Hi, I am trying to fit a Weibull PH model with a gaussian frailty term (kidney data). Is the following approach correct? 1. Fit the model using survReg with the frailty term added in. Kidn1<-survreg(formula = Surv(rtime, event)~ age+sex+gn+an+pkn+frailty.gaussian(patient), data=kidney, dist='weibull') 2. Based on Venables and Ripley (350-353), divide the negative of the coefficients by the scale parameter to obtain the Weibull PH model coefficients. Jindi Jatinder Singh Senior Manager, Analysis and Reporting PRA International 300-730 View Street Victoria, B.C. V8W 3Y7 Tel: 250-483-4416 Fax: 250 483 4588 http://www.prainternational.com e-mail: singhjatinder at praintl.com