Table 1.
Demographic characteristics at first presentation to a paediatric rheumatologist
| ILAR | n (% of total) | Age at symptom onset, median (IQR), years | Age at first presentation, median (IQR), years | Female, n (% within each subtype) |
|---|---|---|---|---|
| Whole cohort | 740 (100) | 6.6 (2.8, 10.7) | 7.6 (3.6, 11.5) | 476 (64) |
| Systemic arthritis | 42 (6) | 6.4 (3.4, 10) | 6.7 (3.6, 10.1) | 32 (76) |
| Persistent oligoarthritis | 353 (48) | 5.5 (2.4, 9.8) | 6.5 (3.1, 10.8) | 225 (64) |
| Extended oligoarthritis | 32 (4) | 4.3 (1.9, 8.4) | 5.3 (2.7, 9.4) | 23 (72) |
| RF(−) polyarthritis | 148 (20) | 5.8 (2.2, 9.4) | 7.5 (3.3, 10.6) | 110 (74) |
| RF(+) polyarthritis | 23 (3) | 11.4 (9.1, 13.4) | 12.2 (9.9, 14.8) | 21 (91) |
| ERA | 51 (7) | 11.8 (10.1, 13.1) | 13 (11.3, 13.9) | 6 (12) |
| PSA | 61 (8) | 9.8 (4.3, 11.6) | 11 (5.7, 13) | 40 (66) |
| Undifferentiated | 30 (4) | 7.1 (2.7, 9.8) | 8.9 (5.8, 10.9) | 19 (63) |
ERA: enthesitis related arthritis.