Survival analysis

Summary

Survival analysis is the part of statistics that studies the time until an event happens. Examples of events are death, relapse of a disease or failure of a machine. Its central objects are the survival function and the hazard function of the event time. Its typical difficulty is censoring. For some subjects the event is not observed during the study, and only a lower bound for their time is known. Standard tools include the Kaplan–Meier estimator, the log-rank test and the proportional hazards model.