Kaplan-Meier Survival Curve

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

The estimate only changes at the moment an event occurs. Between events the probability stays flat, so the line holds level and then drops, producing a staircase rather than a smooth line.

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. Give each KM survival curve its own color and legend entry so the groups stay distinguishable at the point where they diverge. 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 returns 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 part of the plot is as the cohort becomes smaller.