Robust methods for analysing multivariate failure times

In a long term clinical study, the subjects may experience repeated occurre nces of the same type of events or multiple events of entirely different na ture during the following period. In this article, we reviewed the three mo st frequently used extensions to the proportional hazards model for analysi ng such multivariate failure time data. Specifically, we explored the under lying hypotheses for each of these extensions. The three procedures were ap plied to a bladder cancer study.