Patient characteristics per diagnosis.
| Characteristic | RA, n = 43 | UA, n = 88 | OA, n = 12 | PsA, n = 15 | Other, n = 21 |
|---|---|---|---|---|---|
| Age, yrs, median (IQR) | 59 (24) | 55 (20) | 62.5 (9) | 47.5 (14) | 52.5 (33) |
| Sex (women/men) | 23/20 | 52/36 | 7/5 | 6/9 | 11/10 |
| Symptom duration, weeks, median (IQR) | 17.3 (28.2) | 10.7 (20) | 33.8 (78.5) | 30.9 (32.9) | 10.6 (17.3) |
| Rheumatoid factor positivity, n (%) | 27 (62.8) | 21 (23.9) | 0 (0.0) | 4 (26.7) | 2 (9.5) |
| ACPA positivity, n (%) | 21 (48.8) | 20 (22.7) | 0 (0.0) | 3 (20.0) | 1 (4.8) |
| CRP, mg/l, median (IQR) | 8 (19) | 4 (5) | 3 (1) | 4 (10) | 12 (23) |
| 66 Swollen joint count, median (IQR) | 7 (8) | 2 (3) | 3 (3) | 5 (3) | 2 (4) |
RA: rheumatoid arthritis; UA: undifferentiated arthritis; OA: inflammatory osteoarthritis; PsA: psoriatic arthritis; other: other rheumatic diagnoses including reactive arthritis (n = 6), spondylarthropathy (n = 3), gout (n = 2), pseudogout (1), palindromic arthritis (n = 1), paramalignant arthritis (n = 1), lyme disease (n = 1), systemic lupus erythematosus (n = 1), RS3PE (n = 1), sarcoidosis (1), and unspecified other (n = 3); IQR: interquartile range; ACPA: anticitrullinated protein antibodies; CRP: C-reactive protein.