Lui K J
Department of Mathematical Sciences, College of Sciences, San Diego State University, CA 92182-0314, USA.
Stat Med. 1996 Mar 30;15(6):671-8. doi: 10.1002/(SICI)1097-0258(19960330)15:6<671::AID-SIM205>3.0.CO;2-5.
Inverse sampling is a sampling design in which one continues sampling subjects until one obtains a predetermined number of index subjects. This paper derives a procedure for calculation of the minimum required number of index subjects on the basis of the exact conditional test under inverse sampling. This paper studies quantitatively the effect on power calculations of the number of index subjects. To facilitate use of inverse sampling in study designs, this paper further provides a table that summarizes, in a variety of situations, the minimum required number of index subjects for powers equal to 0.90 and 0.80 at 0.05-level. It also includes a discussion on use of the approximation sample size formula derived on the basis of a variance-stabilizing transformation and large sample theory.
逆抽样是一种抽样设计，即持续对受试者进行抽样，直到获得预先确定数量的指标受试者。本文推导了基于逆抽样下精确条件检验来计算所需指标受试者最小数量的程序。本文定量研究了指标受试者数量对效能计算的影响。为便于在研究设计中使用逆抽样，本文还提供了一个表格，总结了在各种情况下，在0.05水平下效能等于0.90和0.80时所需指标受试者的最小数量。它还包括对基于方差稳定变换和大样本理论推导的近似样本量公式的使用讨论。
