Table 1

Characteristics of the 109 study patients with COPD measured at recruitment and of the 32 who recorded FEV1

MedianInterquartile rangeMedianInterquartile range
FEV1=forced expiratory volume in 1 second; FVC=forced vital capacity; PEF=peak expiratory flow; Pao2; Paco2=arterial oxygen and carbon dioxide tensions.
Age (years)68.162.5–73.866.860.7–73.7
FEV1 (l)1.000.74––1.48
FEV1 (% predicted)38.227.0––50.2
FEV1 (% reversibility)5.20–12.86.90–14.1
FVC (l)2.511.86–2.942.602.00–2.90
FEV1/FVC (%)42.333.1–53.345.132.3–53.5
PEF (l/min)200150–264245180–300
Pao2 (kPa)9.008.27–9.519.058.31–9.92
Paco2 (kPa)5.775.40–6.365.855.49–6.46
Smoking (years)4030–504030–46
% of 109% of 32
Sex (male)74.390.6
Chronic dyspnoea45.050.0
Chronic wheeze33.037.5
Chronic cough49.543.8
Chronic sputum production56.043.8
Smoking at recruitment30.831.2
Taking inhaled steroids91.787.5