Evaluate a Longitudinal Surrogate with a Censored Outcome

Provides influence function-based methods to evaluate a longitudinal surrogate marker in a censored time-to-event outcome setting, with plug-in and targeted maximum likelihood estimation options. Details are described in: Agniel D and Parast L (2025). "Robust Evaluation of Longitudinal Surrogate Markers with Censored Data." Journal of the Royal Statistical Society: Series B . A tutorial for this package can be found at < https://www.laylaparast.com/survivalsurrogate> and a Shiny App implementing the package can be found at < https://parastlab.shinyapps.io/survivalsurrogateApp/>.