Table 1

 Baseline characteristics of 386 subjects with COPD by follow up status

Characteristic at baselineAll (n = 386)Re-interviewed (n = 267)Not interviewed (n = 119)p value
VGDF, vapours, gas, dusts, or fume reported at baseline on longest held employment.
*Includes subjects with a history of labour force participation and values for all key study variables (n = 234 for re-interviewed cohort; n = 108 of those not re-interviewed).
Total for income (n = 331) and education (n = 383) reflects missing responses to these items.
Age range (years)0.59
White, non-Hispanic3328623086102860.91
Highest educational level0.92
    High school or less20453142536253
    Some college1052774283127
    College graduate or above741950192421
Annual household income0.49
    <$20 00014444107443742
    $20 000–40 0001083380332831
Chronic bronchitis alone194501324962520.63
Cigarette smoking status0.39
Ever employed3529124291110920.56
Exposure to VGDF*185541285557530.75
Exposure by job matrix*0.94
    Intermediate exposure942764273028
    High exposure risk361125111110
Left work due to lung disease*7923582521190.28