This research sequentially monitors paired survival differences using a new class of non-parametric tests based on functionals of standardized paired weighted log-rank (PWLR) and standardized paired weighted Kaplan-Meier (PWKM) tests. During a trial these tests may alternately assume the role of the more extreme statistic. By monitoring PEMAX, the maximum between the absolute values of the standardized PWLR and PWKM, one combines advantages of rank-based and non rank-based paired testing paradigms. Simulations show that monitoring treatment differences using PEMAX maintains type I error and is nearly as powerful as using the more advantageous of the two tests, in proportional hazards (PH) as well as non-PH situations. Hence, PEMAX preserves power more robustly than individually monitored PWLR and PWKM, while maintaining a reasonably simple approach to design and analysis of results. An example from the Early Treatment Diabetic Retinopathy Study (ETDRS) is given.
Clinical Trials | Statistical Methodology | Statistical Theory | Survival Analysis
Andrei, Adin-Cristian and Murray, Susan, "Asymptotic Results for Simultaneous Group Sequential Analysis of Rank-Based and Weighted Kaplan-Meier Tests with Paired Survival Data in the Presence of Censoring. Technical report" (June 2004). The University of Michigan Department of Biostatistics Working Paper Series. Working Paper 43.