Demographics of UK and US cohorts of patients with juvenile idiopathic arthritis (JIA)
| Cohort | UK cohort | US cohort |
|---|---|---|
| Number of cases | 197 | 210 |
| JIA Subtype at time of starting MTX (%): | ||
| Oligoarticular persistent | 9.1 | 8.6 |
| Oligoarticular extended | 26.4 | 20.9 |
| Polyarticular RF− | 37.6 | 67.6 |
| Polyarticular RF+ | 5.6 | 1.9 |
| Enthesitis related arthritis | 6.0 | 0 |
| Psoriatic | 2.5 | 0.95 |
| Systemic | 10.7 | 0 |
| Unclassified | 2.0 | 0 |
| Female (%) | 132 (67%) | 164 (78%) |
| Median and range of disease duration at starting MTX (decimal years) | 1.00, 11.53 | 1.08, 15.8 |
| Median and range of age at starting MTX (decimal years) | 7.93, 14.97 | 7.25, 18.91 |
| Median and range of active joints at start of MTX | 6, 34 | 8, 61 |
| Median and range of restricted joints at start of MTX | 4, 41 | 4, 44 |
MTX, methotrexate; RF, rheumatoid factor.