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http://dx.doi.org/10.5808/GI.2009.7.3.148

The Effect of Increasing Control-to-case Ratio on Statistical Power in a Simulated Case-control SNP Association Study  

Kang, Moon-Su (Department of Physiology, College of Medicine, Hanyang University)
Choi, Sun-Hee (Department of Physiology, College of Medicine, Hanyang University)
Koh, In-Song (Department of Physiology, College of Medicine, Hanyang University)
Publication Information
Genomics & Informatics / v.7, no.3, 2009 , pp. 148-151 More about this Journal
Abstract
Generally, larger sample size leads to a greater statistical power to detect a significant difference. We may increase the sample size for both case and control in order to obtain greater power. However, it is often the case that increasing sample size for case is not feasible for a variety of reasons. In order to look at change in power as the ratio of control to case varies (1:1 to 4:1), we conduct association tests with simulated data generated by PLINK. The simulated data consist of 50 disease SNPs and 300 non-disease SNPs and we compute powers for disease SNPs. Genetic Power Calculator was used for computing powers with varying the ratio of control to case (1:1, 2:1, 3:1, 4:1). In this study, we show that gains in statistical power resulting from increasing the ratio of control to case are substantial for the simulated data. Similar results might be expected for real data.
Keywords
association study; ratio of control to case; simulated data; SNP; statistical power;
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