Table 1.

Characteristics of selected demographic and exposure variables in CBP cases and controls

CBP cases
Healthy controls
P*
No. (%)No. (%)
Total307 (100.0)299 (100.0)
Age (y)0.500
    ≤2585 (27.7)86 (28.8)
    26-35117 (38.1)97 (32.4)
    36-4581 (26.4)88 (29.4)
    >4524 (7.8)28 (9.4)
Gender0.870
    Male195 (63.5)188 (62.9)
    Female112 (36.5)111 (37.1)
Exposure duration (y)0.252
    ≤5150 (48.9)160 (53.5)
    6-1062 (20.2)66 (22.1)
    11-1537 (12.1)35 (11.7)
    16-2025 (8.1)20 (6.7)
    >2033 (10.7)18 (6.0)
Intensity of exposure (mg/m3)0.687
    ≤40187 (60.9)190 (63.5)
    40-10091 (29.6)86 (28.8)
    >10029 (9.5)23 (7.7)
Smoking0.046
    Yes154 (50.2)137 (45.8)
    No30 (9.8)45 (15.1)
    No data123 (40.0)117 (39.1)
Alcohol consumption0.404
    Yes148 (48.2)151 (50.5)
    No38 (12.4)31 (10.4)
    No data121 (39.4)117 (39.1)
  • * χ2 test for difference in the distributions between the two groups.