Table 2 Multiple logistic regression model for chronic bronchitis (n = 4425)
Crude odds ratio (95% CI)Fully adjusted* odds ratio (95% CI)
Snuff use:
    Never/none-current11
    1–8 times/day1.56 (0.96 to 2.55)1.18 (0.69 to 2.03)
    >8 times/day4.63 (2.09 to 10.22)2.86 (1.17 to 7.02)
Smoking status:
    Never smoked11
    Ex-smoker0.48 (0.12 to 1.99)0.35 (0.09 to 1.46)
    1–4 CPD2.96 (1.43 to 6.11)3.15 (1.44 to 6.89)
    >4 CPD2.31 (1.16 to 4.59)2.54 (1.26 to 5.14)
Asset (tertile) index:
    Lowest rank (poorest)11
    Middle0.44 (0.30 to 0.66)0.69 (0.45 to 1.04)
    Highest rank0.24 (0.10 to 0.63)0.45 (0.17 to 1.15)
Tuberculosis:
    Never11
    Ever9.41 (5.41 to 16.38)7.23 (4.02 to 13.03)
Cooking fuel:
    Gas/Electricity/Paraffin11
    Smoky fuels2.82 (1.92 to 4.14)1.98 (1.32 to 2.96)
Occupational exposure to irritants:
    Never11
    Ever2.12 (1.31 to 3.43)1.95 (1.20 to 3.17)
  • *In addition to these covariates, the model also controlled for age.

  • CPD, cigarettes per day