No, coxph does not have any special code to deal with ordered factors.
You can do it "by hand" by using the pool-adjacent-violators algorithm
1. Fit the data with stage as a categorical
2. Verify that the coefficients are ordered
if so, you are done
if not, assume that they were
0 = stage 1 (implicit coef)
.1= stage 2
.5 = stage 3
.4 = stage 4
Create a new class variable that combines stages 3 and 4, and
return to step 1.
Terry Therneau
______________________________________________
[email protected] 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.
