Date:         Fri, 27 Dec 1996 16:08:27 EST
Reply-To:     Haiyi Xie <Haiyi.Xie@DARTMOUTH.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Haiyi Xie <Haiyi.Xie@DARTMOUTH.EDU>
Subject:      data step question

        I have a "Smoking status" variable like the following for 7-time
periods (0->6), "1" means smoking, "0" means not-smoking in each time period.
 
 
          OBS  SMKG0  SMKG1 SMKG2  SMKG3  SMKG4  SMKG5  SMKG6
 
        1        0        0        0        0        0        0        1
        2        0        0        0        0        0        0        1
        3        0        0        0        0        0        1        1
        4        0        0        1        1        1        1        1
        5        0        0        0        0        0        1        1
        6        1        1        1        1        1        1        0
        7        0        .         1        1        1        1        1
        8        0        0        1        1        0        0        1
        9        0        0        0        0        1        1        1
       10       0        0        0        1        1        1        1
 
I want to compare persons' "MEAN health status" (HS) between "smoking period"
and "non-smoking period" (something like paird t-test).  But I don't know how
to compute "Mean HS in smoking periods" and "Mean HS in non-smoking periods"
for each person.  It seems very simple thing, but I am stuck at this end of the
day.
        Thanks in advance for any help,
 
Haiyi