Table 1

Characteristics of the 132 chronic obstructive pulmonary disease patients in the study, and the 35 who recorded forced expiratory volume in one second (FEV1), measured at recruitment

Patients n13235
Age yrs68.4 (62.5–73.7)65.1 (60.7–73.6)
FEV1 L0.99 (0.74–1.3)1.08 (0.77–1.4)
FEV1 % predicted38.4 (27.0–49.9)36.0 (25.4–50.0)
FEV1 % reversibility5.4 (0–12.6)6.1 (0–12.8)
FVC L2.45 (1.82–2.93)2.6 (1.99–2.90)
FEV1/FVC %42.3 (33.2–53.1)45.3 (33.1–53.7)
PEF L·min−1181 (139–250)240 (162–300)
Pa,O2 mmHg68.4 (62–73)68.4 (62–75)
Pa,CO2 mmHg44.2 (41–48)44.7 (42–50)
Smoking yrs42 (31–50)40 (27–46)
Sex males68.988.6
Chronic dyspnoea48.554.3
Chronic wheeze32.634.3
Chronic cough47.042.9
Chronic sputum production53.845.7
History of smoking95.494.3
Smoking at recruitment31.134.2
Inhaled steroids90.285.7
Oral steroids9.014.2
  • Data are presented as median (interquartile range) or % of patients

  • FVC: forced vital capacity

  • PEF: peak expiratory flow

  • Pa,O2: arterial oxygen tension

  • Pa,CO2: arterial carbon dioxide tension