Differences for Cases and Controls                      1

           Low      Pair     Lwt_d   Smoke_d     Ptd_d      Ht_d      UI_d
      --------------------------------------------------------------------
             1         1       -34         1         1         0         0
             1         2        17         0         0         0         1
             1         3        35         0         0         0         0
             1         4        27         1         1         0         1
             1         5       -12         0         0         0         0