Date:         Wed, 5 Nov 2003 11:54:57 -0500
Reply-To:     Peter Crawford <Peter@CRAWFORDSOFTWARE.DEMON.CO.UK>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Peter Crawford <Peter@CRAWFORDSOFTWARE.DEMON.CO.UK>
Subject:      Re: Retain statment
Comments: To: jannickei@HOTMAIL.COM

Hi
here is an example using retain.
To watch the movement of the diab_found status,
comment the drop statement.

data resolved;
  set <your sas data set>;
   by patient ;  /* declared: sorted by patient and date*/
  if first.patient then
     do;
        diab_found  =0 ;
        inf_diab    =0 ;
     end;
  retain diab_found inf_diab ;
  drop   diab_found ;
  if not inf_diab then
  do;
     if diagnose = 410 then
     do;
       if   diab_found >0 then inf_diab = 1;
       else diab_found= -1; /* too late*/
     end;
     else if diagnose = 250 and not diab_found
             then diab_found = 1;
  end;
run;