Baseline Clinical Characteristics
| Clinical Characteristics | RA-ONLY COhort (N = 3,846) | RA-ild coHORT (N = 115) | P-value |
|---|---|---|---|
| History of Chronic Obstructive Pulmonary Disease, N (%) | 102 (2.7%) | 8 (7.0%) | 0.006 |
| Hypertension, N (%) | 900 (23.4%) | 23 (20.0%) | 0.395 |
| Serious Infection, N (%) | 38 (1.0%) | 3 (2.6%) | 0.091 |
| Rheumatoid Factor Positive, N (%) | 1,388 (36.1%) | 69 (60.0%) | <.001 |
| Joint Stiffness, N (%) | 1,092 (28.4%) | 39 (33.9%) | 0.197 |
| Rheumatoid Nodules, N (%) | 153 (4.0%) | 17 (14.8%) | <.001 |
| Erosive Joint Disease, N (%) | 459 (11.9%) | 23 (20.0%) | 0.009 |
| Anti-CCP Antibody Positive, N (%) | 858 (22.3%) | 45 (39.1%) | <.001 |
| Joint Swelling*, N (%) | 2,861 (58.0%) | 123 (68.0%) | 0.008 |
| Joint Tenderness*, N (%) | 3,728 (75.6%) | 138 (76.2%) | 0.851 |
| ESR**, Mean ± SD, mm/hr | 22.0 ± 22.6 | 30.1 ± 25.5 | <.001 |
| CRP**, Mean ± SD, mg/L | 22.5 ± 13.0 | 60.6 ± 25.0 | 0.086 |
| CDAI, Mean ± SD | 16.4 ± 12.3 | 18.9 ± 15.7 | 0.044 |
| DAS28-CRP, Mean ± SD | 2.6 ± 1.2 | 3.1 ± 1.4 | <.001 |
| DAS28-ESR, Mean ± SD | 3.3 ± 1.4 | 3.9 ± 1.5 | <.001 |
| SDAI, Mean ± SD | 20.2 ± 29.3 | 28.6 ± 40.2 | 0.048 |
* A total of 4,929 non-ILD and 181 ILD patients had joint swelling and tenderness data.
** Variables were calculated among patients who had available information.