 26.7% of men and 26.8% women of normal weight reported a disability. Disability was much higher among obese women than among obese men (46.9% vs 35.2%, P < .001). Movement difficulties were the most common disabilities among obese men and women, affecting 25.3% of men and 37.9% of women. This research contributes to the literature on obesity by including disability as a demographic in characterizing people by body mass index. Because of the high prevalence of disability among those who are obese, public health programs should consider the needs of those with disabilities when designing obesity prevention and treatment programs.

  9. Prevalence rates and epidemiological risk factors for astigmatism in Singapore school children.

    Science.gov (United States)

    Tong, Louis; Saw, Seang-Mei; Carkeet, Andrew; Chan, Wai-Ying; Wu, Hui-Min; Tan, Donald

    2002-09-01

    This study examined the prevalence rate of astigmatism and its epidemiological risk factors in Singapore school children. In a study of school children aged 7 to 9 years old in two schools in Singapore in 1999, a detailed questionnaire was administered to parents regarding reading or close-work habits, past history of close-work, family history, and socioeconomic factors. Cycloplegic refraction was performed five times in each eye. Defining astigmatism as worse than or equal to 0.5, 0.75, and 1 D cylinder in the right eye, the prevalence of astigmatism was calculated. The study population consisted of 1028 children. The prevalence rate of astigmatism (worse than or equal to 1 D cylinder) was 19.2% (95% confidence interval, 16.8 to 21.6). This was not different between genders, ethnic groups, or age (p > 0.05). With-the-rule astigmatism was more common than against-the-rule astigmatism. The prevalence of astigmatism and myopia was 9.8% (95% confidence interval, 8.0 to 11.6). A high AC/A ratio was associated (p = 0.003) with astigmatism, even after exclusion of myopic children. On vectorial analysis, J0 and J45 were associated with the number of hours of playing video games, whereas J45 was also associated with computer use. Only J45 was associated to male gender, a high AC/A ratio, and a family history of myopia. The prevalence rate of astigmatism (> or = 1 D) was 19%. Playing video games and computer use may be associated with astigmatism severity, although the presence of astigmatism (> or = 1 D) was not associated with any nearwork factors. A family history of myopia was associated with oblique astigmatism severity. A high AC/A ratio is associated with astigmatism, and this requires further investigation.

  10. Haldane and the first estimates of the human mutation rate

    Indian Academy of Sciences (India)

    Unknown

    the mouse and dog genomes shows that their selective con- straint is independent of their genic environment. Genome. Res. 14, 852–859. Drake J. W., Charlesworth B., Charlesworth D. and Crow J. F.. 1998 Rates of spontaneous mutation. Genetics 148, 1667–. 1686. Haldane J. B. S. 1927 A mathematical theory of natural ...

  11. Estimated migration rates under scenarios of global climate change.

    Science.gov (United States)

    Jay R. Malcolm; Adam Markham; Ronald P. Neilson; Michael. Oaraci

    2002-01-01

    Greefihouse-induced warming and resulting shifts in climatic zones may exceed the migration capabilities of some species. We used fourteen combinations of General Circulation Models (GCMs) and Global Vegetation Models (GVMs) to investigate possible migration rates required under CO2 doubled climatic forcing.

  12. Estimated glomerular filtration rate at initiation of hemodialysis in a ...

    African Journals Online (AJOL)

    Background: Renal replacement therapy is indicated for patients with end-stage renal disease (ESRD). The glomerular filtration rate (GFR) of ESRD patients at initiation of hemodialysis vary depending on several factors including comorbidities, physicians' practice and geographical region amongst others. Aim: We ...

  13. Drivers and annual estimates of marine wildlife entanglement rates

    NARCIS (Netherlands)

    McIntosh, R.R.; Kirkwood, Roger; Sutherland, D.R.; Dann, Peter

    2015-01-01

    Methods of calculating wildlife entanglement rates are not standardised between studies and often ignore the influence of observer effort, confounding comparisons. From 1997-2013 we identified 359 entangled Australian fur seals at Seal Rocks, south-eastern Australia. Most entanglement materials

  14. Estimating family planning coverage from contraceptive prevalence using national household surveys.

    Science.gov (United States)

    Barros, Aluisio J D; Boerma, Ties; Hosseinpoor, Ahmad R; Restrepo-Méndez, María C; Wong, Kerry L M; Victora, Cesar G

    2015-01-01

    Contraception is one of the most important health interventions currently available and yet, many women and couples still do not have reliable access to modern contraceptives. The best indicator for monitoring family planning is the proportion of women using contraception among those who need it. This indicator is frequently called demand for family planning satisfied and we argue that it should be called family planning coverage (FPC). This indicator is complex to calculate and requires a considerable number of questions to be included in a household survey. We propose a model that can predict FPC from a much simpler indicator - contraceptive use prevalence - for situations where it cannot be derived directly. Using 197 Multiple Indicator Cluster Surveys and Demographic and Health Surveys from 82 countries, we explored least-squares regression models that could be used to predict FPC. Non-linearity was expected in this situation and we used a fractional polynomial approach to find the best fitting model. We also explored the effect of calendar time and of wealth on the models explored. Given the high correlation between the variables involved in FPC, we managed to derive a relatively simple model that depends only on contraceptive use prevalence but explains 95% of the variability of the outcome, with high precision for the estimated regression line. We also show that the relationship between the two variables has not changed with time. A concordance analysis showed agreement between observed and fitted results within a range of ±9 percentage points. We show that it is possible to obtain fairly good estimates of FPC using only contraceptive prevalence as a predictor, a strategy that is useful in situations where it is not possible to estimate FPC directly.

  15. Accuracy Rates of Ancestry Estimation by Forensic Anthropologists Using Identified Forensic Cases.

    Science.gov (United States)

    Thomas, Richard M; Parks, Connie L; Richard, Adam H

    2017-07-01

    A common task in forensic anthropology involves the estimation of the ancestry of a decedent by comparing their skeletal morphology and measurements to skeletons of individuals from known geographic groups. However, the accuracy rates of ancestry estimation methods in actual forensic casework have rarely been studied. This article uses 99 forensic cases with identified skeletal remains to develop accuracy rates for ancestry estimations conducted by forensic anthropologists. The overall rate of correct ancestry estimation from these cases is 90.9%, which is comparable to most research-derived rates and those reported by individual practitioners. Statistical tests showed no significant difference in accuracy rates depending on examiner education level or on the estimated or identified ancestry. More recent cases showed a significantly higher accuracy rate. The incorporation of metric analyses into the ancestry estimate in these cases led to a higher accuracy rate. © 2017 American Academy of Forensic Sciences.

  16. Estimation of the prevalence and direct medical costs of chronic myeloid leukemia in the I.R. of Iran in the era of tyrosine kinase inhibitors.

    Science.gov (United States)

    Daroudi, Rajabali; Mirzania, Mehrzad; Nikravanfard, Nazila; Sadighi, Sanambar; Sedighi, Zahra; Zendehdel, Kazem

    2017-10-01

    After the introduction of tyrosine kinase inhibitors for chronic myeloid leukemia (CML), the survival of these patients has increased significantly. However, these new drugs are expensive and impose considerable expense to patients and governments. Epidemiologic and economic evaluation studies provide good information for resource allocation and decision making. We estimated the incidence, prevalence and direct medical cost of CML in Iran. We used the National Cancer Registry (NCR) data from 2006 to 2009 to estimate the incidence rate of CML (ICD-10 code C92.1). After adjustment for the underestimation of incidence rates, we used survival rates of CML and estimated the 5-year prevalence for these patients. In addition, we used clinical practice guideline, expert opinions and medical tariffs to estimate the direct medical costs through the prevalence approach. After an adjustment for the underestimation, the incidence rate of CML was 0.5 per 100 000 in the I.R. of Iran. The 5-year prevalence was about 2263 cases (2.98 per 100 000). The total direct medical cost of CML was $23 089 323 and the majority of the cost (97%) was related to drug costs. The total cost will increase considerably to $40 728 869 if all patients use the new drug nilotinib (800 mg/day) as a second-line treatment. The increased survival of CML patients and a possible increase in incidence of CML in Iran will most likely lead to a considerable rise in its prevalence and economic burden. © 2016 John Wiley & Sons Australia, Ltd.

  17. Estimation of erosion rate using natural isotop 137Cs

    International Nuclear Information System (INIS)

    Suhartini, Nita; Milne A T; Wai, Zin Oo

    1998-01-01

    The investigation of erosion rate using natural isotope 137 Cs had been done in hilliness area at GOULBURN-NWS-Australia. The presentation of 137 Cs in natural was as a result of nuclear weapon testing in the middle of 1950's. Fallout of 137 Cs input, when it reached the ground, it rapidly adsorbed at the soil. 137 Cs bind very strong at the fine soil, so it can be used as tracer in the study of soil movement. Soil samples were taken using coring device (di=10 cm, h=20 cm), and were brought to laboratorium for short commun analysis. The preparation are drying, weighing, crushing and sieving. The 137 Cs content of fine samples that pass the 1 mm sieve were analyzed using gamma-spectrometer. The total erosion rate was calculate by ploting the 137 Cs values in the topography map of study area. The result showed that erosion was very low, and total erosion rate is 130 kg/ha.y. (authors)

  18. Improving SysSim's Planetary Occurrence Rate Estimates

    Science.gov (United States)

    Ashby, Keir; Ragozzine, Darin; Hsu, Danley; Ford, Eric B.

    2017-10-01

    Kepler's catalog of thousands of transiting planet candidates enables statistical characterization of the underlying planet occurrence rates as a function of period and radius. Due to geometric factors and general noise in measurements, we know that many planets--especially those with a small-radius and/or long-period--were not observed by Kepler.To account for Kepler's detection criteria, Hsu et al. 2017 expanded on work in Lissuaer et al. 2011 to develop the Planetary System Simulator or "SysSim". SysSim uses a forward model to generate simulated catalogs of exoplanet systems, determine which of those simulated planets would have been seen by Kepler in the presence of uncertainties, and then compares those “observed planets” to those actually seen by Kepler. It then uses Approximate Bayesian Computation to infer the posterior probability distributions of the input parameters used to generate the forward model. In Hsu et al. 2017, we focused on matching the observed frequency of planets by solving for the underlying occurrence rate for each bin in a 2-dimensional grid of radius and period. After summarizing the results of Hsu et al. 2017, we show new results that investigate the effect on occurrence rates from including more accurate completeness products (from the Kepler DR25 analysis) into SysSim.

  19. The prevalence rates of refractive errors among children, adolescents, and adults in Germany

    Directory of Open Access Journals (Sweden)

    Sandra Jobke

    2008-10-01

    Full Text Available Sandra Jobke1, Erich Kasten2, Christian Vorwerk31Institute of Medical Psychology, 3Department of Ophthalmology, Otto-von Guericke-University of Magdeburg, Magdeburg, Germany; 2Institute of Medical Psychology, University Hospital Schleswig-Holstein, Luebeck, GermanyPurpose: The prevalence rates of myopia vary between 5% in Australian Aborigines to 84% in Hong Kong and Taiwan, 30% in Norwegian adults, and 49.5% in Swedish schoolchildren. The aim of this study was to determine the prevalence of refractive errors in German children, adolescents, and adults.Methods: The parents (aged 24–65 years and their children (516 subjects aged 2–35 years were asked to fill out a questionnaire about their refractive error and spectacle use. Emmetropia was defined as refractive status between +0.25D and –0.25D. Myopia was characterized as ≤−0.5D and hyperopia as ≥+0.5D. All information concerning refractive error were controlled by asking their opticians.Results: The prevalence rates of myopia differed significantly between all investigated age groups: it was 0% in children aged 2–6 years, 5.5% in children aged 7–11 years, 21.0% in adolescents (aged 12–17 years and 41.3% in adults aged 18–35 years (Pearson’s Chi-square, p = 0.000. Furthermore, 9.8% of children aged 2–6 years were hyperopic, 6.4% of children aged 7–11 years, 3.7% of adolescents, and 2.9% of adults (p = 0.380. The prevalence of myopia in females (23.6% was significantly higher than in males (14.6%, p = 0.018. The difference between the self-reported and the refractive error reported by their opticians was very small and was not significant (p = 0.850.Conclusion: In Germany, the prevalence of myopia seems to be somewhat lower than in Asia and Europe. There are few comparable studies concerning the prevalence rates of hyperopia.Keywords: Germany, hyperopia, incidence, myopia, prevalence

  20. Rates of convergence and asymptotic normality of curve estimators for ergodic diffusion processes

    NARCIS (Netherlands)

    J.H. van Zanten (Harry)

    2000-01-01

    textabstractFor ergodic diffusion processes, we study kernel-type estimators for the invariant density, its derivatives and the drift function. We determine rates of convergence and find the joint asymptotic distribution of the estimators at different points.

  1. Prevalence Estimation and Validation of New Instruments in Psychiatric Research: An Application of Latent Class Analysis and Sensitivity Analysis

    Science.gov (United States)

    Pence, Brian Wells; Miller, William C.; Gaynes, Bradley N.

    2009-01-01

    Prevalence and validation studies rely on imperfect reference standard (RS) diagnostic instruments that can bias prevalence and test characteristic estimates. The authors illustrate 2 methods to account for RS misclassification. Latent class analysis (LCA) combines information from multiple imperfect measures of an unmeasurable latent condition to…

  2. National HIV prevalence estimates for sub-Saharan Africa: controlling selection bias with Heckman-type selection models

    Science.gov (United States)

    Hogan, Daniel R; Salomon, Joshua A; Canning, David; Hammitt, James K; Zaslavsky, Alan M; Bärnighausen, Till

    2012-01-01

    Objectives Population-based HIV testing surveys have become central to deriving estimates of national HIV prevalence in sub-Saharan Africa. However, limited participation in these surveys can lead to selection bias. We control for selection bias in national HIV prevalence estimates using a novel approach, which unlike conventional imputation can account for selection on unobserved factors. Methods For 12 Demographic and Health Surveys conducted from 2001 to 2009 (N=138 300), we predict HIV status among those missing a valid HIV test with Heckman-type selection models, which allow for correlation between infection status and participation in survey HIV testing. We compare these estimates with conventional ones and introduce a simulation procedure that incorporates regression model parameter uncertainty into confidence intervals. Results Selection model point estimates of national HIV prevalence were greater than unadjusted estimates for 10 of 12 surveys for men and 11 of 12 surveys for women, and were also greater than the majority of estimates obtained from conventional imputation, with significantly higher HIV prevalence estimates for men in Cote d'Ivoire 2005, Mali 2006 and Zambia 2007. Accounting for selective non-participation yielded 95% confidence intervals around HIV prevalence estimates that are wider than those obtained with conventional imputation by an average factor of 4.5. Conclusions Our analysis indicates that national HIV prevalence estimates for many countries in sub-Saharan African are more uncertain than previously thought, and may be underestimated in several cases, underscoring the need for increasing participation in HIV surveys. Heckman-type selection models should be included in the set of tools used for routine estimation of HIV prevalence. PMID:23172342

  3. Data on empirically estimated corporate survival rate in Russia

    Directory of Open Access Journals (Sweden)

    Evgeny A. Kuzmin

    2018-02-01

    Full Text Available The article presents data on the corporate survival rate in Russia in 1991–2014. The empirical survey was based on a random sample with the average number of non-repeated observations (number of companies for the survey each year equal to 75,958 (24,236 minimum and 126,953 maximum. The actual limiting mean error ∆p was 2.24% with 99% integrity. The survey methodology was based on a cross joining of various formal periods in the corporate life cycles (legal and business, which makes it possible to talk about a conventionally active time life of companies’ existence with a number of assumptions. The empirical survey values were grouped by Russian regions and industries according to the classifier and consolidated into a single database for analysing the corporate life cycle and their survival rate and searching for deviation dependencies in calculated parameters. Preliminary and incomplete figures were available in the paper entitled “Survival Rate and Lifecycle in Terms of Uncertainty: Review of Companies from Russia and Eastern Europe” (Kuzmin and Guseva, 2016 [3]. The further survey led to filtered processed data with clerical errors excluded. These particular values are available in the article. The survey intended to fill a fact-based gap in various fundamental surveys that involved matters of the corporate life cycle in Russia within the insufficient statistical framework. The data are of interest for an analysis of Russian entrepreneurship, assessment of the market development and incorporation risks in the current business environment. A further heuristic potential is achievable through an ability of forecasted changes in business demography and model building based on the representative data set.

  4. Data on empirically estimated corporate survival rate in Russia.

    Science.gov (United States)

    Kuzmin, Evgeny A

    2018-02-01

    The article presents data on the corporate survival rate in Russia in 1991-2014. The empirical survey was based on a random sample with the average number of non-repeated observations (number of companies) for the survey each year equal to 75,958 (24,236 minimum and 126,953 maximum). The actual limiting mean error ∆ p was 2.24% with 99% integrity. The survey methodology was based on a cross joining of various formal periods in the corporate life cycles (legal and business), which makes it possible to talk about a conventionally active time life of companies' existence with a number of assumptions. The empirical survey values were grouped by Russian regions and industries according to the classifier and consolidated into a single database for analysing the corporate life cycle and their survival rate and searching for deviation dependencies in calculated parameters. Preliminary and incomplete figures were available in the paper entitled "Survival Rate and Lifecycle in Terms of Uncertainty: Review of Companies from Russia and Eastern Europe" (Kuzmin and Guseva, 2016) [3]. The further survey led to filtered processed data with clerical errors excluded. These particular values are available in the article. The survey intended to fill a fact-based gap in various fundamental surveys that involved matters of the corporate life cycle in Russia within the insufficient statistical framework. The data are of interest for an analysis of Russian entrepreneurship, assessment of the market development and incorporation risks in the current business environment. A further heuristic potential is achievable through an ability of forecasted changes in business demography and model building based on the representative data set.

  5. Comparison of Salmonella Prevalence Rates in Bovine Lymph Nodes across Feeding Stages.

    Science.gov (United States)

    Belk, A D; Arnold, A N; Sawyer, J E; Griffin, D B; Taylor, T M; Savell, J W; Gehring, K B

    2018-04-01

    Peripheral lymph nodes (LNs) located in the fatty tissues of beef carcasses have been shown to harbor Salmonella and, thus, potentially contaminate ground beef. Salmonella prevalence within LNs is known to differ among feedlots. Two South Texas feeding operations (identified as locations A and B) known to harbor salmonellae in the feedlot environment, while historically producing cattle with opposing rates (one "high" and one "low") of Salmonella prevalence in LNs, were used in this study. To determine whether this difference was due to cattle source or factors associated with different stages of feeding, weanling steers of common and known origin were followed through normal feeding stages at both operations. Eighty Angus-sired beef steers were harvested at each of four feeding stages: 1, postweaning; 2, background or stocker; 3, 60 days on feed; and 4, 120 days on feed. Left and right subiliac and superficial cervical LNs ( n = 304) were collected from each carcass, and similar node types were pooled by animal ( n = 152). Results showed a difference ( P < 0.05) in prevalence of Salmonella in bovine lymph nodes between location A and location B and among feeding stages in location B. Salmonella was not isolated from any feeding stage 1 (postweaning) or location A LN samples. Within location B, there was an increase in Salmonella prevalence as cattle moved into later stages of feeding: at 22.2% (4 of 18), 77.8% (14 of 18), and 94.4% (17 of 18) for feeding stages 2, 3, and 4, respectively. Although the reasons for the differences seen between feeding operations and for increased Salmonella prevalence in LNs at later feeding stages remain unexplained, these results indicate that factors other than cattle source are likely influencing Salmonella prevalence in LNs.

  6. Prevalence estimates for hypertension in Latin America and the Caribbean: are they useful for surveillance?

    Directory of Open Access Journals (Sweden)

    Pedro Ordúñez

    2001-10-01

    Full Text Available Objective. To apply a recently proposed model and assessment tool created by the authors for critically evaluating the data available on the prevalence of hypertension in LAC and assessing their usefulness for surveillance. Methods. A bibliographic search to identify all publications that estimated the prevalence of hypertension was performed. Each of the papers located was assessed using a critical appraisal tool. Results. Of the 58 studies published between 1966 and 2000, only 28 of them (48% met the critical threshold to be considered useful for surveillance purposes. The distribution of the 28 studies in terms of their usefulness for surveillance was as follows: minimally useful, 16 studies; useful, 8 studies; and very useful, 4 studies. Several methodological shortcomings were identified, from inadequate sampling procedures and sample size to the poor quality of the primary data for planning purposes. Discussion. Published studies on the prevalence of hypertension in Latin America and the Caribbean have, as a whole, limited usefulness for surveillance activities.

  7. Prevalence estimates for hypertension in Latin America and the Caribbean: are they useful for surveillance?

    Directory of Open Access Journals (Sweden)

    Ordúñez Pedro

    2001-01-01

    Full Text Available Objective. To apply a recently proposed model and assessment tool created by the authors for critically evaluating the data available on the prevalence of hypertension in LAC and assessing their usefulness for surveillance. Methods. A bibliographic search to identify all publications that estimated the prevalence of hypertension was performed. Each of the papers located was assessed using a critical appraisal tool. Results. Of the 58 studies published between 1966 and 2000, only 28 of them (48% met the critical threshold to be considered useful for surveillance purposes. The distribution of the 28 studies in terms of their usefulness for surveillance was as follows: minimally useful, 16 studies; useful, 8 studies; and very useful, 4 studies. Several methodological shortcomings were identified, from inadequate sampling procedures and sample size to the poor quality of the primary data for planning purposes. Discussion. Published studies on the prevalence of hypertension in Latin America and the Caribbean have, as a whole, limited usefulness for surveillance activities.

  8. Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) normative elevation rates: comparisons with epidemiological prevalence rates.

    Science.gov (United States)

    Tarescavage, Anthony M; Marek, Ryan J; Finn, Jacob A; Hicks, Adam; Rapier, Jessica L; Ben-Porath, Yossef S

    2013-01-01

    Odland, Berthelson, Sharma, Martin, and Mittenberg ( 2013 ) caution that clinically elevated scale scores produced by members of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 /2011) normative sample raise concerns about the potential for false positive findings of psychopathology. However, the MMPI-2-RF normative sample is intended to represent the general population of the United States, 26.2% of which met criteria for a Diagnostic and Statistical Manual-IV (APA, 1994 ) disorder in a 12-month period (Kessler, Chiu, Demler, & Walters, 2005 ). In the current study we compare scale elevation rates in the MMPI-2-RF normative sample to prevalence rates of mental disorders primarily drawn from the National Comorbidity Study Replication (Kessler et al., 2005 ). Our objective was to evaluate MMPI-2-RF elevation rates in an epidemiological context. Results indicate that MMPI-2-RF scale elevation rates were generally consistent with epidemiological data when examined in the context of standard interpretation guidelines for the inventory. We also reiterate Ben-Porath and Tellegen's (2008/2011) caution that MMPI-2-RF scale elevations alone are not sufficient to indicate the presence of psychiatric disorder. Rather they are best viewed as indications of the need to evaluate the individual for possible disorder(s). Implications of these results, limitations of this study, and future directions in research are discussed.

  9. Dengue virus serological prevalence and seroconversion rates in children and adults in Medellin, Colombia: implications for vaccine introduction.

    Science.gov (United States)

    Carabali, Mabel; Lim, Jacqueline Kyungah; Velez, Diana Carolina; Trujillo, Andrea; Egurrola, Jorge; Lee, Kang Sung; Kaufman, Jay S; DaSilva, Luiz Jacinto; Velez, Ivan Dario; Osorio, Jorge E

    2017-05-01

    Dengue is an important public health problem worldwide. A vaccine has recently been licensed in some countries of Latin America and Asia. Recommendations for dengue vaccine introduction include endemicity and a high serological prevalence of dengue in the territories considering its introduction. A community-based survey was conducted to estimate dengue seroprevalence and age-specific seroconversion rates in a community in Medellin, Colombia, using a dengue serological test (IgG indirect ELISA). Residents were selected at random and were first screened for dengue infection; they were then followed over 2.5 years. A total of 3684 individuals aged between 1 and 65 years participated in at least one survey. The overall dengue seroprevalence was 61%, and only 3.3% of seropositive subjects self-reported a past history of dengue. Among dengue virus (DENV)-naïve subjects with more than two visits (n=1002), the overall seroconversion rate was 8.7% (95% confidence interval 7.3-10.4) per 1000 person-months, over the study period. Overall, the mean age of DENV prevalent subjects was significantly higher than the mean age of seroconverted subjects. Specifically, DENV seropositivity over 70% was observed in participants over 21 years old. Serotype-specific plaque-reduction neutralization tests (PRNT) revealed that all four dengue serotypes were circulating, with DENV4 being most prevalent. These laboratory-based findings could inform dengue vaccine decisions, as they provide age-specific seroprevalence and seroconversion data, evidencing permanent and ongoing dengue transmission in the study area. This study provides evidence for the existing rates of secondary and heterotypic responses, presenting a challenge that must be addressed adequately by the new vaccine candidates. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. Estimation of HPV prevalence in young women in Scotland; monitoring of future vaccine impact

    Science.gov (United States)

    2013-01-01

    Background Estimation of pre-immunisation prevalence of HPV and distribution of HPV types is fundamental to understanding the subsequent impact of HPV vaccination. We describe the type specific prevalence of HPV in females aged 20–21 in Scotland who attended or defaulted from cervical screening using three specimen types; from attenders liquid based cytology and from defaulters urine or self-taken swabs. Methods Residual liquid based cytology samples (n = 2148), collected from women aged 20–21 attending for their first smear were genotyped for HPV. A sample (n = 709) from women who had defaulted from screening was also made available for HPV testing through the use of postal testing kits (either urine samples (n = 378) or self-taken swabs (n = 331)). Estimates of prevalence weighted by deprivation, and for the postal testing kit, also by reminder status and specimen type were calculated for each HPV type. The distribution of HPV types were compared between specimen types and the occurrence of multiple high-risk infections examined. The influence of demographic factors on high-risk HPV positivity and multiple infections was examined via logistic regression. Results The prevalence of any HPV in young women aged 20–21 was 32.2% for urine, 39.5% for self-taken swab, and 49.4% for LBC specimens. Infection with vaccine specific types (HPV 16, 18) or those associated with cross-protection (HPV 31, 33, 45, 51) was common. Individuals were more likely to test positive for high-risk HPV if they resided in an area of high deprivation or in a rural area. The overall distribution of HPV types did not vary between defaulters and attenders. Multiple infections occurred in 48.1% of high-risk HPV positive individuals. Excluding vaccine types the most common pairing was HPV 56 and 66. Conclusions Understanding of the pre-immunisation prevalence of HPV in young women puts Scotland in a prime position to assess the early effect of vaccination as the first highly

  11. Dementia prevalence estimates in sub-Saharan Africa: comparison of two diagnostic criteria.

    Science.gov (United States)

    Paddick, Stella-Maria; Longdon, Anna R; Kisoli, Aloyce; Dotchin, Catherine; Gray, William K; Dewhurst, Felicity; Chaote, Paul; Kalaria, Raj; Jusabani, Ahmed M; Walker, Richard

    2013-04-03

    We have previously reported the prevalence of dementia in older adults living in the rural Hai district of Tanzania according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria. The aim of this study was to compare prevalence rates using the DSM-IV criteria with those obtained using the 10/66 diagnostic criteria, which is specifically designed for use in low- and middle-income countries. In phase I, 1,198 people aged 70 and older were screened for dementia. A stratified sample of 296 was then clinically assessed for dementia according to the DSM-IV criteria. In addition, data were collected according to the protocol of the 10/66 Dementia Research Group, which allowed a separate diagnosis of dementia according to these criteria to be established. The age-standardised prevalence of clinical DSM-IV dementia was 6.4% (95% confidence interval [CI] 4.9-7.9%) and of '10/66 dementia' was 21.6% (95% CI 17.5-25.7%). Education was a significant predictor of '10/66 dementia', but not of DSM-IV dementia. There are large discrepancies in dementia prevalence rates depending on which diagnostic system is used. In rural sub-Saharan Africa, it is not clear whether the association between education and dementia using the 10/66 criteria is a genuine effect or the result of an educational bias within the diagnostic instrument. Despite its possible flaws, the DSM-IV criteria represent an international standard for dementia diagnosis. The 10/66 diagnostic criteria may be more appropriate when identification of early and mild cognitive impairment is required.

  12. Bombay blood group: Is prevalence decreasing with urbanization and the decreasing rate of consanguineous marriage

    Directory of Open Access Journals (Sweden)

    Sujata Mallick

    2015-01-01

    Full Text Available Context: Bombay blood group although rare is found to be more prevalent in the Western and Southern states of India, believed to be associated with consanguineous marriage. Aims: To estimate the prevalence of the Bombay blood group (Oh in the urban population of Puducherry. To find the effect of urbanization on consanguineous marriage and to establish whether consanguinity plays a part in the prevalence of Oh group. To compare Oh group prevalence with that of other neighboring states, where population is not predominantly urban. Settings and Design: This is a descriptive study in a tertiary care hospital in Puducherry, over a period of 6 years. Materials and Methods: All blood samples showing ′O′ group were tested with anti-H lectin. Specialized tests like Adsorption Elution Technique, inhibition assay for determination of secretor status were performed on Oh positive cases. Any history of consanguineous marriage was recorded. Statistical Analysis Used: All variables were categorical variable and percentage and proportions were calculated manually. Results: Analysis of the results of 35,497 study subjects showed that the most common group was ′O′ group constituting 14,164 (39.90% of subjects. Only three "Oh" that is, Bombay phenotype (0.008% were detected. Consanguinity was observed in two cases (66.66%. Conclusions: This study shows the prevalence of Bombay blood group representing the urban population of Puducherry, to be high (0.008% and associated with consanguineous marriage (66.66%. Thus, consanguinity is still an important risk factor present, even in an urban population in Southern India.

  13. Estimated prospective tanker rates for Alaska North Slope crude oil

    International Nuclear Information System (INIS)

    Marks, Roger

    1992-01-01

    Within the next ten years, three significant events will affect the structure of tankering costs for the Alaska North Slope (ANS) oil fields. These are: the double hulling requirement of the Oil Spill Pollution Act of 1990 (OPA90); the ageing of the tanker fleet; and the decline in ANS and West Coast oil production, which will eliminate more costly shipments to the Gulf Coast. The purpose of this paper is to estimate how these will affect tankering costs over the next twenty years. As baseline, the existing fleet is described, followed by a detailed discussion of the above factors. Company specific shipping requirements are calculated as compared to ship-by-ship tonnage availability (based on the current fleet) pursuant to these events, and the resultant tonnage deficit. A model is presented that derives a hypothetical reconstruction scheme to eliminate the deficits on a company specific ship-by-ship basis. The resulting costs are then translated into a weighted average per barrel ANS cost. The specific double hull costs are segregated. (author)

  14. Low-sampling-rate ultra-wideband channel estimation using equivalent-time sampling

    KAUST Repository

    Ballal, Tarig

    2014-09-01

    In this paper, a low-sampling-rate scheme for ultra-wideband channel estimation is proposed. The scheme exploits multiple observations generated by transmitting multiple pulses. In the proposed scheme, P pulses are transmitted to produce channel impulse response estimates at a desired sampling rate, while the ADC samples at a rate that is P times slower. To avoid loss of fidelity, the number of sampling periods (based on the desired rate) in the inter-pulse interval is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this case, and to achieve an overall good channel estimation performance, without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. It is shown that this estimator is related to the Bayesian linear minimum mean squared error (LMMSE) estimator. Channel estimation performance of the proposed sub-sampling scheme combined with the new estimator is assessed in simulation. The results show that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in almost all cases, while in the high SNR regime it also outperforms the LMMSE estimator. In addition to channel estimation, a synchronization method is also proposed that utilizes the same pulse sequence used for channel estimation. © 2014 IEEE.

  15. Decision Tree Rating Scales for Workload Estimation: Theme and Variations

    Science.gov (United States)

    Wietwille, W. W.; Skipper, J. H.; Rieger, C. A.

    1984-01-01

    The modified Cooper-Harper (MCH) scale has been shown to be a sensitive indicator of workload in several different types of aircrew tasks. The MCH scale was examined to determine if certain variations of the scale might provide even greater sensitivity and to determine the reasons for the sensitivity of the scale. The MCH scale and five newly devised scales were studied in two different aircraft simulator experiments in which pilot loading was treated as an independent variable. Results indicate that while one of the new scales may be more sensitive in a given experiment, task dependency is a problem. The MCH scale exhibits consistent sensitivity and remains the scale recommended for general use. The results of the rating scale experiments are presented and the questionnaire results which were directed at obtaining a better understanding of the reasons for the relative sensitivity of the MCH scale and its variations are described.

  16. Gamma Kernel Estimators for Density and Hazard Rate of Right-Censored Data

    Directory of Open Access Journals (Sweden)

    T. Bouezmarni

    2011-01-01

    Full Text Available The nonparametric estimation for the density and hazard rate functions for right-censored data using the kernel smoothing techniques is considered. The “classical” fixed symmetric kernel type estimator of these functions performs well in the interior region, but it suffers from the problem of bias in the boundary region. Here, we propose new estimators based on the gamma kernels for the density and the hazard rate functions. The estimators are free of bias and achieve the optimal rate of convergence in terms of integrated mean squared error. The mean integrated squared error, the asymptotic normality, and the law of iterated logarithm are studied. A comparison of gamma estimators with the local linear estimator for the density function and with hazard rate estimator proposed by Müller and Wang (1994, which are free from boundary bias, is investigated by simulations.

  17. Estimating taxonomic diversity, extinction rates, and speciation rates from fossil data using capture-recapture models

    Science.gov (United States)

    Nichols, J.D.; Pollock, K.H.

    1983-01-01

    Capture-recapture models can be used to estimate parameters of interest from paleobiological data when encouter probabilities are unknown and variable over time. These models also permit estimation of sampling variances and goodness-of-fit tests are available for assessing the fit of data to most models. The authors describe capture-recapture models which should be useful in paleobiological analyses and discuss the assumptions which underlie them. They illustrate these models with examples and discuss aspects of study design.

  18. Risk factors associated with high prevalence rates of hepatitis C infection in Egypt.

    Science.gov (United States)

    Reker, Celeste; Islam, K M

    2014-08-01

    Egypt has the highest reported prevalence of hepatitis C virus (HCV) globally. Until now, no systematic review has been conducted to understand risk factors associated with these high prevalence rates of HCV. This study attempted to identify the various HCV risk factors in Egypt responsible for the high incidence and prevalence rates. Using systematic literature review methods, we searched databases for eligible manuscripts, selecting cohort and case-control studies published in English. Peer-reviewed papers published between 2008 and February 2013 were included. A total of 11 articles met the study selection criteria. The most examined risk factors found during our review analysis were surgery, transfusion, and age (64-82% of total articles; n = 11). Multiple risk factors held significant association with HCV infection in the included research. Based on this review, the main HCV risk factor categories are unsafe medical practices and familial risk factors. Improving medical safety and encouraging familial education on HCV may help reduce the incidence of the disease. Most risk factors for HCV transmission in Egypt are healthcare-associated. Primary prevention of HCV infection remains important to reduce HCV transmission. Further research should also focus on risk factor dynamics of HCV in Egypt to reduce transmission and HCV disease burden. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Survival rate and pressure ulcer prevalence in patients with and without dementia: a retrospective study.

    Science.gov (United States)

    Jaul, E; Rosenzweig, J P; Meiron, O

    2017-07-02

    This retrospective study aimed to investigate the prevalence of pressure ulcers (PUs) in older patients with advanced dementia versus older patients without dementia but with other comorbidities, such as diabetes, ischaemic heart disease and chronic renal failure. PUs were thought to be more prevalent and to present a higher risk of mortality in patients with dementia. PUs were assessed on admission using the European Pressure Ulcer Advisory Panel (EPUAP) staging system. Patients were classified as either with or without dementia according to Reisberg's functional assessment staging test (FAST). The prevalence of PUs and the survival rates were analysed and compared in both groups. The combined effect of PUs and dementia on survival was assessed using the Cox proportional hazard model. The median survival rate of patients with PUs and dementia was 63 days, significantly lower than in patients with PUs without dementia 117 days. Both groups had similar other comorbidities. These findings underscore the requirement for geriatricians and health professionals to be more vigilant in examining PUs as dementia progresses.

  20. Prevalence

    Directory of Open Access Journals (Sweden)

    Ahmed E. Mansour

    2013-07-01

    Conclusion: The prevalence of spontaneous bacterial pleuritis in the studied group of patients with hepatic hydrothorax was 14.3%. Patients with advanced liver disease, low pleural fluid protein, or SBP are at risk for spontaneous bacterial pleuritis.

  1. Assessing bias in community-based prevalence estimates: towards an unduplicated count of problem drinkers and drug users.

    Science.gov (United States)

    Weisner, C; Schmidt, L; Tam, T

    1995-03-01

    General population survey estimates of the overall prevalence of problem drinking and drug use in a community are biased by the exclusion of non-household populations. Estimates based on compiling prevalences in community institutions may also be biased due to over-counting of users of more than one institution. This paper examines prevalence estimates derived from probability samples of problem drinkers in the general population and within alcohol treatment, drug treatment, mental health, criminal justice and welfare agencies in a single US county. Data sets are merged and weighted to reflect a community sample of institutions, and a 17% subset of cases is identified within the institutional samples that are not living in housing units typically included in general population sampling frames. The difference in prevalences of problem drinking in the household and non-household populations is found to be large: 11% and 48%, respectively. Even greater differences are found between estimates of unprescribed weekly drug use (6% and 47%, respectively) and combined problem drinking and weekly drug use (2% and 27%, respectively). This suggests that confining samples to the household population can systematically under-represent the prevalence of problem drinking and drug use. A second source of bias in prevalence is characteristic of studies using records from multiple institutions. When duplication of service use in the five agency samples is considered, it becomes apparent that prevalence may be biased upward due to over-counting of multiple service users.

  2. Estimation of unemployment rates using small area estimation model by combining time series and cross-sectional data

    Science.gov (United States)

    Muchlisoh, Siti; Kurnia, Anang; Notodiputro, Khairil Anwar; Mangku, I. Wayan

    2016-02-01

    Labor force surveys conducted over time by the rotating panel design have been carried out in many countries, including Indonesia. Labor force survey in Indonesia is regularly conducted by Statistics Indonesia (Badan Pusat Statistik-BPS) and has been known as the National Labor Force Survey (Sakernas). The main purpose of Sakernas is to obtain information about unemployment rates and its changes over time. Sakernas is a quarterly survey. The quarterly survey is designed only for estimating the parameters at the provincial level. The quarterly unemployment rate published by BPS (official statistics) is calculated based on only cross-sectional methods, despite the fact that the data is collected under rotating panel design. The study purpose to estimate a quarterly unemployment rate at the district level used small area estimation (SAE) model by combining time series and cross-sectional data. The study focused on the application and comparison between the Rao-Yu model and dynamic model in context estimating the unemployment rate based on a rotating panel survey. The goodness of fit of both models was almost similar. Both models produced an almost similar estimation and better than direct estimation, but the dynamic model was more capable than the Rao-Yu model to capture a heterogeneity across area, although it was reduced over time.

  3. Smoking prevalence in Medicaid has been declining at a negligible rate.

    Directory of Open Access Journals (Sweden)

    Shu-Hong Zhu

    Full Text Available In recent decades the overall smoking prevalence in the US has fallen steadily. This study examines whether the same trend is seen in the Medicaid population.National Health Interview Survey (NHIS data from 17 consecutive annual surveys from 1997 to 2013 (combined N = 514,043 were used to compare smoking trends for 4 insurance groups: Medicaid, the Uninsured, Private Insurance, and Other Coverage. Rates of chronic disease and psychological distress were also compared.Adjusted smoking prevalence showed no detectable decline in the Medicaid population (from 33.8% in 1997 to 31.8% in 2013, trend test P = 0.13, while prevalence in the other insurance groups showed significant declines (38.6%-34.7% for the Uninsured, 21.3%-15.8% for Private Insurance, and 22.6%-16.8% for Other Coverage; all P's<0.005. Among individuals who have ever smoked, Medicaid recipients were less likely to have quit (38.8% than those in Private Insurance (62.3% or Other Coverage (69.8%; both P's<0.001. Smokers in Medicaid were more likely than those in Private Insurance and the Uninsured to have chronic disease (55.0% vs 37.3% and 32.4%, respectively; both P's<0.01. Smokers in Medicaid were also more likely to experience severe psychological distress (16.2% for Medicaid vs 3.2% for Private Insurance and 7.6% for the Uninsured; both P's<0.001.The high and relatively unchanging smoking prevalence in the Medicaid population, low quit ratio, and high rates of chronic disease and severe psychological distress highlight the need to focus on this population. A targeted and sustained campaign to help Medicaid recipients quit smoking is urgently needed.

  4. Inflammatory bowel disease among Bedouin Arabs in southern Israel: urbanization and increasing prevalence rates.

    Science.gov (United States)

    Abu Freha, Naim; Schwartz, Doron; Elkrinawi, Jaber; Ben Yakov, Gil; Abu Tailakh, Muhammad; Munteanu, Daniela; Abu Ganim, Abdelrhman; Fich, Alexander

    2015-03-01

    Inflammatory bowel disease (IBD) has been associated with genetic and environmental factors, including urban living. IBD was rare in the Israeli Bedouin community 30 years ago. Over recent decades, a large proportion of this community has undergone a transition from a nomadic to a western lifestyle. Our aim was to carry out an updated evaluation of the clinical and epidemiological features of IBD in the Bedouin sector of southern Israel. All Bedouin patients with a known diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were included in the retrospective study. The cohort included 31 CD patients and 31 UC patients. The mean age of the patients at diagnosis was 29±10.9 and 35±17.5 years for CD and UC, respectively. The prevalence rate for CD was 15.5/100,000 and the incidence rate was 0.8-3.55/100,000. Fourteen of the CD patients (45%) had ileal disease and 64.5% had inflammatory disease behavior according to the Montreal classification. Eleven of the CD patients (35%) were treated with anti-TNF-α and 26% had undergone surgery. Over the previous decade, the prevalence of UC was 14/100,000 and the incidence was 0.5-2.39/100,000. Eighteen UC patients (58%) had left-sided colitis. Three (9.7%) had undergone total colectomy for severe disease. We found an increased prevalence of IBD in the Bedouin population, associated with their change in lifestyle over previous decades. However, the prevalence is still markedly lower than that in other population groups. A high percentage of patients were treated with anti-TNF-α and/or surgery.

  5. [Diabetes mellitus in Spain: death rates, prevalence, impact, costs and inequalities].

    Science.gov (United States)

    Ruiz-Ramos, Miguel; Escolar-Pujolar, Antonio; Mayoral-Sánchez, Eduardo; Corral-San Laureano, Florentino; Fernández-Fernández, Isabel

    2006-03-01

    Describing the situation of diabetes mellitus (DM) in Spain from a public health perspective. manual review of books and other documents on diabetes mellitus in Spain was conducted. In addition, a specific research of articles published using MeSH terms diabetes mortality, prevalence, incidence, cost, inequalities and Spain was conducted in Medline through Internet (PubMed). Minimun Basic Data Set was utilized as source for complication description by Communities Autonomus. DM is one of the leading cause of mortality and the third one in women. With regard to Autonomous Communities, Canary Islands, Ceuta y Melilla and Andalusia show the greatest mortality with a downward trend. Diabetics present greater mortality than non diabetic patients, being complications the main cause of the over-mortality, especially ischemic heart disease. Estimations of prevalence for DM2 range from 4.8% to 18.7% and for DM1, from .08% to .2%. In pregnancy, it has been noted a prevalence ranging from 4.5% to 16.1%. With respect to incidence per year, it is estimated a range from 146 to 820 per 100,000 inhabitants for DM2 and a range from 10 to 17 new cases annually per 100,000 inhabitants for DM1. Costs for DM1 show very different results, averaging between 1,262 and 3,311 euro per people and year. There are differences for DM2 costs as well, averaging between 381 and 2,560 euro per patient and year. Total costs estimated range from 758 to 4,348 euro per person and year. Relationship between a low socioeconomic level (LSL) and DM2 risk has been proved. Moreover, it has been noted that the less LSL the worse is the disease control, coupled with a greater frequency and more frequent factors of DM2 risk. The knowledge about the situation of the DM as a Public Health problem in Spain is limited. Mortality data available does not gather its real magnitude, and prevalence, incidence, costs and inequalities research are very poor and hardly comparable. In spite of this degree of incertitude, we

  6. Prevalence rates of infection in intensive care units of a tertiary teaching hospital

    Directory of Open Access Journals (Sweden)

    Toufen Junior Carlos

    2003-01-01

    Full Text Available OBJECTIVE: To determine the prevalence rates of infections among intensive care unit patients, the predominant infecting organisms, and their resistance patterns. To identify the related factors for intensive care unit-acquired infection and mortality rates. DESIGN: A 1-day point-prevalence study. SETTING:A total of 19 intensive care units at the Hospital das Clínicas - University of São Paulo, School of Medicine (HC-FMUSP, a teaching and tertiary hospital, were eligible to participate in the study. PATIENTS: All patients over 16 years old occupying an intensive care unit bed over a 24-hour period. The 19 intensive care unit s provided 126 patient case reports. MAIN OUTCOME MEASURES: Rates of infection, antimicrobial use, microbiological isolates resistance patterns, potential related factors for intensive care unit-acquired infection, and death rates. RESULTS: A total of 126 patients were studied. Eighty-seven patients (69% received antimicrobials on the day of study, 72 (57% for treatment, and 15 (12% for prophylaxis. Community-acquired infection occurred in 15 patients (20.8%, non- intensive care unit nosocomial infection in 24 (33.3%, and intensive care unit-acquired infection in 22 patients (30.6%. Eleven patients (15.3% had no defined type. The most frequently reported infections were respiratory (58.5%. The most frequently isolated bacteria were Enterobacteriaceae (33.8%, Pseudomonas aeruginosa (26.4%, and Staphylococcus aureus (16.9%; [100% resistant to methicillin]. Multivariate regression analysis revealed 3 risk factors for intensive care unit-acquired infection: age > 60 years (p = 0.007, use of a nasogastric tube (p = 0.017, and postoperative status (p = 0.017. At the end of 4 weeks, overall mortality was 28.8%. Patients with infection had a mortality rate of 34.7%. There was no difference between mortality rates for infected and noninfected patients (p=0.088. CONCLUSION: The rate of nosocomial infection is high in intensive care

  7. Reducing Bias in Citizens’ Perception of Crime Rates: Evidence From a Field Experiment on Burglary Prevalence

    DEFF Research Database (Denmark)

    Larsen, Martin Vinæs; Olsen, Asmus Leth

    2018-01-01

    Citizens are on average too pessimistic when assessing the trajectory of current crime trends. In this study, we examine whether we can correct this perceptual bias with respect to burglaries. Using a field experiment coupled with a large panel survey (n=4,895), we explore whether a public...... information campaign can reduce misperceptions about the prevalence of burglaries. Embedding the correct information about burglary rates in a direct mail campaign, we find that it is possible to substantially reduce citizens’ misperceptions. The effects are not short lived – they are detectable several weeks...... after the mailer was sent, but they are temporary. Eventually the perceptual bias re-emerges. Our results suggest that if citizens were continually supplied with correct information about crime rates they would be less pessimistic. Reducing bias in citizens’ perception of crime rates might therefore...

  8. Effect of unsampled populations on the estimation of population sizes and migration rates between sampled populations.

    Science.gov (United States)

    Beerli, Peter

    2004-04-01

    Current estimators of gene flow come in two methods; those that estimate parameters assuming that the populations investigated are a small random sample of a large number of populations and those that assume that all populations were sampled. Maximum likelihood or Bayesian approaches that estimate the migration rates and population sizes directly using coalescent theory can easily accommodate datasets that contain a population that has no data, a so-called 'ghost' population. This manipulation allows us to explore the effects of missing populations on the estimation of population sizes and migration rates between two specific populations. The biases of the inferred population parameters depend on the magnitude of the migration rate from the unknown populations. The effects on the population sizes are larger than the effects on the migration rates. The more immigrants from the unknown populations that are arriving in the sample populations the larger the estimated population sizes. Taking into account a ghost population improves or at least does not harm the estimation of population sizes. Estimates of the scaled migration rate M (migration rate per generation divided by the mutation rate per generation) are fairly robust as long as migration rates from the unknown populations are not huge. The inclusion of a ghost population does not improve the estimation of the migration rate M; when the migration rates are estimated as the number of immigrants Nm then a ghost population improves the estimates because of its effect on population size estimation. It seems that for 'real world' analyses one should carefully choose which populations to sample, but there is no need to sample every population in the neighbourhood of a population of interest.

  9. Analysis of HIV early infant diagnosis data to estimate rates of perinatal HIV transmission in Zambia.

    Directory of Open Access Journals (Sweden)

    Kwasi Torpey

    Full Text Available Mother-to-child transmission of HIV (MTCT remains the most prevalent source of pediatric HIV infection. Most PMTCT (prevention of mother-to-child transmission of HIV programs have concentrated monitoring and evaluation efforts on process rather than on outcome indicators. In this paper, we review service data from 28,320 children born to HIV-positive mothers to estimate MTCT rates.This study analyzed DNA PCR results and PMTCT data from perinatally exposed children zero to 12 months of age from five Zambian provinces between September 2007 and July 2010.The majority of children (58.6% had a PCR test conducted between age six weeks and six months. Exclusive breastfeeding (56.8% was the most frequent feeding method. An estimated 45.9% of mothers were below 30 years old and 93.3% had disclosed their HIV status. In terms of ARV regimen for PMTCT, 32.7% received AZT+single dose NVP (sdNVP, 30.9% received highly active antiretroviral treatment (HAART, 19.6% received sdNVP only and 12.9% received no ARVs. Transmission rates at six weeks when ARVs were received by both mother and baby, mother only, baby only, and none were 5.8%, 10.5%, 15.8% and 21.8% respectively. Transmission rates at six weeks where mother received HAART, AZT+sd NVP, sdNVP, and no intervention were 4.2%, 6.8%, 8.7% and 20.1% respectively. Based on adjusted analysis including ARV exposures and non ARV-related parameters, lower rates of positive PCR results were associated with 1 both mother and infant receiving prophylaxis, 2 children never breastfed and 3 mother being 30 years old or greater. Overall between September 2007 and July 2010, 12.2% of PCR results were HIV positive. Between September 2007 and January 2009, then between February 2009 and July 2010, proportions of positive PCR results were 15.1% and 11% respectively, a significant difference.The use of ARV drugs reduces vertical transmission of HIV in a program setting. Non-chemoprophylactic factors also play a significant

  10. Common cause failure rate estimates for diesel generators in nuclear power plants

    International Nuclear Information System (INIS)

    Steverson, J.A.; Atwood, C.L.

    1982-01-01

    Common cause fault rates for diesel generators in nuclear power plants are estimated, using Licensee Event Reports for the years 1976 through 1978. The binomial failure rate method, used for obtaining the estimates, is briefly explained. Issues discussed include correct classification of common cause events, grouping of the events into homogeneous data subsets, and dealing with plant-to-plant variation

  11. Estimating reaction rate constants: comparison between traditional curve fitting and curve resolution

    NARCIS (Netherlands)

    Bijlsma, S.; Boelens, H. F. M.; Hoefsloot, H. C. J.; Smilde, A. K.

    2000-01-01

    A traditional curve fitting (TCF) algorithm is compared with a classical curve resolution (CCR) approach for estimating reaction rate constants from spectral data obtained in time of a chemical reaction. In the TCF algorithm, reaction rate constants an estimated from the absorbance versus time data

  12. Comparing HIV prevalence estimates from prevention of mother-to-child HIV transmission programme and the antenatal HIV surveillance in Addis Ababa

    Directory of Open Access Journals (Sweden)

    Mirkuzie Alemnesh H

    2012-12-01

    Full Text Available Abstract Background In the absence of reliable data, antenatal HIV surveillance has been used to monitor the HIV epidemic since the late 1980s. Currently, routine data from Prevention of Mother-to-child HIV transmission (PMTCT programmes are increasingly available. Evaluating whether the PMTCT programme reports provide comparable HIV prevalence estimates with the antenatal surveillance reports is important. In this study, we compared HIV prevalence estimates from routine PMTCT programme and antenatal surveillance in Addis Ababa with the aim to come up with evidence based recommendation. Methods Summary data were collected from PMTCT programmes and antenatal surveillance reports within the catchment of Addis Ababa. The PMTCT programme data were obtained from routine monthly reports from 2004 to 2009 and from published antenatal HIV surveillance reports from 2003 to 2009. Data were analysed using descriptive statistics. Results In Addis Ababa, PMTCT sites had increased from six in 2004 to 54 in 2009. The site expansion was accompanied by an increased number of women testing. There were marked increases in the rate of HIV testing following the introduction of routine opt-out HIV testing approach. Paralleling these increases, the HIV prevalence showed a steady decline from 10.0% in 2004 to 4.5% in 2009. There were five antenatal surveillance sites from 2003 to 2007 in Addis Ababa and they increased to seven by 2009. Four rounds of surveillance data from five sites showed a declining trend in HIV prevalence over the years. The overall antenatal surveillance data also showed that the HIV prevalence among antenatal attendees had declined from 12.4% in 2003 to 5.5% in 2009. The HIV prevalence estimates from PMTCT programme were 6.2% and 4.5% and from antenatal surveillance 6.1 and 5.5% in 2008 and 2009 respectively. Conclusions There were consistent HIV prevalence estimates from PMTCT programme and from antenatal surveillance reports. Both data sources

  13. Integrating environmental and self-report data to refine cannabis prevalence estimates in a major urban area of Switzerland.

    Science.gov (United States)

    Been, Frederic; Schneider, Christian; Zobel, Frank; Delémont, Olivier; Esseiva, Pierre

    2016-10-01

    Cannabis consumption is a topical subject because of discussions about reviewing current regulations. In this context, having a more comprehensive approach to assess and monitor prevalence and consumption is highly relevant. The objective of this work was to refine current estimates about prevalence of cannabis use by combining self-report data and results derived from wastewater analysis. Self-report data was retrieved from surveys conducted in Switzerland and Europe. Wastewater samples were collected at the wastewater treatment plant of Lausanne, western Switzerland, over a 15 months period. The occurrence of 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH), a specific metabolite of delta-9-tetrahydrocannabinol (THC), was monitored. Bayesian hierarchical models were used to estimate consumption, prevalence and number of cannabis users in the investigated area. According to survey data, 12-months prevalence in western Switzerland was estimated to 6.2% of the population aged 15 or older, with an estimated daily cannabis consumption of 8.1gday(-1)·1000inhab(-1) (at 11.2% purity). The integrative model comprising self-report and wastewater data substantially reduced the uncertainty in the estimates and suggested a last-year prevalence of 9.4%, with a daily cannabis consumption of 14.0gday(-1)·1000inhab(-1). Although in the same order of magnitude, consumption and prevalence estimates obtained with the integrative model were 78% and 52% higher compared to self-report figures, respectively. Interestingly, these figures are similar to discrepancies observed when comparing self-reported alcohol consumption and sales or tax data. The suggested integrative model allowed to account for known sources of uncertainty and provided refined estimates of cannabis prevalence in a major urban area of Switzerland. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Prevalence of human endogenous retroviral element associates with Hodgkin's lymphoma incidence rates

    Directory of Open Access Journals (Sweden)

    Wee Hong Woo

    2014-01-01

    Full Text Available Human endogenous retrovirus-H (HERV-H is implicated in leukaemias and lymphomas, but the precise molecular mechanism underlying HERV-mediated carcinogenesis remains unknown. We determined the prevalence of HERV-H in a cross-section of the Singapore population and explored the relationship between HERV-H positivity and incidence rates for Hodgkin's lymphoma in three major ethnic groups of Singapore. We observed that Malays were 1.11 times likely (95% CI=1.05–1.17; P<0.01, and Indians 1.12 times likely (95% CI=1.07–1.18; P<0.01 to be HERV-H positive when compared to Chinese. Interestingly, the incidence rates of Hodgkin's lymphoma for the three races positively correlated to the respective prevalence rate for HERV-H positivity (r=0.9921 for male; r=0.9801 for female, suggesting that viral inheritance in human may predispose certain racial origin unfavourably to malignancy.

  15. Multiple imputation for non-response when estimating HIV prevalence using survey data.

    Science.gov (United States)

    Chinomona, Amos; Mwambi, Henry

    2015-10-16

    Missing data are a common feature in many areas of research especially those involving survey data in biological, health and social sciences research. Most of the analyses of the survey data are done taking a complete-case approach, that is taking a list-wise deletion of all cases with missing values assuming that missing values are missing completely at random (MCAR). Methods that are based on substituting the missing values with single values such as the last value carried forward, the mean and regression predictions (single imputations) are also used. These methods often result in potential bias in estimates, in loss of statistical information and in loss of distributional relationships between variables. In addition, the strong MCAR assumption is not tenable in most practical instances. Since missing data are a major problem in HIV research, the current research seeks to illustrate and highlight the strength of multiple imputation procedure, as a method of handling missing data, which comes from its ability to draw multiple values for the missing observations from plausible predictive distributions for them. This is particularly important in HIV research in sub-Saharan Africa where accurate collection of (complete) data is still a challenge. Furthermore the multiple imputation accounts for the uncertainty introduced by the very process of imputing values for the missing observations. In particular national and subgroup estimates of HIV prevalence in Zimbabwe were computed using multiply imputed data sets from the 2010-11 Zimbabwe Demographic and Health Surveys (2010-11 ZDHS) data. A survey logistic regression model for HIV prevalence and demographic and socio-economic variables was used as the substantive analysis model. The results for both the complete-case analysis and the multiple imputation analysis are presented and discussed. Across different subgroups of the population, the crude estimates of HIV prevalence are generally not identical but their

  16. Gender differences in drunk driving prevalence rates and trends: a 20-year assessment using multiple sources of evidence.

    Science.gov (United States)

    Schwartz, Jennifer

    2008-09-01

    This research tracked women's and men's drunk driving rates and the DUI sex ratio in the United States from 1982-2004 using three diverse sources of evidence. Sex-specific prevalence estimates and the sex ratio are derived from official arrest statistics from the Federal Bureau of Investigation, self-reports from the Centers for Disease Control and Prevention, and traffic fatality data from the National Highway and Transportation Safety Administration. Drunk driving trends were analyzed using Augmented Dickey Fuller time series techniques. Female DUI arrest rates increased whereas male rates declined then stabilized, producing a significantly narrower sex ratio. According to self-report and traffic data, women's and men's drunk driving rates declined and the gender gap was unchanged. Women's overrepresentation in arrests relative to their share of offending began in the 1990s and accelerated in 2000. Women's arrest gains, contrasted with no systematic change in DUI behavior, and the timing of this shift suggest an increased vulnerability to arrest. More stringent laws and enforcement directed at less intoxicated offenders may inadvertently target female offending patterns.

  17. High prevalence and low cure rate of tuberculosis among patients with HIV in Xinjiang, China.

    Science.gov (United States)

    Maimaiti, Rena; Zhang, Yuexin; Pan, Kejun; Mijiti, Peierdun; Wubili, Maimaitiali; Musa, Maimaitijiang; Andersson, Rune

    2017-01-05

    Tuberculosis and HIV co-epidemics are problems in many parts of the world. Xinjiang is a high tuberculosis and HIV prevalence area in China. We aimed to investigate the prevalence and cure rate of tuberculosis among HIV positive patients in Xinjiang. In a retrospective study between 2006 and 2011, clinical and laboratory data on 333 patients with HIV and tuberculosis were compared to 2668 patients with HIV only. There were 31 HIV positive patients with no data on tuberculosis. The prevalence of tuberculosis co-infection among the HIV positive patients was 11% (95% CI 10-12%), significantly higher than the national figure in China of 2%. In most cases HIV was diagnosed late, with advanced immunodeficiency. The use of isoniazid preventive therapy was only 57.9% in patients without tuberculosis who fulfilled the criteria for receiving this prevention. The cure rate one year after diagnosis was 69.2%, which was lower than the officially reported 91.4% in all tuberculosis cases in Xinjiang in 2011. The hazard of not surviving over the five years was significantly higher in patients with HIV + tuberculosis compared to HIV only after adjusting for sex and Intravenous drug use with HR = 1.84 (95% CI 1.43-2.35; p HIV positive patients in Xinjiang was higher than in China taken as a whole, and HIV was diagnosed late, with underuse of isoniazid preventive therapy. The low cure rate and reduced survival can be due to late diagnosis of HIV and no testing for antibiotic resistance, together with insufficient control of adherence to the treatment regimens for tuberculosis and HIV.

  18. Problematic video game use: estimated prevalence and associations with mental and physical health.

    Science.gov (United States)

    Mentzoni, Rune Aune; Brunborg, Geir Scott; Molde, Helge; Myrseth, Helga; Skouverøe, Knut Joachim Mår; Hetland, Jørn; Pallesen, Ståle

    2011-10-01

    A nationwide survey was conducted to investigate the prevalence of video game addiction and problematic video game use and their association with physical and mental health. An initial sample comprising 2,500 individuals was randomly selected from the Norwegian National Registry. A total of 816 (34.0 percent) individuals completed and returned the questionnaire. The majority (56.3 percent) of respondents used video games on a regular basis. The prevalence of video game addiction was estimated to be 0.6 percent, with problematic use of video games reported by 4.1 percent of the sample. Gender (male) and age group (young) were strong predictors for problematic use of video games. A higher proportion of high frequency compared with low frequency players preferred massively multiplayer online role-playing games, although the majority of high frequency players preferred other game types. Problematic use of video games was associated with lower scores on life satisfaction and with elevated levels of anxiety and depression. Video game use was not associated with reported amount of physical exercise.

  19. Increasing prevalence of HIV-1 subtype A in Greece: estimating epidemic history and origin.

    Science.gov (United States)

    Paraskevis, Dimitrios; Magiorkinis, Emmanouil; Magiorkinis, Gkikas; Sypsa, Vana; Paparizos, Vassilios; Lazanas, Marios; Gargalianos, Panagiotis; Antoniadou, Anastasia; Panos, Georgios; Chrysos, Georgios; Sambatakou, Helen; Karafoulidou, Anastasia; Skoutelis, Athanasios; Kordossis, Theodoros; Koratzanis, Georgios; Theodoridou, Maria; Daikos, Georgios L; Nikolopoulos, Georgios; Pybus, Oliver G; Hatzakis, Angelos

    2007-10-15

    In North America and Europe, human immunodeficiency virus (HIV)-1 infection has typically been dominated by subtype B transmission. More recently, however, non-B subtypes have been increasingly reported in Europe. We analyzed 1158 HIV-1-infected individuals in Greece by DNA sequencing and phylogenetic analyses of protease and partial reverse-transcriptase regions. We found that the prevalence of non-B subtypes has increased over time and that this significant trend can be mainly attributed to subtype A, which eventually surpassed subtype B in prevalence in 2004 (42% and 33%, respectively). Multivariate analysis revealed that the year of HIV diagnosis was independently associated with subtype A infection (odds ratio for being infected with subtype A for a 10-year increase in the time period of diagnosis, 2.09 [95% confidence interval, 1.36-3.24]; PGreece is the result of a single founder event. The date of the most recent common ancestor of the subtype A in Greece was estimated to be 1977.9 (95% highest posterior density interval, 1973.7-1981.9). Subtype A circulates among the long-term residents of Greece. This is in contrast to the situation in most European countries, in which infection with non-B genetic forms is associated either with being an immigrant or heterosexual or with intravenous drug use.

  20. Size estimation, HIV prevalence and risk behaviours of female sex workers in Pakistan

    International Nuclear Information System (INIS)

    Altaf, A.; Aga, A.; McKinizie, M.H.; Abbas, Q.; Jafri, S.B.

    2012-01-01

    Objective: To provide size estimation and to determine risky behaviours and HIV prevalence among female sex workers in Pakistan, which has progressed from a low to concentrated level of HIV epidemic. Methods: A cross-sectional study (geographic mapping and integrated behavioural and biological survey-IBBS) was conducted between August 2005 to January 2006 in Karachi, Hyderabad and Sukkur. A detailed questionnaire and dry blood spot (DBS) specimen for HIV testing were collected by trained interviewers after informed consent. The study was ethically approved by review boards in Canada and Pakistan. Results: About 14,900 female sex workers were estimated to be functional in Sindh. A total of 1158 of them were interviewed for the study. Average age of sex workers was 27.4+- 6.7 years, and the majority 787 (67.9%) were married, and uneducated 764 (65.9%). Sindhi (26.4%) was the predominant ethnicity. Mean number of paid clients was 2.1+-1.2. Three workers were confirmed HIV positive (0.75%, 95 percent CI 0.2-2.2%) from Karachi. Condom use at last sexual act was highest (68%) among brothel-based workers from Karachi, and the lowest in Sukkur where only 1.3% street-based workers reported using a condom at last sexual act. Overall use of illicit drugs through injections was negligible. Conclusion: HIV prevalence among female sex workers in Sindh, Pakistan is low but risky behaviours are present. Well organised service delivery programmes can help promoting safer practices. (author)

  1. Prevalence of cardiovascular risk factors in a middle-income country and estimated cost of a treatment strategy

    Directory of Open Access Journals (Sweden)

    Gabriel Anne

    2006-01-01

    Full Text Available Abstract Background We assessed the prevalence of risk factors for cardiovascular disease (CVD in a middle-income country in rapid epidemiological transition and estimated direct costs for treating all individuals at increased cardiovascular risk, i.e. following the so-called "high risk strategy". Methods Survey of risk factors using an age- and sex-stratified random sample of the population of Seychelles aged 25–64 in 2004. Assessment of CVD risk and treatment modalities were in line with international guidelines. Costs are expressed as US$ per capita per year. Results 1255 persons took part in the survey (participation rate of 80.2%. Prevalence of main risk factors was: 39.6% for high blood pressure (≥140/90 mmHg or treatment of which 59% were under treatment; 24.2% for high cholesterol (≥6.2 mmol/l; 20.8% for low HDL-cholesterol (2 and 22.1% for the metabolic syndrome. Overall, 43% had HBP, high cholesterol or diabetes and substantially increased CVD risk. The cost for medications needed to treat all high-risk individuals amounted to US $45.6, i.e. $11.2 for high blood pressure, $3.8 for diabetes, and $30.6 for dyslipidemia (using generic drugs except for hypercholesterolemia. Cost for minimal follow-up medical care and laboratory tests amounted to $22.6. Conclusion High prevalence of major risk factors was found in a rapidly developing country and costs for treatment needed to reduce risk factors in all high-risk individuals exceeded resources generally available in low or middle income countries. Our findings emphasize the need for affordable cost-effective treatment strategies and the critical importance of population strategies aimed at reducing risk factors in the entire population.

  2. Prevalence rate of supernumerary teeth among non-syndromic South Indian population: An analysis.

    Science.gov (United States)

    Mahabob, M Nazargi; Anbuselvan, G J; Kumar, B Senthil; Raja, S; Kothari, Sucitha

    2012-08-01

    Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stage. The main objective of the study was to determine the prevalence rate of supernumerary teeth in the patients who reported to the Department of Oral Medicine and Radiology and to study the associated clinical complications. A longitudinal observational study was conducted of 2216 patients for a period of 4 months with the documentation of demographic data, the presence of supernumerary teeth, their location, and associated complications such as mechanical trauma, dental caries, and associated pathology. The study recorded 27 supernumerary teeth from the examined 2216 patients. This yields a prevalence of 1.2%, with greater frequency in males which was 1.49% and in females the frequency was 0.85%. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (77.8%). Out of this, 85.7% were classified as mesiodens based on their location. The displacement of adjacent teeth was the most common finding, followed by dental caries. The prevalence of supernumerary teeth in this study was 1.2% which is in agreement with that reported in similar studies and the maxillary mesiodens was the most common location. Displacement of adjacent teeth was the most common finding.

  3. Prevalence rate of supernumerary teeth among non-syndromic South Indian population: An analysis

    Directory of Open Access Journals (Sweden)

    M Nazargi Mahabob

    2012-01-01

    Full Text Available Aim: Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stage. The main objective of the study was to determine the prevalence rate of supernumerary teeth in the patients who reported to the Department of Oral Medicine and Radiology and to study the associated clinical complications. Materials and Methods: A longitudinal observational study was conducted of 2216 patients for a period of 4 months with the documentation of demographic data, the presence of supernumerary teeth, their location, and associated complications such as mechanical trauma, dental caries, and associated pathology. Results: The study recorded 27 supernumerary teeth from the examined 2216 patients. This yields a prevalence of 1.2%, with greater frequency in males which was 1.49% and in females the frequency was 0.85%. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (77.8%. Out of this, 85.7% were classified as mesiodens based on their location. The displacement of adjacent teeth was the most common finding, followed by dental caries. Conclusion: The prevalence of supernumerary teeth in this study was 1.2% which is in agreement with that reported in similar studies and the maxillary mesiodens was the most common location. Displacement of adjacent teeth was the most common finding.

  4. Estimating SEE Error Rates for Complex SoCs With ASERT

    Science.gov (United States)

    Cabanas-Holmen, Manuel; Cannon, Ethan H.; Amort, Tony; Ballast, Jon; Brees, Roger

    2015-08-01

    This paper describes the ASIC Single Event Effects (SEE) Error Rate Tool (ASERT) methodology to estimate the error rates of complex System-on-Chip (SoC) devices. ASERT consists of a top-down analysis to divide the SoC into sensitive cell groups. The SEE error rate is estimated with a bottom-up calculation summing the contribution of all sensitive cell groups, including derating and utilization factors to account for the probability that a cell-level error has a SoC-level impact. The sensitive cell SEE rates are evaluated using test data from specially designed test structures. Standard rate estimation tools are augmented with novel rate estimation approaches for direct proton upsets and for spatial redundancy.

  5. Experiential Learning Based Discussion vs. Lecture Based Discussion: How to Estimate the Unemployment Rate

    OpenAIRE

    Inhyuck "Steve" Ha; Jessica Hollars Wisniewski

    2011-01-01

    This pedagogical method to estimate the unemployment rate is appropriate for an undergraduate course in macroeconomics. Class instructors can use the experiment to make many macroeconomic principles readily apparent to the unskilled reader. This experiment examines the dynamics of calculating the unemployment rate by means of an assessment instrument. Students can learn that the unemployment rate is calculated using estimates of the size of the labor force, which includes individuals who are ...

  6. Microcephaly Case Fatality Rate Associated with Zika Virus Infection in Brazil: Current Estimates.

    Science.gov (United States)

    Cunha, Antonio José Ledo Alves da; de Magalhães-Barbosa, Maria Clara; Lima-Setta, Fernanda; Medronho, Roberto de Andrade; Prata-Barbosa, Arnaldo

    2017-05-01

    Considering the currently confirmed cases of microcephaly and related deaths associated with Zika virus in Brazil, the estimated case fatality rate is 8.3% (95% confidence interval: 7.2-9.6). However, a third of the reported cases remain under investigation. If the confirmation rates of cases and deaths are the same in the future, the estimated case fatality rate will be as high as 10.5% (95% confidence interval: 9.5-11.7).

  7. Prevalence

    Directory of Open Access Journals (Sweden)

    Mohammed Al-Darwish

    2014-07-01

    Conclusion: Results indicated that dental caries prevalence among school children in Qatar has reached critical levels, and is influenced by socio-demographic factors. The mean decayed, missing, and filled teeth values obtained in this study were the second highest detected in the Eastern Mediterranean region.

  8. Child mortality estimation: consistency of under-five mortality rate estimates using full birth histories and summary birth histories.

    Directory of Open Access Journals (Sweden)

    Romesh Silva

    Full Text Available Given the lack of complete vital registration data in most developing countries, for many countries it is not possible to accurately estimate under-five mortality rates from vital registration systems. Heavy reliance is often placed on direct and indirect methods for analyzing data collected from birth histories to estimate under-five mortality rates. Yet few systematic comparisons of these methods have been undertaken. This paper investigates whether analysts should use both direct and indirect estimates from full birth histories, and under what circumstances indirect estimates derived from summary birth histories should be used.Usings Demographic and Health Surveys data from West Africa, East Africa, Latin America, and South/Southeast Asia, I quantify the differences between direct and indirect estimates of under-five mortality rates, analyze data quality issues, note the relative effects of these issues, and test whether these issues explain the observed differences. I find that indirect estimates are generally consistent with direct estimates, after adjustment for fertility change and birth transference, but don't add substantial additional insight beyond direct estimates. However, choice of direct or indirect method was found to be important in terms of both the adjustment for data errors and the assumptions made about fertility.Although adjusted indirect estimates are generally consistent with adjusted direct estimates, some notable inconsistencies were observed for countries that had experienced either a political or economic crisis or stalled health transition in their recent past. This result suggests that when a population has experienced a smooth mortality decline or only short periods of excess mortality, both adjusted methods perform equally well. However, the observed inconsistencies identified suggest that the indirect method is particularly prone to bias resulting from violations of its strong assumptions about recent mortality

  9. Variability of glomerular filtration rate estimation equations in elderly Chinese patients with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Liu X

    2012-10-01

    Full Text Available Xun Liu,1,2,* Mu-hua Cheng,3,* Cheng-gang Shi,1 Cheng Wang,1 Cai-lian Cheng,1 Jin-xia Chen,1 Hua Tang,1 Zhu-jiang Chen,1 Zeng-chun Ye,1 Tan-qi Lou11Division of Nephrology, Department of Internal Medicine, The Third Affiliated Hospital of Sun Yet-sun University, Guangzhou, China; 2College of Biology Engineering, South China University of Technology, Guangzhou, China; 3Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yet-sun University, Guangzhou, China *These authors contributed equally to this paperBackground: Chronic kidney disease (CKD is recognized worldwide as a public health problem, and its prevalence increases as the population ages. However, the applicability of formulas for estimating the glomerular filtration rate (GFR based on serum creatinine (SC levels in elderly Chinese patients with CKD is limited.Materials and methods: Based on values obtained with the technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA renal dynamic imaging method, 319 elderly Chinese patients with CKD were enrolled in this study. Serum creatinine was determined by the enzymatic method. The GFR was estimated using the Cockroft–Gault (CG equation, the Modification of Diet in Renal Disease (MDRD equations, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI equation, the Jelliffe-1973 equation, and the Hull equation.Results: The median of difference ranged from −0.3–4.3 mL/min/1.73 m2. The interquartile range (IQR of differences ranged from 13.9–17.6 mL/min/1.73 m2. Accuracy with a deviation less than 15% ranged from 27.6%–32.9%. Accuracy with a deviation less than 30% ranged from 53.6%–57.7%. Accuracy with a deviation less than 50% ranged from 74.9%–81.5%. None of the equations had accuracy up to the 70% level with a deviation less than 30% from the standard glomerular filtration rate (sGFR. Bland–Altman analysis demonstrated that the mean difference ranged from −3.0–2.4 mL/min/1.73 m2. However, the

  10. Prevalence

    Directory of Open Access Journals (Sweden)

    Jeanesse Scerri

    2013-09-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a major nosocomial pathogen worldwide. Malta is one of the countries with the highest MRSA prevalence in Europe, as identified from hospital blood cultures [1]. However, community prevalence of MRSA has never previously been investigated. This study aimed at establishing the prevalence of community MRSA nasal colonization in Maltese individuals and identifying the clonal characteristics of the detected isolates. Nasal swabs were collected from 329 healthy individuals who were also asked to complete a brief questionnaire about risk factors commonly associated with MRSA carriage and infection. The swabs were transported and enriched in a nutrient broth supplemented with NaCl. The presence of MRSA was then determined by culturing on MRSA Select chromogenic agar and then confirming by several assays, including catalase, coagulase and PBP2a agglutination tests. The isolates were assayed for antibiotic susceptibilities and typed by microarray analysis to determine the clonal characteristics of each strain. The prevalence of MRSA nasal colonization in the healthy Maltese population was found to be 8.81% (95% confidence interval [CI], 5.75–11.87%, much higher than that found in other studies carried out in several countries. No statistical association was found between MRSA carriage and demographics or risk factors; however, this was hindered by the small sample size. Almost all the isolates were fusidic-acid resistant. The majority were found to belong to a local endemic clone (CC5 which seems to be replacing the previously prevalent European clone UK-EMRSA-15 in the country. A new clone (CC50-MRSA-V was also characterized. The presence of such a significant community reservoir of MRSA increases the burdens already faced by the local healthcare system to control the MRSA epidemic. Colonization of MRSA in otherwise healthy individuals may represent a risk for endogenous infection and transmission to

  11. Comparison of modeled sampling strategies for estimation of dairy herd lameness prevalence and cow-level variables associated with lameness.

    Science.gov (United States)

    Hoffman, A C; Moore, D A; Wenz, J R; Vanegas, J

    2013-09-01

    Monitoring herd lameness prevalence has utility for dairy producers and veterinarians in their efforts to reduce lameness, for animal welfare assessment programs, and for researchers. Locomotion scoring is a method used to quantify lameness and calculate prevalence. Because of the time necessary to locomotion score each cow in large dairy herds, a sampling strategy to determine herd lameness prevalence that allows scoring of fewer cows would be useful. Such a sampling strategy must be validated for accuracy compared with the lameness prevalence when all cows in a herd are locomotion scored. The purpose of this study was to assess 3 previously suggested methods of estimating lameness prevalence by strategic sampling of dairy herds. Sampling strategies tested included (1) sampling a calculated number of cows in the middle third of the milking parlor exit order for each pen, (2) sampling a calculated number of cows weighted across pens and distributed evenly within each pen, and (3) sampling all cows in the high production, low production, and hospital pens. Lactating cows on 5 dairy farms in Washington and Oregon (n=4,422) were locomotion scored using a 5-point scale to determine herd-level lameness prevalence (percentage with locomotion score ≥3). Milking parlor exit order, order in headlocks at the feed bunk within each pen, and breed were recorded for each cow. The number of days in lactation, milk production, and parity were collected from farm computer records. Pen grouping strategy for each farm was obtained by interview with farm management. Sampling strategies were modeled using the locomotion score data set for each herd. Estimates of lameness prevalence obtained from the milking parlor exit order sample and the sample distributed across pens were within 5 percentage points of the whole herd prevalence. The third strategy estimated the lameness prevalence within 5 percentage points on 4 farms, but overestimated prevalence on 1 farm. Pen-level prevalence

  12. Food allergies in developing and emerging economies: need for comprehensive data on prevalence rates

    Directory of Open Access Journals (Sweden)

    Boye Joyce Irene

    2012-12-01

    Full Text Available Abstract Although much is known today about the prevalence of food allergy in the developed world, there are serious knowledge gaps about the prevalence rates of food allergy in developing countries. Food allergy affects up to 6% of children and 4% of adults. Symptoms include urticaria, gastrointestinal distress, failure to thrive, anaphylaxis and even death. There are over 170 foods known to provoke allergic reactions. Of these, the most common foods responsible for inducing 90% of reported allergic reactions are peanuts, milk, eggs, wheat, nuts (e.g., hazelnuts, walnuts, almonds, cashews, pecans, etc., soybeans, fish, crustaceans and shellfish. Current assumptions are that prevalence rates are lower in developing countries and emerging economies such as China, Brazil and India which raises questions about potential health impacts should the assumptions not be supported by evidence. As the health and social burden of food allergy can be significant, national and international efforts focusing on food security, food safety, food quality and dietary diversity need to pay special attention to the role of food allergy in order to avoid marginalization of sub-populations in the community. More importantly, as the major food sources used in international food aid programs are frequently priority allergens (e.g., peanut, milk, eggs, soybean, fish, wheat, and due to the similarities between food allergy and some malnutrition symptoms, it will be increasingly important to understand and assess the interplay between food allergy and nutrition in order to protect and identify appropriate sources of foods for sensitized sub-populations especially in economically disadvantaged countries and communities.

  13. Population and antenatal-based HIV prevalence estimates in a high contracepting female population in rural South Africa

    Directory of Open Access Journals (Sweden)

    Barnighausen Till

    2007-07-01

    Full Text Available Abstract Background To present and compare population-based and antenatal-care (ANC sentinel surveillance HIV prevalence estimates among women in a rural South African population where both provision of ANC services and family planning is prevalent and fertility is declining. With a need, in such settings, to understand how to appropriately adjust ANC sentinel surveillance estimates to represent HIV prevalence in general populations, and with evidence of possible biases inherent to both surveillance systems, we explore differences between the two systems. There is particular emphasis on unrepresentative selection of ANC clinics and unrepresentative testing in the population. Methods HIV sero-prevalence amongst blood samples collected from women consenting to test during the 2005 annual longitudinal population-based serological survey was compared to anonymous unlinked HIV sero-prevalence amongst women attending antenatal care (ANC first visits in six clinics (January to May 2005. Both surveillance systems were conducted as part of the Africa Centre Demographic Information System. Results Population-based HIV prevalence estimates for all women (25.2% and pregnant women (23.7% were significantly lower than that for ANC attendees (37.7%. A large proportion of women attending urban or peri-urban clinics would be predicted to be resident within rural areas. Although overall estimates remained significantly different, presenting and standardising estimates by age and location (clinic for ANC-based estimates and individual-residence for population-based estimates made some group-specific estimates from the two surveillance systems more predictive of one another. Conclusion It is likely that where ANC coverage and contraceptive use is widespread and fertility is low, population-based surveillance under-estimates HIV prevalence due to unrepresentative testing by age, residence and also probably by HIV status, and that ANC sentinel surveillance over-estimates

  14. Food insecurity in adults with mood disorders: prevalence estimates and associations with nutritional and psychological health.

    Science.gov (United States)

    Davison, Karen M; Kaplan, Bonnie J

    2015-01-01

    Because little is known about food insecurity in people with mental health conditions, we investigated relationships among food insecurity, nutrient intakes, and psychological functioning in adults with mood disorders. Data from a study of adults randomly selected from the membership list of the Mood Disorder Association of British Columbia (n = 97), Canada, were analyzed. Food insecurity status was based on validated screening questions asking if in the past 12 months did the participant, due to a lack of money, worry about or not have enough food to eat. Nutrient intakes were derived from 3-day food records and compared to the Dietary Reference Intakes (DRIs). Psychological functioning measures included Global Assessment of Functioning, Hamilton Depression scale, and Young Mania Rating Scale. Using binomial tests of two proportions, Mann-Whitney U tests, and Poisson regression we examined: (1) food insecurity prevalence between the study respondents and a general population sample from the British Columbia Nutrition Survey (BCNS; n = 1,823); (2) differences in nutrient intakes based on food insecurity status; and (3) associations of food insecurity and psychological functioning using bivariate and Poisson regression statistics. In comparison to the general population (BCNS), food insecurity was significantly more prevalent in the adults with mood disorders (7.3% in BCNS vs 36.1%; p food-insecure had lower median intakes of carbohydrates and vitamin C (p food insecurity had protein, folate, and zinc intakes below the DRI benchmark of potential inadequacy (p food insecurity and mania symptoms (adjusted prevalence ratio = 2.37, 95% CI 1.49-3.75, p Food insecurity is associated with both nutritional and psychological health in adults with mood disorders. Investigation of interventions aimed at food security and income can help establish its role in enhancing mental health.

  15. Low-sampling-rate ultra-wideband channel estimation using a bounded-data-uncertainty approach

    KAUST Repository

    Ballal, Tarig

    2014-01-01

    This paper proposes a low-sampling-rate scheme for ultra-wideband channel estimation. In the proposed scheme, P pulses are transmitted to produce P observations. These observations are exploited to produce channel impulse response estimates at a desired sampling rate, while the ADC operates at a rate that is P times less. To avoid loss of fidelity, the interpulse interval, given in units of sampling periods of the desired rate, is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this situation and to achieve good performance without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. This estimator is shown to be related to the Bayesian linear minimum mean squared error (LMMSE) estimator. The performance of the proposed sub-sampling scheme was tested in conjunction with the new estimator. It is shown that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in most cases; while in the high SNR regime, it also outperforms the LMMSE estimator. © 2014 IEEE.

  16. Incidence and prevalence rates of diabetes mellitus in Saudi Arabia: An overview.

    Science.gov (United States)

    Alotaibi, Abdulellah; Perry, Lin; Gholizadeh, Leila; Al-Ganmi, Ali

    2017-12-01

    This study aimed to report on the trends in incidence and prevalence rates of diabetes mellitus in Saudi Arabia over the last 25 years (1990-2015). A descriptive review. A systematic search was conducted for English-language, peer reviewed publications of any research design via Medline, EBSCO, PubMed and Scopus from 1990 to 2015. Of 106 articles retrieved, after removal of duplicates and quality appraisal, 8 studies were included in the review and synthesised based on study characteristics, design and findings. Studies originated from Saudi Arabia and applied a variety of research designs and tools to diagnosis diabetes. Of the 8 included studies; three reported type 1 diabetes and five on type 2 diabetes. Overall, findings indicated that the incidence and prevalence rate of diabetes is rising particularly among females, older children/adolescent and in urban areas. Further development are required to assess the health intervention, polices, guidelines, self-management programs in Saudi Arabia. Copyright © 2017. Published by Elsevier Ltd.

  17. Current use of equations for estimating glomerular filtration rate in Spanish laboratories.

    Science.gov (United States)

    Gràcia-Garcia, Sílvia; Montañés-Bermúdez, Rosario; Morales-García, Luis J; Díez-de Los Ríos, M José; Jiménez-García, Juan Á; Macías-Blanco, Carlos; Martínez-López, Rosalina; Ruiz-Altarejos, Joaquín; Ruiz-Martín, Guadalupe; Sanz-Hernández, Sonia; Ventura-Pedret, Salvador

    2012-07-17

    In 2006 the Spanish Society of Clinical Biochemistry and Molecular Pathology (SEQC) and the Spanish Society of Nephrology (S.E.N.) developed a consensus document in order to facilitate the diagnosis and monitoring of chronic kidney disease with the incorporation of equations for estimating glomerular filtration rate (eGFR) into laboratory reports. The current national prevalence of eGFR reporting and the degree of adherence to these recommendations among clinical laboratories is unknown. We administered a national survey in 2010-11 to Spanish clinical laboratories. The survey was through e-mail or telephone to laboratories that participated in the SEQC’s Programme for External Quality Assurance, included in the National Hospitals Catalogue 2010, including both primary care and private laboratories. A total of 281 laboratories answered to the survey. Of these, 88.2% reported on the eGFR, with 61.9% reporting on the MDRD equation and 31.6% using the MDRD-IDMS equation. A total of 42.5% of laboratories always reported serum creatinine values, and other variables only when specifically requested. Regarding the way results were presented, 46.2% of laboratories reported the exact numerical value only when the filtration rate was below 60mL/min/1.73m2, while 50.6% reported all values regardless. In 56.3% of the cases reporting eGFR, an interpretive commentary of it was enclosed. Although a high percentage of Spanish laboratories have added eGFR in their reports, this metric is not universally used. Moreover, some aspects, such as the equation used and the correct expression of eGFR results, should be improved.

  18. Multiple imputation to account for missing data in a survey: estimating the prevalence of osteoporosis.

    Science.gov (United States)

    Kmetic, Andrew; Joseph, Lawrence; Berger, Claudie; Tenenhouse, Alan

    2002-07-01

    Nonresponse bias is a concern in any epidemiologic survey in which a subset of selected individuals declines to participate. We reviewed multiple imputation, a widely applicable and easy to implement Bayesian methodology to adjust for nonresponse bias. To illustrate the method, we used data from the Canadian Multicentre Osteoporosis Study, a large cohort study of 9423 randomly selected Canadians, designed in part to estimate the prevalence of osteoporosis. Although subjects were randomly selected, only 42% of individuals who were contacted agreed to participate fully in the study. The study design included a brief questionnaire for those invitees who declined further participation in order to collect information on the major risk factors for osteoporosis. These risk factors (which included age, sex, previous fractures, family history of osteoporosis, and current smoking status) were then used to estimate the missing osteoporosis status for nonparticipants using multiple imputation. Both ignorable and nonignorable imputation models are considered. Our results suggest that selection bias in the study is of concern, but only slightly, in very elderly (age 80+ years), both women and men. Epidemiologists should consider using multiple imputation more often than is current practice.

  19. Translation of risk factor estimates into on-farm interventions and their effect on Campylobacter broiler flock prevalence

    DEFF Research Database (Denmark)

    Sommer, Helle Mølgaard; Nauta, Maarten; Rosenquist, Hanne

    2016-01-01

    Before deciding upon interventions to control Campylobacter in broiler flocks, it would be useful to estimate the potential effects of different interventions. Certain previously identified risk factors for colonization of broiler flocks with Campylobacter may seem to have large impact...... on the broiler flock prevalence. Nevertheless, interventions related to these risk factors may have only limited effect on the overall prevalence estimate, since in practice only a relatively small fraction of farms are actually amenable for an intervention related to a given risk factor.We present a novel...... had shown to have significant impact on Campylobacter flock prevalence, were translated into practical on-farm interventions. Given the implementation of these interventions the population prevalence was predicted by developing and using a statistical method anchored in the ideas behind standardized...

  20. Changes in yearly birth prevalence rates of children with Down syndrome in the period 1986-2007 in the Netherlands

    NARCIS (Netherlands)

    de Graaf, G.; Hochstenbach, R.; Engelen, J.; Gerssen-Schoorl, K.; Poddighe, P.; Smeets, D.; van Hove, G.; Haveman, M.

    Background The Netherlands are lacking reliable national empirical data in relation to the development of birth prevalence of Down syndrome. Our study aims at assessing valid national live birth prevalence rates for the period 1986-2007. Method On the basis of the annual child/adult ratio of Down

  1. Changes in Yearly Birth Prevalence Rates of Children with Down Syndrome in the Period 1986-2007 in the Netherlands

    Science.gov (United States)

    de Graaf, G.; Haveman, M.; Hochstenbach, R.; Engelen, J.; Gerssen-Schoorl, K.; Poddighe, P.; Smeets, D.; van Hove, G.

    2011-01-01

    Background: The Netherlands are lacking reliable national empirical data in relation to the development of birth prevalence of Down syndrome. Our study aims at assessing valid national live birth prevalence rates for the period 1986-2007. Method: On the basis of the annual child/adult ratio of Down syndrome diagnoses in five out of the eight Dutch…

  2. The reliability of grazing rate estimates from dilution experiments: Have we over-estimated rates of organic carbon consumption by microzooplankton?

    Directory of Open Access Journals (Sweden)

    J. R. Dolan,

    2005-01-01

    Full Text Available According to a recent global analysis, microzooplankton grazing is surprisingly invariant, ranging only between 59 and 74% of phytoplankton primary production across systems differing in seasonality, trophic status, latitude, or salinity. Thus an important biological process in the world ocean, the daily consumption of recently fixed carbon, appears nearly constant. We believe this conclusion is an artefact because dilution experiments are 1 prone to providing over-estimates of grazing rates and 2 unlikely to furnish evidence of low grazing rates. In our view the overall average rate of microzooplankton grazing probably does not exceed 50% of primary production and may be even lower in oligotrophic systems.

  3. Markov models and the ensemble Kalman filter for estimation of sorption rates.

    Energy Technology Data Exchange (ETDEWEB)

    Vugrin, Eric D.; McKenna, Sean Andrew (Sandia National Laboratories, Albuquerque, NM); Vugrin, Kay White

    2007-09-01

    Non-equilibrium sorption of contaminants in ground water systems is examined from the perspective of sorption rate estimation. A previously developed Markov transition probability model for solute transport is used in conjunction with a new conditional probability-based model of the sorption and desorption rates based on breakthrough curve data. Two models for prediction of spatially varying sorption and desorption rates along a one-dimensional streamline are developed. These models are a Markov model that utilizes conditional probabilities to determine the rates and an ensemble Kalman filter (EnKF) applied to the conditional probability method. Both approaches rely on a previously developed Markov-model of mass transfer, and both models assimilate the observed concentration data into the rate estimation at each observation time. Initial values of the rates are perturbed from the true values to form ensembles of rates and the ability of both estimation approaches to recover the true rates is examined over three different sets of perturbations. The models accurately estimate the rates when the mean of the perturbations are zero, the unbiased case. For the cases containing some bias, addition of the ensemble Kalman filter is shown to improve accuracy of the rate estimation by as much as an order of magnitude.

  4. Direct Magnitude Estimation of Articulation Rate in Boys with Fragile X Syndrome

    Science.gov (United States)

    Zajac, David J.; Harris, Adrianne A.; Roberts, Joanne E.; Martin, Gary E.

    2009-01-01

    Purpose: To compare the perceived articulation rate of boys with fragile X syndrome (FXS) with that of chronologically age-matched (CA) boys and to determine segmental and/or prosodic factors that account for perceived rate. Method: Ten listeners used direct magnitude estimation procedures to judge the articulation rates of 7 boys with FXS only, 5…

  5. Estimating Infiltration Rates for a Loessal Silt Loam Using Soil Properties

    Science.gov (United States)

    M. Dean Knighton

    1978-01-01

    Soil properties were related to infiltration rates as measured by single-ringsteady-head infiltometers. The properties showing strong simple correlations were identified. Regression models were developed to estimate infiltration rate from several soil properties. The best model gave fair agreement to measured rates at another location.

  6. Examination of anonymous canine faecal samples provides data on endoparasite prevalence rates in dogs for comparative studies.

    Science.gov (United States)

    Hinney, Barbara; Gottwald, Michaela; Moser, Jasmine; Reicher, Bianca; Schäfer, Bhavapriya Jasmin; Schaper, Roland; Joachim, Anja; Künzel, Frank

    2017-10-15

    Several endoparasites of dogs cannot only be detrimental to their primary host but might also represent a threat to human health because of their zoonotic potential. Due to their high dog population densities, metropolitan areas can be highly endemic for such parasites. We aimed to estimate the prevalence of endoparasites in dogs in the Austrian capital of Vienna by examining a representative number of canine faecal samples and to compare the prevalences with two neighbouring peri-urban and rural regions. In addition we analysed whether the density of dog populations and cleanliness of dog zones correlated with parasite occurrence. We collected 1001 anonymous faecal samples from 55 dog zones from all 23 districts of the federal state of Vienna, as well as 480 faecal samples from the Mödling district and Wolkersdorf with a peri-urban and rural character, respectively. Faeces were examined by flotation and by Baermann technique. Additionally we evaluated 292 Viennese, 102 peri-urban and 50 rural samples for Giardia and Cryptosporidium by GiardiaFASTest ® and CryptoFASTest ® . Samples from "clean" dog zones were compared to samples from "dirty" zones. The infection rate of Toxocara was surprisingly low, ranging from 0.6% to 1.9%. Trichuris was the most frequent helminth (1.8-7.5%) and Giardia the most frequent protozoan (4.0-10.8%). Ancylostomatidae, Crenosoma, Capillaria, Taeniidae, Cystoisospora and Sarcocystis were found in 1.8-2.2%, 0-0.9%, 0-0.9%, 0-0.6%, 0.3-3.1% and 0-0.6% of the samples, respectively. Samples from "dirty" dog zones in Vienna showed a significantly higher rate of parasites overall (p=0.003) and of Trichuris (p=0.048) compared to samples from "clean" dog zones. There were no statistically significant differences in densely vs. less densely populated areas of Vienna. Samples from the rural region of Wolkersdorf had significantly higher overall parasite, Trichuris and Cystoisospora prevalences than the peri-urban Mödling district and Vienna (p

  7. Evaluation of test-strategies for estimating probability of low prevalence of paratuberculosis in Danish dairy herds

    DEFF Research Database (Denmark)

    Sergeant, E.S.G.; Nielsen, Søren S.; Toft, Nils

    2008-01-01

    -sensitivity and specificity; use of a distribution of observed values (rather than a fixed, low value) for design prevalence; and estimates of the probability of low prevalence (Pr-Low) based on a specific number of test-positive animals, rather than for a result less than or equal to a specified cut-point number of reactors...... of this study was to develop a method to estimate the probability of low within-herd prevalence of paratuberculosis for Danish dairy herds. A stochastic simulation model was developed using the R(R) programming environment. Features of this model included: use of age-specific estimates of test....... Using this model, five herd-testing strategies were evaluated: (1) milk-ELISA on all lactating cows; (2) milk-ELISA on lactating cows 4 years old; (4) faecal culture on all lactating cows; and (5) milk-ELISA plus faecal culture in series on all lactating cows. The five testing strategies were evaluated...

  8. Estimating the Smoking Ban Effects on Smoking Prevalence, Quitting and Cigarette Consumption in a Population Study of Apprentices in Italy

    Directory of Open Access Journals (Sweden)

    Luca Pieroni

    2015-08-01

    Full Text Available Objectives: We evaluated the effects of the Italian 2005 smoking ban in public places on the prevalence of smoking, quitting and cigarette consumption of young workers. Data and Methods: The dataset was obtained from non-computerized registers of medical examinations for a population of workers with apprenticeship contracts residing in the province of Viterbo, Italy, in the period 1996–2007. To estimate the effects of the ban, a segmented regression approach was used, exploiting the discontinuity introduced by the application of the law on apprentices’ smoking behavior. Results: It is estimated that the Italian smoking ban generally had no effect on smoking prevalence, quitting ratio, or cigarette consumption of apprentices. However, when the estimates were applied to subpopulations, significant effects were found: −1% in smoking prevalence, +2% in quitting, and −3% in smoking intensity of apprentices with at least a diploma.

  9. Estimating the Smoking Ban Effects on Smoking Prevalence, Quitting and Cigarette Consumption in a Population Study of Apprentices in Italy.

    Science.gov (United States)

    Pieroni, Luca; Muzi, Giacomo; Quercia, Augusto; Lanari, Donatella; Rundo, Carmen; Minelli, Liliana; Salmasi, Luca; dell'Omo, Marco

    2015-08-13

    We evaluated the effects of the Italian 2005 smoking ban in public places on the prevalence of smoking, quitting and cigarette consumption of young workers. The dataset was obtained from non-computerized registers of medical examinations for a population of workers with apprenticeship contracts residing in the province of Viterbo, Italy, in the period 1996-2007. To estimate the effects of the ban, a segmented regression approach was used, exploiting the discontinuity introduced by the application of the law on apprentices' smoking behavior. It is estimated that the Italian smoking ban generally had no effect on smoking prevalence, quitting ratio, or cigarette consumption of apprentices. However, when the estimates were applied to subpopulations, significant effects were found: -1% in smoking prevalence, +2% in quitting, and -3% in smoking intensity of apprentices with at least a diploma.

  10. Psychotropic medication in the French child and adolescent population: prevalence estimation from health insurance data and national self-report survey data

    Directory of Open Access Journals (Sweden)

    Legleye Stéphane

    2009-11-01

    Full Text Available Abstract Background The aim of this work is to estimate the French frequencies of dispensed psychotropic prescriptions in children and adolescents. Prevalence estimations of dispensed prescriptions are compared to the frequencies of use of psychotropic reported by 17 year-old adolescents. Methods Prescription data is derived from national health insurance databases. Frequencies of dispensed prescriptions are extrapolated to estimate a range for the 2004 national rates. Self-report data is derived from the 2003 and 2005 ESCAPAD study, an epidemiological study based on a questionnaire focused on health and drug consumption. Results The prevalence estimation shows that the prevalence of prescription of a psychotropic medication to young persons between 3 and 18 years is about 2.2%. In 2005, the self-report study (ESCAPAD shows that 14.9% of 17 year-old adolescents took medication for "nerves" or "to sleep" during the previous 12 months. The same study in 2003 also shows that 62.3% of adolescents aged 17 and 18 reporting psychotropic use, took the medication for anxiety and 56.8% to sleep. Only 49.7% of these medications are suggested by a doctor. Conclusion This study underlines a similar range of prevalence of psychotropic prescriptions in France to that observed in other European countries. Nevertheless, the proportion of antipsychotics and benzodiazepines seems to be higher, whereas the proportion of methylphenidate is lower. Secondly, a disparity between the prevalence of dispensed prescriptions and the self-report of actual use of psychotropics has been highlighted by the ESCAPAD study which shows that these treatments are widely used as "self-medication".

  11. A study to estimate prevalence and risk factors of Obstructive Sleep Apnoea Syndrome in a semi-urban Indian population.

    Science.gov (United States)

    Singh, Abhijeet; Prasad, Rajendra; Garg, Rajiv; Kant, Surya; Hosmane, Giridhar B; Dubey, Abhisek; Agarwal, Abhisek; Verma, Ram Kishun

    2017-05-18

    Obstructive Sleep Apnea Syndrome (OSAS) has been recognised as a major cause of morbidity and mortality in developing countries like India. There is still a paucity of Indian studies regarding the prevalence of OSAS. The current single centre prospective cross-sectional study was undertaken to know prevalence estimates for key symptoms and features that can indicate the presence of OSAS in an Indian population. A survey was conducted on subjects with age groups ≥ 25 years at King George's Medical University, Lucknow, Uttar Pradesh, India from August 2009 to July 2011. Data was recorded during the interview on the basis of Berlin Questionnaire (BQ). Risk factors for OSAS were also evaluated. Risk group categorization for OSAS was done with the help of a questionnaire and overnight polysomnography was performed in each group to measure apnea and hypopnea index (AHI). Out of 1816 subjects, 1512 (response rate 83.3%) finally participated in the survey with mean age 42.6±11.2 years, males 67.9% and females 32.1%. Of them 6.2% were found to be at high-risk OSAS; 12.2% were obese (Body Mass Index ≥30 kg/m2) and 33.5% of the obese population were at high-risk OSAS. Among high-risk patients with OSAS, 62.4% had hypertension. Statistically significant and independent risk factors found for OSAS were obesity, large neck size, alcoholism and use of sedatives/tranquillizers. High-risk category predicted an AHI ≥5 with a sensitivity of 86.3% (95% CI 73.1-93.8), specificity of 93.1% (95% CI 89.1-95.7), positive and negative predictive values of 70.9% (95% CI 57.9-81.4) and 97.2% (95% CI 94.1-98.8) respectively. It can be concluded that BQ questionnaire can still be used as a pre-assessment tool for predicting persons at risk for OSAS in clinical practice. Further studies on estimation of prevalence of OSAS by applying BQ are warranted in near future from other regions of India.

  12. An estimation of the prevalence and progression of chronic kidney disease in a rural diabetic cambodian population.

    Directory of Open Access Journals (Sweden)

    Bernadette Thomas

    Full Text Available To date, there are no known estimates of the prevalence of chronic kidney disease within Cambodia, the vast majority of whose citizens live in rural areas with limited access to renal replacement therapy.Observational analysis of patients from the Takeo province in Cambodia who presented to MoPoTsyo, a non-governmental organization, for screening and management of diabetes mellitus between 2010 and 2012 (n = 402; 75% females. Estimated glomerular filtration rate (eGFR was calculated using the CKD-Epi equation.On average, women were younger, with a higher percentage of hypercholesterolemia but also high-density lipoprotein level. Men had a higher serum creatinine level (1.31 mg/dl than that of women (1.13 mg/dl at 95% CI. More than half of all screened patients had a reduced eGFR; 60% (95% CI 55%, 65% had an eGFR<60 ml/min/1.73 m(2; 54% (49%, 59% had an eGFR 30-60 ml/min/1.73 m(2, and 5.7% (3.4%, 8.0% with eGFR 15-30 ml/min/1.73 m(2. Women had a greater prevalence of stage 3 CKD (57% women vs. 47% men and stage 4 CKD (7.0% vs. 2.0%. The adjusted odds ratio for females compared to males having an eGFR <60 ml/min/1.73 m(2 was 3.19 (95% CI 1.78, 5.43; p value<0.001. Thirty-two percent of patients lost ≥ 5 ml/min/1.73 m2 eGFR during median follow-up time of 433 days (IQR 462 days days.Over one-half of Cambodians with diabetes mellitus had reduced eGFR, implying a point-prevalence of chronic kidney disease of 1.2% in among adult Cambodians within the country. This high burden of kidney disease in a society that lacks universal access to renal replacement therapy underscores the importance of early diagnosis - a largely unmet need in Cambodia.

  13. Prevalence rate of post-traumatic stress disorders (PTSD and other psychological disorders among Saudi firefighters

    Directory of Open Access Journals (Sweden)

    Mohammed Alghamd

    2013-08-01

    Full Text Available Background: Firefighters have a high probability of being exposed to a variety of traumatic events. Potentially traumatic events can occur during a single rescue such as: providing aid to seriously injured or helpless victims. Moreover, firefighters who are injured in the line of duty may have to retire as a consequence of their injury. The psychological cost of this exposure may increase the risk of long-term problems, such as post-traumatic stress disorder (PTSD symptoms, depression, and anxiety. Objective: The purpose of this study was to investigate the prevalence of PTSD symptoms, depression, anxiety, and assess related variables such as coping strategies and social support among Saudi firefighters. Method: Two hundred firefighters completed the Fire-fighter Trauma History Screen (FTHS to measure the number of traumatic events, Screen for Post-traumatic Stress Symptoms (SPTSS scale to assess the prevalence of PTSD symptoms, Hospital Anxiety and Depression Scales (HADS to assess depression and anxiety, Brief Cope (BC scale to measure coping strategies used, and Social Support scale was used to evaluate the firefighter's support received. Results: The results showed that 84% (169/200 of firefighters were exposed to at least one traumatic event. The result presented that 57% (96/169 of exposure firefighters fully met the DSM-IV criteria for PTSD with high levels of depression and anxiety; 39% (66/169 partially met the PTSD criteria. However, only 4% participants have not met the PTSD criteria. The results also revealed that adaptive coping strategies and higher perceived social support was associated with lower levels of PTSD. Conclusion: The high prevalence rate of PTSD related to the type and severity of the traumatic events and years of experience in the job. Accordingly, many firefighters were severely affected by their experiences, and we should be developing methods to help them.

  14. Alpha-1 antitrypsin Pi*SZ genotype: estimated prevalence and number of SZ subjects worldwide

    Directory of Open Access Journals (Sweden)

    Blanco I

    2017-06-01

    Full Text Available Ignacio Blanco,1 Patricia Bueno,2 Isidro Diego,3 Sergio Pérez-Holanda,4 Beatriz Lara,5 Francisco Casas-Maldonado,6 Cristina Esquinas,7 Marc Miravitlles7,8 1Alpha1-Antitrypsin Deficiency Spanish Registry (REDAAT, Lung Foundation Breathe, Spanish Society of Pneumology (SEPAR, Barcelona, Spain; 2Internal Medicine Department, County Hospital of Jarrio, Principality of Asturias, Spain; 3Materials and Energy Department, School of Mining Engineering, Oviedo University, Principality of Asturias, Spain; 4Surgical Department, University Central Hospital of Asturias, Oviedo, Spain; 5Respiratory Medicine Department, Coventry and Warwickshire University Hospital, Coventry, UK; 6Pneumology Department, University Hospital San Cecilio, Granada, Spain; 7Pneumology Department, Hospital Universitari Vall d’Hebron, Barcelona, Spain; 8CIBER de Enfermedades Respiratorias (CIBERES, Barcelona, Spain Abstract: The alpha-1 antitrypsin (AAT haplotype Pi*S, when inherited along with the Pi*Z haplotype to form a Pi*SZ genotype, can be associated with pulmonary emphysema in regular smokers, and less frequently with liver disease, panniculitis, and systemic vasculitis in a small percentage of people, but this connection is less well established. Since the detection of cases can allow the application of preventive measures in patients and relatives with this congenital disorder, the objective of this study was to update the prevalence of the SZ genotype to achieve accurate estimates of the number of Pi*SZ subjects worldwide, based on studies performed according to the following criteria: 1 samples representative of the general population, 2 AAT phenotyping characterized by adequate methods, and 3 selection of studies with reliable results assessed with a coefficient of variation calculated from the sample size and 95% confidence intervals. Studies fulfilling these criteria were used to develop tables and maps with an inverse distance-weighted (IDW interpolation method, to

  15. Estimates of Radiation Dose Rates Near Large Diameter Sludge Containers in T Plant

    CERN Document Server

    Himes, D A

    2002-01-01

    Dose rates in T Plant canyon during the handling and storage of large diameter storage containers of K Basin sludge were estimated. A number of different geometries were considered from which most operational situations of interest can be constructed.

  16. Estimation of glucose rate of appearance from cgs and subcutaneous insulin delivery in type 1 diabetes

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-08-31

    Method and System for providing estimates of Glucose Rate of Appearance from the intestine (GRA) using continuous glucose sensor measurements (CGS) taken from the subcutaneous of a diabetes patient and the amount of insulin administered to the patient.

  17. Type I Error Rates and Power Estimates of Selected Parametric and Nonparametric Tests of Scale.

    Science.gov (United States)

    Olejnik, Stephen F.; Algina, James

    1987-01-01

    Estimated Type I Error rates and power are reported for the Brown-Forsythe, O'Brien, Klotz, and Siegal-Tukey procedures. The effect of aligning the data using deviations from group means or group medians is investigated. (RB)

  18. Estimation of evaporation rates over the Arabian Sea from Satellite data

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, M.V.; RameshBabu, V.; Rao, L.V.G.; Sastry, J.S.

    Utilizing both the SAMIR brightness temperatures of Bhaskara 2 and GOSSTCOMP charts of NOAA satellite series, the evaporation rates over the Arabian Sea for June 1982 are estimated through the bulk aerodynamic method. The spatial distribution...

  19. High rates of obesity prevalence in adults living in central Greece: data from the ARGOS study.

    Science.gov (United States)

    Koukoulis, George N; Sakka, Christina; Katsaros, Fotis; Goutou, Maria; Tsirona, Sofia; Tsiapali, Efthimia; Piterou, Aristea; Stefanidis, Ioannis; Stathakis, Nikolaos

    2010-01-01

    To investigate the prevalence of obesity in adults of a large region of Central Greece. The target group was adults aged 18 to 79 years who were residents of the region of Thessaly for at least one year. A sample of 852 individuals stratified for sex and age were included. Each subject underwent a thorough physical examination and body mass index (BMI) was calculated from body weight and height. Waist and hip circumferences as well as body fat content were additionally measured. Mean (SD) BMI for the total population was 27.5+/-5.5 and was significantly higher in males than in females (28.2+/-4.4 vs. 26.9+/-6.2, p102cm for men, >88cm for women), was comparable in males (40.4%) and females (35.3%). There was a positive association between obesity, central obesity, and age. The prevalence of overweight (19.5%) and obesity (9.4%) in the age-range of 18-29 years almost doubled in the next decade of age and attained the highest value, respectively, in the age-range of 50 to 59 (48.2%), and of 60 to 70 years group (38.9%). The rates of overweight and obesity in the population of Thessaly are relatively high with overweight being more prominent in males than in females, whereas MO was higher in females compared to males.

  20. Prevalence and Clinical Correlation of Superficial Fungal Foot Infection in Thai Naval Rating Cadets.

    Science.gov (United States)

    Ongsri, Punyawee; Bunyaratavej, Sumanas; Leeyaphan, Charussri; Pattanaprichakul, Penvadee; Ongmahutmongkol, Pattachee; Komoltri, Chulaluk; Kulthanan, Kanokvalai

    2018-02-13

    Superficial fungal foot infection is one of the most important dermatological diseases currently affecting military personnel. Many Thai naval rating cadets are found to suffer from superficial fungal foot infections and their sequels. To investigate prevalence, potent risk factors, responding pathogens and clinical correlation of superficial fungal foot infection in Thai naval rating cadets training in Naval rating school, Sattahip, Thailand. This cross-sectional study was performed in August 2015. Validated structured questionnaire was used regarding information about behaviors and clinical symptoms. Quality of life was assessed by Dermatology Quality of Life Index (DLQI) questionnaire and clinical presentation demonstrated by Athlete's foot severity score (AFSS). Laboratory investigations including direct microscopic examination and fungal culture were performed and recorded. All of the participants were informed and asked for their consent. A total of 788 Thai naval rating cadets with a mean age of 19 yr were enrolled. There were 406 (51.5%) participants suspected of fungal skin infection from questionnaire screening. After clinical examination, 303 participants (38.5%) were found to have foot lesions (AFSS ≥1). Superficial fungal foot infection was diagnosed with microscopic examination and fungal culture in 57 participants, giving a point prevalence of 7.2%. Tinea pedis was diagnosed in 54 participants with the leading causative organism being Trichophyton mentagrophytes (52.8%). Other 3 participants were diagnosed as cutaneous candidiasis. Wearing combat shoes more than 8 h was found to be a predisposing factor (p = 0.029), taking a shower less than two times a day (p = 0.008), and wearing sandals during shower (p = 0.055) was found to be protective against infection. Most fungal feet infection cases noticed their feet abnormalities (p < 0.001) including scales (p < 0.001), vesicles (p = 0.003) and maceration at interdigital web spaces (p < 0.001). Mean

  1. An estimation of the domain of attraction and convergence rate for Hopfield continuous feedback neural networks

    International Nuclear Information System (INIS)

    Cao Jinde

    2004-01-01

    In this Letter, the domain of attraction of memory patterns and exponential convergence rate of the network trajectories to memory patterns for Hopfield continuous associative memory are estimated by means of matrix measure and comparison principle. A new estimation is given for the domain of attraction of memory patterns and exponential convergence rate. These results can be used for the evaluation of fault-tolerance capability and the synthesis procedures for Hopfield continuous feedback associative memory neural networks

  2. Investigation of Bicycle Travel Time Estimation Using Bluetooth Sensors for Low Sampling Rates

    OpenAIRE

    Mei, Zhenyu; Wang, Dianhai; Chen, Jun; Wang, Wei

    2014-01-01

    Filtering the data for bicycle travel time using Bluetooth sensors is crucial to the estimation of link travel times on a corridor. The current paper describes an adaptive filtering algorithm for estimating bicycle travel times using Bluetooth data, with consideration of low sampling rates. The data for bicycle travel time using Bluetooth sensors has two characteristics. First, the bicycle flow contains stable and unstable conditions. Second, the collected data have low sampling rates (less t...

  3. Rates of convergence for Bayes and maximum likelihood estimation for mixture of normal densities

    NARCIS (Netherlands)

    Ghosal, S.; van der Vaart, A.W.

    2001-01-01

    We study the rates of convergence of the maximum likelihood estimator (MLE) and posterior distribution in density estimation problems, where the densities are location or location-scale mixtures of normal distributions with the scale parameter lying between two positive numbers. The true density is

  4. On estimates of the rate of convergence In the global limit theorems for Homogeneous markov chains

    OpenAIRE

    Gharib, M. [محمد غريب محمود

    1997-01-01

    In this paper some estimates are obtained for the remainder term in the limit theorems for the weighted sum of random variables forming a homogeneous Markov chain with arbitrary set of possible states . The achieved results make it possible to estimate the rate of convergence in these theorems in the metric of the space Lp, 1

  5. Using combined accelerometer and heart rate data to estimate physical fitness

    NARCIS (Netherlands)

    Tönis, Thijs; Vollenbroek-Hutten, Miriam Marie Rosé; Hermens, Hermanus J.

    2011-01-01

    Description of the results of an experiment performed on a treadmill, in which heart rate and accelerometer parameters were combined to estimate physical fitness. This to ultimately develop a method to estimate physical fitness (VO2max) in the home environment of a patient.

  6. A Bayes linear Bayes method for estimation of correlated event rates.

    Science.gov (United States)

    Quigley, John; Wilson, Kevin J; Walls, Lesley; Bedford, Tim

    2013-12-01

    Typically, full Bayesian estimation of correlated event rates can be computationally challenging since estimators are intractable. When estimation of event rates represents one activity within a larger modeling process, there is an incentive to develop more efficient inference than provided by a full Bayesian model. We develop a new subjective inference method for correlated event rates based on a Bayes linear Bayes model under the assumption that events are generated from a homogeneous Poisson process. To reduce the elicitation burden we introduce homogenization factors to the model and, as an alternative to a subjective prior, an empirical method using the method of moments is developed. Inference under the new method is compared against estimates obtained under a full Bayesian model, which takes a multivariate gamma prior, where the predictive and posterior distributions are derived in terms of well-known functions. The mathematical properties of both models are presented. A simulation study shows that the Bayes linear Bayes inference method and the full Bayesian model provide equally reliable estimates. An illustrative example, motivated by a problem of estimating correlated event rates across different users in a simple supply chain, shows how ignoring the correlation leads to biased estimation of event rates. © 2013 Society for Risk Analysis.

  7. Estimated amount of 24-hour urine sodium excretion is positively correlated with stomach and breast cancer prevalence in Korea.

    Science.gov (United States)

    Park, Jung Hwan; Kim, Yong Chul; Koo, Ho Seok; Oh, Se Won; Kim, Suhnggwon; Chin, Ho Jun

    2014-09-01

    Stomach cancer is one of the most common cancers in Korea. The aim of this study was to identify the association between the prevalence of cancer, particularly stomach cancer, and the amount of 24-hr urine sodium excretion estimated from spot urine specimens. The study included 19,083 subjects who took part in the Korean National Health and Nutritional Examination Survey between 2009 and 2011. The total amount of urine sodium excreted in a 24-hr period was estimated by using two equations based on the values for spot urine sodium and creatinine. In subjects who had an estimated 24-hr urine sodium excretion of more than two standard deviations above the mean (group 2), the prevalence of stomach cancer was higher than in subjects with lower 24-hr sodium excretion (group 1). By using the Tanaka equation to estimate it, the prevalence of stomach cancer was 0.6% (114/18,331) in group 1, whereas it was 1.6% (9/568) in group 2 (P=0.006). By using the Korean equation, the prevalence was 0.6% (115/18,392) in group 1, and 1.6% in group 2 (8/507) (P=0.010). By using the Tanaka equation, breast cancer in women is more prevalent in group 2 (1.9%, 6/324) than group 1 (0.8%, 78/9,985, P=0.039). Higher salt intake, as defined by the estimated amount of 24-hr urine sodium excretion, is positively correlated with a higher prevalence of stomach or breast cancer in the Korean population.

  8. Estimating blue whale skin isotopic incorporation rates and baleen growth rates: Implications for assessing diet and movement patterns in mysticetes.

    Science.gov (United States)

    Busquets-Vass, Geraldine; Newsome, Seth D; Calambokidis, John; Serra-Valente, Gabriela; Jacobsen, Jeff K; Aguíñiga-García, Sergio; Gendron, Diane

    2017-01-01

    Stable isotope analysis in mysticete skin and baleen plates has been repeatedly used to assess diet and movement patterns. Accurate interpretation of isotope data depends on understanding isotopic incorporation rates for metabolically active tissues and growth rates for metabolically inert tissues. The aim of this research was to estimate isotopic incorporation rates in blue whale skin and baleen growth rates by using natural gradients in baseline isotope values between oceanic regions. Nitrogen (δ15N) and carbon (δ13C) isotope values of blue whale skin and potential prey were analyzed from three foraging zones (Gulf of California, California Current System, and Costa Rica Dome) in the northeast Pacific from 1996-2015. We also measured δ15N and δ13C values along the lengths of baleen plates collected from six blue whales stranded in the 1980s and 2000s. Skin was separated into three strata: basale, externum, and sloughed skin. A mean (±SD) skin isotopic incorporation rate of 163±91 days was estimated by fitting a generalized additive model of the seasonal trend in δ15N values of skin strata collected in the Gulf of California and the California Current System. A mean (±SD) baleen growth rate of 15.5±2.2 cm y-1 was estimated by using seasonal oscillations in δ15N values from three whales. These oscillations also showed that individual whales have a high fidelity to distinct foraging zones in the northeast Pacific across years. The absence of oscillations in δ15N values of baleen sub-samples from three male whales suggests these individuals remained within a specific zone for several years prior to death. δ13C values of both whale tissues (skin and baleen) and potential prey were not distinct among foraging zones. Our results highlight the importance of considering tissue isotopic incorporation and growth rates when studying migratory mysticetes and provide new insights into the individual movement strategies of blue whales.

  9. Reducing false arrhythmia alarm rates using robust heart rate estimation and cost-sensitive support vector machines.

    Science.gov (United States)

    Zhang, Qiang; Chen, Xianxiang; Fang, Zhen; Zhan, Qingyuan; Yang, Ting; Xia, Shanhong

    2017-02-01

    To lessen the rate of false critical arrhythmia alarms, we used robust heart rate estimation and cost-sensitive support vector machines. The PhysioNet MIMIC II database and the 2015 PhysioNet/CinC Challenge public database were used as the training dataset; the 2015 Challenge hidden dataset was for testing. Each record had an alarm labeled with asystole, extreme bradycardia, extreme tachycardia, ventricular tachycardia or ventricular flutter/fibrillation. Before alarm onsets, 300 s multimodal data was provided, including electrocardiogram, arterial blood pressure and/or photoplethysmogram. A signal quality modified Kalman filter achieved robust heart rate estimation. Based on this, we extracted heart rate variability features and statistical ECG features. Next, we applied a genetic algorithm (GA) to select the optimal feature combination. Finally, considering the high cost of classifying a true arrhythmia as false, we selected cost-sensitive support vector machines (CSSVMs) to classify alarms. Evaluation on the test dataset showed the overall true positive rate was 95%, and the true negative rate was 85%.

  10. How badly are we doing? Estimating misclassification rates of shallow landslide susceptibility maps

    Science.gov (United States)

    Papritz, Andreas; von Ruette, Jonas; Lehmann, Peter; Rickli, Christian; Or, Dani

    2010-05-01

    An important motivation for continuing efforts in landslide susceptibility mapping is the need for reliable maps of landslide-prone areas. 'Reliable' means that a map should not systematically under- or overpredict landslide incidence and provide a fair measure of its predictive power. Probabilistic susceptibility maps may be generated by various statistical methods (logistic regression, neural networks, classification trees, etc.). These methods must be 'trained' with data on past landslide occurrence and information about conditioning features (terrain, geology, land use, vegetation, soil, ...). Once trained, most approaches fit observed landslide incidences in training areas reasonably well. If probabilistic predictions are thresholded, the error rate (total percentage of misclassifications), the true positive rate (sensitivity) and false positive rate (1- specificity) - which form the receiver operating characteristics curve (ROC) when plotted against each other for several thresholds - provide, seemingly, a favourable picture of the predictive power of the methods. However, these apparent misclassification rates give too small estimates of the true rates. Remedy for bias is cross-validation, which provides nearly unbiased estimates, but suffers from large random variation. The large variance of cross-validation estimates can be mitigated by bootstrapping. Efron and Tibshirani [1] proposed the .632+ bootstrap for estimating the true error rate. Adler and Lausen [2] extended the method for estimating ROC curves. We use the .632+ bootstrap to estimate misclassification rates (ROC curve, bias score [3]) of landslide susceptibility maps, generated by logistic regression and a random forest classifier. The methods are trained with data on incidence of shallow landslides, released in a pre-alpine catchment in Switzerland during a heavy rainfall in summer 2005. Geomorphological terrain attributes and information on land use are used as conditioning features. Two event

  11. Estimated Prevalence of the Target Population for Brain-Computer Interface Neurotechnology in the Netherlands.

    Science.gov (United States)

    Pels, Elmar G M; Aarnoutse, Erik J; Ramsey, Nick F; Vansteensel, Mariska J

    2017-07-01

    People who suffer from paralysis have difficulties participating in society. Particularly burdensome is the locked-in syndrome (LIS). LIS patients are not able to move and speak but are cognitively healthy. They rely on assistive technology to interact with the world and may benefit from neurotechnological advances. Optimal research and design of such aids requires a well-defined target population. However, the LIS population is poorly characterized and the number of patients in this condition is unknown. Here we estimated and described the LIS patient population in the Netherlands to define the target population for assistive (neuro)technology. We asked physicians in the Netherlands if they had patients suffering from severe paralysis and communication problems in their files. Physicians responding affirmatively were asked to fill out a questionnaire on the patients' status. We sent out 9570 letters to general practitioners (GPs), who reported 83 patients. After first screening, the GPs of 46 patients received the questionnaire. Based on the responses, 26 patients were classified as having LIS. Extrapolation of these numbers resulted in a prevalence of 0.73 patients per 100 000 inhabitants. Notable results from the questionnaire were the percentage of patients with neuromuscular disease (>50%) and living at home (>70%). We revealed an etiologically diverse group of LIS patients. The functioning and needs of these patients were, however, similar and many relied on assistive technology. By characterizing the LIS population, our study may contribute to optimal development of assistive (neuro)technology.

  12. Estimating cancer incidence, prevalence, and the number of cancer patients treated with antitumor therapy in 2015 and 2020 -  analysis of the Czech National Cancer Registry.

    Science.gov (United States)

    Dusek, L; Pavlík, T; Májek, O; Büchler, T; Muzik, J; Maluskova, D; Koptíková, J; Bortlicek, Z; Abrahámová, J

    2015-01-01

    Cancer burden in the Czech population ranks among the highest worldwide, which introduces a strong need for a prospective modelling of cancer incidence and prevalence rates. Moreover, a prediction of number of cancer patients requiring active antitumor therapy is also an important issue. This paper presents the stage-specific predictions of cancer incidence and prevalence, and the stage- and region-specific patients requiring active antitumor therapy for the most common cancer diagnoses in the Czech Republic for years 2015 and 2020. The stage-specific estimates are also presented with regard to the treatment phase as newly diagnosed patients, patients treated for non-terminal recurrence, and patients treated for terminal recurrence. Data of the Czech National Cancer Registry from 1977 to 2011 has been used for the analysis, omitting the records of patients diagnosed as death certificate only or at autopsy. In total, 1,777,775 incidences have been considered for the estimation using a statistical model utilizing solely the population-based cancer registry data. All estimates have been calculated with respect to the changing demographic structure of the Czech population and the clinical stage at diagnosis. Considering year 2011 as the baseline, we predict 89%, 15%, 31% and 32% increase in prostate, colorectal, female breast and lung cancer incidence, respectively, in 2020 resulting in 13,153, 9,368, 8,695, and 8,604 newly dia-g--nosed cancer patients in that year, respectively. Regarding cancer prevalence in 2020, the estimated increase is 140%, 40%, 51%, and 17% for prostate, colorectal, female breast and lung cancer, respectively, meaning that more than 100,000 prevalent female breast cancer patients as well as more than 100,000 prevalent prostate cancer patients are expected in the Czech Republic. The estimated numbers of patients requiring active antitumor therapy for prostate, colorectal, female breast and lung cancer in the Czech Republic in 2020 are 23,652, 14

  13. National survey of risk factors for non-communicable disease in Vietnam: prevalence estimates and an assessment of their validity

    OpenAIRE

    Bui, Tan Van; Blizzard, Christopher Leigh; Luong, Khue Ngoc; Truong, Ngoc Le Van; Tran, Bao Quoc; Otahal, Petr; Gall, Seana; Nelson, Mark R.; Au, Thuy Bich; Ha, Son Thai; Phung, Hai Ngoc; Tran, Mai Hoang; Callisaya, Michele; Srikanth, Velandai

    2016-01-01

    Abstract Background To estimate the prevalence of non-communicable disease (NCD) risk factors at a provincial level in Vietnam, and to assess whether the summary estimates allow reliable inferences to be drawn regarding regional differences in risk factors and associations between them. Methods Participants (n = 14706, 53.5 % females) aged 25–64 years were selected by multi-stage stratified cluster sampling from eight provinces each representing one of the eight geographical regions of Vietna...

  14. The trend of pressure ulcer prevalence rates in German hospitals: results of seven cross-sectional studies.

    Science.gov (United States)

    Kottner, Jan; Wilborn, Doris; Dassen, Theo; Lahmann, Nils

    2009-05-01

    Pressure ulcer prevalence rates provide useful information about the magnitude of this health problem. Only limited information on pressure ulcers in Germany was available before 2001. The purpose of this study was to compare results of seven pressure ulcer prevalence surveys which were conducted annually between 2001 and 2007 and to explore whether pressure ulcer prevalence rates decreased. The second aim was to evaluate if the measured prevalence rates of our sample could be generalised for all German hospitals. Results of seven point pressure ulcer prevalence studies conducted in 225 German hospitals were analysed. Chi-square tests, chi-square trend tests and one-way ANOVA to assess differences and trends across the years were applied. The sample was stratified according to pressure ulcer risk and speciality. Finally, study samples were compared with the potential population. In total data of 40,247 hospital patients were analysed. The overall pressure ulcer prevalence rate in German hospitals was 10.2%. Patient samples of each year were comparable regarding gender, age and pressure ulcer risk. Pressure ulcer prevalence rates decreased from 13.9% (year 2001) to 7.3% (year 2007) (pcare units remained stable. With some limitations our study results are representative for all hospitals within Germany. It is highly probable that the decrease of prevalence rates was due to an increased awareness of the pressure ulcer problem in Germany and subsequent efforts to improve pressure ulcer prevention and treatment. The quality of clinical practice regarding pressure ulcer prevention and treatment has improved. However, pressure ulcers are still relevant and require attention. In 2007, one out of 10 hospital patients who were at pressure ulcer risk had at least one pressure related skin damage.

  15. Sex- and Age-Adjusted Population Analysis of Prevalence Estimates for Hidradenitis Suppurativa in the United States.

    Science.gov (United States)

    Garg, Amit; Kirby, Joslyn S; Lavian, Jonathan; Lin, Gloria; Strunk, Andrew

    2017-08-01

    The true prevalence of hidradenitis suppurativa (HS) is unknown. To establish standardized overall and group-specific prevalence estimates for HS in the United States. This retrospective analysis included a demographically heterogeneous population-based sample of more than 48 million unique patients across all US census regions. As of October 27, 2016, a total of 47 690 patients with HS were identified using electronic health record data. Standardized overall point prevalence for HS and sex-, age-, and race-specific prevalence estimates of HS in the general US population. Of the 47 690 patients with HS (26.2% men and 73.8% women), the overall HS prevalence in the US population sample was 0.10%, or 98 per 100 000 persons (95% CI, 97-99 per 100 000 persons). The adjusted prevalence in women was 137 per 100 000 (95% CI, 136-139 per 100 000), more than twice that of men (58 per 100 000; 95% CI, 57-59 per 100 000; P United States that disproportionately affects female patients, young adults, and African American and biracial patients.

  16. Applied Prevalence Ratio estimation with different Regression models: An example from a cross-national study on substance use research.

    Science.gov (United States)

    Espelt, Albert; Marí-Dell'Olmo, Marc; Penelo, Eva; Bosque-Prous, Marina

    2016-06-14

    To examine the differences between Prevalence Ratio (PR) and Odds Ratio (OR) in a cross-sectional study and to provide tools to calculate PR using two statistical packages widely used in substance use research (STATA and R). We used cross-sectional data from 41,263 participants of 16 European countries participating in the Survey on Health, Ageing and Retirement in Europe (SHARE). The dependent variable, hazardous drinking, was calculated using the Alcohol Use Disorders Identification Test - Consumption (AUDIT-C). The main independent variable was gender. Other variables used were: age, educational level and country of residence. PR of hazardous drinking in men with relation to women was estimated using Mantel-Haenszel method, log-binomial regression models and poisson regression models with robust variance. These estimations were compared to the OR calculated using logistic regression models. Prevalence of hazardous drinkers varied among countries. Generally, men have higher prevalence of hazardous drinking than women [PR=1.43 (1.38-1.47)]. Estimated PR was identical independently of the method and the statistical package used. However, OR overestimated PR, depending on the prevalence of hazardous drinking in the country. In cross-sectional studies, where comparisons between countries with differences in the prevalence of the disease or condition are made, it is advisable to use PR instead of OR.

  17. [Variability and trends in dementia drug consumption in Castile-La Mancha (Spain). Estimated prevalence of Alzheimer's disease].

    Science.gov (United States)

    Criado-Alvarez, J J; Romo Barrientos, C

    2010-05-01

    Alzheimer disease (AD) is one of the most prevalent degenerative disorders in the population over 65 years. We believe that the prevalence in Spain is between 4-11% for the population over 65 years-old. Drugs are currently available to treat this disease in its different phases. We estimated the prevalence of AD by calculating the defined daily doses per 100 inhabitants over 65 years old and days of dementia drugs (therapeutic group N06DA and N06DX) for the years 2004-2008 for each of the provinces of Castile-La Mancha (Spain). We have provided the data requirements specified by the Regional Health Service of Castile-La Mancha. The prevalence of AD is than 2.98 per 100-days for the whole region, there is variation in drug use and consumption, with a predominance of donepezil in all provinces except Guadalajara. On the whole, the consumption of these drugs has increased by 8% annually. The consumption of dementia drugs is used to estimate the distribution of AD in Castile-La Mancha (Spain). These figures do not yet accurately estimate the prevalence of the disease, despite the increase in consumption. We can establish the variability in medical practice for this disease.

  18. Simple approximation for estimating centerline gamma absorbed dose rates due to a continuous Gaussian plume

    International Nuclear Information System (INIS)

    Overcamp, T.J.; Fjeld, R.A.

    1987-01-01

    A simple approximation for estimating the centerline gamma absorbed dose rates due to a continuous Gaussian plume was developed. To simplify the integration of the dose integral, this approach makes use of the Gaussian cloud concentration distribution. The solution is expressed in terms of the I1 and I2 integrals which were developed for estimating long-term dose due to a sector-averaged Gaussian plume. Estimates of tissue absorbed dose rates for the new approach and for the uniform cloud model were compared to numerical integration of the dose integral over a Gaussian plume distribution

  19. Calculating site-specific evolutionary rates at the amino-acid or codon level yields similar rate estimates

    Directory of Open Access Journals (Sweden)

    Dariya K. Sydykova

    2017-05-01

    Full Text Available Site-specific evolutionary rates can be estimated from codon sequences or from amino-acid sequences. For codon sequences, the most popular methods use some variation of the dN∕dS ratio. For amino-acid sequences, one widely-used method is called Rate4Site, and it assigns a relative conservation score to each site in an alignment. How site-wise dN∕dS values relate to Rate4Site scores is not known. Here we elucidate the relationship between these two rate measurements. We simulate sequences with known dN∕dS, using either dN∕dS models or mutation–selection models for simulation. We then infer Rate4Site scores on the simulated alignments, and we compare those scores to either true or inferred dN∕dS values on the same alignments. We find that Rate4Site scores generally correlate well with true dN∕dS, and the correlation strengths increase in alignments with greater sequence divergence and more taxa. Moreover, Rate4Site scores correlate very well with inferred (as opposed to true dN∕dS values, even for small alignments with little divergence. Finally, we verify this relationship between Rate4Site and dN∕dS in a variety of empirical datasets. We conclude that codon-level and amino-acid-level analysis frameworks are directly comparable and yield very similar inferences.

  20. Hemoglobin correction factors for estimating the prevalence of iron deficiency anemia in pregnant women residing at high altitudes in Bolivia

    Directory of Open Access Journals (Sweden)

    Jennifer Hadary Cohen

    1999-12-01

    Full Text Available This study had two primary objectives: 1 to derive a method to determine hemoglobin cutoffs that could be used to better estimate the prevalence of iron deficiency anemia in pregnancy at high altitudes and 2 to estimate the prevalence of anemia in a sample of pregnant women residing in two cities in Bolivia, La Paz (3 600 meters and El Alto (4 000 meters. We derived a hemoglobin-altitude curve from previously published data on the mean hemoglobin concentrations of nonanemic women of childbearing age at various altitudes. In addition, we abstracted data on hemoglobin concentration during pregnancy from medical records of women from La Paz and El Alto who had given birth at a maternity hospital in La Paz between January and June of 1996. Using our approach and two other previously published, currently used methods, we calculated and compared prevalences of iron deficiency anemia in this population using hemoglobin cutoffs determined from a hemoglobin-altitude curve corrected for pregnancy. The hemoglobin-altitude curve derived in this study provided a better fit to data for women of childbearing age than the two other models. Those models used cutoffs based on non-iron-replete populations of children or men, both of which were residing below 4 000 m, and then extrapolated to women and higher altitudes. The estimated prevalences of iron deficiency anemia in pregnancy using the hemoglobin cutoffs determined in this study were higher than those estimated by the two other approaches.

  1. Estimation of the prevalence at animal level of paratuberculosis in female cattle of Saxony-Anhalt (Germany

    Directory of Open Access Journals (Sweden)

    Nicolai Denzin

    2011-11-01

    Full Text Available Johne’s disease (paratuberculosis is a chronic, untreatable disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis. It leads to economic losses in livestock production but is also suspected to be involved in the pathogenesis of Crohn’s disease in humans. In 2007/2008 a study was conducted to estimate the prevalence at animal level of paratuberculosis among the female cattle of Saxony-Anhalt (Germany. In order to keep study costs low and participating farms confidential, no farms were visited to actively draw samples. Instead, animals were pre-selected in a formal random sampling process and additionally tested by ELISA for paratuberculosis when samples suitable for serology were routinely submitted to the State Office of Consumer Protection Saxony-Anhalt for any diagnostics. Out of 896 samples, 38 tested positive, giving an apparent prevalence of 4.2%. Based on the test quality traits of the ELISA employed in the study (POURQUIER® ELISA Paratuberculosis the true prevalence was estimated to 6.7% (95% CI, 3.0-10.4%. No spatial clustering of positive results was detected by a scan statistic. Prevalence estimates for age strata tended to show an incline to a maximum at age class of 5 years and a subsequent decline with higher age classes. Estimates tended to show an incline with herd size.

  2. Estimating medication stopping fraction and real-time prevalence of drug use in pharmaco-epidemiologic databases

    DEFF Research Database (Denmark)

    Støvring, Henrik; Pottegård, Anton; Hallas, Jesper

    2017-01-01

    Purpose: To introduce the reverse waiting time distribution (WTD) and show how it can be used to estimate stopping fractions and real-time prevalence of treatment in pharmacoepidemiological studies. Methods: The reverse WTD is the distribution of time from the last dispensed prescription of each...

  3. A novel approach to estimating the prevalence of untaxed cigarettes in the USA: findings from the 2009 and 2010 international tobacco control surveys.

    Science.gov (United States)

    Fix, Brian V; Hyland, Andrew; O'Connor, Richard J; Cummings, K Michael; Fong, Geoffrey T; Chaloupka, Frank J; Licht, Andrea S

    2014-03-01

    Increases in tobacco taxes are effective in reducing tobacco consumption, but because of the addictive nature of cigarettes, smokers often seek out less expensive sources of cigarettes. The objective of this study is to estimate the prevalence of cigarette packs that are untaxed by the state in which the participant resides in a sample of US smokers at two time points. Data for this study were taken from the 2009 and 2010 waves of the International Tobacco Control United States Survey. Members of this nationally representative cohort of smokers were invited to send us an unopened pack of their usual brand of cigarettes. In 2009, 318 packs were received from 401 eligible participants (79%). In 2010, 366 packs were received from 491 eligible participants (75%). In total, 20% of the packs in 2009 and 21% in 2010 were classified as untaxed by the participant's state of residence. The prevalence of untaxed cigarettes was higher in states with higher-excise taxes. Smokers who do not have a plan to quit were significantly more likely to have sent back a pack that was classified as untaxed by the participant's state of residence. One in five packs were untaxed with rates higher in states with higher-excise taxes. It is unclear whether these estimates differ from the actual prevalence of cigarettes that are untaxed by a smoker's state of residence. Harmonisation of excise tax rates across all 50 US states might be one method of reducing or eliminating the incentive to avoid or evade these taxes.

  4. Use of Pyranometers to Estimate PV Module Degradation Rates in the Field: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Vignola, Frank; Peterson, Josh; Kessler, Rich; Mavromatakis, Fotis; Dooraghi, Mike; Sengupta, Manajit

    2016-08-01

    This paper describes a methodology that uses relative measurements to estimate the degradation rates of PV modules in the field. The importance of calibration and cleaning is illustrated. The number of years of field measurements needed to measure degradation rates with data from the field is cut in half using relative comparisons.

  5. Estimating the spread rate of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer using fluorescence

    Science.gov (United States)

    Toni Antikainen; Anti Rohumaa; Christopher G. Hunt; Mari Levirinne; Mark Hughes

    2015-01-01

    In plywood production, human operators find it difficult to precisely monitor the spread rate of adhesive in real-time. In this study, macroscopic fluorescence was used to estimate spread rate (SR) of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer. This method could be an option when developing automated real-time SR measurement for...

  6. Constrained least squares methods for estimating reaction rate constants from spectroscopic data

    NARCIS (Netherlands)

    Bijlsma, S.; Boelens, H.F.M.; Hoefsloot, H.C.J.; Smilde, A.K.

    2002-01-01

    Model errors, experimental errors and instrumental noise influence the accuracy of reaction rate constant estimates obtained from spectral data recorded in time during a chemical reaction. In order to improve the accuracy, which can be divided into the precision and bias of reaction rate constant

  7. Estimating morbidity rates from electronic medical records in general practice. Evaluation of a grouping system.

    NARCIS (Netherlands)

    Biermans, M.C.J.; Verheij, R.A.; Bakker, D.H. de; Zielhuis, G.A.; Robbe, P.F.

    2008-01-01

    OBJECTIVES: In this study, we evaluated the internal validity of EPICON, an application for grouping ICPC-coded diagnoses from electronic medical records into episodes of care. These episodes are used to estimate morbidity rates in general practice. METHODS: Morbidity rates based on EPICON were

  8. On the estimation of failure rates for living PSAs in the presence of model uncertainty

    International Nuclear Information System (INIS)

    Arsenis, S.P.

    1994-01-01

    The estimation of failure rates of heterogeneous Poisson components from data on times operated to failures is reviewed. Particular emphasis is given to the lack of knowledge on the form of the mixing distribution or population variability curve. A new nonparametric epirical Bayes estimation is proposed which generalizes the estimator of Robbins for different times of observations for the components. The behavior of the estimator is discussed by reference to two samples typically drawn from the CEDB, a component event database designed and operated by the Ispra JRC

  9. On Kolmogorov asymptotics of estimators of the misclassification error rate in linear discriminant analysis

    KAUST Repository

    Zollanvari, Amin

    2013-05-24

    We provide a fundamental theorem that can be used in conjunction with Kolmogorov asymptotic conditions to derive the first moments of well-known estimators of the actual error rate in linear discriminant analysis of a multivariate Gaussian model under the assumption of a common known covariance matrix. The estimators studied in this paper are plug-in and smoothed resubstitution error estimators, both of which have not been studied before under Kolmogorov asymptotic conditions. As a result of this work, we present an optimal smoothing parameter that makes the smoothed resubstitution an unbiased estimator of the true error. For the sake of completeness, we further show how to utilize the presented fundamental theorem to achieve several previously reported results, namely the first moment of the resubstitution estimator and the actual error rate. We provide numerical examples to show the accuracy of the succeeding finite sample approximations in situations where the number of dimensions is comparable or even larger than the sample size.

  10. On Kolmogorov Asymptotics of Estimators of the Misclassification Error Rate in Linear Discriminant Analysis.

    Science.gov (United States)

    Zollanvari, Amin; Genton, Marc G

    2013-08-01

    We provide a fundamental theorem that can be used in conjunction with Kolmogorov asymptotic conditions to derive the first moments of well-known estimators of the actual error rate in linear discriminant analysis of a multivariate Gaussian model under the assumption of a common known covariance matrix. The estimators studied in this paper are plug-in and smoothed resubstitution error estimators, both of which have not been studied before under Kolmogorov asymptotic conditions. As a result of this work, we present an optimal smoothing parameter that makes the smoothed resubstitution an unbiased estimator of the true error. For the sake of completeness, we further show how to utilize the presented fundamental theorem to achieve several previously reported results, namely the first moment of the resubstitution estimator and the actual error rate. We provide numerical examples to show the accuracy of the succeeding finite sample approximations in situations where the number of dimensions is comparable or even larger than the sample size.

  11. A matlab framework for estimation of NLME models using stochastic differential equations: applications for estimation of insulin secretion rates.

    Science.gov (United States)

    Mortensen, Stig B; Klim, Søren; Dammann, Bernd; Kristensen, Niels R; Madsen, Henrik; Overgaard, Rune V

    2007-10-01

    The non-linear mixed-effects model based on stochastic differential equations (SDEs) provides an attractive residual error model, that is able to handle serially correlated residuals typically arising from structural mis-specification of the true underlying model. The use of SDEs also opens up for new tools for model development and easily allows for tracking of unknown inputs and parameters over time. An algorithm for maximum likelihood estimation of the model has earlier been proposed, and the present paper presents the first general implementation of this algorithm. The implementation is done in Matlab and also demonstrates the use of parallel computing for improved estimation times. The use of the implementation is illustrated by two examples of application which focus on the ability of the model to estimate unknown inputs facilitated by the extension to SDEs. The first application is a deconvolution-type estimation of the insulin secretion rate based on a linear two-compartment model for C-peptide measurements. In the second application the model is extended to also give an estimate of the time varying liver extraction based on both C-peptide and insulin measurements.

  12. Updated prevalence rates of overweight and obesity in 4- to 10-year-old children in Germany. Results from the telephone-based KiGGS Wave 1 after correction for bias in parental reports.

    Science.gov (United States)

    Brettschneider, Anna-Kristin; Schienkiewitz, Anja; Schmidt, Steffen; Ellert, Ute; Kurth, Bärbel-Maria

    2017-04-01

    The nationwide 'German Health Interview and Examination Survey for Children and Adolescents' (KiGGS), conducted in 2003-2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regular monitoring. Recently, a follow-up-KiGGS Wave 1 (2009-2012)-was carried out as a telephone-based survey, providing parent-reported height and weight from 5155 children aged 4-10 years. Since parental reports lead to a bias in prevalence rates of weight status, a correction is needed. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from parent reports, weight status categories based on parent-reported and measured height and weight were used to estimate a correction formula according to an established procedure. The corrected prevalence rates derived from KiGGS Wave 1 for overweight, including obesity, in children aged 4-10 years in Germany showed that stagnation is reached compared to the KiGGS baseline study (2003-2006). The rates for overweight, including obesity, in Germany have levelled off. However, they still remain at a high level, indicating a need for further public health action. What is Known: • In the last decades, prevalence of overweight and obesity has risen. Now a days, the prevalence seems to be stagnating. • In Germany, prevalence estimates of overweight and obesity are only available from regional or non-representative studies. What is New: • This article gives an update for prevalence rates of overweight and obesity amongst children aged 4-10 years in Germany based on a nationwide and representative sample. • Results show that stagnation in prevalence rates for overweight in children in Germany is reached.

  13. National estimates of Australian gambling prevalence: f indings from a dual-frame omnibus survey.

    Science.gov (United States)

    Dowling, N A; Youssef, G J; Jackson, A C; Pennay, D W; Francis, K L; Pennay, A; Lubman, D I

    2016-03-01

    The increase in mobile telephone-only households may be a source of bias for traditional landline gambling prevalence surveys. Aims were to: (1) identify Australian gambling participation and problem gambling prevalence using a dual-frame (50% landline and 50% mobile telephone) computer-assisted telephone interviewing methodology; (2) explore the predictors of sample frame and telephone status; and (3) explore the degree to which sample frame and telephone status moderate the relationships between respondent characteristics and problem gambling. A total of 2000 adult respondents residing in Australia were interviewed from March to April 2013. Participation in multiple gambling activities and Problem Gambling Severity Index (PGSI). Estimates were: gambling participation [63.9%, 95% confidence interval (CI) = 61.4-66.3], problem gambling (0.4%, 95% CI = 0.2-0.8), moderate-risk gambling (1.9%, 95% CI = 1.3-2.6) and low-risk gambling (3.0%, 95% CI = 2.2-4.0). Relative to the landline frame, the mobile frame was more likely to gamble on horse/greyhound races [odds ratio (OR) = 1.4], casino table games (OR = 5.0), sporting events (OR = 2.2), private games (OR = 1.9) and the internet (OR = 6.5); less likely to gamble on lotteries (OR = 0.6); and more likely to gamble on five or more activities (OR = 2.4), display problem gambling (OR = 6.4) and endorse PGSI items (OR = 2.4-6.1). Only casino table gambling (OR = 2.9) and internet gambling (OR = 3.5) independently predicted mobile frame membership. Telephone status (landline frame versus mobile dual users and mobile-only users) displayed similar findings. Finally, sample frame and/or telephone status moderated the relationship between gender, relationship status, health and problem gambling (OR = 2.9-7.6). Given expected future increases in the mobile telephone-only population, best practice in population gambling research should use dual frame sampling

  14. Application of Statistical Methods of Rain Rate Estimation to Data From The TRMM Precipitation Radar

    Science.gov (United States)

    Meneghini, R.; Jones, J. A.; Iguchi, T.; Okamoto, K.; Liao, L.; Busalacchi, Antonio J. (Technical Monitor)

    2000-01-01

    The TRMM Precipitation Radar is well suited to statistical methods in that the measurements over any given region are sparsely sampled in time. Moreover, the instantaneous rain rate estimates are often of limited accuracy at high rain rates because of attenuation effects and at light rain rates because of receiver sensitivity. For the estimation of the time-averaged rain characteristics over an area both errors are relevant. By enlarging the space-time region over which the data are collected, the sampling error can be reduced. However. the bias and distortion of the estimated rain distribution generally will remain if estimates at the high and low rain rates are not corrected. In this paper we use the TRMM PR data to investigate the behavior of 2 statistical methods the purpose of which is to estimate the rain rate over large space-time domains. Examination of large-scale rain characteristics provides a useful starting point. The high correlation between the mean and standard deviation of rain rate implies that the conditional distribution of this quantity can be approximated by a one-parameter distribution. This property is used to explore the behavior of the area-time-integral (ATI) methods where fractional area above a threshold is related to the mean rain rate. In the usual application of the ATI method a correlation is established between these quantities. However, if a particular form of the rain rate distribution is assumed and if the ratio of the mean to standard deviation is known, then not only the mean but the full distribution can be extracted from a measurement of fractional area above a threshold. The second method is an extension of this idea where the distribution is estimated from data over a range of rain rates chosen in an intermediate range where the effects of attenuation and poor sensitivity can be neglected. The advantage of estimating the distribution itself rather than the mean value is that it yields the fraction of rain contributed by

  15. A Kalman-Filter Approach to Estimating the Natural Rate of Unemployment

    Directory of Open Access Journals (Sweden)

    Victor V. Claar

    2005-08-01

    Full Text Available The terms “NAIRU” and “natural rate of unemployment” are not interchangeable. Further, while there is a consensus that the NAIRU represents an empirical macroeconomic relationship, little agreement exists regarding what is meant by the “natural rate of unemployment.” This paper estimates the natural rate of unemployment, defined here as the unemployment rate corresponding to equilibrium in the labor market. Rather than employ a Phillips curve, the model utilizes a macroeconomic-principles-level decomposition of the unemployment rate into its cyclical and noncyclical components. We then evaluate the estimated natural rate series by examining its relationship to structural variables from the labor market

  16. Estimating rate of occurrence of rare events with empirical bayes: A railway application

    International Nuclear Information System (INIS)

    Quigley, John; Bedford, Tim; Walls, Lesley

    2007-01-01

    Classical approaches to estimating the rate of occurrence of events perform poorly when data are few. Maximum likelihood estimators result in overly optimistic point estimates of zero for situations where there have been no events. Alternative empirical-based approaches have been proposed based on median estimators or non-informative prior distributions. While these alternatives offer an improvement over point estimates of zero, they can be overly conservative. Empirical Bayes procedures offer an unbiased approach through pooling data across different hazards to support stronger statistical inference. This paper considers the application of Empirical Bayes to high consequence low-frequency events, where estimates are required for risk mitigation decision support such as as low as reasonably possible. A summary of empirical Bayes methods is given and the choices of estimation procedures to obtain interval estimates are discussed. The approaches illustrated within the case study are based on the estimation of the rate of occurrence of train derailments within the UK. The usefulness of empirical Bayes within this context is discussed

  17. Interrelation between the prevalence rate of suicides and the length of working hours

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    P. A. Korotkov

    2017-01-01

    Full Text Available It is known that overworking as well as deficiency of work (plenty of free time are major factors of a suicide on an individual level which allows when passing to the level of a real social group (employees to suppose of existence of a certain optimum of working time or a parabolic (U-shaped connection between the suicide rate and an average duration of working time. From the theoretical point of view the supposed parabolic dependence of the level of prevalence of suicides from an average duration of working time of employees is described from the point of view of suicidology: excessive increase of working time is an external tendency which prevents satisfaction of actual needs of an employee and limits physically the space (off-work time for their realization. Multidirectional tendencies form a life conflict which has crucial significance when transferring to a suicidal phase. The objective of this article consists in a qualitative assessment of an influence of “an average duration of working time” on the level of prevalence of suicides when other things are fixed (economic, social, religious and others in a relatively stable social situation. For the econometric analysis, reliable and comparable data of the European database of detailed mortality data of the World Health Organization and Eurostat are used for 22 European countries for the period from 1998 till 2012. Based on analysis of a dynamics of the studied variables different hypothesis have been made: 1 about existence of statistically significant linear or logarithmic dependence of the level of prevalence of suicides from an average factual duration of working time inside a country 2 about existence of a parabolic (U-shaped dependence of the level of prevalence of suicides from an average factual duration of working time between countries. A set of panel unit root tests and stationarity testify that the examined variables are unsteady variables with integratedness order I(1. The

  18. Using prevalence indices to aid interpretation and comparison of agreement ratings between two or more observers.

    Science.gov (United States)

    Burn, Charlotte C; Weir, Alex A S

    2011-05-01

    Veterinary clinical and epidemiological investigations demand observer reliability. Kappa (κ) statistics are often used to adjust the observed percentage agreement according to that expected by chance. In highly homogenous populations, κ ratings can be poor, despite percentage agreements being high, because the probability of chance agreement is also high. Veterinary researchers are often unsure how to interpret these ambiguous results. It is suggested that prevalence indices (PIs), reflecting the homogeneity of the sample, should be reported alongside percentage agreements and κ values. Here, a published PI calculation is extended, permitting extrapolation to situations involving three or more observers. A process is proposed for classifying results into those that do and do not attain clinically useful ratings, and those tested on excessively homogenous populations and which are therefore inconclusive. Pre-selection of balanced populations, or adjustment of scoring thresholds, can help reduce population homogeneity. Reporting PIs in observer reliability studies in veterinary science and other disciplines enables reliability to be interpreted usefully and allows results to be compared between studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Methods for estimating disease transmission rates: Evaluating the precision of Poisson regression and two novel methods

    DEFF Research Database (Denmark)

    Kirkeby, Carsten Thure; Hisham Beshara Halasa, Tariq; Gussmann, Maya Katrin

    2017-01-01

    Precise estimates of disease transmission rates are critical for epidemiological simulation models. Most often these rates must be estimated from longitudinal field data, which are costly and time-consuming to conduct. Consequently, measures to reduce cost like increased sampling intervals...... or subsampling of the population are implemented. To assess the impact of such measures we implement two different SIS models to simulate disease transmission: A simple closed population model and a realistic dairy herd including population dynamics. We analyze the accuracy of different methods for estimating...... the transmission rate. We use data from the two simulation models and vary the sampling intervals and the size of the population sampled. We devise two new methods to determine transmission rate, and compare these to the frequently used Poisson regression method in both epidemic and endemic situations. For most...

  20. The impact of urbanization and population density on childhood Plasmodium falciparum parasite prevalence rates in Africa.

    Science.gov (United States)

    Kabaria, Caroline W; Gilbert, Marius; Noor, Abdisalan M; Snow, Robert W; Linard, Catherine

    2017-01-26

    Although malaria has been traditionally regarded as less of a problem in urban areas compared to neighbouring rural areas, the risk of malaria infection continues to exist in densely populated, urban areas of Africa. Despite the recognition that urbanization influences the epidemiology of malaria, there is little consensus on urbanization relevant for malaria parasite mapping. Previous studies examining the relationship between urbanization and malaria transmission have used products defining urbanization at global/continental scales developed in the early 2000s, that overestimate actual urban extents while the population estimates are over 15 years old and estimated at administrative unit level. This study sought to discriminate an urbanization definition that is most relevant for malaria parasite mapping using individual level malaria infection data obtained from nationally representative household-based surveys. Boosted regression tree (BRT) modelling was used to determine the effect of urbanization on malaria transmission and if this effect varied with urbanization definition. In addition, the most recent high resolution population distribution data was used to determine whether population density had significant effect on malaria parasite prevalence and if so, could population density replace urban classifications in modelling malaria transmission patterns. The risk of malaria infection was shown to decline from rural areas through peri-urban settlements to urban central areas. Population density was found to be an important predictor of malaria risk. The final boosted regression trees (BRT) model with urbanization and population density gave the best model fit (Tukey test p value <0.05) compared to the models with urbanization only. Given the challenges in uniformly classifying urban areas across different countries, population density provides a reliable metric to adjust for the patterns of malaria risk in densely populated urban areas. Future malaria risk

  1. Effect of nutrition survey ‘cleaning criteria’ on estimates of malnutrition prevalence and disease burden: secondary data analysis

    Directory of Open Access Journals (Sweden)

    Sonya Crowe

    2014-05-01

    Full Text Available Tackling childhood malnutrition is a global health priority. A key indicator is the estimated prevalence of malnutrition, measured by nutrition surveys. Most aspects of survey design are standardised, but data ‘cleaning criteria’ are not. These aim to exclude extreme values which may represent measurement or data-entry errors. The effect of different cleaning criteria on malnutrition prevalence estimates was unknown. We applied five commonly used data cleaning criteria (WHO 2006; EPI-Info; WHO 1995 fixed; WHO 1995 flexible; SMART to 21 national Demographic and Health Survey datasets. These included a total of 163,228 children, aged 6–59 months. We focused on wasting (low weight-for-height, a key indicator for treatment programmes. Choice of cleaning criteria had a marked effect: SMART were least inclusive, resulting in the lowest reported malnutrition prevalence, while WHO 2006 were most inclusive, resulting in the highest. Across the 21 countries, the proportion of records excluded was 3 to 5 times greater when using SMART compared to WHO 2006 criteria, resulting in differences in the estimated prevalence of total wasting of between 0.5 and 3.8%, and differences in severe wasting of 0.4–3.9%. The magnitude of difference was associated with the standard deviation of the survey sample, a statistic that can reflect both population heterogeneity and data quality. Using these results to estimate case-loads for treatment programmes resulted in large differences for all countries. Wasting prevalence and caseload estimations are strongly influenced by choice of cleaning criterion. Because key policy and programming decisions depend on these statistics, variations in analytical practice could lead to inconsistent and potentially inappropriate implementation of malnutrition treatment programmes. We therefore call for mandatory reporting of cleaning criteria use so that results can be compared and interpreted appropriately. International consensus

  2. Call for early prevention: prevalence rates of overweight among Turkish and Moroccan children in The Netherlands.

    Science.gov (United States)

    van Dommelen, Paula; Schönbeck, Yvonne; HiraSing, Remy A; van Buuren, Stef

    2015-10-01

    Monitoring overweight in risk groups is necessary. Our aim is to assess the trend in overweight and obesity in Turkish and Moroccan children in the Netherlands since 1997 and to monitor the levels of lifestyle-related behaviours in 2009. We selected cross-sectional data of Turkish and Moroccan children aged 2-18 years from two national Growth Studies performed in 1997 and 2009 in the Netherlands. Lifestyle-related behaviours were obtained in the 2009 study by questionnaire. In 2009, 31.9% of Turkish and 26.6% of Moroccan children had overweight, whereas this was, respectively, 26.7% and 19.6% in 1997. Already at 2 years, 21.1% in Turkish and 22.7% in Moroccan children had overweight in 2009. The prevalence of obesity was above 4% from 3 years onwards. High (i.e. ≥ 25%) prevalence rates of unhealthy lifestyle-related behaviours were found for not having breakfast (26-49%) among Turkish and Moroccan adolescent (i.e. 15-18 years) girls, consuming no fruit (29-45%) and watching TV/PC ≥ 2 h (35-72%) among all Turkish and Moroccan adolescents, no walking/cycling to school/day care among preschool children (2-4 years) (28-56%) and adolescents (34-94%), drinking ≥ 2 glasses of sweet beverages (44-74%) and being children. An upward trend of overweight and obesity occurred in Turkish and Moroccan children. Already at 2 years of age, one out of five Turkish and Moroccan children had overweight, which calls for early prevention with attention to specific lifestyle-related behaviours. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  3. Equipment errors: A prevalent cause for fallacy in blood pressure recording - A point prevalence estimate from an indian health university

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    Badrinarayan Mishra

    2013-01-01

    Full Text Available Background: Blood pressure (BP recording is the most commonly measured clinical parameter. Standing mercury sphygmomanometer is the most widely used equipment to record this. However, recording by sphygmomanometer is subject to observer and instrumental error. The different sources of equipment error are faulty manometer tube calibration, baseline deviations and improper arm bladder cuff dimensions. This is further compounded by a high prevalence of arm bladder miss-cuffing in the target population. Objectives: The study was designed to assess the presence of equipment malcalibrations, cuff miss-matching and their effect on BP recording. Materials and Methods: A cross-sectional check of all operational sphygmomanometers in a health university was carried out for the length of the manometer tube, deviation of resting mercury column from "0" level, the width and length of arm bladder cuff and extent of bladder cuff-mismatch with respect to outpatient attending population. Results: From the total of 50 apparatus selected, 39 (78% were from hospital setups and 11 (22% from pre-clinical departments. A manometer height deficit of 13 mm was recorded in 36 (92.23% of the equipment in hospital and 11 (100% from pre-clinical departments. Instruments from both settings showed significant deviation from recommended dimensions in cuff bladder length, width and length to width ratio (P < 0.001. Significant number of apparatus from hospital setups showed presence of mercury manometer baseline deviation either below or above 0 mmHg at the resting state (χ2 = 5.61, D. F. = 1, P = 0.02. Positive corelationship was observed between manometer height deficit, baseline deviation and width of arm cuff bladder (Pearson correlation, P < 0.05. Bladder cuff mismatching in response to the target population was found at 48.52% for males and 36.76% for females. The cumulative effect of these factors can lead to an error in the range of 10-12 mmHg. Conclusion : Faulty

  4. Estimating diabetes prevalence in South Auckland: how accurate is a method that combines lists of linked health datasets?

    Science.gov (United States)

    Thornley, Simon; Marshall, Roger; Jackson, Gary; Smith, James; Chan, Wing-Cheuk; Wright, Craig; Gentles, Dudley; Jackson, Rod

    2010-12-17

    To assess the accuracy of a method for estimating adult diabetes prevalence that combines linked, routine health datasets in South Auckland, New Zealand. We used a simple algorithm that combined records of laboratory testing, drug dispensing and hospital diagnoses applied to National Health Index-linked health data in South Auckland to estimate the prevalence of diabetes in 2007. We investigated the sensitivity of this 'combined list' algorithm against a gold standard of individuals with diagnosed diabetes enrolled in a Chronic Care Management programme (CCMP). We also assessed the sensitivity of this algorithm against an estimated diabetes population generated using capture-recapture methods. From the combined-list algorithm, 25,797 (7.2%) South Aucklanders aged 15 years and over had diabetes. During this period, 10,725 patients were enrolled in the CCMP. The combined list algorithm correctly identified (sensitivity) 10,351/10,725 (96.5%) of those enrolled. When we used the capture-recapture estimated diabetes population as an alternative gold standard, 34,418 [9.5%] of South Aucklanders 15 years and over had diabetes, with the sensitivity of the combined list method falling to about 75% (25,797/34,418). Linked health data provide reasonably accurate estimates of diabetes prevalence in a New Zealand population; particularly for cases with longstanding or complicated disease.

  5. Estimation of Circadian Body Temperature Rhythm Based on Heart Rate in Healthy, Ambulatory Subjects.

    Science.gov (United States)

    Sim, Soo Young; Joo, Kwang Min; Kim, Han Byul; Jang, Seungjin; Kim, Beomoh; Hong, Seungbum; Kim, Sungwan; Park, Kwang Suk

    2017-03-01

    Core body temperature is a reliable marker for circadian rhythm. As characteristics of the circadian body temperature rhythm change during diverse health problems, such as sleep disorder and depression, body temperature monitoring is often used in clinical diagnosis and treatment. However, the use of current thermometers in circadian rhythm monitoring is impractical in daily life. As heart rate is a physiological signal relevant to thermoregulation, we investigated the feasibility of heart rate monitoring in estimating circadian body temperature rhythm. Various heart rate parameters and core body temperature were simultaneously acquired in 21 healthy, ambulatory subjects during their routine life. The performance of regression analysis and the extended Kalman filter on daily body temperature and circadian indicator (mesor, amplitude, and acrophase) estimation were evaluated. For daily body temperature estimation, mean R-R interval (RRI), mean heart rate (MHR), or normalized MHR provided a mean root mean square error of approximately 0.40 °C in both techniques. The mesor estimation regression analysis showed better performance than the extended Kalman filter. However, the extended Kalman filter, combined with RRI or MHR, provided better accuracy in terms of amplitude and acrophase estimation. We suggest that this noninvasive and convenient method for estimating the circadian body temperature rhythm could reduce discomfort during body temperature monitoring in daily life. This, in turn, could facilitate more clinical studies based on circadian body temperature rhythm.

  6. ICD-11 Prevalence Rates of Posttraumatic Stress Disorder and Complex Posttraumatic Stress Disorder in a German Nationwide Sample.

    Science.gov (United States)

    Maercker, Andreas; Hecker, Tobias; Augsburger, Mareike; Kliem, Sören

    2018-01-27

    Prevalence rates are still lacking for posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) diagnoses based on the new ICD-11 criteria. In a nationwide representative German sample (N = 2524; 14-99 years), exposure to traumatic events and symptoms of PTSD or CPTSD were assessed with the International Trauma Questionnaire. A clinical variant of CPTSD with a lower threshold for core PTSD symptoms was also calculated, in addition to conditional prevalence rates dependent on trauma type and differential predictors. One-month prevalence rates were as follows: PTSD, 1.5%; CPTSD, 0.5%; and CPTSD variant, 0.7%. For PTSD, the highest conditional prevalence was associated with kidnapping or rape, and the highest CPTSD rates were associated with sexual childhood abuse or rape. PTSD and CPTSD were best differentiated by sexual violence. Combined PTSD and CPTSD (ICD-11) rates were in the range of previously reported prevalences for unified PTSD (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; ICD-10). Evidence on differential predictors of PTSD and CPTSD is still preliminary.

  7. Ultrasonic 3-D Vector Flow Method for Quantitative In Vivo Peak Velocity and Flow Rate Estimation.

    Science.gov (United States)

    Holbek, Simon; Ewertsen, Caroline; Bouzari, Hamed; Pihl, Michael Johannes; Hansen, Kristoffer Lindskov; Stuart, Matthias Bo; Thomsen, Carsten; Nielsen, Michael Bachmann; Jensen, Jorgen Arendt

    2017-03-01

    Current clinical ultrasound (US) systems are limited to show blood flow movement in either 1-D or 2-D. In this paper, a method for estimating 3-D vector velocities in a plane using the transverse oscillation method, a 32×32 element matrix array, and the experimental US scanner SARUS is presented. The aim of this paper is to estimate precise flow rates and peak velocities derived from 3-D vector flow estimates. The emission sequence provides 3-D vector flow estimates at up to 1.145 frames/s in a plane, and was used to estimate 3-D vector flow in a cross-sectional image plane. The method is validated in two phantom studies, where flow rates are measured in a flow-rig, providing a constant parabolic flow, and in a straight-vessel phantom ( ∅=8 mm) connected to a flow pump capable of generating time varying waveforms. Flow rates are estimated to be 82.1 ± 2.8 L/min in the flow-rig compared with the expected 79.8 L/min, and to 2.68 ± 0.04 mL/stroke in the pulsating environment compared with the expected 2.57 ± 0.08 mL/stroke. Flow rates estimated in the common carotid artery of a healthy volunteer are compared with magnetic resonance imaging (MRI) measured flow rates using a 1-D through-plane velocity sequence. Mean flow rates were 333 ± 31 mL/min for the presented method and 346 ± 2 mL/min for the MRI measurements.

  8. Individual differences in rate of encoding predict estimates of visual short-term memory capacity (K).

    Science.gov (United States)

    Jannati, Ali; McDonald, John J; Di Lollo, Vincent

    2015-06-01

    The capacity of visual short-term memory (VSTM) is commonly estimated by K scores obtained with a change-detection task. Contrary to common belief, K may be influenced not only by capacity but also by the rate at which stimuli are encoded into VSTM. Experiment 1 showed that, contrary to earlier conclusions, estimates of VSTM capacity obtained with a change-detection task are constrained by temporal limitations. In Experiment 2, we used change-detection and backward-masking tasks to obtain separate within-subject estimates of K and of rate of encoding, respectively. A median split based on rate of encoding revealed significantly higher K estimates for fast encoders. Moreover, a significant correlation was found between K and the estimated rate of encoding. The present findings raise the prospect that the reported relationships between K and such cognitive concepts as fluid intelligence may be mediated not only by VSTM capacity but also by rate of encoding. (c) 2015 APA, all rights reserved).

  9. A Bayesian framework to estimate diversification rates and their variation through time and space

    Directory of Open Access Journals (Sweden)

    Silvestro Daniele

    2011-10-01

    Full Text Available Abstract Background Patterns of species diversity are the result of speciation and extinction processes, and molecular phylogenetic data can provide valuable information to derive their variability through time and across clades. Bayesian Markov chain Monte Carlo methods offer a promising framework to incorporate phylogenetic uncertainty when estimating rates of diversification. Results We introduce a new approach to estimate diversification rates in a Bayesian framework over a distribution of trees under various constant and variable rate birth-death and pure-birth models, and test it on simulated phylogenies. Furthermore, speciation and extinction rates and their posterior credibility intervals can be estimated while accounting for non-random taxon sampling. The framework is particularly suitable for hypothesis testing using Bayes factors, as we demonstrate analyzing dated phylogenies of Chondrostoma (Cyprinidae and Lupinus (Fabaceae. In addition, we develop a model that extends the rate estimation to a meta-analysis framework in which different data sets are combined in a single analysis to detect general temporal and spatial trends in diversification. Conclusions Our approach provides a flexible framework for the estimation of diversification parameters and hypothesis testing while simultaneously accounting for uncertainties in the divergence times and incomplete taxon sampling.

  10. Accelerometry estimates field metabolic rate in giant Australian cuttlefish Sepia apama during breeding.

    Science.gov (United States)

    Payne, Nicholas L; Gillanders, Bronwyn M; Seymour, Roger S; Webber, Dale M; Snelling, Edward P; Semmens, Jayson M

    2011-03-01

    1. Estimating the metabolic rate of animals in nature is central to understanding the physiological, behavioural and evolutionary ecology of animals. Doubly labelled water and heart-rate methods are the most commonly used approaches, but both have limitations that preclude their application to some systems. 2. Accelerometry has emerged as a powerful tool for estimating energy expenditure in a range of animals, but is yet to be used to estimate field metabolic rate in aquatic taxa. We combined two-dimensional accelerometry and swim-tunnel respirometry to estimate patterns of energy expenditure in giant Australian cuttlefish Sepia apama during breeding. 3. Both oxygen consumption rate (Vo2) and swimming speed showed strong positive associations with body acceleration, with coefficients of determination comparable to those using similar accelerometers on terrestrial vertebrates. Despite increased activity during the day, field metabolic rate rarely approached Vo2, and night-time Vo2 was similar to that at rest. 4. These results are consistent with the life-history strategy of this species, which has a poor capacity to exercise anaerobically, and a mating strategy that is visually based. With the logistical difficulties associated with observation in aquatic environments, accelerometry is likely to prove a valuable tool for estimating energy expenditure in aquatic animals. © 2010 The Authors. Journal compilation © 2010 British Ecological Society.

  11. TR-BREATH: Time-Reversal Breathing Rate Estimation and Detection.

    Science.gov (United States)

    Chen, Chen; Han, Yi; Chen, Yan; Lai, Hung-Quoc; Zhang, Feng; Wang, Beibei; Liu, K J Ray

    2018-03-01

    In this paper, we introduce TR-BREATH, a time-reversal (TR)-based contact-free breathing monitoring system. It is capable of breathing detection and multiperson breathing rate estimation within a short period of time using off-the-shelf WiFi devices. The proposed system exploits the channel state information (CSI) to capture the miniature variations in the environment caused by breathing. To magnify the CSI variations, TR-BREATH projects CSIs into the TR resonating strength (TRRS) feature space and analyzes the TRRS by the Root-MUSIC and affinity propagation algorithms. Extensive experiment results indoor demonstrate a perfect detection rate of breathing. With only 10 s of measurement, a mean accuracy of can be obtained for single-person breathing rate estimation under the non-line-of-sight (NLOS) scenario. Furthermore, it achieves a mean accuracy of in breathing rate estimation for a dozen people under the line-of-sight scenario and a mean accuracy of in breathing rate estimation of nine people under the NLOS scenario, both with 63 s of measurement. Moreover, TR-BREATH can estimate the number of people with an error around 1. We also demonstrate that TR-BREATH is robust against packet loss and motions. With the prevailing of WiFi, TR-BREATH can be applied for in-home and real-time breathing monitoring.

  12. A methodology for estimating occupant CO2 source generation rates from measurements in small commercial buildings

    International Nuclear Information System (INIS)

    Lawrence, Thomas M.; Braun, James E.

    2007-01-01

    It is necessary to know CO 2 source generation rates and system flow parameters, such as supply flow rate and overall room ventilation effectiveness, in order to evaluate cost savings for demand-controlled ventilation applied to commercial buildings. This paper presents a methodology for estimating schedules for generation rates and flow parameters using short-term testing. These parameters are used within a model that predicts return air CO 2 concentrations as part of an overall energy analysis model. As a first step in developing the methodology, two different parameter estimation techniques were evaluated using simulated data. Each method gave models that provide good predictions of return air CO 2 concentrations, but differed in terms of the identified parameters. The preferred parameter estimation method provides estimates of both average hourly source generation rates and day-to-day variations. This technique was applied to three different types of commercial buildings using field monitored data. The sites are small commercial buildings with packaged HVAC equipment and included modular schoolrooms, children's play areas in fast food restaurants and a pharmacy retail store. The impact of the length of model training data period on estimated CO 2 generation rates was investigated. Eight weeks of data is sufficient for training. Expressed in terms of the coefficient of variation, the errors in predicted CO 2 concentrations ranged from 4% to 15% depending on the sites. The predicted frequency of time that CO 2 concentrations were within a given range agreed well with the field measured data. (author)

  13. Estimated prevalence of halitosis: a systematic review and meta-regression analysis

    DEFF Research Database (Denmark)

    Silva, Manuela Ferrari; Manzolli Leite, Fabio Renato; Ferreira, Larissa Barbosa

    2018-01-01

    and abstract evaluation. Thirteen articles met inclusion criteria. The combined prevalence of halitosis was found to be 31.8% (95% CI 24.6-39.0%). Methodological aspects such as the year of publication and the socioeconomic status of the country where the study was conducted seemed to influence the prevalence...

  14. Hepatitis C in HIV-infected individuals: a systematic review and meta-analysis of estimated prevalence in Africa.

    Science.gov (United States)

    Azevedo, Tiago Castro Lopes; Zwahlen, Marcel; Rauch, Andri; Egger, Matthias; Wandeler, Gilles

    2016-01-01

    Although hepatitis C virus (HCV) screening is recommended for all HIV-infected patients initiating antiretroviral therapy, data on epidemiologic characteristics of HCV infection in resource-limited settings are scarce. We searched PubMed and EMBASE for studies assessing the prevalence of HCV infection among HIV-infected individuals in Africa and extracted data on laboratory methods used. Prevalence estimates from individual studies were combined for each country using random-effects meta-analysis. The importance of study design, population and setting as well as type of test (anti-HCV antibody tests and polymerase chain reactions) was examined with meta-regression. Three randomized controlled trials, 28 cohort studies and 121 cross-sectional analyses with 108,180 HIV-infected individuals from 35 countries were included. The majority of data came from outpatient populations (55%), followed by blood donors (15%) and pregnant women (14%). Based on estimates from 159 study populations, anti-HCV positivity prevalence ranged between 3.3% (95% confidence interval (CI) 1.8-4.7) in Southern Africa and 42.3% (95% CI 4.1-80.5) in North Africa. Study design, type of setting and age distribution did not influence this prevalence significantly. The prevalence of replicating HCV infection, estimated from data of 29 cohorts, was 2.0% (95% CI 1.5-2.6). Ten studies from nine countries reported the HCV genotype of 74 samples, 53% were genotype 1, 24% genotype 2, 14% genotype 4 and 9% genotypes 3, 5 or 6. The prevalence of anti-HCV antibodies is high in HIV-infected patients in Africa, but replicating HCV infection is rare and varies widely across countries.

  15. Rare chromosome abnormalities, prevalence and prenatal diagnosis rates from population-based congenital anomaly registers in Europe.

    Science.gov (United States)

    Wellesley, Diana; Dolk, Helen; Boyd, Patricia A; Greenlees, Ruth; Haeusler, Martin; Nelen, Vera; Garne, Ester; Khoshnood, Babak; Doray, Berenice; Rissmann, Anke; Mullaney, Carmel; Calzolari, Elisa; Bakker, Marian; Salvador, Joaquin; Addor, Marie-Claude; Draper, Elizabeth; Rankin, Judith; Tucker, David

    2012-05-01

    The aim of this study is to quantify the prevalence and types of rare chromosome abnormalities (RCAs) in Europe for 2000-2006 inclusive, and to describe prenatal diagnosis rates and pregnancy outcome. Data held by the European Surveillance of Congenital Anomalies database were analysed on all the cases from 16 population-based registries in 11 European countries diagnosed prenatally or before 1 year of age, and delivered between 2000 and 2006. Cases were all unbalanced chromosome abnormalities and included live births, fetal deaths from 20 weeks gestation and terminations of pregnancy for fetal anomaly. There were 10,323 cases with a chromosome abnormality, giving a total birth prevalence rate of 43.8/10,000 births. Of these, 7335 cases had trisomy 21,18 or 13, giving individual prevalence rates of 23.0, 5.9 and 2.3/10,000 births, respectively (53, 13 and 5% of all reported chromosome errors, respectively). In all, 473 cases (5%) had a sex chromosome trisomy, and 778 (8%) had 45,X, giving prevalence rates of 2.0 and 3.3/10,000 births, respectively. There were 1,737 RCA cases (17%), giving a prevalence of 7.4/10,000 births. These included triploidy, other trisomies, marker chromosomes, unbalanced translocations, deletions and duplications. There was a wide variation between the registers in both the overall prenatal diagnosis rate of RCA, an average of 65% (range 5-92%) and the prevalence of RCA (range 2.4-12.9/10,000 births). In all, 49% were liveborn. The data provide the prevalence of families currently requiring specialised genetic counselling services in the perinatal period for these conditions and, for some, long-term care.

  16. Minimax Rate-optimal Estimation of High-dimensional Covariance Matrices with Incomplete Data*

    Science.gov (United States)

    Cai, T. Tony; Zhang, Anru

    2016-01-01

    Missing data occur frequently in a wide range of applications. In this paper, we consider estimation of high-dimensional covariance matrices in the presence of missing observations under a general missing completely at random model in the sense that the missingness is not dependent on the values of the data. Based on incomplete data, estimators for bandable and sparse covariance matrices are proposed and their theoretical and numerical properties are investigated. Minimax rates of convergence are established under the spectral norm loss and the proposed estimators are shown to be rate-optimal under mild regularity conditions. Simulation studies demonstrate that the estimators perform well numerically. The methods are also illustrated through an application to data from four ovarian cancer studies. The key technical tools developed in this paper are of independent interest and potentially useful for a range of related problems in high-dimensional statistical inference with missing data. PMID:27777471

  17. Estimating the Backup Reaction Wheel Orientation Using Reaction Wheel Spin Rates Flight Telemetry from a Spacecraft

    Science.gov (United States)

    Rizvi, Farheen

    2013-01-01

    A report describes a model that estimates the orientation of the backup reaction wheel using the reaction wheel spin rates telemetry from a spacecraft. Attitude control via the reaction wheel assembly (RWA) onboard a spacecraft uses three reaction wheels (one wheel per axis) and a backup to accommodate any wheel degradation throughout the course of the mission. The spacecraft dynamics prediction depends upon the correct knowledge of the reaction wheel orientations. Thus, it is vital to determine the actual orientation of the reaction wheels such that the correct spacecraft dynamics can be predicted. The conservation of angular momentum is used to estimate the orientation of the backup reaction wheel from the prime and backup reaction wheel spin rates data. The method is applied in estimating the orientation of the backup wheel onboard the Cassini spacecraft. The flight telemetry from the March 2011 prime and backup RWA swap activity on Cassini is used to obtain the best estimate for the backup reaction wheel orientation.

  18. Models for estimating projections for disease prevalence and burden: a systematic review focusing on chronic obstructive pulmonary disease.

    Science.gov (United States)

    McLean, Susannah; Barbour, Victoria; Wild, Sarah; Simpson, Colin; Sheikh, Aziz

    2015-10-01

    Epidemiological models for estimating the prevalence and burden of disease inform health policy and service planning decisions. Our aim was to describe the challenges in evaluating such models using the example of epidemiological models for chronic obstructive pulmonary disease (COPD). Two reviewers searched Medline, Embase, CAB Abstracts and World Health Organization (WHO) Databases from 1980 to November 2013 for epidemiological models of COPD prevalence and burden. Two reviewers extracted data and assessed the quality of the studies. We then undertook a descriptive and narrative synthesis of data. We identified 22 models employing a variety of techniques to calculate the prevalence and/or burden of COPD. Models calculated prevalence and/or mortality or other facet of disease burden using demographics and risk factors or trends, Markov-type modelling and microsimulation modelling. The six models which scored highly on the quality framework were: the Peabody model, which generated estimates of COPD prevalence; the WHO DISMOD II model which produced burden estimates in terms of disability adjusted life years with COPD and life years lost to COPD; the Atsou model which gave the life expectancy gains of individual smokers who quit smoking and associated costs; two Dutch COPD models which produced estimates of mortality and health care costs related to COPD; and the Pichon-Riviere model which gave the costs and cost effectiveness of smoking quit programmes. The field of chronic disease modelling is burgeoning. As a result, policy makers need to understand how to interpret epidemiological models and their data sources. © The Author(s) 2015.

  19. Lichen forage ingestion rates of free-roaming caribou estimated with fallout cesium-137

    International Nuclear Information System (INIS)

    Hanson, W.C.; Whicker, F.W.; Lipscomb, J.F.

    1975-01-01

    Lichen forage ingestion rates of free-roaming caribou herds in northern Alaska during 1963 to 1970 were estimated by applying a two-compartment, eight parameter cesium-137 kinetics model to measured fallout 137 Cs concentrations in lichen and caribou. Estimates for winter equilibrium periods (January to April) for each year ranged from 3.7 to 6.9 kg dry weight lichens per day for adult female caribou. Further refinement of these estimations were obtained by calculating probabilistic distributions of intake rates by stochastic processes based upon the mean and standard error intervals of the eight parameters during 1965 and 1968. A computer program generated 1,000 randomly sampled values within each of the eight parameter distributions. Results substantiate the contention that lichen forage ingestion rates by free-roaming caribou are significantly greater than previously held

  20. Time delay estimation in a reverberant environment by low rate sampling of impulsive acoustic sources

    KAUST Repository

    Omer, Muhammad

    2012-07-01

    This paper presents a new method of time delay estimation (TDE) using low sample rates of an impulsive acoustic source in a room environment. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. The RIR is considered a sparse phenomenon and a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) is utilized for its estimation from the low rate sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR and their difference yields the desired time delay. Low sampling rates reduce the hardware and computational complexity and decrease the communication between the microphones and the centralized location. The performance of the proposed technique is demonstrated by numerical simulations and experimental results. © 2012 IEEE.

  1. Estimating the Effective Lower Bound for the Czech National Bank's Policy Rate

    OpenAIRE

    Kolcunova, Dominika; Havranek, Tomas

    2018-01-01

    The paper focuses on the estimation of the effective lower bound for the Czech National Bank's policy rate. The effective lower bound is determined by the value below which holding and using cash would be more convenient than deposits with negative yields. This bound is approximated based on storage, the insurance and transportation costs of cash and the costs associated with the loss of the convenience of cashless payments and complemented with the estimate based on interest charges, which p...

  2. Estimation of water erosion rates using RUSLE3D in Alicante province (Spain)

    OpenAIRE

    Garcia Rodríguez, Jose Luis; Giménez Suárez, Martín Cruz; Arraiza Bermudez-Cañete, Maria Paz

    2015-01-01

    The purpose of this study was the estimation of current and potential water erosion rates in Alicante Province using RUSLE3D (Revised Universal Soil Loss Equation-3D) model with Geographical Information System (GIS) support by request from the Valencia Waste Energy Use. RUSLE3D uses a new methodology for topographic factor estimation (LS factor) based on the impact of flow convergence allowing better assessment of sediment distribution detached by water erosion. In RUSLE3D equation, the effec...

  3. A New Approach for Mobile Advertising Click-Through Rate Estimation Based on Deep Belief Nets

    OpenAIRE

    Chen, Jie-Hao; Zhao, Zi-Qian; Shi, Ji-Yun; Zhao, Chong

    2017-01-01

    In recent years, with the rapid development of mobile Internet and its business applications, mobile advertising Click-Through Rate (CTR) estimation has become a hot research direction in the field of computational advertising, which is used to achieve accurate advertisement delivery for the best benefits in the three-side game between media, advertisers, and audiences. Current research on the estimation of CTR mainly uses the methods and models of machine learning, such as linear model or re...

  4. Simultaneous use of mark-recapture and radiotelemetry to estimate survival, movement, and capture rates

    Science.gov (United States)

    Powell, L.A.; Conroy, M.J.; Hines, J.E.; Nichols, J.D.; Krementz, D.G.

    2000-01-01

    Biologists often estimate separate survival and movement rates from radio-telemetry and mark-recapture data from the same study population. We describe a method for combining these data types in a single model to obtain joint, potentially less biased estimates of survival and movement that use all available data. We furnish an example using wood thrushes (Hylocichla mustelina) captured at the Piedmont National Wildlife Refuge in central Georgia in 1996. The model structure allows estimation of survival and capture probabilities, as well as estimation of movements away from and into the study area. In addition, the model structure provides many possibilities for hypothesis testing. Using the combined model structure, we estimated that wood thrush weekly survival was 0.989 ? 0.007 ( ?SE). Survival rates of banded and radio-marked individuals were not different (alpha hat [S_radioed, ~ S_banded]=log [S hat _radioed/ S hat _banded]=0.0239 ? 0.0435). Fidelity rates (weekly probability of remaining in a stratum) did not differ between geographic strata (psi hat=0.911 ? 0.020; alpha hat [psi11, psi22]=0.0161 ? 0.047), and recapture rates ( = 0.097 ? 0.016) banded and radio-marked individuals were not different (alpha hat [p_radioed, p_banded]=0.145 ? 0.655). Combining these data types in a common model resulted in more precise estimates of movement and recapture rates than separate estimation, but ability to detect stratum or mark-specific differences in parameters was week. We conducted simulation trials to investigate the effects of varying study designs on parameter accuracy and statistical power to detect important differences. Parameter accuracy was high (relative bias [RBIAS] inference from this model, study designs should seek a minimum of 25 animals of each marking type observed (marked or observed via telemetry) in each time period and geographic stratum.

  5. Using 210Pb measurements to estimate sedimentation rates on river floodplains

    International Nuclear Information System (INIS)

    Du, P.; Walling, D.E.

    2012-01-01

    Growing interest in the dynamics of floodplain evolution and the important role of overbank sedimentation on river floodplains as a sediment sink has focused attention on the need to document contemporary and recent rates of overbank sedimentation. The potential for using the fallout radionuclides 137 Cs and excess 210 Pb to estimate medium-term (10–10 2 years) sedimentation rates on river floodplains has attracted increasing attention. Most studies that have successfully used fallout radionuclides for this purpose have focused on the use of 137 Cs. However, the use of excess 210 Pb potentially offers a number of advantages over 137 Cs measurements. Most existing investigations that have used excess 210 Pb measurements to document sedimentation rates have, however, focused on lakes rather than floodplains and the transfer of the approach, and particularly the models used to estimate the sedimentation rate, to river floodplains involves a number of uncertainties, which require further attention. This contribution reports the results of an investigation of overbank sedimentation rates on the floodplains of several UK rivers. Sediment cores were collected from seven floodplain sites representative of different environmental conditions and located in different areas of England and Wales. Measurements of excess 210 Pb and 137 Cs were made on these cores. The 210 Pb measurements have been used to estimate sedimentation rates and the results obtained by using different models have been compared. The 137 Cs measurements have also been used to provide an essentially independent time marker for validation purposes. In using the 210 Pb measurements, particular attention was directed to the problem of obtaining reliable estimates of the supported and excess or unsupported components of the total 210 Pb activity of sediment samples. Although there was a reasonable degree of consistency between the estimates of sedimentation rate provided by the 137 Cs and excess 210 Pb

  6. Challenges in developing estimates of exposure rate near the Nevada Test Site

    International Nuclear Information System (INIS)

    Thompson, C.B.; McArthur, R.D.

    1996-01-01

    As one of several dose reconstruction projects, the Off-site Radiation Exposure Review Project needed to develop models that reflect processes and lifestyles of the past and obtain accurate and adequate historical data to drive the models. One of the critical pieces, ultimately used to estimate the potential dose to people in the area surrounding the Nevada Test Site, was the development of exposure rate estimates used as input to the external and internal dose models. The historical data available for making these estimates were collected in manners and for purposes not necessarily consistent with the needs of this task. The Town Data Base is the culmination of the effort to develop those estimates for the Project's Phase I region (or for locations near the Nevada Test Site that were primarily covered by ground monitoring at the time of the nuclear tests). It includes estimates of discernible exposure rate at 353 populated locations in Arizona, California, Nevada, and Utah and for 74 nuclear tests at the Nevada Test Site. Each dose reconstruction effort has similarities with, and variations from, others. This paper describes some of the challenges encountered in creating the Town Data Base and the approaches used to address them. These challenges included collecting historical data, incorporating net exposure rate values of zero into the estimates, defining a discernible fallout level, handling the lack of measurements at some locations and creating dispersion estimates. The approaches were developed to create open-quotes bestclose quotes estimates and to use actual data (as opposed to assumed values) as the primary source where such data were available. A summary of the spatial distribution of these estimates and a comparison of relative levels of fallout by location are also included

  7. Modeling and estimating the jump risk of exchange rates: Applications to RMB

    Science.gov (United States)

    Wang, Yiming; Tong, Hanfei

    2008-11-01

    In this paper we propose a new type of continuous-time stochastic volatility model, SVDJ, for the spot exchange rate of RMB, and other foreign currencies. In the model, we assume that the change of exchange rate can be decomposed into two components. One is the normally small-cope innovation driven by the diffusion motion; the other is a large drop or rise engendered by the Poisson counting process. Furthermore, we develop a MCMC method to estimate our model. Empirical results indicate the significant existence of jumps in the exchange rate. Jump components explain a large proportion of the exchange rate change.

  8. Ultrasonic 3-D Vector Flow Method for Quantitative In Vivo Peak Velocity and Flow Rate Estimation

    DEFF Research Database (Denmark)

    Holbek, Simon; Ewertsen, Caroline; Bouzari, Hamed

    2017-01-01

    Current clinical ultrasound (US) systems are limited to show blood flow movement in either 1-D or 2-D. In this paper, a method for estimating 3-D vector velocities in a plane using the transverse oscillation method, a 32×32 element matrix array, and the experimental US scanner SARUS is presented....... The aim of this paper is to estimate precise flow rates and peak velocities derived from 3-D vector flow estimates. The emission sequence provides 3-D vector flow estimates at up to 1.145 frames/s in a plane, and was used to estimate 3-D vector flow in a cross-sectional image plane. The method...... is validated in two phantom studies, where flow rates are measured in a flow-rig, providing a constant parabolic flow, and in a straight-vessel phantom ( ∅=8 mm) connected to a flow pump capable of generating time varying waveforms. Flow rates are estimated to be 82.1 ± 2.8 L/min in the flow-rig compared...

  9. Value of the "Test & Treat" Strategy for Uninvestigated Dyspepsia at Low Prevalence Rates of Helicobacter pylori in the Population.

    Science.gov (United States)

    Agréus, Lars; Talley, Nicholas J; Jones, Michael

    2016-06-01

    In populations with a low prevalence rate of Helicobacter pylori (H. pylori) infection from Western countries, guidelines for the management of uninvestigated dyspepsia generally recommend that the "test and treat" strategy should be avoided in favor of empiric proton-pump inhibitor therapy in younger patients (on average pylori infection has fallen from about 30% to about 10% in Sweden and other countries. We aimed to explore whether the rationale for test and treat is relevant in contemporary clinical practice. In settings with an infection rate in the adult population of 30% and 10%, we modeled the positive and negative predictive values for indirect (nonendoscopy) tests on current H. pylori infection with a presumed sensitivity and specificity of 95%. We then calculated the difference in false-negative and false-positive test outcome, and eradication prescription rates in the two scenarios. While the positive predictive value for the test decreased from 0.89 to 0.68 when the prevalence of H. pylori fell from 30% to 10%, there were only 1% more false-negative tests and 1% less false-positive tests. The eradication prescription rate would decrease by 18% with a 10% prevalence rate. The recommendation to stop applying "test and treat" at lower prevalence rates of H. pylori should be reconsidered. The test and treat strategy is the preferred approach for most patients who present with dyspepsia. © 2015 John Wiley & Sons Ltd.

  10. Extraspinal incidental findings on routine MRI of lumbar spine: Prevalence and reporting Rates in 1278 patients

    Energy Technology Data Exchange (ETDEWEB)

    Tuncel, Sedat Alpaslan; Cagli, Bekir; Tekatas, Aslan; Kirici, Yadigar Mehmet; Unlu, Ercument; Genchellac, Haken [Trakya University Faculty of Medicine, Balkan Campus, Edirne (Turkmenistan)

    2015-08-15

    The aim of the present study was to determine the prevalence and reporting rate of incidental findings (IF) in adult outpatients undergoing lumbar magnetic resonance imaging (MRI). Re-evaluation of a total of 1278 lumbar MRI images (collected from patients with a mean age of 50.5 years, range 16-91 years) captured between August 2010-August 2011 was done by a neuroradiologist and a musculoskeletal radiologist. IFs were classified according to organ or system (liver, gallbladder, kidney, bladder, uterus, ovary, lymph node, intestine and aorta). The rate of reporting of a range of IF was examined. The outcome of each patient's treatment was evaluated based on review of hospital records and by telephone interviews. A total of 253 IFs were found in 241 patients (18.8% of 1278). Among these, clinically significant IFs (n = 34) included: 2 renal masses (0.15%), 2 aortic aneurysms (0.15%), 2 cases of hydronephrosis (0.15%), 11 adrenal masses (0.86%), 7 lymphadenopathies (0.55%), 6 cases of endometrial or cervical thickening (0.47%), 1 liver hemangioma (0.08%), 1 pelvic fluid (0.08%) and 2 ovarian dermoid cysts (0.15%). Overall, 28% (71/253) of IFs were included in the clinical reports, while clinically significant findings were reported in 41% (14/34) of cases. Extraspinal IFs are commonly detected during a routine lumbar MRI, and many of these findings are not clinically significant. However, IFs including clinically important findings are occasionally omitted from formal radiological reports.

  11. Two-component mixture cure rate model with spline estimated nonparametric components.

    Science.gov (United States)

    Wang, Lu; Du, Pang; Liang, Hua

    2012-09-01

    In some survival analysis of medical studies, there are often long-term survivors who can be considered as permanently cured. The goals in these studies are to estimate the noncured probability of the whole population and the hazard rate of the susceptible subpopulation. When covariates are present as often happens in practice, to understand covariate effects on the noncured probability and hazard rate is of equal importance. The existing methods are limited to parametric and semiparametric models. We propose a two-component mixture cure rate model with nonparametric forms for both the cure probability and the hazard rate function. Identifiability of the model is guaranteed by an additive assumption that allows no time-covariate interactions in the logarithm of hazard rate. Estimation is carried out by an expectation-maximization algorithm on maximizing a penalized likelihood. For inferential purpose, we apply the Louis formula to obtain point-wise confidence intervals for noncured probability and hazard rate. Asymptotic convergence rates of our function estimates are established. We then evaluate the proposed method by extensive simulations. We analyze the survival data from a melanoma study and find interesting patterns for this study. © 2011, The International Biometric Society.

  12. Propargyl Recombination: Estimation of the High Temperature, Low Pressure Rate Constant from Flame Measurements

    DEFF Research Database (Denmark)

    Rasmussen, Christian Lund; Skjøth-Rasmussen, Martin Skov; Jensen, Anker

    2005-01-01

    3 at temperatures below 1000 K, while data at high temperature and low pressure only can be obtained from flames. In the present work, an estimate of the rate constant for the reaction at 1400 +/- 50 K and 20 Torr is obtained from analysis of the fuel-rich acetylene flame of Westmoreland, Howard......, and Longwell. Based on an accurate modeling of the flame structure, in particular the concentration profile of propargyl, we estimate the rate constant by fitting the kinetic modeling predictions to the measured benzene and phenyl profiles. The best agreement is obtained with k = 1.3 x 10(12) cm(3)/mol...

  13. Global prevalence of diabetes: estimates for 2000 and projections for 2030

    DEFF Research Database (Denmark)

    Wild, Sarah; Roglic, Gojka; Green, Anders

    2004-01-01

    . The total number of people with diabetes is projected to rise from 171 million in 2000 to 366 million in 2030. The prevalence of diabetes is higher in men than women, but there are more women with diabetes than men. The urban population in developing countries is projected to double between 2000 and 2030....... The most important demographic change to diabetes prevalence across the world appears to be the increase in the proportion of people 65 years of age. CONCLUSIONS — These findings indicate that the “diabetes epidemic” will continue even if levels of obesity remain constant. Given the increasing prevalence...

  14. Direct estimation of the mitochondrial DNA mutation rate in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Cathy Haag-Liautard

    2008-08-01

    Full Text Available Mitochondrial DNA (mtDNA variants are widely used in evolutionary genetics as markers for population history and to estimate divergence times among taxa. Inferences of species history are generally based on phylogenetic comparisons, which assume that molecular evolution is clock-like. Between-species comparisons have also been used to estimate the mutation rate, using sites that are thought to evolve neutrally. We directly estimated the mtDNA mutation rate by scanning the mitochondrial genome of Drosophila melanogaster lines that had undergone approximately 200 generations of spontaneous mutation accumulation (MA. We detected a total of 28 point mutations and eight insertion-deletion (indel mutations, yielding an estimate for the single-nucleotide mutation rate of 6.2 x 10(-8 per site per fly generation. Most mutations were heteroplasmic within a line, and their frequency distribution suggests that the effective number of mitochondrial genomes transmitted per female per generation is about 30. We observed repeated occurrences of some indel mutations, suggesting that indel mutational hotspots are common. Among the point mutations, there is a large excess of G-->A mutations on the major strand (the sense strand for the majority of mitochondrial genes. These mutations tend to occur at nonsynonymous sites of protein-coding genes, and they are expected to be deleterious, so do not become fixed between species. The overall mtDNA mutation rate per base pair per fly generation in Drosophila is estimated to be about 10x higher than the nuclear mutation rate, but the mitochondrial major strand G-->A mutation rate is about 70x higher than the nuclear rate. Silent sites are substantially more strongly biased towards A and T than nonsynonymous sites, consistent with the extreme mutation bias towards A+T. Strand-asymmetric mutation bias, coupled with selection to maintain specific nonsynonymous bases, therefore provides an explanation for the extreme base

  15. A large meta-analysis of the global prevalence rates of S. aureus and MRSA contamination of milk.

    Science.gov (United States)

    Ou, Qianting; Zhou, Junli; Lin, Dongxin; Bai, Chan; Zhang, Ting; Lin, Jialing; Zheng, Haoqu; Wang, Xiaojie; Ye, Jiaping; Ye, Xiaohua; Yao, Zhenjiang

    2017-07-07

    Past reports have indicated a high prevalence of milk contaminated with Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA), but the pooled prevalence rates of S. aureus and MRSA in pasteurized and boiled cow's milk, raw cow's milk, and raw Caprinae milk (raw sheep's milk and raw goat's milk) and across different periods, continents, economic conditions and purchase locations remain inconsistent. We searched relevant articles published in PubMed, EMBASE, and Web of Science before July 2016. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement was used to evaluate the quality of 93 included studies. We observed that the pooled prevalence rates of S. aureus contamination in pasteurized and boiled cow's milk, raw cow's milk, and raw Caprinae milk were 15.4% (95% CI, 6.1-27.5%), 33.5% (95% CI, 29.5-37.7%) and 25.8% (95% CI, 17.5-35.0%), respectively. The pooled prevalence rates of MRSA contamination were 4.9% (95% CI, 0.0-15.7%), 2.3% (95% CI, 1.3-3.6%), and 1.1% (95% CI, 0.5-1.8%), respectively. The prevalence of S. aureus contamination in raw cow's milk increased over time. However, the pooled prevalence of raw cow's milk contaminated with S. aureus was lowest in European studies. These findings give an indication of the consequence of better milk regulation in Europe. High S. aureus prevalence rates in raw milk collected from farms and processing companies pose a potential threat to consumers. The implementation of good hygiene practices, appropriate health knowledge, and food safety principles at the farm level, as well as the prudent use of antibiotics in veterinary medicine and heat treatment before drinking, are necessary to reduce the potential risk of S. aureus and MRSA contamination.

  16. Using Final Kepler Catalog Completeness and Reliability Products in Exoplanet Occurrence Rate Estimates

    Science.gov (United States)

    Bryson, Steve; Burke, Christopher; Batalha, Natalie Marie; Thompson, Susan E.; Coughlin, Jeffrey; Christiansen, Jessie; Mullally, Fergal; Shabram, Megan; Kepler Team

    2018-01-01

    Burke et. al. 2015 presented an exoplanet occurrence rate estimate based on the Q1-Q16 Kepler Planet Candidate catalog. That catalog featured uniform planet candidate vetting and analytic approximations to the detection completeness (the fraction of true planets that would be detected) for each target star. We present an extension of that occurrence rate work using the final DR25 Kepler Planet Candidate catalog products, which uses higher-accuracy detection completeness data for each target star, and adds estimates of vetting completeness (the fraction of detected true planets correctly identified as planet candidates) and vetting reliability (the fraction of planet candidates that are true planets). These completeness and reliability products are based on synthetic manipulations of Kepler data, including transit injection, data scrambling, and inversion. We describe how each component is incorporated into the occurrence rate estimate, and how they impact the occurrence rate estimate both individually and in combination. We discuss the strengths and weaknesses of the completeness and reliability products and how they impact our confidence in the occurrence rate values uncertainties. This work is an example of how the community can use the DR25 completeness and reliability products, which are publicly available at the NASA Exoplanet Archive (http://exoplanetarchive.ipac.caltech.edu) and the Mikulski Archive for Space Telescopes (http://archive.stsci.edu/kepler).

  17. Annual survival rate estimate of satellite transmitter–marked eastern population greater sandhill cranes

    Science.gov (United States)

    Fronczak, David L.; Andersen, David E.; Hanna, Everett E.; Cooper, Thomas R.

    2015-01-01

    Several surveys have documented the increasing population size and geographic distribution of Eastern Population greater sandhill cranes Grus canadensis tabida since the 1960s. Sport hunting of this population of sandhill cranes started in 2012 following the provisions of the Eastern Population Sandhill Crane Management Plan. However, there are currently no published estimates of Eastern Population sandhill crane survival rate that can be used to inform harvest management. As part of two studies of Eastern Population sandhill crane migration, we deployed solar-powered global positioning system platform transmitting terminals on Eastern Population sandhill cranes (n  =  42) at key concentration areas from 2009 to 2012. We estimated an annual survival rate for Eastern Population sandhill cranes from data resulting from monitoring these cranes by using the known-fates model in the MARK program. Estimated annual survival rate for adult Eastern Population sandhill cranes was 0.950 (95% confidence interval  =  0.885–0.979) during December 2009–August 2014. All fatalities (n  =  5) occurred after spring migration in late spring and early summer. We were unable to determine cause of death for crane fatalities in our study. Our survival rate estimate will be useful when combined with other population parameters such as the population index derived from the U.S. Fish and Wildlife Service fall survey, harvest, and recruitment rates to assess the effects of harvest on population size and trend and evaluate the effectiveness of management strategies.

  18. Estimating Exchange Rate Exposure over Various Return Horizons: Focusing on Major Countries in East Asia

    Directory of Open Access Journals (Sweden)

    Jeong Wook Lee

    2016-12-01

    Full Text Available In this paper, we estimate the exchange rate exposure, indicating the effect of exchange rate movements on firm values, for a sample of 1,400 firms in seven East Asian countries. The exposure estimates based on various exchange rate variables, return horizons and a control variable are compared. A key result from our analysis is that the long term effect of exchange rate movements on firm values is greater than the short term effect. And we find very similar results from using other exchange rate variables such as the U.S. dollar exchange rate, etc. Second, we add exchange rate volatility as a control variable and find that the extent of exposure is not much changed. Third, we examine the changes in exposure to exchange rate volatility with an increase in return horizon. Consequently the ratio of firms with significant exposures increases with the return horizons. Interestingly, the increase of exposure with the return horizons is faster for exposure to volatility than for exposure to exchange rate itself. Taken as a whole, our findings suggest that the so-called "exposure puzzle" may be a matter of the methodology used to measure exposure.

  19. Analytical methods of leakage rate estimation from a containment under a LOCA

    International Nuclear Information System (INIS)

    Chun, M.H.

    1981-01-01

    Three most outstanding maximum flow rate formulas are identified from many existing models. Outlines of the three limiting mass flow rate models are given along with computational procedures to estimate approximate amount of fission products released from a containment to environment for a given characteristic hole size for containment-isolation failure and containment pressure and temperature under a loss of coolant accident. Sample calculations are performed using the critical ideal gas flow rate model and the Moody's graphs for the maximum two-phase flow rates, and the results are compared with the values obtained from then mass leakage rate formula of CONTEMPT-LT code for converging nozzle and sonic flow. It is shown that the critical ideal gas flow rate formula gives almost comparable results as one can obtain from the Moody's model. It is also found that a more conservative approach to estimate leakage rate from a containment under a LOCA is to use the maximum ideal gas flow rate equation rather than the mass leakage rate formula of CONTEMPT-LT. (author)

  20. The lifetime prevalence of anxiety disorders in Iceland as estimated by the US National Institute of Mental Health Diagnostic Interview Schedule.

    Science.gov (United States)

    Líndal, E; Stefánsson, J G

    1993-07-01

    The lifetime prevalence of anxiety disorders was estimated in a study of the prevalence of mental disorders in Iceland. The survey instrument was an Icelandic translation of the US National Institute of Mental Health Diagnostic Interview Schedule. The cohort consisted of one half of those born in the year 1931. The participation rate was 79.3%. The overall prevalence of anxiety disorders was 44%, with phobia effecting 18%. The most common anxiety disorder was generalized anxiety, which had a prevalence of 22% and was more common among women. Simple phobia was the most common of the phobic disorders (8.8%), followed by agoraphobia without panic (3.8%), and social phobia (3.5%). The female-male ratio for anxiety disorders was 2:1. Of those with simple phobia, the most common items were a fear of heights (41%); claustrophobia (34%); being on public transportation (31%); the fear of being in crowds and speaking in front of others (28%); of being alone (24%); of insects (22%); of bad weather (21%); and of being in water (aquaphobia) (20%). In addition, 17% of the respondents listed phobias not cited in the DSM-III, and of those with the most common phobic disorder, only 9% had consulted a physician because of this condition. Post-traumatic stress disorder was found to affect women exclusively. Comorbidity shows a mean of at least 3 additional diagnoses.

  1. Advantages of video questionnaire in estimating asthma prevalence and risk factors for school children: findings from an asthma survey in American Indian youth.

    Science.gov (United States)

    Yeh, Fawn; Rhoades, Everett R; Tarpay, Martha; Eichner, June E

    2010-09-01

    The aims of the present study were to estimate the prevalence and risk factors of asthma among a sample of American Indian youth and to evaluate survey instruments used in determining asthma prevalence and risk factors. Three hundred and fifty-two adolescents aged 9 to 21 years enrolled in an Indian boarding school completed an asthma screening. The survey instruments were a written questionnaire and a video-illustrated questionnaire prepared from the International Study of Asthma and Allergies in Childhood (ISAAC), school health records, and a health questionnaire. Participants also underwent spirometry testing. The prevalence of self-reported asthma varied from 12.7% to 13.4% depending upon the instrument used and the questions asked. A history of hay fever, respiratory infections, and family history of asthma were found to be risk factors for asthma by all instruments. Female gender and living on a reservation were significantly associated with asthma by some, but not all, instruments. Airway obstruction was highly associated with one asthma symptom (wheeze) shown in the video questionnaire. Associations for most risk factors with asthma were strongest for the video questionnaire. The prevalence of self-reported asthma among these American Indian youth was similar to rates reported for other ethnic groups. The video-based questionnaire may be the most sensitive tool for identifying individuals at risk for asthma.

  2. Natural history of benign prostatic hyperplasia: Appropriate case definition and estimation of its prevalence in the community

    NARCIS (Netherlands)

    J.L.H.R. Bosch (Ruud); W.C.J. Hop (Wim); W.J. Kirkels (Wim); F.H. Schröder (Fritz)

    1995-01-01

    textabstractThere is no consensus about a case definition of benign prostatic hyperplasia (BPH). In the present study, BPH prevalence rates were determined using various case definitions based on a combination of clinical parameters used to describe the properties of BPH: symptoms of prostatism,

  3. Vaccine shot-limiting: Estimating the prevalence, indicators, and impact on vaccination status - Michigan, 2012.

    Science.gov (United States)

    Weinberg, Meghan; Dietz, Stephanie; Potter, Rachel; Swanson, Robert; Miller, Corinne; McFadden, Jevon

    2017-02-15

    Concerns regarding vaccine safety and pain have prompted certain parents to limit the number of shots their child receives per visit. We estimated the prevalence of shot-limited children in Michigan, described their characteristics, assessed whether shot-limited children were up-to-date on recommended vaccinations, and investigated possible intervention points for vaccination education. We analyzed vaccination registry and birth record data of children born in Michigan during 2012 who had ⩾2 vaccination visits, with ⩾1 visits after age 5months. Shot-limited was defined as receiving ⩽2 shots at all visits through age 24months. Nonlimited children received >2 shots at ⩾1 visits. Up-to-date vaccination was based on receipt of a seven-vaccine series and was determined at ages 24months and 35months. Risk ratios (RR) were calculated using risk regression. Of 101,443 children, a total of 2,967 (3%) children were shot-limited. Mothers of shot-limited children were more likely to be white (RR: 1.2; 95% confidence interval [CI]: 1.2-1.2), college graduate (RR: 1.9; 95% CI: 1.9-2.0), and married (RR: 1.5; 95% CI: 1.5-1.5). Compared with nonlimited children, shot-limited children were more likely to be born in a nonhospital setting (RR: 11.7; 95% CI: 9.4-14.6) and have a midwife attendant (RR: 1.9; 95% CI: 1.7-2.1). Shot-limited children were less likely to be up-to-date on recommended vaccinations (RR: 0.2; 95% CI: 0.2-0.3); this association was stronger for those with a midwife birth attendant (RR: 0.1; 95% CI: 0.1-0.2) rather than a medical doctor (RR: 0.3; 95% CI: 0.2-0.3). Shot-limited children are less likely to be up-to-date on vaccinations, possibly leading to increased risk for vaccine-preventable diseases. This association was stronger for those with a midwife birth attendant. This analysis should prompt targeted education, such as to midwives, concerning risks associated with shot-limiting behavior. Published by Elsevier Ltd.

  4. Estimation of variance components and genetic trends for twinning rate in Holstein dairy cattle of Iran.

    Science.gov (United States)

    Ghavi Hossein-Zadeh, N; Nejati-Javaremi, A; Miraei-Ashtiani, S R; Kohram, H

    2009-07-01

    Calving records from the Animal Breeding Center of Iran, collected from January 1991 to December 2007 and comprising 1,163,594 Holstein calving events from 2,552 herds, were analyzed using a linear animal model, linear sire model, threshold animal model, and threshold sire model to estimate variance components, heritabilities, genetic correlations, and genetic trends for twinning rate in the first, second, and third parities. The overall twinning rate was 3.01%. Mean incidence of twins increased from first to fourth and later parities: 1.10, 3.20, 4.22, and 4.50%, respectively. For first-parity cows, a maximum frequency of twinning was observed from January through April (1.36%), and second- and third-parity cows showed peaks from July to September (at 3.35 and 4.55%, respectively). The phenotypic rate of twinning decreased from 1991 to 2007 for the first, second, and third parities. Sire predicted transmitting abilities were estimated using linear sire model and threshold sire model analyses. Sire transmitting abilities for twinning rate in the first, second, and third parities ranged from -0.30 to 0.42, -0.32 to 0.31, and -0.27 to 0.30, respectively. Heritability estimates of twinning rate for parities 1, 2, and 3 ranged from 1.66 to 10.6%, 1.35 to 9.0%, and 1.10 to 7.3%, respectively, using different models for analysis. Heritability estimates for twinning rate, obtained from the analysis of threshold models, were greater than the estimates of linear models. Solutions for age at calving for the first, second, and third parities demonstrated that cows older at calving were more likely to have twins. Genetic correlations for twinning rate between parities 2 and 3 were greater than correlations between parities 1 and 2 and between parities 1 and 3. There was a slightly increasing trend for twinning rate in parities 1, 2, and 3 over time with the analysis of linear animal and linear sire models, but the trend for twinning rate in parities 1, 2, and 3 with threshold

  5. Clinical, cytogenetic, and molecular diagnosis of Angelman syndrome: Estimated prevalence rate in a Danish country

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, M.B.; Brondum-Nielsen, K.; Hansen, L.K.; Wulff, K.

    1995-06-19

    Angelman syndrome (AS) was initially considered a rather rare abnormality, but in later years, with the possibilities for cytogenetic and molecular diagnosis an increasing number of patients have been reported. The incidence is quoted to be around 1:20,000. The etiology of AS is associated with the lack of maternal allele(s) of one or more loci at 15q11-q13, and is considered an effect of parental imprinting of that region, since a similar deficiency of paternal alleles leads to Prader-Willi syndrome. 9 refs., 1 tab.

  6. Organic carbon sedimentation rates in Asian mangrove coastal ecosystems estimated by 210PB chronology

    International Nuclear Information System (INIS)

    Tateda, Y.; Wattayakorn, G.; Nhan, D.D.; Kasuya, Y.

    2004-01-01

    Organic carbon balance estimation of mangrove coastal ecosystem is important for understanding of Asian coastal carbon budget/flux calculation in global carbon cycle modelling which is powerful tool for the prediction of future greenhouse gas effect and evaluation of countermeasure preference. Especially, the organic carbon accumulation rate in mangrove ecosystem was reported to be important sink of carbon as well as that in boreal peat accumulation. For the estimation of 10 3 years scale organic carbon accumulation rates in mangrove coastal ecosystems, 14 C was used as long term chronological tracer, being useful in pristine mangrove forest reserve area. While in case of mangrove plantation of in coastal area, the 210 Pb is suitable for the estimation of decades scale estimation by its half-life. Though it has possibility of bio-/physical- turbation effect in applying 210 Pb chronology that is offset in case of 10 3 years scale estimation, especially in Asian mangrove ecosystem where the anthropogenic physical turbation by coastal fishery is vigorous.In this paper, we studied the organic carbon and 210 Pb accumulation rates in subtropical mangrove coastal ecosystems in Japan, Vietnam and Thailand with 7 Be analyses to make sure the negligible effect of above turbation effects on organic carbon accumulation. We finally concluded that 210 Pb was applicable to estimate organic carbon accumulation rates in these ecosystems even though the physical-/bio-turbation is expected. The measured organic carbon accumulation rates using 210 Pb in mangrove coastal ecosystems of Japan, Vietnam and Thailand were 0.067 4.0 t-C ha -1 y -1 . (author)

  7. State-Space Dynamic Model for Estimation of Radon Entry Rate, based on Kalman Filtering

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Jílek, K.

    2007-01-01

    Roč. 98, - (2007), s. 285-297 ISSN 0265-931X Grant - others:GA SÚJB JC_11/2006 Institutional research plan: CEZ:AV0Z10300504 Keywords : air ventilation rate * radon entry rate * state-space modeling * extended Kalman filter * maximum likelihood estimation * prediction error decomposition Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.963, year: 2007

  8. Challenges associated with drunk driving measurement: combining police and self-reported data to estimate an accurate prevalence in Brazil.

    Science.gov (United States)

    Sousa, Tanara; Lunnen, Jeffrey C; Gonçalves, Veralice; Schmitz, Aurinez; Pasa, Graciela; Bastos, Tamires; Sripad, Pooja; Chandran, Aruna; Pechansky, Flavio

    2013-12-01

    Drunk driving is an important risk factor for road traffic crashes, injuries and deaths. After June 2008, all drivers in Brazil were subject to a "Zero Tolerance Law" with a set breath alcohol concentration of 0.1 mg/L of air. However, a loophole in this law enabled drivers to refuse breath or blood alcohol testing as it may self-incriminate. The reported prevalence of drunk driving is therefore likely a gross underestimate in many cities. To compare the prevalence of drunk driving gathered from police reports to the prevalence gathered from self-reported questionnaires administered at police sobriety roadblocks in two Brazilian capital cities, and to estimate a more accurate prevalence of drunk driving utilizing three correction techniques based upon information from those questionnaires. In August 2011 and January-February 2012, researchers from the Centre for Drug and Alcohol Research at the Universidade Federal do Rio Grande do Sul administered a roadside interview on drunk driving practices to 805 voluntary participants in the Brazilian capital cities of Palmas and Teresina. Three techniques which include measures such as the number of persons reporting alcohol consumption in the last six hours but who had refused breath testing were used to estimate the prevalence of drunk driving. The prevalence of persons testing positive for alcohol on their breath was 8.8% and 5.0% in Palmas and Teresina respectively. Utilizing a correction technique we calculated that a more accurate prevalence in these sites may be as high as 28.2% and 28.7%. In both cities, about 60% of drivers who self-reported having drank within six hours of being stopped by the police either refused to perform breathalyser testing; fled the sobriety roadblock; or were not offered the test, compared to about 30% of drivers that said they had not been drinking. Despite the reduction of the legal limit for drunk driving stipulated by the "Zero Tolerance Law," loopholes in the legislation permit many

  9. Existence detection and embedding rate estimation of blended speech in covert speech communications.

    Science.gov (United States)

    Li, Lijuan; Gao, Yong

    2016-01-01

    Covert speech communications may be used by terrorists to commit crimes through Internet. Steganalysis aims to detect secret information in covert communications to prevent crimes. Herein, based on the average zero crossing rate of the odd-even difference (AZCR-OED), a steganalysis algorithm for blended speech is proposed; it can detect the existence and estimate the embedding rate of blended speech. First, the odd-even difference (OED) of the speech signal is calculated and divided into frames. The average zero crossing rate (ZCR) is calculated for each OED frame, and the minimum average ZCR and AZCR-OED of the entire speech signal are extracted as features. Then, a support vector machine classifier is used to determine whether the speech signal is blended. Finally, a voice activity detection algorithm is applied to determine the hidden location of the secret speech and estimate the embedding rate. The results demonstrate that without attack, the detection accuracy can reach 80 % or more when the embedding rate is greater than 10 %, and the estimated embedding rate is similar to the real value. And when some attacks occur, it can also reach relatively high detection accuracy. The algorithm has high performance in terms of accuracy, effectiveness and robustness.

  10. Diversity dynamics in Nymphalidae butterflies: effect of phylogenetic uncertainty on diversification rate shift estimates.

    Directory of Open Access Journals (Sweden)

    Carlos Peña

    Full Text Available The species rich butterfly family Nymphalidae has been used to study evolutionary interactions between plants and insects. Theories of insect-hostplant dynamics predict accelerated diversification due to key innovations. In evolutionary biology, analysis of maximum credibility trees in the software MEDUSA (modelling evolutionary diversity using stepwise AIC is a popular method for estimation of shifts in diversification rates. We investigated whether phylogenetic uncertainty can produce different results by extending the method across a random sample of trees from the posterior distribution of a Bayesian run. Using the MultiMEDUSA approach, we found that phylogenetic uncertainty greatly affects diversification rate estimates. Different trees produced diversification rates ranging from high values to almost zero for the same clade, and both significant rate increase and decrease in some clades. Only four out of 18 significant shifts found on the maximum clade credibility tree were consistent across most of the sampled trees. Among these, we found accelerated diversification for Ithomiini butterflies. We used the binary speciation and extinction model (BiSSE and found that a hostplant shift to Solanaceae is correlated with increased net diversification rates in Ithomiini, congruent with the diffuse cospeciation hypothesis. Our results show that taking phylogenetic uncertainty into account when estimating net diversification rate shifts is of great importance, as very different results can be obtained when using the maximum clade credibility tree and other trees from the posterior distribution.

  11. Improving Satellite-Based Snowfall Estimation: A New Method for Classifying Precipitation Phase and Estimating Snowfall Rate

    Science.gov (United States)

    Sims, Elizabeth M.

    In order to study the impact of climate change on the Earth's hydrologic cycle, global information about snowfall is needed. To achieve global measurements of snowfall over both land and ocean, satellites are necessary. While satellites provide the best option for making measurements on a global scale, the task of estimating snowfall rate from these measurements is a complex problem. Satellite-based radar, for example, measures effective radar reflectivity, Ze, which can be converted to snowfall rate, S, via a Ze-S relation. Choosing the appropriate Ze-S relation to apply is a complicated problem, however, because quantities such as particle shape, size distribution, and terminal velocity are often unknown, and these quantities directly affect the Ze-S relation. Additionally, it is important to correctly classify the phase of precipitation. A misclassification can result in order-of-magnitude errors in the estimated precipitation rate. Using global ground-based observations over multiple years, the influence of different geophysical parameters on precipitation phase is investigated, with the goal of obtaining an improved method for determining precipitation phase. The parameters studied are near-surface air temperature, atmospheric moisture, low-level vertical temperature lapse rate, surface skin temperature, surface pressure, and land cover type. To combine the effects of temperature and moisture, wet-bulb temperature, instead of air temperature, is used as a key parameter for separating solid and liquid precipitation. Results show that in addition to wet-bulb temperature, vertical temperature lapse rate also affects the precipitation phase. For example, at a near-surface wet-bulb temperature of 0°C, a lapse rate of 6°C km-1 results in an 86 percent conditional probability of solid precipitation, while a lapse rate of -2°C km-1 results in a 45 percent probability. For near-surface wet-bulb temperatures less than 0°C, skin temperature affects precipitation

  12. Selecting and applying cesium-137 conversion models to estimate soil erosion rates in cultivated fields.

    Science.gov (United States)

    Li, Sheng; Lobb, David A; Tiessen, Kevin H D; McConkey, Brian G

    2010-01-01

    The fallout radionuclide cesium-137 ((137)Cs) has been successfully used in soil erosion studies worldwide. However, discrepancies often exist between the erosion rates estimated using various conversion models. As a result, there is often confusion in the use of the various models and in the interpretation of the data. Therefore, the objective of this study was to test the structural and parametrical uncertainties associated with four conversion models typically used in cultivated agricultural landscapes. For the structural uncertainties, the Soil Constituent Redistribution by Erosion Model (SCREM) was developed and used to simulate the redistribution of fallout (137)Cs due to tillage and water erosion along a simple two-dimensional (horizontal and vertical) transect. The SCREM-predicted (137)Cs inventories were then imported into the conversion models to estimate the erosion rates. The structural uncertainties of the conversion models were assessed based on the comparisons between the conversion-model-estimated erosion rates and the erosion rates determined or used in the SCREM. For the parametrical uncertainties, test runs were conducted by varying the values of the parameters used in the model, and the parametrical uncertainties were assessed based on the responsive changes of the estimated erosion rates. Our results suggest that: (i) the performance/accuracy of the conversion models was largely dependent on the relative contributions of water vs. tillage erosion; and (ii) the estimated erosion rates were highly sensitive to the input values of the reference (137)Cs level, particle size correction factors and tillage depth. Guidelines were proposed to aid researchers in selecting and applying the conversion models under various situations common to agricultural landscapes.

  13. Estimation of leak rate through circumferential cracks in pipes in nuclear power plants

    Directory of Open Access Journals (Sweden)

    Jai Hak Park

    2015-04-01

    Full Text Available The leak before break (LBB concept is widely used in designing pipe lines in nuclear power plants. According to the concept, the amount of leaking liquid from a pipe should be more than the minimum detectable leak rate of a leak detection system before catastrophic failure occurs. Therefore, accurate estimation of the leak rate is important to evaluate the validity of the LBB concept in pipe line design. In this paper, a program was developed to estimate the leak rate through circumferential cracks in pipes in nuclear power plants using the Henry–Fauske flow model and modified Henry–Fauske flow model. By using the developed program, the leak rate was calculated for a circumferential crack in a sample pipe, and the effect of the flow model on the leak rate was examined. Treating the crack morphology parameters as random variables, the statistical behavior of the leak rate was also examined. As a result, it was found that the crack morphology parameters have a strong effect on the leak rate and the statistical behavior of the leak rate can be simulated using normally distributed crack morphology parameters.

  14. Estimation of construction and demolition waste using waste generation rates in Chennai, India.

    Science.gov (United States)

    Ram, V G; Kalidindi, Satyanarayana N

    2017-06-01

    A large amount of construction and demolition waste is being generated owing to rapid urbanisation in Indian cities. A reliable estimate of construction and demolition waste generation is essential to create awareness about this stream of solid waste among the government bodies in India. However, the required data to estimate construction and demolition waste generation in India are unavailable or not explicitly documented. This study proposed an approach to estimate construction and demolition waste generation using waste generation rates and demonstrated it by estimating construction and demolition waste generation in Chennai city. The demolition waste generation rates of primary materials were determined through regression analysis using waste generation data from 45 case studies. Materials, such as wood, electrical wires, doors, windows and reinforcement steel, were found to be salvaged and sold on the secondary market. Concrete and masonry debris were dumped in either landfills or unauthorised places. The total quantity of construction and demolition debris generated in Chennai city in 2013 was estimated to be 1.14 million tonnes. The proportion of masonry debris was found to be 76% of the total quantity of demolition debris. Construction and demolition debris forms about 36% of the total solid waste generated in Chennai city. A gross underestimation of construction and demolition waste generation in some earlier studies in India has also been shown. The methodology proposed could be utilised by government bodies, policymakers and researchers to generate reliable estimates of construction and demolition waste in other developing countries facing similar challenges of limited data availability.

  15. Estimating rates of local species extinction, colonization and turnover in animal communities

    Science.gov (United States)

    Nichols, James D.; Boulinier, T.; Hines, J.E.; Pollock, K.H.; Sauer, J.R.

    1998-01-01

    Species richness has been identified as a useful state variable for conservation and management purposes. Changes in richness over time provide a basis for predicting and evaluating community responses to management, to natural disturbance, and to changes in factors such as community composition (e.g., the removal of a keystone species). Probabilistic capture-recapture models have been used recently to estimate species richness from species count and presence-absence data. These models do not require the common assumption that all species are detected in sampling efforts. We extend this approach to the development of estimators useful for studying the vital rates responsible for changes in animal communities over time; rates of local species extinction, turnover, and colonization. Our approach to estimation is based on capture-recapture models for closed animal populations that permit heterogeneity in detection probabilities among the different species in the sampled community. We have developed a computer program, COMDYN, to compute many of these estimators and associated bootstrap variances. Analyses using data from the North American Breeding Bird Survey (BBS) suggested that the estimators performed reasonably well. We recommend estimators based on probabilistic modeling for future work on community responses to management efforts as well as on basic questions about community dynamics.

  16. A type of sample size design in cancer clinical trials for response rate estimation.

    Science.gov (United States)

    Liu, Junfeng

    2011-01-01

    During the early stage of cancer clinical trials, when it is not convenient to construct an explicit hypothesis testing, a study on a new therapy often calls for a response rate (p) estimation concurrently with or right before a typical phase II study. We consider a two-stage process, where the acquired information from Stage I (with a small sample size (m)) would be utilized for sample size (n) recommendation for Stage II study aiming for a more accurate estimation. Once a sample size design and a parameter estimation protocol are applied, we study the overall utility (cost-effectiveness) in connection with the cost due to patient recruitment and treatment as well as the loss due to mean squared error from parameter estimation. Two approaches will be investigated including the posterior mixture method (a Bayesian approach) and the empirical variance method (a frequentist approach). We also discuss response rate estimation under truncated parameter space using maximum likelihood estimation with regard to sample size and mean squared error. The profiles of p-specific expected sample size, mean squared error and risk under different approaches motivate us to introduce the concept of "admissible sample size (design)". Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Reliability of estimated glomerular filtration rate in patients treated with platinum containing therapy

    DEFF Research Database (Denmark)

    Lauritsen, Jakob; Gundgaard, Maria G; Mortensen, Mette S

    2014-01-01

    Estimates of glomerular filtration rate (eGFR) are widely used when administering nephrotoxic chemotherapy. No studies performed in oncology patients have shown whether eGFR can safely substitute a measured GFR (mGFR) based on a marker method. We aimed to assess the validity of four major formulas...

  18. An expert system for estimating production rates and costs for hardwood group-selection harvests

    Science.gov (United States)

    Chris B. LeDoux; B. Gopalakrishnan; R. S. Pabba

    2003-01-01

    As forest managers shift their focus from stands to entire ecosystems alternative harvesting methods such as group selection are being used increasingly. Results of several field time and motion studies and simulation runs were incorporated into an expert system for estimating production rates and costs associated with harvests of group-selection units of various size...

  19. Estimation of shutdown heat generation rates in GHARR-1 due to ...

    African Journals Online (AJOL)

    Fission products decay power and residual fission power generated after shutdown of Ghana Research Reactor-1 (GHARR-1) by reactivity insertion accident were estimated by solution of the decay and residual heat equations. A Matlab program code was developed to simulate the heat generation rates by fission product ...

  20. ESTIMATING SPECIATION AND EXTINCTION RATES FROM DIVERSITY DATA AND THE FOSSIL RECORD

    NARCIS (Netherlands)

    Etienne, Rampal S.; Apol, M. Emile F.

    Understanding the processes that underlie biodiversity requires insight into the evolutionary history of the taxa involved. Accurate estimation of speciation, extinction, and diversification rates is a prerequisite for gaining this insight. Here, we develop a stochastic birth-death model of

  1. estimated glomerular filtration rate and risk of survival in acute stroke

    African Journals Online (AJOL)

    2014-03-03

    Mar 3, 2014 ... the risk of survival in acute stroke. INTRODUCTION. Stroke is independently associated with impairment in the structure and function of the glomerulus. (1). Estimated Glomerular Filtration Rate (GFR) as determined by the four-item Modification of diet in renal disease (MDRD) equation is a fairly reliable.

  2. Cross-contamination in the kitchen: estimation of transfer rates for cutting boards, hands and knives

    NARCIS (Netherlands)

    Asselt, van E.D.; Jong, de A.E.I.; Jonge, de R.; Nauta, M.J.

    2008-01-01

    Aims: To quantify cross-contamination in the home from chicken to readyto-eat salad. Methods and Results: Based on laboratory scenarios performed by de Jong et al. (2008), transfer rates were estimated for Campylobacter jejuni and Lactobacillus casei as a tracer organism. This study showed that

  3. Metazooplankton community structure, feeding rate estimates, and hydrography in a meltwater-influenced Greenlandic fjord

    DEFF Research Database (Denmark)

    Tang, K.W.; Nielsen, Torkel Gissel; Munk, Peter

    2011-01-01

    2008, and estimated feeding rates for some of the larger species groups. Within the 4 regional domains that were covered in the study (continental slope, continental shelf, outer sill region, and main fjord basin), salty coastal water and glacial runoff mixed to various extents, and 7 water masses...

  4. Probabilistic estimation of residential air exchange rates for population-based human exposure modeling

    Science.gov (United States)

    Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER meas...

  5. Estimate Of The Decay Rate Constant of Hydrogen Sulfide Generation From Landfilled Drywall

    Science.gov (United States)

    Research was conducted to investigate the impact of particle size on H2S gas emissions and estimate a decay rate constant for H2S gas generation from the anaerobic decomposition of drywall. Three different particle sizes of regular drywall and one particle size of paperless drywa...

  6. Neural estimation of kinetic rate constants from dynamic PET-scans

    DEFF Research Database (Denmark)

    Fog, Torben L.; Nielsen, Lars Hupfeldt; Hansen, Lars Kai

    1994-01-01

    A feedforward neural net is trained to invert a simple three compartment model describing the tracer kinetics involved in the metabolism of [18F]fluorodeoxyglucose in the human brain. The network can estimate rate constants from positron emission tomography sequences and is about 50 times faster ...

  7. Nonparametric change point estimation for survival distributions with a partially constant hazard rate.

    Science.gov (United States)

    Brazzale, Alessandra R; Küchenhoff, Helmut; Krügel, Stefanie; Schiergens, Tobias S; Trentzsch, Heiko; Hartl, Wolfgang

    2018-04-05

    We present a new method for estimating a change point in the hazard function of a survival distribution assuming a constant hazard rate after the change point and a decreasing hazard rate before the change point. Our method is based on fitting a stump regression to p values for testing hazard rates in small time intervals. We present three real data examples describing survival patterns of severely ill patients, whose excess mortality rates are known to persist far beyond hospital discharge. For designing survival studies in these patients and for the definition of hospital performance metrics (e.g. mortality), it is essential to define adequate and objective end points. The reliable estimation of a change point will help researchers to identify such end points. By precisely knowing this change point, clinicians can distinguish between the acute phase with high hazard (time elapsed after admission and before the change point was reached), and the chronic phase (time elapsed after the change point) in which hazard is fairly constant. We show in an extensive simulation study that maximum likelihood estimation is not robust in this setting, and we evaluate our new estimation strategy including bootstrap confidence intervals and finite sample bias correction.

  8. Estimates of Annual Soil Loss Rates in the State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Grasiela de Oliveira Rodrigues Medeiros

    Full Text Available ABSTRACT: Soil is a natural resource that has been affected by human pressures beyond its renewal capacity. For this reason, large agricultural areas that were productive have been abandoned due to soil degradation, mainly caused by the erosion process. The objective of this study was to apply the Universal Soil Loss Equation to generate more recent estimates of soil loss rates for the state of São Paulo using a database with information from medium resolution (30 m. The results showed that many areas of the state have high (critical levels of soil degradation due to the predominance of consolidated human activities, especially in growing sugarcane and pasture use. The average estimated rate of soil loss is 30 Mg ha-1 yr-1 and 59 % of the area of the state (except for water bodies and urban areas had estimated rates above 12 Mg ha-1 yr-1, considered as the average tolerance limit in the literature. The average rates of soil loss in areas with annual agricultural crops, semi-perennial agricultural crops (sugarcane, and permanent agricultural crops were 118, 78, and 38 Mg ha-1 yr-1 respectively. The state of São Paulo requires attention to conservation of soil resources, since most soils led to estimates beyond the tolerance limit.

  9. Estimation of rate of degradation (Kd) of starch in the rumen and its ...

    African Journals Online (AJOL)

    Torben Hvelplund

    Abstract. Fractional rate of degradation (kd) of fermentable nutrients in the rumen is an important parameter in modern feed evaluation systems based on mechanistic models. Estimates of kd for starch was obtained on 19 starch sources originating from barley, wheat, oat, maize and peas and treated in different ways both.

  10. National Estimates of Exposure to Traumatic Events and PTSD Prevalence Using DSM-IV and DSM-5 Criteria

    Science.gov (United States)

    Kilpatrick, Dean G.; Resnick, Heidi S.; Milanak, Melissa E.; Miller, Mark W.; Keyes, Katherine M.; Friedman, Matthew J.

    2014-01-01

    Prevalence of posttraumatic stress disorder (PTSD) defined according to the American Psychiatric Association’s Diagnostic and Statistical Manual fifth edition (DSM-5; 2013) and fourth edition (DSM-IV; 1994) was compared in a national sample of U.S. adults (N = 2,953) recruited from an online panel. Exposure to traumatic events, PTSD symptoms, and functional impairment were assessed online using a highly structured, self-administered survey. Traumatic event exposure using DSM-5 criteria was high (89.7%), and exposure to multiple traumatic event types was the norm. PTSD caseness was determined using Same Event (i.e., all symptom criteria met to the same event type) and Composite Event (i.e., symptom criteria met to a combination of event types) definitions. Lifetime, past-12-month, and past 6-month PTSD prevalence using the Same Event definition for DSM-5 was 8.3%, 4.7%, and 3.8% respectively. All 6 DSM-5 prevalence estimates were slightly lower than their DSM-IV counterparts, although only 2 of these differences were statistically significant. DSM-5 PTSD prevalence was higher among women than among men, and prevalence increased with greater traumatic event exposure. Major reasons individuals met DSM-IV criteria, but not DSM-5 criteria were the exclusion of nonaccidental, nonviolent deaths from Criterion A, and the new requirement of at least 1 active avoidance symptom. PMID:24151000

  11. The validated hypoallergenic cosmetics rating system: its 30-year evolution and effect on the prevalence of cosmetic reactions.

    Science.gov (United States)

    Verallo-Rowell, Vermén M

    2011-01-01

    The validated hypoallergenic (vh) rating system was initiated in 1988 to try to objectively validate the "hypoallergenic" claim in cosmetics. To show how the system rates cosmetic hypoallergenicity and to compare the prevalence of cosmetic contact dermatitis (CCD) among users of regular cosmetics versus cosmetics with high VH numbers. (1) Made a VH list based on top allergens from patch-test results published by the North American Contact Dermatitis Group (NACDG) and the European Surveillance System on Contact Allergies (ESSCA); (2) reviewed global regulatory, cosmetic, drug, packaging, and manufacturing practices to show how allergens may contaminate products; (3) compared cosmetic ingredients lists against the VH list to obtain the VH rating (the more allergens absent, the higher the VH rating); and (4) obtained CCD prevalence among users of regular cosmetics versus users of cosmetics with high VH ratings. (1) Two VH lists (1988, 2003) included only cosmetic allergens in the NACDG surveys, the third (2007) included cosmetic and potential contaminant noncosmetic allergens, and the fourth (2010) adds ESSCA patch-test surveys. (2) CCD prevalence is 0.05 to 0.12% (average, 0.08%) among users of cosmetics with high VH ratings versus 2.4 to 36.3% among users of regular cosmetics. The VH rating system is shown to objectively validate the hypoallergenic cosmetics claim.

  12. A physiological counterpoint to mechanistic estimates of "internal power" during cycling at different pedal rates

    DEFF Research Database (Denmark)

    Hansen, Ernst Albin; Jørgensen, Lars Vincents; Sjøgaard, Gisela

    2004-01-01

    Reported values of "internal power" (IP) during cycling, generated by the muscles to overcome energy changes of moving body segments, are considerably different for various biomechanical models, reflecting the different criteria for estimation of IP. The present aim was to calculate IP from......, respectively, being remarkably close to the kinematic estimate of one model (IP(Willems-COM): 14, 43, and 95 W) and reasonably close to another kinematic estimate (IP(Winter): 8, 29, and 81 W). For all kinematic models there was no significant effect of performing 3-D versus 2-D analyses. IP increased...... significantly with pedal rate - leg movements accounting for the largest fraction. Further, external power (EP) affected IP significantly such that IP was larger at moderate than at low EP at the majority of the pedal rates applied but on average this difference was only 8%....

  13. Expanding vaccine efficacy estimation with dynamic models fitted to cross-sectional prevalence data post-licensure

    Directory of Open Access Journals (Sweden)

    Erida Gjini

    2016-03-01

    Full Text Available The efficacy of vaccines is typically estimated prior to implementation, on the basis of randomized controlled trials. This does not preclude, however, subsequent assessment post-licensure, while mass-immunization and nonlinear transmission feedbacks are in place. In this paper we show how cross-sectional prevalence data post-vaccination can be interpreted in terms of pathogen transmission processes and vaccine parameters, using a dynamic epidemiological model. We advocate the use of such frameworks for model-based vaccine evaluation in the field, fitting trajectories of cross-sectional prevalence of pathogen strains before and after intervention. Using SI and SIS models, we illustrate how prevalence ratios in vaccinated and non-vaccinated hosts depend on true vaccine efficacy, the absolute and relative strength of competition between target and non-target strains, the time post follow-up, and transmission intensity. We argue that a mechanistic approach should be added to vaccine efficacy estimation against multi-type pathogens, because it naturally accounts for inter-strain competition and indirect effects, leading to a robust measure of individual protection per contact. Our study calls for systematic attention to epidemiological feedbacks when interpreting population level impact. At a broader level, our parameter estimation procedure provides a promising proof of principle for a generalizable framework to infer vaccine efficacy post-licensure.

  14. Reliability of current estimates of schistosomiasis prevalence in the Rainforest Zone of the state of Pernambuco, Northeastern Brazil.

    Science.gov (United States)

    Favre, Tereza C; Ximenes, Ricardo A A; Galvão, Aline F; Pereira, Ana Paula B; Wanderlei, Tereza N; Barbosa, Constança S; Pieri, Otávio S

    2006-09-01

    The Program for Schistosomiasis Control within the Unified Health System (PCE-SUS) was implemented by 1999 in the Rainforest Zone or "Zona da Mata" of Pernambuco (ZMP) aiming to carry out biennial stool surveys of whole populations through municipal health organs followed by treatment of the positives through the local units of the Family Health Program (PSF). Yearly reports from the Health Department of Pernambuco State (SES/PE) from 2002 to 2004 on the PCE-SUS surveys were assessed to evaluate whether the current estimates of prevalence in the municipalities of the ZMP are based on reliable samples so as to allow considerations on the real situation of schistosomiasis in that area. The surveys carried out in that period did not follow the major principles underlying sampling design, thus posing problems in both precision and validity of the estimates. Only 12 out of 43 municipalities had minimally reliable estimates: five with moderate prevalence (10-50%) and seven with low prevalence (plan adequate control strategies.

  15. Prevalence rate and antibiotic susceptibility of oral viridans group streptococci (VGS) in healthy children population.

    Science.gov (United States)

    Rozkiewicz, D; Daniluk, T; Sciepuk, M; Zaremba, M L; Cylwik-Rokicka, D; Luczaj-Cepowicz, E; Milewska, R; Marczuk-Kolada, G; Stokowska, W

    2006-01-01

    The aim of this study was to evaluated the prevalence rate of oral viridans group streptococci (VGS) and their susceptibilities to some antibiotics in healthy children. Samples of pharyngeal swabs and supragingival dental plaques for microbiological studies were collected from 206 healthy children, aged 4-18 years. Additionally, 75 samples of carious lesions from children with dental caries were included. The streptococci were isolated and identified using standard methods and commercial identification kits. For performance of antibacterial susceptibility testing of VGS strains disk diffusion and/or breakpoints procedures were used according to NCCLS standards and criteria. A total of 425 VGS strains were tested against penicillin, ampicillin, erythromycin, clindamycin, tetracycline, doxycycline, ciprofloxacin and vancomycin. A total of 239 VGS strains belonging to 8 species from pharyngeal swabs of 192 (93.2%) children were isolated. VGS strains from supragingival plaques were isolated in 149 (72.3%) healthy children (p mitis species were isolated most frequently from 4-5 year old as compared to 12 and 18 year old children (p or = 2.0 mg/L) was shown in 71 (16.7%) strains, 33 (46.5%) of them belonged to S. mitis species. VGS strains were also resistant to erythromycin (23.5%), clindamycin (23.1%), tetracyclines (T-52%, DOX-16%), gentamycin (25.9%) and ciprofloxacin (55.2%). All VGS strains were vancomycin - susceptible. 1. In the oral cavities of healthy children, approximately 98% of streptococci belonged to two VGS groups, i.e. mitis and salivarius groups. Streptococci of mutans and anginosus groups were isolated sporadically (2%). 2. We observed difference in susceptibility to penicillin and other antibiotics between the various species of viridans groups streptococci. Mitis group strains (except S. pneumoniae) were more frequently penicillin-resistant (23%) in comparison to salivarius group of VGS strains (9%) (p = 0.0001).

  16. Prevalence and rupture rate of cerebral aneurysms discovered during intra-arterial chemotherapy of brain tumors.

    Science.gov (United States)

    Bourekas, E C; Newton, H B; Figg, G M; Slone, H W

    2006-02-01

    During the administration of intra-arterial (IA) chemotherapy for the treatment of brain tumors (BTs), angiography may demonstrate asymptomatic, incidental cerebral aneurysms. The prevalence and complication rate of incidental aneurysms in patients undergoing IA chemotherapy remains unknown. It remains unclear whether the presence of an aneurysm represents an increased risk or a contraindication to this form of treatment. We performed a chart and angiography review of BT patients receiving IA chemotherapy over the previous 16 months. Seventy-eight patients were identified with primary (39) and metastatic (39) BTs. The cohort consisted of 40 men and 38 women, with a mean age of 47.8 years (range, 22-80 years). During initial angiography, 8 patients (10.3%) were identified with incidental cerebral aneurysms. The aneurysms were saccular and varied in size from 2-4 mm (mean, 3 mm). Seven of the 8 patients continued IA chemotherapy after detection of the aneurysm, for a total of 35 IA procedures. Of these 7 patients, 5 expired from nonaneurysmal complications (mean survival, 5.4 months; range, 2-10 months); 4 from the primary tumor, and one from an infected craniotomy site. Two patients continue to survive; one remains in treatment, and the other has completed 12 months of IA therapy. There were no aneurysmal complications during or after IA treatment in any of the BT patients. Incidental aneurysms may be more common in patients with BTs than the general population. In our patient population, there was no indication that an incidental aneurysm was reason to preclude or delay the use of IA chemotherapy.

  17. Tissue perfusion rate estimation with compression-based photoacoustic-ultrasound imaging

    Science.gov (United States)

    Choi, Min; James Shapiro, A. M.; Zemp, Roger

    2018-01-01

    Tissue perfusion is essential for transporting blood oxygen and nutrients. Measurement of tissue perfusion rate would have a significant impact in clinical and preclinical arenas. However, there are few techniques to image this important parameter and they typically require contrast agents. A label-free methodology based on tissue compression and imaging with a high-frequency photoacoustic-ultrasound system is introduced for estimating and visualizing tissue perfusion rates. Experiments demonstrate statistically significant differences in depth-resolved perfusion rates in a human subject with various temperature exposure conditions.

  18. Computed tomography (CT) findings in 88 neurofibromatosis 1 (NF1) patients: Prevalence rates and correlations of thoracic findings

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Ken, E-mail: k-ueda@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine (Japan); Honda, Osamu [Department of Radiology, Osaka University Graduate School of Medicine (Japan); Satoh, Yukihisa [Department of Diagnostic Radiology, Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan); Kawai, Misa; Gyobu, Tomoko; Kanazawa, Toru; Hidaka, Shojiro; Yanagawa, Masahiro [Department of Radiology, Osaka University Graduate School of Medicine (Japan); Sumikawa, Hiromitsu [Department of Diagnostic Radiology, Osaka Rosai Hospital (Japan); Tomiyama, Noriyuki [Department of Radiology, Osaka University Graduate School of Medicine (Japan)

    2015-06-15

    Highlights: • Various thoracic CT findings, including cysts, mediastinal masses, etc. were found. • Cysts show upper and peripheral dominant distribution. • The number, size, and distribution of the pulmonary cysts in NF-1 revealed significant correlation. • It is suspected that thoracic CT findings in NF-1 occur independently. - Abstract: Purpose: To evaluate the prevalence rates and the correlations of thoracic computed tomography (CT) findings of neurofibromatosis 1 (NF1) in 88 patients. Materials and methods: Chest CT images of 88 NF1 patients were independently reviewed by three observers, and the CT findings were evaluated. If abnormal findings were present, their number, size, and distribution were recorded. The prevalence rate of each CT finding was calculated, and the correlations between CT findings were analyzed. Results: Of the 88 cases, 13 were positive for cysts, 16 for emphysema, 8 for nodules, 8 for GGNs (ground glass nodules), 13 for mediastinal masses, 20 for scoliosis, 44 for subcutaneous nodules, and 34 for skin nodules. Cysts showed upper and peripheral dominant distributions. Regarding 13 mediastinal masses, 2 were diagnosed as malignant peripheral nerve sheath tumors (MPNSTs), 1 was diagnosed as primary lung cancer, 2 were diagnosed as lateral meningocele, 3 were diagnosed as neurofibromas, and the remaining 7 were considered neurofibromas. There was a significant correlation between the prevalence of subcutaneous nodules and that of skin nodules. Significant positive correlations were also seen between size and number, size and rate of central distribution, and number and rate of central distribution of cysts. Conclusion: Various CT findings were found in NF-1 patients, and the prevalence rates of subcutaneous and skin nodules were higher than other findings. Though the prevalence rates of subcutaneous nodules and skin nodules were significantly correlated, the other CT findings in NF-1 occurred independently. The number, size, and

  19. Questionnaire layout and wording influence prevalence and risk estimates of respiratory symptoms in a population cohort.

    Science.gov (United States)

    Ekerljung, Linda; Rönmark, Eva; Lötvall, Jan; Wennergren, Göran; Torén, Kjell; Lundbäck, Bo

    2013-01-01

    Results of epidemiological studies are greatly influenced by the chosen methodology. The study aims to investigate how two frequently used questionnaires (Qs), with partly different layout, influence the prevalence of respiratory symptoms. A booklet containing two Qs, the Global Allergy and Asthma European Network Q and the Obstructive Lung Disease in Northern Sweden Q, was mailed to 30,000 subjects aged 16-75years in West Sweden; 62% responded. Sixteen questions were included in the analysis: seven identical between the Qs, four different in set-up and five with the same layout but different wording. Comparisons were made using differences in proportions, observed agreement and Kappa statistics.  Identical questions yielded similar prevalences with high observed agreement and kappa values. Questions with different set-up or differences in wording resulted in significantly different prevalences with lower observed agreement and kappa values. In general, the use of follow-up questions, excluding subjects answering no to the initial question, resulted in 2.9-6.7% units lower prevalence. The question set-up has great influences on epidemiological results, and specifically questions that are set up to be excluded based on a previous no answer leads to lower prevalence compared with detached questions. Therefore, Q layout and exact wording of questions has to be carefully considered when comparing studies. © 2012 Blackwell Publishing Ltd.

  20. Comparison of type 2 diabetes prevalence estimates in Saudi Arabia from a validated Markov model against the International Diabetes Federation and other modelling studies

    Science.gov (United States)

    Al-Quwaidhi, Abdulkareem J.; Pearce, Mark S.; Sobngwi, Eugene; Critchley, Julia A.; O’Flaherty,