Comparison of spirometry data for patients with IP and the general population
| Mean (SD) or n (%) | Mean (SD) or n (%) | Difference: β (95% CI) or OR (95% CI) | Difference: β (95% CI) or OR (95% CI) | ||
|---|---|---|---|---|---|
| Variable | N/n | General population (N=1492) | IP patients (N=373) | Adjusted for smoking | Adjusted for smoking and BMI |
| Demographic characteristics | |||||
| Age, years | 1492/373 | 62 (11) | 62 (11) | ||
| Gender, female | 1492/373 | 1012 (68%) | 253 (68%) | ||
| Smoking status | |||||
| Never | 767 (51.4%) | 125 (33.5%) | |||
| Past | 607 (40.7%) | 195 (52.3%) | |||
| Current | 118 (7.9%) | 53 (14.2%) | |||
| BMI, kg/m2 | 1490/373 | 26.6 (4.1) | 27.9 (5.0) | ||
| Abnormal lung function test | |||||
| Medication for respiratory symptoms | 1492/373 | 41 (2.8%) | 45 (12.1%) | ||
| FEV1 | 1492/373 | 2.36 (0.71) | 2.28 (0.69) | −0.08 (−0.13 to −0.02) | −0.06 (−0.11 to −0.01) |
| FVC | 1492/373 | 2.82 (0.87) | 2.88 (0.86) | 0.06 (−0.01 to 0.13) | 0.08 (0.01 to 0.15) |
| Obstructive lung disease | 1124/277 | 55 (4.9%) | 32 (11.6%) | 2.01 (1.26 to 3.22) | 2.05 (1.27 to 3.29) |
| Restrictive lung disease | 1296/287 | 227 (17.5%) | 42 (14.6%) | 0.76 (0.53 to 1.10) | 0.71 (0.49 to 1.03) |
N=general population/n=patients with IP with available data.
BMI, body mass index; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; IP, inflammatory polyarthritis.