Table 4

Annual days of lost productivity in a general population and in a hospital population

CovariatePopulation-recruited COPD cases and controls (N=160); (95% CI)Hospital recruited COPD cases and population-recruited controls (N=209); (95% CI)
COPD status
 No COPDRefRef
 COPD, FEV1 <80% of predicted5.8 (1.4 to 10.1)330.6 (327.8 to 333.3)
Sex
 MaleRefRef
 Female9.5 (5.7 to 13.3)8.3 (5.9 to 10.6)
Age, per year0.06 (−0.24 to 0.37)0.17 (−0.03 to 0.37)
Smoking habit
 Current smokerRefRef
 Ex-smoker0.8 (−3.3 to 5.0)1.0 (−1.5 to 3.4)
Education
 UniversityRefRef
 Secondary4.23 (−0.3 to 8.8)5.0 (2.0 to 8.0)
 Primary6.2 (1.0 to 11.5)25.5 (22.1 to 28.9)
Constant−4.22 (−20.7 to 12.2)−10.0 (−20.7 to 0.6)
  • Results from quantile median regression models.

  • COPD, here defined by FEV1/FVC<0.7 postbronchodilation and FEV1 <80% of predicted values.

  • COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.