Date:         Tue, 3 May 2005 15:44:45 -0700
Reply-To:     neilanessa@MSN.COM
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         neilanessa@MSN.COM
Organization: http://groups.google.com
Subject:      Re: Drug Combo Seq. Number
Comments: To: sas-l@uga.edu
In-Reply-To:  <1115136005.437204.244130@z14g2000cwz.googlegroups.com>
Content-Type: text/plain; charset="iso-8859-1"

Or could be as simple as:
DO IF $CASENUM=1.
+  COMPUTE combo=0.
ELSE.
+  DO IF drug1 <> lag(drug1) OR drug2 <> lag(drug2) OR drug3 <>
lag(drug3) OR drug4 <> lag(drug4)  .
+    COMPUTE combo=LAG(combo)+1.
+  ELSE .
+    COMPUTE combo=LAG(COMBO).
+  END IF.
END IF.
Neila