Association between baseline joint inflammation and joint inflammation in the same joint during follow-up within three different JIA categories
| JIA category | OR (95% CI) |
| Oligoarticular arthritis | 3.4 (2.1 to 5.6) |
| Polyarticular (RF-negative) arthritis | 4.1 (3.6 to 4.6) |
| Juvenile psoriatic arthritis | 1.8 (1.2 to 2.7) |
JIA, juvenile idiopathic arthritis; RF, rheumatoid factor.