/******************************************************************************
 * Programme : Prévalence réelle vs artificielle : L'astuce SAS pour des prédictions enfin fiables
 * Reference : EXEMPL10AD
 * Source    : https://www.wearecas.eu/en/sampleCode/EXEMPL10AD
 ******************************************************************************/

/* --- BLOC 1 --- */
title 'Example 5. Stratified Sampling';

data Screen;
   do Disease='Present','Absent';
      do Test=1,0;
         input Count @@;
         output;
      end;
   end;
   datalines;
950  50
 10 990
;

/* --- BLOC 2 --- */
proc logistic data=Screen;
   freq Count;
   model Disease(event='Present')=Test
         / pevent=.5 .01 ctable pprob=.5;
run;