Baseline characteristics of seronegative and seropositive subjects with early inflammatory arthritis. Values are n (%) unless otherwise specified.
| Characteristics | Seronegative, n = 216 | n | Seropositive, n = 625 | n | p |
|---|---|---|---|---|---|
| Age, yrs, mean (SD) | 57 (15) | 216 | 51 (14) | 624 | < 0.0001 |
| Male | 67 (31) | 216 | 145 (23) | 625 | 0.0225 |
| Symptom duration, days, mean (SD) | 166 (87) | 216 | 192 (98) | 625 | 0.0007 |
| Ever smoker | 111 (52) | 215 | 369 (59) | 624 | 0.055 |
| SJC28, mean (SD) | 8.8 (6.8) | 211 | 6.5 (5.6) | 611 | < 0.0001 |
| TJC28, mean (SD) | 9.3 (7.2) | 211 | 7.1 (6.0) | 611 | < 0.0001 |
| ESR, mean (SD) | 24.9 (22.0) | 211 | 27.3 (22.6) | 597 | 0.6513 |
| CRP, mg/l, mean (SD) | 13.8 (18.2) | 205 | 13.4 (16.9) | 601 | 0.7864 |
| Erosions | 58 (32) | 181 | 124 (24) | 517 | 0.0335 |
| DAS28, mean (SD) | 5.0 (1.6) | 203 | 4.8 (1.5) | 576 | 0.0493 |
| HAQ, mean (SD) | 0.65 (0.65) | 199 | 0.59 (0.64) | 605 | 0.2741 |
| 1987 ACR RA criteria | 128 (61) | 211 | 432 (71) | 611 | 0.007 |
| 2010 ACR/ EULAR RA criteria | 139 (66) | 211 | 529 (86) | 615 | < 0.0001 |
| 1987 ACR or 2010 ACR/EULAR RA criteria | 179 (84) | 211 | 573 (93) | 615 | 0.0007 |
| DMARD | 178 (86) | 207 | 534 (88) | 607 | 0.4567 |
| Biologics | 5 (2) | 207 | 18 (3) | 607 | 0.8112 |
| Corticosteroids | 120 (58) | 207 | 310 (51) | 607 | 0.0859 |
SJC28: swollen joint count of 28 joints; TJC28: tender joint count of 28 joints; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; DAS28: 28-joint Disease Activity Score; HAQ: Health Assessment Questionnaire; ACR: American College of Rheumatology; RA: rheumatoid arthritis; EULAR: European League Against Rheumatism; DMARD: disease-modifying antirheumatic drug.