How do I add statistics to my SurvivalPlot? Eg: median survival time, Logrank's P-value, HR from Cox

[morenayan]

proc lifetest data=sascomp.adqs method=PL plots=(survival(atrisk cl) logsurv) alpha=0.05;
   time RETIME*STATUS(0);  
   strata Group;          
run;

This is my PROC LIFETEST program, which can output a survival plot for me.

I've already know if I add survival(test), then I can add log rank's P-value on my plot, which is:

proc lifetest data=sascomp.adqs method=PL plots=(survival(test atrisk cl) logsurv) alpha=0.05;
   time RETIME*STATUS(0);  
   strata Group;          
run;

But I don't know how to add median survival time and HR from Cox. Please help me, many thanks!

[FreelanceReinh · Accepted solution]

Hello @morenayan,

I see two possible approaches: One was suggested in the 2023 post Re: Kaplan Meier using proc lifetest and involves reproducing the Kaplan-Meier plot with PROC SGPLOT and using TEXT statements. The second approach might be simpler because it just modifies the existing Kaplan-Meier plot (template), which is relatively easy thanks to the comprehensive macros that SAS has provided for this purpose (see Controlling the Survival Plot by Modifying Graph Templates). Below I provide an example using the SAS-supplied dataset SASHELP.BMT, based on the example Adding a Small Inset Table with Event Information from the documentation.

/* Create sample data for demonstration */

data have;
set sashelp.bmt(where=(group ne 'ALL'));
run;

/* Compute statistics */

ods select none;

ods output homtests=ht quartiles=qt;
proc lifetest data=have;
time t*status(0);
strata group;
run;

ods output parameterestimates=est;
proc phreg data=have;
class group;
model t*status(0)=group / rl;
run;

ods select all;

/* Combine and format statistics */

data stats;
merge qt(where=(percent=50) drop=t:)
      est(keep=ClassVal0 h: rename=(ClassVal0=Group));
by group;
length hr $20;
if hazardratio=. then hr='Ref';
else hr=put(HazardRatio,best4.)||' ('||put(HRLowerCL,best4.)||'-'||put(HRUpperCL,best4.)||')';
run;

proc format;
value med
.='NE'
other=[4.];
run;

/* Write statistics to macro variables */

proc sql noprint;
select probchisq into :pval from ht where test like 'L%';
select group, estimate format=med., lowerlimit format=med., upperlimit format=med., hr
  into :grp1-, :med1-, :lcl1-, :ucl1-, :hr1- from stats;
quit;

/* Modify inset of Kaplan-Meier plot to contain statistics */

%ProvideSurvivalMacros /* from https://support.sas.com/documentation/onlinedoc/stat/ex_code/151/templft.html */

%let InsetOpts  = ;
%let LegendOpts = title="+ Censored" location=inside autoalign=(Bottom);

%macro StmtsBottom;
%let t = / textattrs=(weight=bold);
layout gridded / columns=3 border=TRUE autoalign=(TopRight);
  entry halign=left "Logrank  p=&pval"; entry " "; entry " ";
  entry " "; entry " "; entry " ";
  entry halign=left "Group" &t; entry "Median (95% CI)" &t; entry "HR (95% CI)" &t;
  entry halign=left "&grp1"; entry "&med1 (&lcl1-&ucl1)"; entry "&hr1";
  entry halign=left "&grp2"; entry "&med2 (&lcl2-&ucl2)"; entry "&hr2";
endlayout;
%mend;

%CompileSurvivalTemplates

/* Create the modified Kaplan-Meier plot */

ods graphics on;
proc lifetest data=have plots=(survival(test atrisk cl) logsurv);
time t*status(0);
strata group;
run;

Result:

[morenayan]

HI, thanks!!!

i've already solved my problem perfectly by using the second solutions you've provived.