Semiparametric modeling of lifetime data with crossing survival curves via Yang and Prentice model with piecewise exponential baseline distribution. Details about the model can be found in (Demarqui and Mayrink 2021) <doi.org/10.1214/20-BJPS471>. Model fitting carried out via likelihood-based and Bayesian approaches. The package also provides point and interval estimation for the crossing survival times.
References
Demarqui FN, Mayrink VD (2021). “Yang and Prentice model with piecewise exponential baseline distribution for modeling lifetime data with crossing survival curves.” Brazilian Journal of Probability and Statistics, 35(1), 172 -- 186. doi:10.1214/20-BJPS471 .
Yang S, Prentice RL (2005). “Semiparametric analysis of short-term and long-term hazard ratios with two-sample survival data.” Biometrika, 92(1), 1-17.
Stan Development Team (2019). RStan: the R interface to Stan. R package version 2.19.2. https://mc-stan.org