C HAPTER 1 Introduction What Is Survival Analysis? 1 What Is Survival Data? 2 Why Use Survival Analysis? 4 Approaches to Survival Analysis 5 What You Need to Know 6 Computing Notes 7 W HAT I S S URVIVAL A NALYSIS ? Survival analysis is a class of statistical methods for studying the occurrence and timing of events. These methods are most often applied to the study of deaths. In fact, they were originally designed for that purpose, which explains the name. That name is somewhat unfortunate, however, because it encourages a highly restricted view of the potential applications of these methods. Survival analysis is extremely useful for studying many different kinds of events in both the social and natural sciences, including disease onset, equipment failures, earthquakes, automobile accidents, stock market crashes, revolutions, job terminations, births, marriages,