Hi, I need some help to manage frailty in Survreg function; in particular I'm looking for more information about frailty in survreg function applied to a loglogistic hazard function. Actually I need to develope a predictor for frailty random variable realization (similar to the Proportional Hazard Model's one based on Laplace Tansforms' ratio). I can't find any documentation about AFT models with Gamma Frailty developed in "survival package". Any reference paper to suggest? Thank a million Francesca [[alternative HTML version deleted]]