C HAPTER 2 Basic Concepts of Survival Analysis 15 Repeated Events, and Other Topics." Aside from that, there are three important lessons here: 1. First, in designing and conducting studies, you should do everything possible to reduce the amount of random censoring. You can't rely on statistical methods to completely adjust for such censoring. 2. Second, you should make an effort to measure and include in the model any covariates that are likely to affect the rate of censoring. 3. Third, in studies with high levels of random censoring, you may want to place less confidence in your results than calculated confidence intervals indicate. D ESCRIBING S URVIVAL D ISTRIBUTIONS All of the standard approaches to survival analysis are probabilistic or stochastic. That is, the times at which events occur are assumed to be realizations of some random process. It follows that T, the event time for