Log-rank and stratified log-rank tests  

作　　者：Ting Ye Jun Shao Yanyao Yi 

机构地区：[1]Department of Biostatistics,University of Washington,Seattle,WA,USA [2]School of Statistics,East China Normal University,Shanghai,People’s Republic of China [3]Department of Statistics,University of Wisconsin,Madison,WI,USA [4]Global Statistical Sciences,Eli Lilly and Company,Indianapolis,IN,USA

出　　处：《Statistical Theory and Related Fields》2023年第4期309-317,共9页统计理论及其应用（英文）

摘　　要：In randomized clinical trials with right-censored time-to-event outcomes,the popular log-rank test without adjusting for baseline covariates is asymptotically valid for treatment effect under simple randomization of treatments but is too conservative under covariate-adaptive random-ization.The stratified log-rank test,which adjusts baseline covariates in the test procedure by stratification,is asymptotically valid regardless of what treatment randomization is applied.In the literature,however,under simple randomization there is no affirmative conclusion about whether the stratified log-rank test is asymptotically more powerful than the unstratified log-rank test.In this article we show when the stratified and unstratified log-rank tests aim for the same null hypothesis and that,under simple randomization,the stratified log-rank test is asymp-totically more powerful than the unstratified log-rank test in the region of alternative hypothesis that is specified by a Cox proportional hazards model.We also provide some discussion about why we do not have an affirmative conclusion in general.

关 键 词：Baseline covariates covariate-adaptive randomization null hypothesis of no treatment effect Pitman’s relative effciency TIME-TO-EVENT validity of tests 

分 类 号：O21[理学—概率论与数理统计]