Baseline characteristics
| DMARD (n=3464) | Anti-TNF (n=10649) | |||
|---|---|---|---|---|
| No baseline RA-ILD (n=3396) | Baseline RA-ILD (n=68) | No baseline RA-ILD (n=10350) | Baseline RA-ILD (n=299) | |
| Mean (SD) age (years) | 60 (12) | 68 (9) | 56 (12) | 63 (10) |
| Females, n (%) | 2462 (73) | 60 | 7889 (76) | 57 |
| Mean (SD) DAS28 | 5.1 (1.3) | 5.2 (1.2) | 6.5 (1.0) | 6.7 (1.0) |
| Mean (SD) HAQ | 1.5 (0.8) | 1.8 (0.7) | 2.0 (0.6) | 2.1 (0.5) |
| Median (IQR) disease duration (years) | 6 (1–15) | 12 (5–22) | 11 (6–19) | 12 (7–20) |
| RhF positivity, n (%) | 1953 (58) | 50 (74) | 6616 (64) | 226 (76) |
| Baseline EARA, n (%) | 602 (18) | 26 (38) | 2812 (27) | 163 (55) |
| Baseline steroid use, n (%) | 759 (22) | 37 (54) | 4522 (44) | 171 (57) |
| Diabetes, n (%) | 219 (7) | 10 (15) | 592 (6) | 17 (6) |
| COPD/asthma, n (%) | 622 (18) | 19 (28) | 1352 (13) | 73 (25) |
| Smoking, n (%) | ||||
| Current | 796 (23) | 16 (24) | 2270 (22) | 61 (20) |
| Former | 1338 (39) | 36 (53) | 3878 (37) | 166 (56) |
| Never | 1245 (37) | 16 (24) | 4139 (40) | 72 (24) |
| Median (IQR) number of prior DMARDs | 2 (1–3) | 4 (2–5) | 4 (3–5) | 4 (3–5) |
| Baseline methotrexate use, n (%) | 2097 (64) | 20 (30) | 5693 (57) | 109 (38) |
COPD, chronic obstructive pulmonary disease; DAS28, disease activity score; DMARD, disease-modifying antirheumatic drug; EARA, extra-articular manifestations of rheumatoid arthritis; HAQ, Health Assessment Questionnaire; RA-ILD, rheumatoid arthritis-associated interstitial lung disease; RhF, rheumatoid factor; TNF, tumour necrosis factor.