Blinded sample size re-estimation with unequal variances and center effects in clinical trials
Blinded sample size re-estimation with unequal variances and center effects in clinical trials
复制标题
临床试验中方差和中心效应不等的盲样本量重估
DOI：
10.1080/03610929808832102
复制
发表时间：
1998
影响因子：
0.8
通讯作者：
J. Long
中科院分区：
文献类型：
--
作者：
W. Shih;J. Long
先前在文献中开发的两阶段样本量重估计程序（例如，Shih，1992；Gould 和 Shih，1992）将随机临床试验的盲数据视为来自两个等方差正态分布的混合物的样本。本文研究了该程序应用于方差不等且存在临床中心阻塞效应的情况。我们通过模拟表明，在这两种情况下，重估计程序都是仍然能够正确更新样本大小以获得所需的功率并将 1 类误差保持在标称水平。
The two-stage sample size re-estimation procedure developed previously in the literature (e.g.,Shih, 1992; Gould and Shih, 1992) treats the blinded data from a randomized clinical trial as a sample from a mixture of two normal distributions of equal variances.This paper investigates the procedure when being applied to the situations where the variances are unequal and blocking effects by clinical centers are present.We show by simulations that in both situations the re-estimation procedure is still capable to update the sample size properly for attaining the required power and preserving the type-1 error at the nominal level.