Bristol D R
Schering-Plough Research Institute, Kenilworth, New Jersey 07033.
J Biopharm Stat. 1993 Sep;3(2):159-66. doi: 10.1080/10543409308835057.
Interim analyses are often employed to terminate comparative clinical trials for ethical or economic reasons when the evidence indicates that one treatment is superior to the other. Here an interim analysis is proposed for the situation where a one-sided test is to be performed. The proposed interim analysis consists of a one-sided test to terminate the clinical trial if it appears that the null hypothesis of interest is true. By noting that incorporation of a single interim analysis is similar to the two-stage procedure used for constructing a test procedure with power independent of the unknown variance, it also includes estimation of the variance, which can be used to control the power of the test if the trial is not terminated. Various properties of this two-stage procedure and derivation of the constants needed for its implementation are presented.
出于伦理或经济原因，当证据表明一种治疗方法优于另一种治疗方法时，中期分析通常用于终止比较性临床试验。本文针对单侧检验的情况提出了一种中期分析方法。所提出的中期分析包括一个单侧检验，如果感兴趣的原假设似乎为真，则终止临床试验。通过注意到纳入单一中期分析类似于用于构建功效与未知方差无关的检验程序的两阶段程序，它还包括方差估计，如果试验未终止，该估计可用于控制检验的功效。本文给出了该两阶段程序的各种性质及其实施所需常数的推导。
