The Kaplan-Meier estimator is a non-parametric statistic used to estimate the survival function from lifetime data in the presence of right-censored observations. It defines the instantaneous probability that an individual survives beyond a specified time point, calculated as the product of conditional probabilities at each event occurrence divided by those remaining at risk. This method belongs to the domain of biostatistics and reliability engineering, providing a fundamental tool for analyzing time-to-event data where subjects may drop out or experience events before their final status is known.
Prerequisite chain context: requires Right-Censoring Mechanism in Survival Analysis.