On multiple comparisons among K samples subject to unequal patterns of censorship

Two multiple comparisons procedures for determining which of K arbitrarily censored populations differ from each other are proposed. The procedures are based on multiple comparisons using the generalized Wilcoxon and log-rank statistics. The procedures incorporate a pairwise ranking scheme, rather than the joint ranking scheme proposed by Breslow (1970) and Crowley and Thomas (1975). A conservative testing method suggested by an inequality due to Šidák (1967) is given; a numerical example is presented.