firstly i think you want old1 on id-pc level, not id level ie pc as rows, not as cols, then you want to merge region from old2 onto old1, by pc (first sort old1 by pc). Then you have id and region on the same dataset, and you could use eg a simple proc freq or proc sort with nodupkey and dupout=...., to see how many ids have multiple regions ... View more

very difficult to understand what you're saying, but you might want proc transpose ... View more

but you don't have therapy in your model. Isn't that the most important thing? You seem to be interested in gender, but surely therapy is more likely to influence patient outcomes? It depends on why the study was designed, the objective and hypotheses etc. Personally, I'm not too familiar with glimmix, i used it many years ago when it was just a macro sas hadn't fully released. I would tend to use nlmixed. Glimmix v nlmixed is an interesting discussion tho : http://www2.sas.com/proceedings/forum2007/179-2007.pdf ... View more

to answer your first question, it would be wasteful to discard data but if there's some reason for using the first obs for each patient you can reduce the data set using "proc sort data=data nodupkey; by patient; run;"   you're right, however, with your second post, ie you likely want to use the repeated values for each patient. We would need to know more about the design of the study, eg the order the treatments were received, what exactly the outcome is etc. A cross over design is not uncommon and is maybe analogous. You can likely find SAS code examples online for a binary outcome. Note that you would not use proc logistic, in that case. Maybe you use proc nlmixed or genmod: https://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_intromix_a0000000216.htm ... View more

can you not generate eg 1000 random samples and then use a by statement (by samp) in the proc freq? ... View more