topic Why was the output different after adding disply options to PROC LIFETEST? in SAS Programming

Why was the output different after adding disply options to PROC LIFETEST?

oddsratio — Mon, 08 Nov 2021 08:30:02 GMT

Hi. My task is to analyze a very simple and straightforward cancer registry. My output was significantly different after changing the option, even though in my opinion it was just for display purposes. Below I have included both code and their outputs for your reference. Could you please explain what happened and which version is better? I really appreciate your time and help.

Version one

proc lifetest data=registry atrisk plot=(survival (atrisk=0 to 5 by 1 atrisktickonly)) 
			  outsurv=ci95 maxtime=5 timelist=(0 to 5 by 1) reduceout; 
	time survyr*vital(1); 
	strata rgroup1/ test=all;
	label survyr ='Time in years' rgroup1="race"; 
run;

Version two
- test and outside was added in the first for plot

proc lifetest data=registry atrisk plot=(survival ( test atrisk=0 to 5 by 1 atrisktickonly outside)) 
			  timelist=(0 to 5 by 1) outsurv=ci95 maxtime=5 timelist=(0 to 5 by 1) reduceout; 
	time survyr*vital(1); 
	strata rgroup1/ test=all;
	label survyr ='Time in years' rgroup1="race"; 
run;

Re: Why was the output different after adding disply options to PROC LIFETEST?

FreelanceReinh — Mon, 08 Nov 2021 09:45:11 GMT

Hi @oddsratio,

I can reproduce the issue using SASHELP sample data (as in https://documentation.sas.com/doc/en/pgmsascdc/9.4_3.3/statug/statug_code_liftex2.htm), but only after modifying the template as described in Customizing the Kaplan-Meier Survival Plot. Specifically, I had to set the VIEWMIN= option to 0.5 in order to get a y-axis similar to that in your plots:

%ProvideSurvivalMacros

%let yOptions = linearopts=(viewmin=0.5 viewmax=1);

%CompileSurvivalTemplates

Did you modify the template in a similar way? Using the default viewmin=0 (or a sufficiently small value >0) should resolve the issue.

Re: Why was the output different after adding disply options to PROC LIFETEST?

oddsratio — Sat, 13 Nov 2021 00:20:50 GMT

Thank you so much for helping me out. You are right! By using the default setting view in=0, the difference was resolved.