Landmark analysis
Date created: 2021-11-02
Typically used in Survival analysis settings to overcome guarantee-time bias.
Landmark analysis is when you select a time point during follow-up and analyze only the subjects who have survived until then. Any subjects who were lost to follow-up or died prior to the landmark are excluded. You then classify response and apply the usual survival analysis methods.
Choosing the landmark
- Late landmarks = smaller sample size & lower statistical power
- Early landmarks = late responders are misclassified as non-responders, low Sensitivity
Usually the landmark is picked from a clinically meaningful period, or you use multiple landmark times for sensitivity analyses.