Table 5

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 predicted0 (−5.2 to 5.2)312.4 (305.4 to 319.5)
Per added comorbidity5.0 (2.6 to 7.4)5.1 (3.2 to 7.1)
Per added exacerbation of respiratory symptoms6.50 (6.2 to 6.8)0.7 (0.1 to 1.3)
Sex
 MaleRefRef
 Female7.5 (3.0 to 12.0)4.8 (−0.6 to 10.3)
Age, per year0.0 (−0.4 to 0.4)0.1 (−0.4 to 0.6)
Smoking habit
 Current smokerRefRef
 Ex-smoker0.0 (−4.7 to 4.7)1.6 (−4.0 to 7.1)
Education
 UniversityRefRef
 Secondary6.5 (1.3 to 11.7)3.9 (−2.9 to 10.8)
 Primary8.5 (2.4 to 14.6)27.6 (19.9 to 35.4)
Constant−6.5 (−25.4 to 12.4)−7.0 (−31.5 to 17.5)
  • Results from quantile median regression models showing effects of comorbid conditions and exacerbations of respiratory symptoms.

  • 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.