Kaplan-Meier Estimator

The Kaplan-Meier estimator, also known as the product limit estimator, is a non-parametric statistic used to estimate the survival function from lifetime data. It is most often used in medical research to measure how long patients survive after a treatment, but it applies equally to other time to event data such as the duration of unemployment, the failure rate of machine parts, or the time before fruit is removed from a plant by animals. The method is credited to Edward L. Kaplan and Paul Meier, who had separately submitted similar work to the Journal of the American Statistical Association; the journal's editor, John Tukey, persuaded them to combine their work into the single 1958 paper that introduced the estimator, which has since been cited more than 34,000 times.