How to overlay 2 survival plots with adjustment of confounders

[Chung-Li]

Sanjay,

Thank you for trying to help!

The SAS I'm using is in version 9.4.

Regarding to the data, it's a traditional survival data which contains

#1 event variable: allcause, 0 as not dead, 1 as dead

#2 follow-up time: followtime

#3 main independent variable: NewSurgeIndex: 1, 2, and 3 represent 3 different groups

#4 other confounders: sex age bmi_1 smoke alcohol ldl_c meansbp nightdaysbpratio

Again, what I'm trying to do is to estimate survival probability for NewSurgeIndex with adjusting for confounders.

Moreover, in order to make these three groups comparable, so I need to draw these three survival curves on the same graph.

Actually, I've came out one way to achieve this:

ODS GRAPHICS ON;
PROC PHREG DATA=one PLOTS(OVERLAY)=SURVIVAL;
		CLASS NewSurgeIndex;
	MODEL followtime*allcause(0)= sex age bmi_1 smoke alcohol ldl_c 
				  meansbp nightdaysbpratio NewSurgeIndex;
	BASELINE COVARIATES=one OUT=Pred1 SURVIVAL=_ALL_/ DIRADJ GROUP=NewSurgeIndex;
ODS GRAPHICS OFF;

However, very welcome if you have any better idea!

[Rick_SAS · Accepted solution]

Using a categorical variable in the CLASS statement is the usual way to compare groups. As you've seen, this also overlays the various groups on the ODS graphics that the procedure creates.

[Chung-Li]

Thank you Rick!
Now I can use it more confidently.