Table 2 Health characteristics of Control, ‘COPD Risk (undiagnosed)’ and ‘COPD Diagnosed’ groups
|  | All | Control group | ‘COPD Risk (undiagnosed)’ group | ‘COPD Diagnosed’ group | Risk vs. Control, p value | Diagnosed vs. Control, p value | Risk vs. Diagnosed, p value |
|---|---|---|---|---|---|---|---|
|  | (n = 19,994) | (n = 16,161) | (n = 3320) | (n = 513) |  |  |  |
Smoking, n (%) | 0.000 | < 0.001 | < 0.001 | ||||
 Never smoked | 15,019 (75.1) | 13,342 (82.6) | 1367 (41.2) | 310 (60.4) |  |  |  |
 Former smoker | 1246 (6.23) | 868 (5.37) | 332 (10.0) | 46 (8.97) |  |  |  |
 Current smoker | 3729 (18.7) | 1951 (12.1) | 1621 (48.8) | 157 (30.6) |  |  |  |
Alcohol use, n (%) | < 0.001 | < 0.001 | 0.030 | ||||
 2–3 times a week or more | 3726 (18.6) | 2542 (15.7) | 1050 (31.6) | 134 (26.1) |  |  |  |
 Once a week or less often | 7895 (39.5) | 6327 (39.1) | 1351 (40.7) | 217 (42.3) |  |  |  |
 I do not drink alcohol | 8373 (41.9) | 7292 (45.1) | 919 (27.7) | 162 (31.6) |  |  |  |
BMI, n (%) | < 0.001 | 0.008 | 0.023 | ||||
 Overweight/ Obese (BMI ≥ 25) | 4272 (21.4) | 3141 (19.4) | 1006 (30.3) | 125 (24.4) |  |  |  |
 Normal (18.5 ≥ BMI < 25) | 13,257 (66.3) | 10,884 (67.3) | 2032 (61.2) | 341 (66.5) |  |  |  |
 Underweight (BMI < 18.5) | 1826 (9.13) | 1595 (9.87) | 194 (5.84) | 37 (7.21) |  |  |  |
 Decline to answer | 639 (3.20) | 541 (3.35) | 88 (2.65) | 10 (1.95) |  |  |  |
Exercise level (per month), n (%) | < 0.001 | 0.032 | 0.003 | ||||
 No exercise (0 days) | 7272 (36.4) | 5795 (35.9) | 1281 (38.6) | 196 (38.2) |  |  |  |
 Occasional (1–10 days) | 7388 (37.0) | 6063 (37.5) | 1118 (33.7) | 207 (40.4) |  |  |  |
 Frequent (11+ days) | 5334 (26.7) | 4303 (26.6) | 921 (27.7) | 110 (21.4) |  |  |  |
Charlson Comorbidity Index, mean ± SD | 0.000 | 0.000 | 0.000 | ||||
 CCI | 0.17 ± 0.52 | 0.10 ± 0.38 | 0.32 ± 0.74 | 1.37 ± 0.78 |  |  |  |
Diagnosed of asthma, n (%) | < 0.001 | < 0.001 | < 0.001 | ||||
 Yes | 357 (1.79) | 191 (1.18) | 117 (3.52) | 49 (9.55) |  |  |  |
Annual physical check-up, n (%) | < 0.001 | < 0.001 | < 0.001 | ||||
 Yes | 6451 (32.3) | 4809 (29.8) | 1378 (41.5) | 264 (51.5) |  |  |  |
Digital health tools usage, n (%) | < 0.001 | < 0.001 | < 0.001 | ||||
 1+ tools used | 8886 (44.4) | 7337 (45.4) | 1256 (37.8) | 293 (57.1) |  |  |  |
 None used | 11,108 (55.6) | 8824 (54.6) | 2064 (62.2) | 220 (42.9) |  |  |  |
COPD symptom scores (LFQ), mean ± SD |  |  |  | ||||
 Frequency of mucus productiona | 4.23 ± 0.83 | 4.43 ± 0.67 | 3.34 ± 0.87 | 3.57 ± 0.88 | 0.000 | 0.000 | 0.000 |
 Frequency of wheezinga | 4.55 ± 0.71 | 4.73 ± 0.50 | 3.74 ± 0.92 | 4.00 ± 0.86 | 0.000 | 0.000 | 0.000 |
 Frequency of dyspnoeaa | 4.07 ± 0.91 | 4.27 ± 0.79 | 3.17 ± 0.86 | 3.58 ± 0.94 | 0.000 | 0.000 | 0.000 |
LFQ sum score, mean ± SD |  |  |  | ||||
 LFQ score | 21.1 ± 3.00 | 22.2 ± 1.88 | 16.1 ± 1.89 | 18.8 ± 3.37 | 0.000 | 0.000 | 0.000 |