options nodate pageno=1 linesize=80 pagesize=60;

data migraine;
   input Gender $ Treatment $ Improve $ Frequency @@;
   datalines;
female Active  Better 16  female Active  Same 11
female Placebo Better  5  female Placebo Same 20
male   Active  Better 12  male   Active  Same 16
male   Placebo Better  7  male   Placebo Same 19
;

 
 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
                   /dist = poi 
         link= log type1 type3;
run;


 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*treatment
          /dist = poi 
         link= log type1 type3;
run;

 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*improve 
          /dist = poi 
         link= log type1 type3;
run;

 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         treatment*improve
          /dist = poi 
         link= log type1 type3;
run;

 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*treatment gender*improve
          /dist = poi 
         link= log type1 type3;
run;


 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*treatment  treatment*improve
          /dist = poi 
         link= log type1 type3;
run;


 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*improve treatment*improve
          /dist = poi 
         link= log type1 type3;
run;


 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*improve treatment*improve gender*treatment 
          /dist = poi 
         link= log type1 type3;
run;

 proc genmod data=migraine;
 class gender treatment improve;
 model frequency = gender treatment improve 
         gender*improve treatment*improve gender*treatment gender*improve*treatment
          /dist = poi 
         link= log type1 type3;
run;