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. 2018 Jan 14;8(1):e018404. doi: 10.1136/bmjopen-2017-018404

Table 1.

Baseline variables

Characteristic No COPD, n=494 323 COPD (self-report), n=8317 GOLD COPD, n=2620
Count % Count % P value Count % P value
Sex <0.001 <0.001
 Male 224 906 45.5 4268 51.3 1426 54.4
 Female 269 417 54.5 4049 48.7 1194 45.6
Age <0.001 <0.001
Median: 58 Median: 62 Median: 63
IQR: 50–63 IQR: 57–66 IQR: 59–66
Ethnicity <0.001 <0.001
 White 464 770 94.5 8052 97.3 2620 100
 Other 26 821 5.4 219 2.6 0 0
 Missing 2732 46 0 0
Socioeconomic deprivation quintile <0.001 <0.001
 1 (least deprived) 99 672 20.2 1015 12.2 309 11.8
 2 98 977 20.0 1142 13.7 362 13.8
 3 99 013 20.1 1399 16.8 440 16.8
 4 98 660 20.0 1735 20.9 580 22.2
 5 (most deprived) 98 385 19.7 3015 36.3 926 35.4
 Missing 616 11 3
Smoking status <0.001 <0.001
 Current 50 817 10.3 2172 26.3 833 32.2
 Previous 169 015 34.4 4083 49.5 1398 54.0
 Never 271 602 55.3 1999 24.2 360 13.9
 Missing 2889 63 29
Alcohol frequency <0.001 <0.001
 Daily 100 070 20.3 1720 20.7 618 23.6
 3–4 times/week 114 058 23.1 1404 16.9 475 18.2
 1–2 times/week 127 459 25.9 1863 22.5 561 21.5
 1–3 times/month 54 979 11.2 894 10.8 289 11.1
 Occasional 56 707 11.5 1322 15.9 387 14.8
 Never 39 569 8.0 1092 13.2 284
 Missing 1481 22 6 10.9
BMI <0.001 <0.001
 <18.5 2478 0.5 148 1.8 56 2.2
 18.5–24.9 155 282 31.8 2185 26.8 829 31.9
 25.0–29.9 211 102 43.2 3165 38.9 1049 40.4
 >30 119 813 24.5 2647 32.5 665 25.6
 Missing 5648 172 21
Physical activity <0.001 <0.001
 High 49 827 10.6 250 3.1 70 2.7
 Medium 387 766 79.6 5838 72.0 1902 73.3
 Low 18 354 3.8 589 7.3 203 7.8
 None 31 425 6.4 1433 17.7 421 16.2
 Missing 6951 207 24
FEV1 (% predicted) <0.001 <0.001
 >80 272 109 78.0 1853 39.2 399 15.2
 50–79 71 727 20.6 2022 42.8 1409 53.8
 <50 4841 1.4 851 18.0 812 31.0
 Missing 145 646 3591 1061

BMI, body mass index; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1  s; GOLD, Global Initiative for Chronic Obstructive Lung Disease.