Data d1;
   Set COVD.DADEDview;
   Array dx{25} HLTH_DX_CODE_1-HLTH_DX_CODE_25;
   symp = 0;
   do i = 1 to 25 while(not missing(dx{i}));
      if dx{i}=:"R13" then symp = 1;
   end;
   drop i;
   if symp;
run;