Hi Haikuo, I know this is avery old post but I was wondering for your code, you counted the same comb more than once in different ways such as abc, abcd, would it be possible to count the combination only once. So if ptid used abcd together, can you adjust the code to list this as only abcd? also could the frequency be adjusted to reflect that the patient had only 1 combination of these med?  ... View more

Oops..you're right Vince, I forgot to change the variable name!:smileyblush: Thanks a lot for your help! ... View more

Another possibility is PROC FMM if you are running SAS/STAT12.1.  This proc enables you to specify a mixing probability function (say a binomial) and a model distribution (say the gamma), at least as I read the documentation, especially Example 37.1.  I have to provide the caveat that I have not yet run any real data through PROC FMM, so I will be curious to find out if you are able to use the procedure. Steve Denham ... View more

Will do so, Steve. Thank you so much for your help! Pooja ... View more