Table 1. Comparison between rheumatoid arthritis patients with and without abnormalities on screening tests for lung abnormalities, adjusted for confounders (rheumatoid nodules and Sjögren's syndrome).a .
| Characteristic | No abnormalities | Any abnormalityb | p |
|---|---|---|---|
| (n = 101) | (n = 145) | ||
| Female | 89 (88) | 120 (82.8) | 0.007 |
| Age, years | 54.3 ± 10.4 | 58.0 ± 10.6 | 0.013 |
| RF-positive | 73 (72.3) | 107 (73.8) | 0.002 |
| Disease duration, years | 16.9 ± 10.7 | 16.2 ± 10.2 | 0.07 |
| Smoking status | |||
| Ever | 38 (37.6) | 88 (60.7) | < 0.0001 |
| Current | 10 (9.9) | 33 (22.8) | 0.0005 |
| Former | 28 (27.7) | 55 (37.9) | 0.086 |
| Exposures | |||
| Mold | 23 (22.8) | 31 (21.4) | 0.66 |
| Birds | 18 (17.8) | 23 (15.9) | 0.88 |
| Feather pillow | 12 (11.9) | 16 (11.0) | 0.80 |
| Occupational | 8 (7.9) | 21 (14.5) | 0.34 |
| Drugs | |||
| Methotrexate | 88 (87.1) | 138 (95.2) | 0.11 |
| Chloroquine | 83 (82.2) | 110 (75.9) | 0.35 |
| Leflunomide | 67 (66.3) | 104 (71.7) | 0.18 |
| Sulfasalazine | 48 (47.5) | 63 (43.4) | 0.47 |
| Azathioprine | 21 (20.8) | 36 (24.8) | 0.046 |
| Biologic | 37 (36.6) | 34 (23.4) | 0.18 |
| MRC dyspnea scale category | |||
| Fit | 85 (84.2) | 117 (80.7) | 0.24 |
| Moderate dyspnea | 16 (15.8) | 27 (18.6) | 0.23 |
| Severe dyspnea | 0 | 1 (0.7) | 0.80 |
RF: rheumatoid factor; and MRC: Medical Research Council. aValues expressed as n (%) or as mean ± SD. bOn any one of the three diagnostic tests applied (chest X-ray, spirometry, or pulse oximetry).