I am trying to predict the impact of readmission events (continuous) and type of readmission (medical, surgical, other) on total hospital costs. Because costs are skewed by nature, I am applying gamma distribution with log link function. Below is the model
PROC GENMOD data = abc;
class type (ref='medical') gender (ref='F')/param=ref;
model cost = event type age gender /dist=gamma link=log type3;
run;
1) Is the model correct?
2) How can I get marginal effects from the coefficients for different variables. i.e. is there a SAS option that will give me hospital cost within each level of type of readmission and for male and female?
3) I know modified park test will help us determine whether to use gamma distribution or not, but I can't seem to find that option in SAS.
