Power calculations for preclinical studies using a K-sample rank test and the Lehmann alternative hypothesis
Power calculations for preclinical studies using a K-sample rank test and the Lehmann alternative hypothesis
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DOI：
10.1002/sim.2268
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发表时间：
2006-08-15
影响因子：
2
通讯作者：
Heller, Glenn
中科院分区：
文献类型：
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作者：
Heller, Glenn
在具有连续结果衡量的小样本比较研究中，通常使用检验统计量的渐近分布来进行功率计算。当样本量很小时，这种渐近结果可能是一个很差的近似结果。另一种方法是使用基于等级的测试统计量，即精确的功率计算。当组的数量大于两个时，执行精确功率计算所需的计算量是令人望而却步的。为了降低计算负担，在Lehmann备择假设下，采用蒙特卡罗重抽样方法逼近k样本秩检验统计量的精确幂函数。这种方法的激励例子是动物研究的设计，其中每组动物的数量通常很少。版权所有(C)2005 John Wiley&Sons，Ltd.
Power calculations in a small sample comparative study, with a continuous outcome measure, are typically undertaken using the asymptotic distribution of the test statistic. When the sample size is small, this asymptotic result can be a poor approximation. An alternative approach, using a rank based test statistic, is an exact power calculation. When the number of groups is greater than two, the number of calculations required to perform an exact power calculation is prohibitive. To reduce the computational burden, a Monte Carlo resampling procedure is used to approximate the exact power function of a k-sample rank test statistic under the family of Lehmann alternative hypotheses. The motivating example for this approach is the design of animal studies, where the number of animals per group is typically small. Copyright (c) 2005 John Wiley & Sons, Ltd.