Is the order of treatments fixed? For instance, if a patient starts on A and is negative, is the next treatment always B?  Does the same apply if B is negative, would the next treatment be C?  If this is the case, you have a repeated measures design where you likely have structural zeroes (for instance, patient 4, which started with B, so that there is structural zero for that patient for treatment A).  If this all describes what you have, look at the first few examples in the PROC GEE documentation, and see whether the alternating logistic regression method might work for you.   SteveDenham ... View more

data have; input Id reg; datalines; 1 1 1 1 1 3 1 3 1 3 1 4 2 2 2 2 2 2 2 3 ; data want; set have; by Id reg notsorted; if first.Id then reg_seq=1; else if first.reg the reg_seq+1; run; ... View more

Group by ID, Date No AND @heretolearn wrote: Hello!   I am trying to figure out how to calculate the sum by two variables using proc sql.   This is what I have: id      date              change 1       1/3/15           1 1       1/3/15           0 1       1/3/15           1 1       2/1/15           -1 2       4/1/10           1 2       4/1/10           -1 2       7/10/10         0   This is what I need: id      date              all_change    min_change   max_change 1       1/3/15           2                   0                    1   1       2/1/15           -1                 -1                   -1 2       4/1/10           0                  -1                    1 2       7/10/10         0                   0                    0   I tried using this: Proc sql; Create table change as Select id ,date ,sum(change) AS all_change ,min(change) AS min_change ,max(change) AS max_change From dataset group by id and date; Quit;   Instead of giving me the sum, min, and max by each id's set of dates, it takes the values for all ids. So I get the same sum of all the change rows in the full dataset for all the ids.   Can anyone let me know what I am doing wrong?   ... View more