Table 1

Demographics and background characteristics of participants in the study

CharacteristicPatients with COPDGOLD IIGOLD IIIGOLD IVSmoker controlsNon-smoker controls
n1831848750233285228
Age, years63.4 (7.0)63.5 (7.1)63.5 (6.9)62.6 (6.9)55.8 (8.9)54.0 (8.9)
Sex, men/women1207/624517/331515/235175/58165/12089/139
Women, %343931254261
Current smoker, %35373625570
Former smoker, %65636475437
Pack-years48.4 (27.2)48.2 (29.0)48.8 (25.6)48.1 (25.9)31.9 (22.3)0.2 (1.1)
Pre-bronchodilator FEV1, litres1.25 (0.49)1.60 (0.44)1.04 (0.28)0.67 (0.15)3.20 (0.72)3.24 (0.79)
Pre-bronchodilator FEV1, % predicted44.7 (15.0)57.5 (9.6)36.9 (7.0)23.3 (4.0)104.2 (12.0)112.3 (14.0)
Pre-bronchodilator FVC, litres2.81 (0.87)3.14 (0.87)2.66 (0.75)2.13 (0.66)4.23 (0.97)4.12 (0.98)
Pre-bronchodilator FVC, % predicted80.3 (19.8)90.7 (16.5)75.4 (16.9)58.1 (14.0)112.1 (14.2)118.2 (14.6)
FEV1/FVC0.447 (0.113)0.518 (0.92)0.403 (0.91)0.332 (0.76)0.762 (0.61)0.789 (0.51)
ICS use, %7260808510
LABA use, %6859767910
Tiotropium use, %47405156<10
Emphysema
 n1563719652192256192
 %LAA17.5 (12.1)12.2 (9.6)20.2 (11.6)27.9 (12.5)2.5 (3.2)4.2 (4.3)
Radiologist score
 <5%430 (26%)290 (37%)120 (18%)20 (9%)249 (90%)195 (98%)
 5–25%370 (22%)212 (27%)133 (20%)25 (12%)24 (9%)3 (2%)
 25–50%316 (19%)145 (19%)131 (19%)40 (19%)5 (2%)1 (<1%)
 >50%553 (33%)130 (17%)296 (44%)127 (60%)00
  • Data are given as mean (SD) unless otherwise indicated.

  • FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; GOLD, Global initiative for chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; %LAA, per cent low attenuation area; LABA, long-acting β2 agonist.