Pasternack B S, Shore R E
Am J Epidemiol. 1981 Feb;113(2):182-91. doi: 10.1093/oxfordjournals.aje.a113082.
This paper proposes the use of group sequential methods of calculate sample sizes for cohort and case-control study designs. The methods are based upon the theory of repeated significance tests, one of several sequential methods currently available. Group sequential methods permit repeated significance testing of relative risks obtained from periodically accumulated data while maintaining the required overall level of significance. Tables are presented for cohort and case-control studies in which the average sample size required for a group sequential design is compared to that of the conventionl fixed sample size plan for the usual constant relative risk situation. The tables show that group sequential designs are in general more efficient than fixed sample size plans for cohort and case-control studies. Computer simulations showed that group sequential methods can be employed when stratified data analyses are to be used and when the sample sizes of the two study groups are unequal.
本文提出了使用成组序贯方法来计算队列研究和病例对照研究设计的样本量。这些方法基于重复显著性检验理论，是目前可用的几种序贯方法之一。成组序贯方法允许对从定期积累的数据中获得的相对风险进行重复显著性检验，同时保持所需的总体显著性水平。文中给出了队列研究和病例对照研究的表格，其中将成组序贯设计所需的平均样本量与常规固定样本量计划在通常恒定相对风险情况下所需的样本量进行了比较。表格显示，对于队列研究和病例对照研究，成组序贯设计总体上比固定样本量计划更有效。计算机模拟表明，当要使用分层数据分析以及两个研究组的样本量不相等时，可以采用成组序贯方法。
