Haiyi - If you load your medication and severity information into arrays, all you need to do is loop though the medication array looking for "1". If you find one, increment a counter (for the number of times medication was taken) and write out the severity value for that same array index.

For example, try the following code:

data meds(keep=id taken sev); infile cards missover;

input id tmed1-tmed6 tsev1-tsev6;

array tmed(6); array tsev(6);

taken = 0; do i = 1 to 6; if tmed(i) then do; taken + 1; sev = tsev(i); output; end; end;

cards;

01 0 0 0 1 1 1 3 4 5 7 6 5 02 0 1 1 1 1 1 9 8 4 5 3 4 03 0 0 1 1 1 1 6 5 3 4 2 3 04 0 0 0 0 1 1 9 3 4 6 7 5 ; run;

The results are:

16:30 Tuesday, April 15, 1997 2

OBS ID TAKEN SEV

1 1 1 7 2 1 2 6 3 1 3 5 4 2 1 8 5 2 2 4 6 2 3 5 7 2 4 3 8 2 5 4 9 3 1 3 10 3 2 4 11 3 3 2 12 3 4 3 13 4 1 7 14 4 2 5

Now, you could do your analysis on the variables TAKEN and SEVERITY.

Hope this helps-

Pete Lund WA State Office of Financial Management peter.lund@ofm.wa.gov

---------- From: Haiyi Xie[SMTP:Haiyi.Xie@DARTMOUTH.EDU] Sent: Wednesday, April 16, 1997 7:37 AM To: Multiple recipients of list SAS-L Subject: simple data step quesition

Suppose I have 4 subjects (each subject was measured weekly for 6 times), and two variables. The first variable is "taking medicine or not" (1 = take medicine, 0 = not yet take medicine). The second variable is "severity of mental health symptom" (1 = not severe at all, 10 = very severe).

01 0 0 0 1 1 1 3 4 5 7 6 5 02 0 1 1 1 1 1 9 8 4 5 3 4 03 0 0 1 1 1 1 6 5 3 4 2 3 04 0 0 0 0 1 1 9 3 4 6 7 5

I wanted to compute means and standard deviations of "severity" score when people took medicine at the first time, the second time and so forth. I other words, I need to line up subjects in terms of the first time they took medicine, then compute some descriptive statistics for variable "severity".

Can somebody point me out how to do it in SAS data step? Thank you very much.

Haiyi