This module introduces statistical techniques to analyze a "time to event outcome variable," which is a different type of outcome variable than those considered in the previous modules. A time to event variable reflects the time until a participant has an event of interest (e.g., heart attack, goes into cancer remission, death). Statistical analysis of time to event variables requires different techniques than those described thus far for other types of outcomes because of the unique features of time to event variables. Statistical analysis of these variables is called time to event analysis or survival analysis even though the outcome is not always death. What we mean by "survival" in this context is remaining free of a particular outcome over time.