Survival, Kaplan-Meier, left truncation
On Wed, 7 Jan 2004, Rau, Roland wrote:
Dear all, I have data from 1970 to 1990 for people above age 50. Now I want to calculate survival curves by age starting at age 50 using the Kaplan Meier Estimator. The problem I have is that there are already people in 1970 who are older than 50 years. I guess this is called delayed entry or left truncation (?).
Yes
I thought the code would be: roland <- survfit(Surv(time=age.enter, time2=age.exit, event=status, type="interval")~1, weights=gewicht, type="kaplan-meier") But then R tells me that it can handle only right-censored or counting data.
The `interval' type is for interval-censored data. Left-truncated, right-censored data are so easy to handle with hazard-based models that they are the default. You want roland <- survfit(Surv(age.enter, age.exit, status)) -thomas Thomas Lumley Assoc. Professor, Biostatistics tlumley at u.washington.edu University of Washington, Seattle