Screening programs, such as annual mammography, are undertaken to reduce mortality and/or morbidity from chronic diseases such as cancer. Matched case-control studies have been used to assess the effectiveness of screening programs because of their relative simplicity and low cost. In such studies, the exposure history for controls consists of the number of screening examinations received prior...

In the study of complex diseases, it may be important to test hypotheses related to gene-gene (G x G) interaction. The success of such studies depends critically on obtaining adequate sample sizes. In this paper, the author investigates sample size requirements for studies of G x G interaction, focusing on four study designs: the matched-case-control design, the case-sibling design, the case-pa...

Case-control sampling is an extremely common design used to generate data to estimate effects of exposures or treatments on a binary outcome of interest when the proportion of cases (i.e., binary outcome equal to 1) in the population of interest is low. Case-control sampling represents a biased sample of a target population of interest by sampling a disproportional number of cases. Case-control...