Suppose I have time to event data for 100 subjects, with event indicator (1=Event, 0=Censored) and a Time variable (maximum follow-up of 2 years).
I also have a risk score for each of the subject and I'd like to generate time-dependent ROC and get the AUC at time = 2 years.
However, all of the events happened within the first year and no events between 1-2. With the below code, SAS is only generating AUC up to 1 year.
proc phreg data=Indat concordance plots=roc rocoptions(at=2) ;
model TIME*EVENT(0)=HM3RS;
run;
It gives a warning that say "you have chosen At= time greater than the maximum observed. " Can someone help me to understand this? I thought for Cumulative/Dynamic ROC, everything before 2 years can be taken into account, even though there is no event between 1-2 year.
Thank you!
