Table 1.
Univariable association of diagnostic variables with COPD defined by expert panel, FEV1/FVC <0.7 and FEV1/FVC <LLN
| Diagnostic variable | Missing, % | Total, n = 400 | COPD panel, n = 118 | OR (95% CI) | COPD <0.7, n = 134 | OR (95% CI) | COPD LLN, n = 83 | OR (95% CI) |
|---|---|---|---|---|---|---|---|---|
| Symptoms and signs | ||||||||
| Age in years, mean (SD) | 0 | 63 (9) | 66 (10) | 1.3 (1.1 to 1.4)a | 66(10) | 1.3 (1.2 to 1.5)a | 64 (10) | 1.1 (0.9 to 1.2)a |
| Male sex | 0 | 182 (46) | 73 (62) | 2.6 (1.7 to 4.0) | 74(55) | 1.8 (1.2 to 2.7) | 42 (51) | 1.3 (0.8 to 2.1) |
| Current smoking | 6 | 111 (28) | 56 (48) | 3.7 (2.3 to 5.9) | 50(37) | 2.0 (1.3 to 3.1) | 34 (41) | 2.2 (1.3 to 3.6) |
| Cardiovascular diseaseb | 0 | 78 (20) | 39 (33) | 3.1 (1.8 to 5.1) | 40(30) | 2.9 (1.7 to 4.9) | 23 (28) | 2.0 (1.1 to 3.5) |
| Phlegm | 2 | 301 (75) | 98 (83) | 1.9 (1.1 to 3.3) | 109(81) | 1.7 (1.0 to 2.8) | 71 (86) | 2.2 (1.2 to 4.3) |
| Wheezing (symptom) | 4 | 197 (49) | 76 (64) | 2.4 (1.5 to 3.8) | 82(61) | 2.1 (1.4 to 3.2) | 53 (64) | 2.1 (1.3 to 3.5) |
| Dyspnoea | 2 | 218 (55) | 68 (58) | 1.2 (0.8 to 1.8) | 76(57) | 1.1 (0.8 to 1.7) | 47 (57) | 1.1 (0.7 to 1.8) |
| >20 pack-years of smoking | 6 | 131 (33) | 63 (53) | 3.6 (2.3 to 5.7) | 62(46) | 2.5 (1.6 to 3.8) | 39 (47) | 2.2 (1.3 to 3.6) |
| Daily cough last 3 months | 6 | 282 (71) | 86 (73) | 1.2 (0.7 to 1.9) | 96(72) | 1.1 (0.7 to 1.7) | 56 (68) | 0.8 (0.5 to 1.4) |
| Dyspnoea MRC score >3c | 6 | 116 (29) | 37 (31) | 1.2 (0.7 to 1.9) | 39(29) | 1.0 (0.6 to 1.6) | 25 (30) | 1.1 (0.6 to 1.8) |
| Allergyb,d | 7 | 51 (13) | 12 (10) | 0.7 (0.4 to 1.4) | 16(12) | 0.9 (0.5 to 1.7) | 10 (12) | 0.9 (0.4 to 1.9) |
| Wheezing (auscultation) | 3 | 54 (14) | 27 (23) | 2.8 (1.6 to 5.0) | 26(19) | 2.0 (1.1 to 3.7) | 16 (19) | 1.8 (0.9 to 3.3) |
| Diminished breath sounds | 3 | 46 (12) | 25 (21) | 3.3 (1.8 to 6.3) | 21(16) | 1.8 (1.0 to 3.3) | 13 (16) | 1.6 (0.8 to 3.2) |
| CRP | ||||||||
| Mean level in mg/l (SD) | 9 | 9.8 (18.2) | 12.1 (17.5) | 1.03 (0.99 to 1.07)e | 10.8 (15.9) | 1.01 (0.98 to 1.05)e | 12.7 (18.7) | 1.03 (0.99 to 1.06)e |
| >10 mg/l | 9 | 84 (21) | 28 (24) | 1.3 (0.8 to 2.1) | 32 (24) | 1.3 (0.8 to 2.1) | 23 (28) | 1.6 (0.9 to 2.8) |
| >20 mg/l | 9 | 47 (12) | 19 (16) | 1.7 (0.9 to 3.3) | 22 (16) | 1.9 (1.0 to 3.5) | 15 (18) | 1.9 (1.0 to 3.8) |
Values are numbers (percentages) unless mentioned otherwise. COPD = chronic obstructive pulmonary disease. FEV1 = forced expiratory volume in 1 s. FVC = forced vital capacity. LLN = lower limit of normal. OR = univariable odds ratio. SD = standard deviation.
a
Per 5 years.
b
Diagnosed before the study, according to medical file of GP.
c
Medical Research Council (MRC) score, situations in which the subject is dyspnoeic: 1, never; 2, only during strenuous exercise; 3, walking fast or uphill; 4, walking with people of the same age; 5, walking flat; 6, in rest.
d
Pollen, house dust mite, cats or dogs.
e
Per 5 mg/L CRP increase.