Maximally Selected x2 Statistics for k× 2 Tables
Maximally Selected x2 Statistics for k× 2 Tables
复制标题
k× 2 表的最大选择 x2 统计
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
D. Rabinowitz
中科院分区：
文献类型：
--
作者：
R. Betensky;D. Rabinowitz
摘要在流行病学分析中，通常将连续结果总结为高于或低于阈值。对于这种二分结局，可以使用关联或趋势的常用x2统计量来检验研究人群各分层的比例是否相等。但是，如果选择阈值以最大化检验统计量，则标称x2参考分布是不正确的。本文给出了k× 2表中最大选择x2统计量的结合和趋势的渐近分布。该方法说明了艾滋病临床试验的数据。模拟实验的结果，评估在中等样本量的渐近分布的准确性也报告。
Summary. It is common in epidemiologic analyses to summarize continuous outcomes as falling above or below a threshold. With such a dichotomized outcome, the usual x2 statistics for association or trend can be used to test for equality of proportions across strata of the study population. However, if the threshold is chosen to maximize the test statistic, the nominal x2 reference distributions are incorrect. In this paper, the asymptotic distributions of maximally selected x2 statistics for association and for trend for the k× 2 table are derived. The methodology is illustrated with data from an AIDS clinical trial. The results of simulation experiments that assess the accuracy of the asymptotic distributions in moderate sample sizes are also reported.