What does the Kaplan-Meier Curve measure?

The Kaplan-Meier curve is a statistical tool primarily used in survival analysis to estimate the probability of an event, such as death or failure, over time. By constructing this curve, researchers can visualize the proportion of patients expected to survive beyond a certain time point following a specific treatment or intervention. This is particularly beneficial when analyzing time-to-event data in clinical studies, as it provides a straightforward representation of survival rates over a study period.

The curve is particularly valuable because it can account for censored data—instances where patients leave the study before the event occurs, either due to loss to follow-up or being alive at the study's end. Each step down in the curve corresponds to an event occurrence, and the areas between the steps provide insight into survival probabilities at various time intervals. Therefore, it specifically measures the proportion of patients living for a certain duration after treatment, making it a fundamental tool in assessing treatment efficacy in clinical trials.