Table 3

Combined risk estimates from studies on bladder cancer and consumption of chlorinated drinking water by sex and exposure category

Exposure categoryMeta-OR (95% CI)Number of studiesTest for heterogeneity p valueSelected method
*Includes the cohort studies that do not provide risk estimates by duration of consumption.
Both sexes
    Mid-term1.1 (1.0 to 1.2)50.84Fixed effects
    Long term1.4 (1.2 to 1.7)50.55Fixed effects
    Ever exposed1.2 (1.1 to 1.4)6*0.61Fixed effects
    Mid-term1.3 (1.0 to 1.7)40.08Random effects
    Long term1.6 (1.2 to 2.2)40.11Random effects
    Ever exposed1.4 (1.1 to 1.9)5*0.01Random effects
    Mid-term1.0 (0.7 to 1.6)30.09Random effects
    Long term1.4 (0.6 to 3.6)30.01Random effects
    Ever exposed1.2 (0.7 to 1.8)5*0.01Random effects