A computer program to estimate power and relative efficiency of flexibly matched case-control studies.

Objectives: We recently introduced the concept of flexible matching strategies with varying proportions of a dichotomous matching factor among controls to increase power and efficiency of case-control studies. We now present a method and a computer program to calculate power and relative efficiency compared to an unmatched design varying the proportion of the matching factor in controls over all possible values from 0 to 100 percent.

Methods: For all these values, the program calculates the expected variance of the combined Mantel-Haenszel odds ratio and determines the power using the standard error of the expected combined Mantel-Haenszel odds ratio under the null hypothesis as derived from the Mantel-Haenszel test statistic without continuity correction.

Cohort- and age-related decline in elder's life satisfaction: is there really a paradox?

Absence of age-related decline in elder's life satisfaction (LS), found in several studies from the last quarter of the twentieth century, has been labelled a "paradox", as it contrasts with increasing psycho-social and health risks in old age. To explain these findings, the present study was based on the hypothesis of a cohort effect on the LS of those born in the first half of the twentieth century, which might have overlayed and thus obscured the age-related decline in cross-sectional studies. In addition, it was hypothesized that the age-related decline in LS accelerates over the old age period such that the "paradox" would not hold for old-old subjects.

Ageing and person-environment fit in different urban neighbourhoods.

Based on the "complementary-congruence model" of person-environment fit, this study focuses on housing in old age as an interaction between housing needs and housing conditions in urban settings. The research aims are (1) to establish a set of housing-related person-environment (p-e) fit indices based on the relationship between environmental needs and existing conditions in different physical and social domains, and to describe housing among elders aged 51-80 years and in different urban districts with these indices; the study distinguishes between basic, higher-order and social needs relating to housing; (2) to explain outdoor place attachment as an indicator for quality of life in different urban districts with a set of predictors including these person-environment fit indices. Data were drawn from telephone-based interviews with 365 older adults (51-80 years) who were questioned about individual housing needs and housing conditions.

Genotype and plasma concentration of cystatin C in patients with coronary heart disease and risk for secondary cardiovascular events.

Objective: Cysteine proteases and their inhibitors such as cystatin C are assumed to play an important role in the pathogenesis of atherosclerosis and coronary heart disease (CHD). The aim of the study was to investigate the impact of cystatin C polymorphisms on cystatin C plasma levels and on prognosis of patients with CHD.

Methods And Results: Four polymorphisms in the promoter and exon 1 of the cystatin C gene (-82GC, -5GA, +4AC, and +148AG) and cystatin C plasma levels were determined in a cohort of 1013 patients with manifest CHD and aged 30 to 70 years participating in an in-hospital rehabilitation program.

Housing and health in later life.

The goal of this paper is to compile recent data on the housing and health in old age, with special emphasis on geropsychological and gerontological studies. The authors first introduce their understanding of both housing and health. Second, theoretical models that are important to understand better the relation between housing- and health-related outcomes are incorporated into an analytic scheme.

A computer program to estimate power and relative efficiency to assess multiplicative interactions in flexibly matched case-control studies.

Matching on one of two possibly interacting exposures can increase power and efficiency to estimate multiplicative interactions in case-control studies. We recently introduced the concept of flexible matching strategies with varying proportions of a dichotomous matching factor among controls to further increase power and efficiency. In order to facilitate the application of this concept, we developed a computer program which provides estimates of power and efficiency varying the proportion of the matching factor in controls over all possible values from 1 to 99%.

Relationship between infectious burden, systemic inflammatory response, and risk of stable coronary artery disease: role of confounding and reference group.

Aim: The purpose of the study was to assess the association between seropositivity to various infectious agents and stable coronary artery disease (CAD), controlling simultaneously for a variety of potential confounders. We also investigated whether the choice of a larger reference group might affect the results, and whether or not seropositivity to multiple agents was associated with a systemic inflammatory response.

Methods: We assessed the simultaneous prevalence of antibodies against Helicobacter pylori, Chlamydia, cytomegalovirus, and herpes simplex virus in 312 patients with angiographically proven coronary artery disease (CAD) and in 479 age and sex matched controls.

Article predictors of wellbeing and autonomy before and after geriatric rehabilitation.

The aim of this study was to explore changes in the correlational association between predictors (i.e. sociodemographics, subjective health, social support, anxiety and coping) and outcome measures (i.

Varying the importance of a prospective memory task: differential effects across time- and event-based prospective memory.

Only few studies have addressed the issue of task importance in prospective memory. Most of them, but not all, have shown that perceived task importance does improve prospective memory performance. However, there is little understanding of (1) the conditions under which importance of the prospective memory task makes a difference in performance and (2) the mechanisms by which perceived task importance has an effect on prospective memory performance.