options nodate pagesize=54 linesize=80; /* Read in the input file */ data ex0503; * infile '../../../data/biostat/ex0503.dat'; infile 'C:\biostat\data\ex0503.dat'; input drgcls cancer cancer_r; run; proc sort; by cancer_r descending drgcls; /* Obtain crosstabs and relative risk based on drgcls and reversed cancer (SAS default is to model the probability in the "lowest" category) */ /* Must do these 2-at-a-time, SAS won't compute relative risks for tables not 2x2 */ /* Data sorted by descending drgcls so level 1 will be baseline group (denominator) */ proc freq order=data; where drgcls ne 3; table drgcls*cancer_r / relrisk; run; proc freq order=data; where drgcls ne 2; table drgcls*cancer_r / relrisk; run; quit;