Table 4

Multivariable conditional logistic regression models of cryptosporidiosis among patients with AIDS according to pattern of tap water consumption and adjusted for potential confounders

Cases (n = 49)
 Controls (n = 99)

Models and variables
 N
 (%)
 N
 (%)
 Odds Ratio
 95% CI
Model 1





     Tap water at home





          Never
 2
 (4)
 31
 (31)
 1.00
 Reference
          Sometimes
 20
 (41)
 30
 (30)
 7.70
 1.63, 36.3
          Always
 27
 (55)
 38
 (38)
 6.76
 1.37, 33.5
     Tap water outside home





          Never
 29
 (59)
 81
 (82)
 1.00
 Reference
          Sometimes
 4
 (8)
 8
 (8)
 1.59
 0.38, 6.73
          Always
 16
 (33)
 10
 (10)
 3.16
 1.23, 8.13
     Exposure to fecal materiala





          No
 42
 (86)
 87
 (88)
 1.00
 Reference
          Yes
 7
 (14)
 12
 (12)
 1.03
 0.32, 3.36
     Filtered municipal water





          Filtered
 27
 (55)
 51
 (52)
 1.00
 Reference
          Mixed
 14
 (29)
 37
 (37)
 0.77
 0.35, 1.74
          Unfiltered
 11
 (16)
 8
 (11)
 1.19
 0.34, 4.20
Model 2: Composite water variable





     Tap water exposureb





          Lowest exposure
 2
 (4)
 29
 (29)
 1.00
 Reference
          Intermediate exposure
 35
 (71)
 64
 (65)
 6.92
 1.55, 30.9
          Highest exposure
 12
 (24)
 6
 (6)
 23.6
 4.08, 137
     Exposure to fecal materiala





          No
 42
 (86)
 87
 (88)
 1.00
 Reference
          Yes
 7
 (14)
 12
 (12)
 0.96
 0.30, 3.06
     Filtered municipal water





          Filtered
 27
 (55)
 51
 (52)
 1.00
 Reference
          Mixed
 14
 (29)
 37
 (37)
 0.81
 0.37, 1.77
          Unfiltered
 11
 (16)
 8
 (11)
 1.23
 0.38, 4.02

aHad sex with partner who had diarrhea, cared for person with diarrhea, or touched something soiled with feces from person with diarrhea bModel 2 tap water composite exposure variable (Lowest = never consumed tap water both inside and outside the home; Highest = always consumed tap water both inside and outside the home)

Aragón et al. BMC Public Health 2003 3:2   doi:10.1186/1471-2458-3-2