options nodate pagesize=54 linesize=80;

/* Read in the input file   */

data ex0501;
* infile '../../../data/biostat/ex0501.dat';
infile 'C:\biostat\data\ex0501.dat';
input pamid skev pamid_r skev_r;
run;

/* Obtain crosstabs and relative risk based on reversed pamid and skev (SAS default is to model
the probability in the "lowest" category) */

proc freq;
table pamid_r*skev_r / relrisk;
run;

quit;