Clinical and physical performance data
| Normal | Non-obstructive | Undiagnosed COPD | Over-diagnosed COPD | Diagnosed COPD | |
| N (%) | 18 361 (86) | 1099 (5.2) | 809 (3.8) | 756 (3.6) | 217 (1.02) |
| Comorbidities | |||||
| Asthma | 1965 (11) | 202 (18)*† | 246 (31)*† | 253 (34)*† | 89 (42)* |
| CAD | 1015 (6) | 131 (12)* | 57 (7.1)† | 103 (14)* | 32 (15)* |
| CHF | 1618 (9) | 198 (18)* | 69 (9)† | 138 (18)* | 34 (16)* |
| Diabetes | 2787 (15) | 339 (31)*† | 107 (13)† | 204 (27)*† | 42 (19) |
| Mood disorders | 2951 (16.1) | 174 (15.8) | 116 (14.3) | 212 (28.1)* | 61 (28.2)* |
| Comorbid index | |||||
| 0 | 2015 (11) | 84 (7.6)*† | 66 (8.2)† | 23 (3)* | 8 (3.7)* |
| 1 | 7519 (41) | 420 (38.2) | 353 (43.6) | 165 (21.8) | 45 (20.7) |
| 2 | 6238 (34) | 382 (34.8) | 275 (34) | 307 (40.6) | 100 (46.1) |
| 3 and more | 2589 (14) | 213 (19.4) | 115 (14.2) | 261 (34.6) | 64 (29.5) |
| Fall in 12 month | 1779 (10.1)† | 107 (10.4)† | 72 (9.2)† | 98 (13.6)* | 33 (16.3)* |
| Symptoms, n (%) | |||||
| SOB | 5593 (30.6) | 552 (50.6)†* | 388 (48.2)*† | 455 (60.4)*† | 164 (77)* |
| Wheeze | 2863 (15.6) | 326 (29.9)*† | 307 (38)*† | 381 (50.5)*† | 150 (69.8)* |
| Cough | 4719 (25.8) | 351 (32.1)* | 293 (36.3)* | 386 (51.2)* | 134 (61.8)* |
| Cold | 664 (3.6) | 80 (7.3)* | 55 (6.8)* | 122 (16.2)* | 39 (18.1)* |
| Any symptom | 9150 (50.1) | 739 (67.8)* | 567 (70.4)* | 624 (82.5)* | 201 (93.1)* |
| Healthcare utilisation | |||||
| Mean±SD | 3.5±1.4 | 3.5±1.5 | 3.4±1.4* | 3.7±1.5* | 3.8±1.6* |
| TUG (s) | |||||
| Mean (SD) | 9.3±2.1 | 10.4±3.5* | 9.4±1.8 | 10.2±2.8* | 10.6±3.1* |
| HGS (kg) | |||||
| Mean (SD) | 35.6±11.9 | 35.1±11.7 | 34.4±11.8* | 32.3±11.3* | 32±10.9* |
| 4 metres walk (s) | |||||
| Median (IQR) | 4.0 (3.6, 4.6) | 4.4. (3.8, 5.1) | 4.1 (3.6, 4.6) | 4.3 (3.8, 5.0) | 4.4 (3.9, 5.1) |
Comorbidity index was calculated as the sum of self-reported comorbidities. Healthcare utilisation was calculated as the sum of 10 types of healthcare used in the past 6 months, including visits to family physician, medical specialty, psychologist, dentist, ophthalmologist or optometrist, physiotherapist, social worker, emergency department, hospital overnight and nursing home.
*P<0.05 compared with normal category.
†P<0.05 compared with diagnosed COPD using unadjusted analysis (analysis of variance or Mann-Whitney test).
CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; HGS, handgrip strength; SOB, shortness of breath; TUG, Timed-Up-and-Go.