Thanks Ballard, Never tried this, I will give this a shot instead of typing it out ... View more

Thank you for pointing this Ballardw, the datasets were identical in variables and variable type so it worked out well ... View more

Thanks for pointing that Statdave. It makes sense to use dist=binomial in proc genmod to model probability. ... View more

Thanks for pointing to the right direction StatDave, I found some useful ways to do DID analysis in that document. looks like the two group assumption has to be there. I across some papers where the researchers split the same group into two.    ... View more

Makes perfect sense, that it is used to compare competing models. I am glad that you mentioned, I kept wondering about the reference for "smaller is better".    I will rerun my analysis and see how it goes ... View more

It worked, thank you for the clarification. ... View more

Awesome, I ran this and got the crude rates that I had calculated using a long convoluted code, being a new SAS user :). This one is so much more efficient.   I am now interested in knowing if my results are significant.  I think we are already discussing this in another post started by me that you have answered, and I will keep an eye on that one.    For those who are following this, here is the link to the other post   https://communities.sas.com/t5/Statistical-Procedures/how-to-compute-Incidence-rate-and-incidence-rate-ratios-with/m-p/619162#M29810 ... View more

oops, new to this community. I just fixed it. ... View more