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Cohort Data (cohort + data)
Selected AbstractsBenchmark dose estimation based on epidemiologic cohort dataENVIRONMETRICS, Issue 5 2005Knashawn H. Morales Abstract Risk assessments based on epidemiologic studies are becoming increasingly common in evaluating environmental health risks and setting health standards. This article will discuss and compare some of the available methods for exposure,response modeling and risk estimation based on environmental epidemiologic studies with age-specific incidence and mortality data. Recommendations will be made regarding approaches that can be used in practice. Copyright © 2005 John Wiley & Sons, Ltd. [source] The Overlap Syndrome of Depression and Delirium in Older Hospitalized PatientsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2009Jane L. Givens MD OBJECTIVES: To measure the prevalence, predictors, and posthospitalization outcomes associated with the overlap syndrome of coexisting depression and incident delirium in older hospitalized patients. DESIGN: Secondary analysis of prospective cohort data from the control group of the Delirium Prevention Trial. SETTING: General medical service of an academic medical center. Follow-up interviews at 1 month and 1 year post-hospital discharge. PARTICIPANTS: Four hundred fifty-nine patients aged 70 and older who were not delirious at hospital admission. MEASUREMENTS: Depressive symptoms assessed at hospital admission using the 15-item Geriatric Depression Scale (cutoff score of 6 used to define depression), daily assessments of incident delirium from admission to discharge using the Confusion Assessment Method, activities of daily living at admission and 1 month postdischarge, and new nursing home placement and mortality determined at 1 year. RESULTS: Of 459 participants, 23 (5.0%) had the overlap syndrome, 39 (8.5%) delirium alone, 121 (26.3%) depression alone, and 276 (60.1%) neither condition. In adjusted analysis, patients with the overlap syndrome had higher odds of new nursing home placement or death at 1 year (adjusted odds ratio (AOR)=5.38, 95% confidence interval (CI)=1.57,18.38) and 1-month functional decline (AOR=3.30, 95% CI=1.14,9.56) than patients with neither condition. CONCLUSION: The overlap syndrome of depression and delirium is associated with significant risk of functional decline, institutionalization, and death. Efforts to identify, prevent, and treat this condition may reduce the risk of adverse outcomes in older hospitalized patients. [source] Serial Cohabitation and the Marital Life CourseJOURNAL OF MARRIAGE AND FAMILY, Issue 4 2008Daniel T. Lichter Using cohort data from the National Longitudinal Survey of Youth, this paper tracks the experiences of serial cohabitors. Results indicate that only a minority of cohabiting women (about 15% , 20%) were involved in multiple cohabitations. Serial cohabitations were overrepresented among economically disadvantaged groups, especially those with low income and education. They also were less likely than single-instance cohabiting unions to end in marriage rather than dissolve. If serial cohabitors married, divorce rates were very high , more than twice as high as for women who cohabited only with their eventual husbands. The results suggest the need to balance the government's current preoccupation with marriage promotion with greater support of "at risk" unions that marriage promotion initiatives have helped create. [source] Hierarchical related regression for combining aggregate and individual data in studies of socio-economic disease risk factorsJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2008Christopher Jackson Summary., To obtain information about the contribution of individual and area level factors to population health, it is desirable to use both data collected on areas, such as censuses, and on individuals, e.g. survey and cohort data. Recently developed models allow us to carry out simultaneous regressions on related data at the individual and aggregate levels. These can reduce ,ecological bias' that is caused by confounding, model misspecification or lack of information and increase power compared with analysing the data sets singly. We use these methods in an application investigating individual and area level sociodemographic predictors of the risk of hospital admissions for heart and circulatory disease in London. We discuss the practical issues that are encountered in this kind of data synthesis and demonstrate that this modelling framework is sufficiently flexible to incorporate a wide range of sources of data and to answer substantive questions. Our analysis shows that the variations that are observed are mainly attributable to individual level factors rather than the contextual effect of deprivation. [source] High prevalence information from different sources affects the development of false beliefsAPPLIED COGNITIVE PSYCHOLOGY, Issue 2 2010Celine van Golde To examine the effects of high and low false prevalence information from different sources on false beliefs, subjects took part in two sessions. In the first session, subjects rated the plausibility of different childhood events, how confident they were that they had experienced those events and their memories of those events. In the second session, 2,weeks later, subjects received high prevalence information about one target event and low prevalence information about another. Subjects received the information in a third-person description, a newspaper article, or cohort data about previous students' experiences, or they received no information. High prevalence newspaper and cohort information increased subjects' plausibility ratings compared to no information and third-person descriptions. High prevalence newspaper information also increased subjects' belief ratings. Our findings contribute to the growing literature demonstrating the role of false high prevalence information in the development of false beliefs. Copyright © 2009 John Wiley & Sons, Ltd. [source] Marginal Hazards Regression for Retrospective Studies within Cohort with Possibly Correlated Failure Time DataBIOMETRICS, Issue 2 2009Sangwook Kang Summary A retrospective dental study was conducted to evaluate the degree to which pulpal involvement affects tooth survival. Due to the clustering of teeth, the survival times within each subject could be correlated and thus the conventional method for the case,control studies cannot be directly applied. In this article, we propose a marginal model approach for this type of correlated case,control within cohort data. Weighted estimating equations are proposed for the estimation of the regression parameters. Different types of weights are also considered for improving the efficiency. Asymptotic properties of the proposed estimators are investigated and their finite sample properties are assessed via simulations studies. The proposed method is applied to the aforementioned dental study. [source] Case,Cohort Analysis with Accelerated Failure Time ModelBIOMETRICS, Issue 1 2009Lan Kong Summary In a case,cohort design, covariates are assembled only for a subcohort that is randomly selected from the entire cohort and any additional cases outside the subcohort. This design is appealing for large cohort studies of rare disease, especially when the exposures of interest are expensive to ascertain for all the subjects. We propose statistical methods for analyzing the case,cohort data with a semiparametric accelerated failure time model that interprets the covariates effects as to accelerate or decelerate the time to failure. Asymptotic properties of the proposed estimators are developed. The finite sample properties of case,cohort estimator and its relative efficiency to full cohort estimator are assessed via simulation studies. A real example from a study of cardiovascular disease is provided to illustrate the estimating procedure. [source] Transition pathways for young people with complex disabilities: exploring the economic consequencesCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 4 2008M. Knapp Abstract Background Disabled young people with complex needs face particular challenges when they reach adulthood and seek to move from school to employment or further education. There are potentially substantial personal and social costs arising from these challenges. Methods We sought evidence from recent UK research, policy and related literatures; undertook exploratory statistical analyses of birth cohort data; and analysed information provided by 30 disabled young people requiring high levels of practical and communication support. Results The personal, family and social costs that result from unsuccessful transition are substantial and wide-ranging. Health service and local authority expenditure are important elements, but do not allow young people to achieve the educational or employment goals to which they aspire, resulting in considerable costs for the state, whether through missing opportunities to contribute to the economy or through dependence on welfare benefits. Conclusions The considerable sums currently spent on disabled children and young people are clearly not enough, or not deployed appropriately, to enable those who reach adulthood to fulfil their ambitions, or to meet government policy intentions for young people to achieve economic well-being. [source] | |||||||||||||