Log-rank test

A statistical test to compare the survival distributions of two (or more) groups.

This test is used when one wants to test the null hypothesis: that there is no difference in the probability of an event (e.g. death) between the two groups at any time point. The analysis is based on the times of events (or deaths), and it is most likely to detect a difference between the groups compared when the risk of an event is greater for one group.