Table 3

Poisson regression analysis of mortality (rate ratio) from asthma, chronic bronchitis, and emphysema combined by smoking habit and cumulative exposure to total dust (mg/m3.y), controlled for age (<65, 65–69, 70–74, 75–79, ≥80) and calendar period (1962–79,1980–96) (restricted to workers employed for >3 y)

Smoking includedSmoking not included
Deaths (n)Rate ratio95% CIRate ratio95% CI
*Mean dose; arithmetic mean cumulative exposure of total dust.
Smoking status:
    Former22.00.3 to 12.1
    Smoker223.41.0 to 11.5
    Unknown21.60.3 to 9.8
Exposure to total dust (mg/m3.y):
    0.1–14.923.00.3 to to 40.9
    15–69.9124.50.6 to to 35.0
    ≥70145.10.7 to to 42.1
Evaluation of linear trend:p Valuep Value
    Scores 1,2,3,40.070.08
    Mean dose*0.100.16