Table 2. Comparison between rheumatoid arthritis patients with absent or low tobacco smoke exposure and those with high tobacco smoke exposure, adjusted for confounders (rheumatoid nodules and Sjögren's syndrome).a .
| Characteristic | Absent or low TSE | High TSE | p |
|---|---|---|---|
| (n = 161) | (n = 85) | ||
| Female | 138 (86) | 71 (83.5) | 0.50 |
| Age, years | 54.9 ± 11.2 | 59.5 ± 9.0 | 0.006 |
| RF-positive | 116 (72.0) | 64 (75.3) | 0.79 |
| Disease duration, years | 16.6 ± 10.3 | 16.3 ± 10.5 | |
| Abnormalities | |||
| On spirometry | 39 (24.2) | 35 (41.2) | 0.05 |
| On chest X-rays | 59 (36.6) | 51 (60.0) | < 0.001 |
| On pulse oximetry | 15 (9.3) | 18 (21.2) | 0.02 |
| Exposures | |||
| Mould | 34 (21.1) | 20 (23.5) | 0.39 |
| Birds | 29 (18.0) | 12 (14.1) | 0.56 |
| Feather pillow | 16 (9.9) | 12 (14.1) | 0.40 |
| Occupational | 16 (9.9) | 13 (15.3) | 0.15 |
| Drugs | |||
| Methotrexate | 145 (90.1) | 81 (95.3) | 0.11 |
| Chloroquine | 130 (80,8) | 63 (74.1) | 0.35 |
| Leflunomide | 114 (70.8) | 57 (67.1) | 0.26 |
| Sulfasalazine | 67 (41.6) | 44 (51.8) | 0.20 |
| Azathioprine | 34 (21.1) | 23 (27.1) | 0.54 |
| Biologic | 48 (29.8) | 23 (27.1) | 0.71 |
| MRC dyspnea scale category | |||
| Fit | 138 (85.7) | 64 (75.3) | 0.03 |
| Moderate dyspnea | 23 (14.3) | 20 (23.5) | 0.06 |
| Severe dyspnea | 0 | 1 (1.2) | - |
TSE: tobacco smoke exposure; RF: rheumatoid factor; and MRC: Medical Research Council. aValues expressed as n (%) or as mean ± SD.