Table 2

Demographics of UK and US cohorts of patients with juvenile idiopathic arthritis (JIA)

CohortUK cohortUS cohort
Number of cases197210
JIA Subtype at time of starting MTX (%):
 Oligoarticular persistent9.18.6
 Oligoarticular extended26.420.9
 Polyarticular RF−37.667.6
 Polyarticular RF+5.61.9
 Enthesitis related arthritis6.00
 Female (%)132 (67%)164 (78%)
 Median and range of disease duration at starting MTX (decimal years)1.00, 11.531.08, 15.8
 Median and range of age at starting MTX (decimal years)7.93, 14.977.25, 18.91
 Median and range of active joints at start of MTX6, 348, 61
 Median and range of restricted joints at start of MTX4, 414, 44
  • MTX, methotrexate; RF, rheumatoid factor.