Cook R J, Lawless J F
Department of Statistics and Actuarial Science, University of Waterloo, Ontario, Canada.
Biometrics. 1996 Dec;52(4):1311-23.
A method of interim monitoring is described for longitudinal comparative studies in which the outcome of interest is a recurrent event and treatment comparisons are based on expected numbers of events. The nonparametric methods described by Cook, Lawless, and Nadeau (1996, Biometrics 52, 116-130) are generalized to provide a robust estimate of the covariance matrix for a sequence of test statistics calculated over time. The error spending function methodology of Lan and DeMets (1983, Biometrika 70, 659-663) is adopted to control the experimental type I error rate. A simulation study indicates satisfactory frequency properties of this procedure for the moderate to large scale trials for which it is intended. Extensions of this approach to handle stratified designs and studies with multitype recurrent events are indicated. Data from a kidney transplant study (Cole et al., 1994, Transplantation 57, 60-67) are used for illustrative purposes.
本文描述了一种用于纵向比较研究的中期监测方法，其中感兴趣的结果是复发事件，治疗比较基于预期事件数。库克、劳利斯和纳多（1996年，《生物统计学》52卷，第116 - 130页）描述的非参数方法被推广，以提供对随时间计算的一系列检验统计量协方差矩阵的稳健估计。采用了兰和德梅茨（1983年，《生物计量学》70卷，第659 - 663页）的误差消耗函数方法来控制实验I型错误率。一项模拟研究表明，该程序对于其适用的中大规模试验具有令人满意的频率特性。指出了该方法在处理分层设计和具有多种类型复发事件的研究方面的扩展。来自一项肾移植研究（科尔等人，1994年，《移植》57卷，第60 - 67页）的数据用于说明目的。
