Table 2.
Baseline characteristics of children in the study sample
| Characteristic | All children with JIA | Presence of arthritis | Absence of arthritis | p value |
|---|---|---|---|---|
| No. of children | 26 | 13 | 13 | |
| Girls | 14 (54%) | 9 (69%) | 5 (39%) | .24a |
| Age at MRI in years | 14.3 (11.2–16.5) | 14.0 (9.8–17.0) | 14.4 (11.6–15.7) | .78b |
| JIA ILAR subtype | ||||
| Oligoarthritis; persistent | 16 (62%) | 9 (69%) | 7 (54%) | .69a |
| Oligoarthritis; extended | 2 (8%) | 1 (8%) | 1 (9%) | > .99a |
| Polyarthritis; RF negative | 7 (27%) | 3 (23%) | 4 (31%) | > .99a |
| Enthesitis-related arthritis | 1 (4%) | 0 (0%) | 1 (8%) | > .99a |
| No. of clinically inflamed joints | 1.0 (1.0–2.0) | 1.0 (1.0–1.5) | 2.0 (1.0–3.0) | .16b |
| No. of joints with limited range of motion | 1.0 (0.0–2.0) | 1.0 (1.0–1.5) | 1.0 (0.5– 2.0) | .40b |
| Physician's global assessment of overall disease activityc | 13.5 (5.0–17.8) | 15.0 (5.0–19.0) | 10.0 (1.5–15.0) | .15b |
| CRP, mg/l | 0.5 (0.3–1.7) | 1.3 (0.4–2.5) | 0.3 (0.2–0.5) | .08b |
| ESR, mm/h | 2.0 (2.0–8.5) | 8.0 (2.0–11.5) | 2.0 (2.0–2.8) | .08b |
| Drug treatment | ||||
| No medication | 14 (54%) | 7 (54%) | 7 (54%) | > .99a |
| NSAIDs | 6 (23%) | 3 (23%) | 3 (23%) | > .99a |
| MTX or other cDMARD | 4 (15%) | 2 (15%) | 2 (15%) | > .99a |
| bDMARD | 2 (8%) | 1 (8%) | 1 (8%) | > .99a |
Data are displayed as numbers (frequencies) or median (interquartile range), unless otherwise stated
JIA, juvenile idiopathic arthritis; ILAR, International League of Associations for Rheumatology; RF, rheumatoid factor; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; CE, contrast-enhanced; NSAIDS, nonsteroidal anti-inflammatory drug; MTX, methotrexate; cDMARD, conventional disease-modifying antirheumatic drug; bDMARD, biologic disease-modifying antirheumatic drug
aFisher’s exact test
bMann–Whitney U test
cVisual analogue scale: 0 mm = best, 100 mm = worst