Data collected on the time to an event-such as the death of a patient in a medical study-is known as survival data. The methods for analyzing survival data can also be used to analyze data on the time to events such as the recurrence of a disease or relief from symptoms. The text begins with an introduction to survival analysis and a description of four studies in which survival data was obtained. These and other data sets are then used to illustrate the techniques presented in the following chapters. Designed for statisticians in medical research institutes, this book also meets the need for an intermediate text which emphasizes the application of the methodology to survival data arising from medical studies.