SurrogateOutcome is an R package to estimate the proportion of treatment effect on a censored primary outcome that is explained by the treatment effect on a censored surrogate outcome/event.
More details on the method are available in Parast, Tian, Cai (2020). Assessing the Value of a Censored Surrogate Outcome. Lifetime Data Analysis, 26(2): 245-265. doi:10.1007/s10985-019-09473-1.
The package also implements the optimal transformation approach described in Wang X, Cai T, Tian L, Parast L (2025). Model-free Approach to Evaluate a Censored Intermediate Outcome as a Surrogate for Overall Survival. Statistics in Medicine, 44(20-22): e70268. doi:10.1002/sim.70268.
Go here to view a tutorial for this package: SurrogateOutcome Tutorial. We also have a Shiny App here: SurrogateOutcome Shiny App.