Hello list, and thank you in advance. I'm unable to generate predicted values when specifying newdata using phreg and aftreg models in the eha package, but I do not have the same problem with a proportional hazards model from coxph. Without the newdata argument the predicted values are returned, but with "newdata=<model.dataframe>" coxph is fine but both aftreg and phreg models return an "Error in predict.coxph(f.ph.eha, newdata = mort, type = "lp") : Data is not the same size as it was in the original fit" message. Since I ultimately want a parametric model and the "real" data is left truncated and right censored, I think the aftreg function in the eha package is what I must use. Following is my sample code, without the output. #~ All models generated successfully --------------------------------- f.ph <- coxph(Surv(enter, exit, event) ~ ses, data = mort) f.ph.eha <- phreg(Surv(enter, exit, event) ~ ses, data = mort) f.aft <- aftreg(Surv(enter, exit, event) ~ ses, data = mort) #~ All fits generated successfully ----------------------------------- f.ph.fit <- predict(f.ph, type='lp') f.ph.eha.fit <- predict(f.ph.eha, type='lp') f.aft.fit <- predict(f.aft, type='lp') #~ First fit generated successfully, others output error-------------------- f.ph.fit <- predict(f.ph, newdata=mort, type='lp') f.ph.eha.fit <- predict(f.ph.eha, newdata=mort, type='lp') f.aft.fit <- predict(f.aft, newdata=mort, type='lp') Mike