After doing logrank analysis on three or more survival curves, can I post test for differences between pairs of curves?
The need for multiple comparisons When you compare three or more survival curves at once, you get a single P value testing the null hypothesis that all the samples come from populations with identical survival, and that all differences are due to chance. Often, you’ll want to drill down and compare curves two at a time. If you don’t adjust for multiple comparisons, it is easy to fool yourself. If you compare many groups, the chances are high that one or more pair of groups will be ‘significantly different’ purely due to chance. To protect yourself from making this mistake, you should correct for multiple comparisons. How multiple comparisons of survival curves work Multiple comparison tests after ANOVA are complicated because they not only use a stricter threshold for significance, but also include data from all groups when computing scatter, and use this value with every comparison. By quantifying scatter from all groups, not just the two you are comparing, you gain some degrees of fr
