The Mean, Median, and Confidence Intervals of the Kaplan-Meier Survival Estimate—Computations and Applications

Abstract

This short note points out estimators of the mean, median, and the associated confidence intervals of the Kaplan-Meier product limit estimate. Some uses of the estimator of the mean are described. In addition, differences among popular software packages in the calculation of both the mean and median and associated confidence intervals are demonstrated and are due to default settings in the software. Simple examples of the calculations are provided using S-Plus, R, SAS, Stata, and SPSS.