A Modified Log Rank Test for Highly Stratified Data
提出一种修正的对数秩检验，在无分层效应时完全有效，且在大数量分层下比标准分层对数秩检验更高效，同时适用于删失模式依赖治疗组的历史对照研究。
Clinical trials often employ a stratified randomization so that treatment arms are balanced within prognostic factors. In these circumstances the use of the ordinary log rank test for comparing treatment groups with respect to survival is invalid. The stratified log rank test, although valid, loses efficiency as the number of strata increases. This paper proposes a modified log rank test that is fully efficient when there is no strata effect and is more efficient than the stratified log rank test when the number of strata is large. Furthermore, the test has been designed so as to remain valid when the censoring pattern depends on the treatment group as it would in a historically controlled study.