06-23-2017 11:05 PM
I have two separate clinical trial datasets that have the same variables and sites are numbered consecutively for each clinical trial. I have combined both clinical trials into one dataset using the set statement. I also have a flag for each clinical trial. I have a unique subject id that is unique across both clincial trial datasets. I am clustering patients within sites. The sites ids are the same in many cases across both clinical trials. Is that a problem with proc mixed and using siteid as the clustering variable? Does siteid need to be unique in the combined dataset eventhough the patient id is unique? I have a feeling it is, but wanted to confirm.
I used the following code:
proc mixed data=analysisaim1 covtest method=ML order=data;
model chgql=trial racecat cntrycat totcomorbid suppcare ecogb NumPt trtdur/solution ddfm=kr;
I am using SAS 9.4 TS. Any help you could provide would be greatly appreciated. Thanks.
06-24-2017 06:04 PM
The side IDs should be unique for the nesting you describe. Easy to handle. First, trial should be listed in the class statement (I can't imagine how trial is a continuous variable). then in the random statement, use subject=siteid(trial);
06-24-2017 07:44 PM