Sample size to test for interaction between a specific exposure and a second risk factor in a pair-matched case-control study

✍ Scribed by Peihua Qiu; Melvin L. Moeschberger; Glen E. Cooke; Pascal J. Goldschmidt-Clermont

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 128 KB
• Volume: 19
• Category: Article
• ISSN: 0277-6715
• DOI: 10.1002/(sici)1097-0258(20000415)19:7<923::aid-sim341>3.0.co;2-o

✦ Synopsis

We discuss a sample size calculation for a pair-matched case-control study to test for interaction between a speci"c exposure and a second risk factor. The second risk factor could be either binary or continuous. An algorithm for the calculation of sample size is suggested which is based on a logistic regression model that relates the logarithm of the disease-exposure odds ratio to the second risk factor. This problem is motivated by a study comparing the prevalence of GP-IIIa Pl polymorphism (the exposure) in individuals with and without myocardial infarction (case-control). One of the hypotheses in this study is whether or not there is an interaction between the prevalence of GP-IIIa Pl polymorphism and a second risk factor such as smoking status and homocysteine level. We introduce the algorithm in detail with several numerical examples.