RANK COVARIANCE METHODS FOR THE ANALYSIS OF SURVIVAL-DATA

A procedure for comparing survival times between several groups of patients through rank analysis of covariance was introduced by WOOLSON and LACHENBRUCH (1983). It is a modification of Quade's rank analysis of covariance procedure (1967) and can be used for the analysis of right-censored data. In this paper, two additional modifications of Quade's original test statistic are proposed and compared to the original modification introduced by Woolson and Lachenbruch. These statistics are compared to one another and to the score test from Cox's proportional hazards model by way of a limited Monte Carlo study. One of the statistics, Q(R2), is recommended for general use for the rank analysis of covariance of right-censored survivorship data.