The purpose of this article is to present in elementary mathematical and statistical terms a simple way to quickly and effectively teach and understand case-control studies, as they are commonly done in dynamic populations-without using the rare disease assumption. Our focus is on case-control studies of disease incidence ('incident case-control studies'); we will not consider the situation of ...

Classic (or ‘‘cumulative’’) case-control sampling designs do not admit inferences about quantities of interest other than risk ratios and then only by making the rare events assumption. Probabilities, risk differences, number needed to treat, and other quantities cannot be computed without knowledge of the population incidence fraction. Similarly, density (or ‘‘risk set’’) case-control sampling...

Cohort and case-control methodologies are the main tools for analytical epidemiological research. Other important types of epidemiological studies mainly for generating hypotheses include cross-sectional and ecological, or correlation studies. The conclusions that can be drawn from findings of these types of studies are, however, much weaker compared to those of cohort and case-control studies....

A new era of automatic train control has begun, in which mass transit trains will be commanded with precision beyond the capabilities of past systems. Although transit properties such as San Francisco's Bay Area Rapid Transit (BART) have controlled their trains automatically for decades, the control systems have limited capability. Increases in capacity now require trains to run closer together...

Case–control studies are used often in epidemiologic studies to investigate the association between disease and one or more risk factors. With increasing frequency, the set of risk factors being considered includes genotypes at one or more susceptibility, candidate, or marker loci (see Markers). The goals of association studies will differ, depending on the state of knowledge about a given dise...

I read with interest the article on computerized tests to evaluate psychomotor performance in children with specific learning disabilities (SpLD) by taur and colleagues1. the study was conducted with the aim to compare the performance on a battery of six psychomotor tests of children with SpLD and those without any learning disabilities (controls) using computerized tests. the authors deserve c...

BACKGROUND The case-control design can be used to evaluate the benefit of cancer screening programmes. MATERIALS AND METHODS This paper outlines the main methodological features of the case-control design in this context, and indicates some potential biases. It also reviews the existing case-control literature on mammographic screening. RESULTS Case-control studies consistently indicate a r...

Several genome-wide searches for disease-associated gene variations have been recently reported (Spinola et al, 2006; Herbert et al, 2006). However, complex diseases can be caused by combinations of several unlinked gene variations. Unfortunately, an exhaustive search among all possible corresponding multi-SNPs can be unfeasible even for small number of SNPs let alone the complete genome. Disea...