Baseline characteristics for the patients with OJIA and PJIA starting their first MTX
| OJIA | PJIA | |
| Patient characteristics | ||
| N | 39 | 74 |
| Sex, female (%) | 31 (79) | 53 (72) |
| Median age at onset (year) (IQR) | 4.5 (1.9–8.5) | 7.5 (4.3–11.8) |
| Median disease duration (year) (IQR) | 0.8 (0.3–1.9) | 0.5 (0.2–1.1) |
| ANA+ (%) | 16 (41) | 33 (45) |
| Rheumatoid factor+ (%) | 0 (0) | 5 (8) |
| HLA-B27+ (%) | 4 (25) | 6 (16) |
| Subtype of JIA | ||
| Oligoarticular (%) | 39 (100) | 19 (26) |
| Persistent (%) | 38 (97) | |
| Extended (%) | 19 (26) | |
| Polyarticular RF− (%) | 48 (65) | |
| Polyarticular RF+ (%) | 6 (8) | |
| Psoriatic arthritis (%) | 1 (1) | |
| Undifferentiated arthritis (%) | 1 (2.6) | |
| Disease activity at baseline | ||
| Median parent/patient VAS (IQR) | 45 (8-65) | 46 (25-70) |
| Median PGA (IQR) | 20 (15-35) | 30 (20-41) |
| Median number of active joints (IQR) | 2 (1-3) | 6.0 (3.0–9.3) |
| Median cJADAS (IQR) | 8.0 (4.0–10.0) | 14.5 (10.1–20.0) |
| Uveitis present (%) | 0 (0) | 1 (1) |
| Comedication at start MTX | ||
| IA steroids (%) | 6 (15) | 10 (14) |
| Prednisolon (%) | 1 (3) | 9 (12) |
ANA, antinuclear antibody; cJADAS, clinical juvenile arthritis disease activity score; HLA, human leucocyte antigen; IA, intra-articular; JIA, juvenile idiopathic arthritis; MTX, methotrexate; OJIA, oligoarticular JIA; PGA, physician’s global assessment; PJIA, polyarticular course JIA; RF, rheumatoid factor; VAS, Visual Analogue Scale.