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. 2019 May 28;29:22. doi: 10.1038/s41533-019-0135-9

Table 1.

Characteristics of the study subjects categorized by spirometry-confirmed COPD in the development cohort

All Total subjects COPD patients divided by GOLD stage
COPD Non-COPD P a GOLD I GOLD II GOLD III–IV P b
Numbers 301 147 154 40 82 25
Age, years 70.7 ± 13.2 75.2 ± 11.3 66.5 ± 13.5 <0.001 77.9 ± 9.9c 75.0 ± 11.2c 72.3 ± 10.8 <0.001
Gender, male (%) 287 (95) 139 (95) 148 (96) 0.524c 39 (98) 77 (94) 23 (92) 0.652c
Current smoker (%) 128 (43) 56 (38) 72 (47) 0.129c 14 (35) 30 (37) 12 (48) 0.315c
Smoking pack-years 45.4 ± 25.0 50.6 ± 26.0 40.3 ± 20.1 <0.001 52.3 ± 29.9d 49.5 ± 25.9d 51.7 ± 19.8 0.004
Peak flow meter
Best PEFR (L/min) 383 ± 148 290 ± 120 472 ± 113 <0.001 403 ± 101d 270 ± 85d,e 174 ± 96d,e,f <0.001
PEFR, % pred. 79 ± 28 63 ± 25 95 ± 20 <0.001 89 ± 19 57 ± 18d,e 38 ± 16d,e,f <0.001
AT score
Total 8.1 ± 6.9 10.2 ±8.0 6.1 ± 4.9 <0.001 5.7 ± 4.1 11.4 ± 8.4d,e 13.2 ± 8.6d,e <0.001
Cough 1.8 ± 1.4 2.0 ± 1.4 1.6 ± 1.3 0.011 1.7 ± 1.2 2.2 ± 1.6d 1.9 ± 1.3 0.018
Phlegm 1.8 ± 1.4 2.0 ± 1.5 1.5 ± 1.3 0.001 1.6 ± 1.2 2.1 ± 1.5d 2.4 ± 1.6d 0.001
Chest tightness 1.0 ± 1.3 1.2 ± 1.5 0.8 ± 1.0 0.002 0.7 ± 1.1 1.4 ± 1.6d,e 1.4 ± 1.6 <0.001
Breathlessness 1.1 ± 1.5 1.6 ± 1.7 0.7 ± 1.0 <0.001 0.3 ± 0.6 1.9 ± 1.8d,e 2.4 ± 1.6d,e <0.001
Activity limitation 0.6 ± 1.2 0.9 ± 1.5 0.3 ± 0.9 <0.001 0.3 ± 0.9 0.9 ± 1.6d 1.5 ± 1.6d,e <0.001
Confidence 0.3 ± 1.0 0.5 ± 1.2 0.6 ± 1.1 <0.001 0.1 ± 0.2 0.6 ± 1.4d,e 1.0 ± 1.5d,e <0.001
Sleep 0.7 ± 1.2 0.8 ± 1.3 0.6 ± 1.1 0.114 0.4 ± 0.8 1.0 ± 1.4e 1.1 ± 1.2 0.009
Energy 0.9 ± 1.2 1.2 ± 1.4 0.6 ± 1.0 <0.001 0.6 ± 1.0 1.4 ± 1.5d,e 1.4 ± 1.3d,e <0.001
Spirometry, pre-BD
FEV1 (L) 1.96 ± 0.75 1.47 ± 0.53 2.44 ± 0.62 <0.001 1.93 ± 0.50d 1.43 ± 0.39d,e 0.87 ± 0.20d,e,f <0.001
FEV1, % pred. 81 ± 24 66 ± 20 96 ± 16 <0.001 90 ± 12d 62 ± 9d,e 39 ± 9d,e,f <0.001
FVC (L) 2.83 ± 0.80 2.52 ± 0.77 3.12 ± 0.72 <0.001 2.99 ± 0.74 2.47 ± 0.68d,e 1.95 ± 0.66d,e,f <0.001
FVC, % pred. 84 ± 17 79 ± 19 89 ± 14 <0.001 95 ± 14 76 ± 15d,e 62 ± 17d,e,f <0.001
FEV1/FVC (%) 68 ± 14 58 ± 12 78 ± 7 <0.001 65 ± 7d 58 ± 11d,e 47 ± 14d,e,f <0.001
Spirometry, post-BD
FEV1 (L) 2.05 ± 0.75 1.56 ± 0.55 2.52 ± 0.61 <0.001 2.05 ± 0.52d 1.50 ± 0.38d,e 0.94 ± 0.22d,e,f <0.001
FEV1, % pred. 85 ± 23 70 ± 20 99 ± 16 <0.001 96 ± 12 66 ± 8d,e 42 ± 8d,e,f <0.001
FVC (L) 3.02 ± 0.93 2.82 ± 1.07 3.20 ± 0.72 <0.001 3.22 ± 0.73 2.68 ± 0.68d,e 2.21 ± 0.66d,e,f <0.001
FVC, % pred. 89 ± 17 86 ± 19 92 ± 15 0.003 103 ± 14d 83 ± 16d,f 70 ± 17d,e,f <0.001
FEV1/FVC (%) 68 ± 15 56 ± 12 79 ± 6 <0.001 63 ± 5d 56 ± 11d,e 44 ± 14d,e,f <0.001

Data are presented as means ± standard deviation

% pred. percent predicted value, BD bronchodilation, CAT COPD assessment test, COPD chronic obstructive pulmonary disease, FEV1 forced expiratory volume in the first second, FVC forced expiratory capacity, PEFR peak expiratory flow rate

aIndependent t-test, COPD vs. non-COPD

bOne-way ANOVA test, compare 4 groups: non-COPD, GOLD I, GOLD II, and GOLD III-IV

cChi-square test

dPost-hoc Bonferroni test, P < 0.05, vs. non-COPD

ePost-hoc Bonferroni test, P < 0.05, vs. GOLD I

fPost-hoc Bonferroni test, P < 0.05, vs. GOLD II