You have still not given me enough information to reproduce your problem. "Why doesn't it include all years?" I have no way of knowing, since we have no data.
--- begin included message -- halo david when I use type= 'interval' Call: survfit(formula = Surv(ingreso, fecha, estado, type = "interval") ~ categoria) and when I use just Call: survfit(formula = Surv(ingreso, fecha, estado) ~ categoria) I don t know why when I use type = "interval" it does not survival calculed for very year regards ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.