STE–PoS for 
The calculation of the PoS requires the likelihood and a prior to deriving the posterior distribution of the conditional survival probabilities, from which then the posterior predictive distribution of long-term survivors can be generated. Given the likelihood in equation (In this small sample setting with strictly limited available information, the choice of the prior distributions is sensitive. In order to achieve a rather weakly informative prior distribution for the long-term survival probability, we choose negative log-Gamma distributions with shape parameter 
