The Kaplan-Meier Estimator as a Sum over Units

A sum-wise formulation is proposed for the Kaplan-Meier product limit estimator of partially right-censored survival data. The derived representation permits to write the population’s estimator as a sum over its individual units’ semi-empirical estimators. This intuitive decomposition is applied to visualize the different contributions of failed and censored units to the overall population estimator.