survival analysis

Syllable breakdown

Dictionary meaning

a branch of statistics that analyses the time until an event of interest occurs — most commonly death but also relapse, recovery, employment, equipment failure, or any other discrete event — handling the complication of censoring, which occurs when the event has not been observed by the end of the study period for some participants; the most widely used non-parametric method of survival analysis is the Kaplan-Meier estimator, which produces a step-function estimate of the survival function by recalculating survival probability at each observed event time; the log-rank test compares survival curves between groups; the Cox proportional hazards regression model — the most widely used regression method in survival analysis — estimates the hazard ratio associated with each predictor while controlling for others, under the assumption that the hazard ratio is constant over time; survival analysis is fundamental to clinical trials, epidemiological cohort studies, and engineering reliability analysis

Examples

• Survival analysis showed that patients in the treatment group had significantly longer time to disease progression than controls.
• The proportional hazards assumption was tested using Schoenfeld residuals before interpreting the Cox regression results.

Synonyms: time-to-event analysis, failure time analysis