# surrosurv

Evaluation of Failure Time Surrogate Endpoints in Individual Patient
Data Meta-Analyses

## Description

Provides functions for the evaluation of surrogate endpoints when
both the surrogate and the true endpoint are failure time variables. The
approaches implemented are: (1) the two-step approach (Burzykowski et
al, 2001) <DOI:10.1111/1467-9876.00244>
with a copula model (Clayton, Plackett, Hougaard) at the first step and
either a linear regression of log-hazard ratios at the second step
(either adjusted or not for measurement error); (2) mixed proportional
hazard models estimated via mixed Poisson GLM.