A general class of nonparametric tests for survival analysis.

Tarone and Ware (1977, Biometrika 64, 156-160) developed a general class of s-sample test statistics for right-censored survival data that includes the log-rank and modified Wilcoxon procedures. Subsequently, many authors have considered two- and s-sample classes in detail. In this paper a family of nonparametric statistics is shown to unify existing and generate new test statistics for the s (greater than or equal to 2)-sample, s-sample trend, and single continuous covariate problems.