Creating Adjusted Survival Curves

57078 — Mon, 23 Sep 2013 22:01:28 GMT

I am using the inverse-probability method published by Cole et al (Adjusted survival curves with inverse probability weights) to create my weights however instead of using these weights in the COX procedure, proc phreg, I would like to use them in Proc Lifetest.

proc lifetest data=SDEHP3 plots=(s) graphics outsurv=ph2_survival;

time phage*phcensor1(1);strata dhCAT ;

freq stw;

run;

The benefit is that I can use the medians with confidence intervals as my adjusted median survival times for each strata where as in Cox there are no ages with confidence intervals.

Does anyone see a problem with using inverse probability weights in the weight statement of proc lifetest to produce adjusted KM curves?

Thanks!

Re: Creating Adjusted Survival Curves

1zmm — Tue, 24 Sep 2013 12:57:09 GMT

I don't know the answer to your question.

Another article deals directly with your question (Statistics in Medicine 24:3089-3110).

However, with PROC LIFETEST, you might consider the FREQ statement option, NOTRUNCATE,

that prevents truncation on non-integer weights and the use of Wilcoxon scores (=n_i) instead of the default

log-rank test scores (=1) so that these weights are incorporated in the estimation.

topic Creating Adjusted Survival Curves in Statistical Procedures

Creating Adjusted Survival Curves

Re: Creating Adjusted Survival Curves