Table 2

Summary of results

Smoking statusNo of studiesOR (95% CI)
A. Men
    Ever smoker
        Total71.89 (1.56 to 2.28)
        Case–control studies61.87 (1.53 to 2.29)
        Cohort studies12.04 (1.10 to 3.79)
    Current smoker
        Total71.87 (1.49 to 2.34)
        Case–control studies61.89 (1.49 to 2.40)
        Cohort studies11.60 (0.70 to 3.80)
    Past smoker
        Total51.76 (1.33 to 2.31)
        Case–control studies41.79 (1.34 to 2.38)
        Cohort studies11.40 (0.50 to 3.80)
B. Women
    Ever smoker
        Total121.27 (1.12 to 1.44)
        Case–control studies71.27 (1.05 to 1.54)
        Cohort studies51.27 (1.07 to 1.50)
    Current smoker
        Total121.31 (1.12 to 1.54)
        Case–control studies61.19 (0.88 to 1.61)
        Cohort studies51.37 (1.13 to 1.65)
    Past smoker
        Total101.22 (1.06 to 1.40)
        Case–control studies51.24 (1.04 to 1.48)
        Cohort studies51.20 (0.96 to 1.49)
  • OR, odds ratio.