Table 1

Clinical characteristics of patients

CharacteristicsLaval (n=403)UBC (n=270)Groningen (n=175)
Age (years)63.4±9.863.9±10.059.7±10.0
Male/female (n)224/179144/12683/92
Body mass index (kg/m2)26.6±5.225.7±5.424.6±4.1
FEV1% predicted82.2±17.683.6±22.372.4±24.9
FEV1/FVC0.68±0.100.69±0.130.64±0.16
COPD (%)209 (51.9)114 (42.2)112 (64.0)
 Stage 1: mild80 (38.2)43 (37.7)16 (14.3)
 Stage 2: moderate117 (56.0)60 (52.6)30 (26.8)
 Stage 3: severe11 (5.3)2 (1.8)11 (9.8)
 Stage 4: very severe1 (0.5)9 (7.9)44 (39.3)
 Missing data0011 (9.8)
Non-COPD (%)194 (48.1)156 (57.8)63 (36.0)
Smoking (%)
 Smoker89 (22.1)91 (33.7)12 (6.9)
 Ex-smoker281 (69.7)150 (55.6)117 (66.9)
 Non-smoker33 (8.2)16 (5.9)43 (24.6)
 Missing data013 (4.8)3 (1.7)
Pack years (years)48.6±27.446.0±28.632.1±18.1
  • Continuous variables are presented as means±SDs.

  • UBC, University of British Columbia.