LINEAR RANK-TESTS FOR THE NONRESPONDERS PROBLEM WITH CENSORED-DATA

In a two-sample setting, a two-parameter mixture model is postulated for the treated patients where a proportion of the patients improve and the remaining proportion of nonresponders behave like the control patients. The response is subject to random censoring. Censored data versions of linear rank statistics are developed in order to detect improvement due to treatment. The tests are compared to standard tests such as the log-rank test in terms of asymptotic relative efficiency, empirical power, and performance on real data.