Kaplan-Meier Survival Curve

A Kaplan-Meier survival curve is a stepwise graph that estimates the probability of survival over time. Each drop marks an event, and tick marks show censored observations rather than new events.

A survival curve is drawn as steps because the estimate only changes when an event occurs. Between events the probability stays flat, so the line becomes a staircase rather than a smooth curve.

Tick marks represent censored observations — participants who left follow-up or had no event by the end of the study. They do not cause the curve to drop, but they matter for interpreting how much evidence remains at later time points.

To compare two Kaplan-Meier survival curves, plot them on the same axes and assess how consistently they separate over time. In formal analysis, a log-rank test is commonly used to evaluate whether the difference between groups is statistically meaningful.

You can generate a Kaplan-Meier survival curve on SciFig by describing the group structure and survival pattern you need. The tool gives you a clean stepwise plot that can be relabeled, refined, and exported for a manuscript, report, or presentation.

The number-at-risk table shows how many participants remain under observation at each time point. It helps readers judge how reliable the later parts of a Kaplan-Meier survival curve are as the cohort becomes smaller.