Kaplan-Meier (tertile) plots
A Kaplan-Meier plot [Kaplan & Meier 1958 J. Amer. Statist. Assoc. 53:457] shows the survival of patient subgroups over time. For tertile-based grouping, the cohort of patients is split into three equal portions (tertiles) according to their marker expression scores. This is done separately for each marker. Where cohorts have a number of patients not exactly divisible by three, the groups will have slightly different numbers. This will also occur if more than a third of patients share the same score (as may be the case for categorical scoring).
The difference in survival between the groups is tested for significance using the log-rank (Mantel-Cox) test [Mantel 1966 Cancer Chemother. Rep. 50:163].
Available for: continuous scoring
[Top]Viewing the results
See accessing and interpreting survival analysis results.
[Top]Example output
Figure 1: Example Kaplan-Meier plot based on marker score tertiles.