Table 2.
Clinical characteristics of subgroups in the juvenile idiopathic arthritis (JIA) cohort
| Characteristics | Remission off medicationa | Inactive diseasea | Active diseasea |
|---|---|---|---|
| Values | Values | Values | |
| N = 43 | N = 20 | N = 33 | |
| Female sex, n (%) | 25 (58) | 15 (75) | 28 (85) |
| Age at onset, years, median (IQR) | 8.3 (3.1–11.8) | 3.7 (2.2–8.5) | 7.0 (2.6–12.3) |
| Age at visit, years, median (IQR) | 24.2 (20.3–26.5) | 18.8 (17.5–21.8) | 22.7 (19.2–26.5) |
| Systemic arthritis, n (%)b | 1 (2) | – | – |
| Oligoarticular persistent, n (%)b | 17 (40) | 5 (25) | 5 (15) |
| Oligoarticular extended, n (%)b | 3 (7) | 5 (25) | 10 (30) |
| Polyarthritis RF positive arthritis, n (%)b | – | 1 (5) | 1 (3) |
| Polyarthritis RF negative arthritis, n (%)b | 13 (30) | 4 (20) | 6 (18) |
| Psoriatic arthritis, n (%)b | 1 (2) | – | 3 (9) |
| Enthesitis-related arthritis, n (%)b | 3 (7) | 2 (10) | 2 (6) |
| Undifferentiated arthritis, n (%)b | 5 (12) | 3 (15) | 6 (18) |
| DMARDs ever, n (%) | 9 (18) | 19 (37) | 23 (45) |
| Biologics ever, n (%) | 2 (5) | 13 (35) | 22 (60) |
| HAQ, median (IQR) | 0 (0–0) | 0 (0–0.125) | 0.125 (0–0.25) |
| SF-36 PCS, mean (± SD) | 55.7 (7.0) | 52.2 (7.4) | 44.6 (9.8) |
| SF-36 MCS, mean (± SD) | 48.8 (12.3) | 44.6 (12.7) | 48.1 (10.0) |
N numbers; IQR interquartile range, 1st–3rd; RF rheumatoid factor; DMARDs disease-modifying anti-rheumatic drugs; Biologics biologic drugs; HAQ Health Assessment Questionnaire, 0–3 (0= lowest, 3 = highest); SD standard deviation; SF-36 Short-form 36 Health Status Questionnaire, 0–100 (< 40 poor health); PCS physical component summary; MCS mental component summary
aDisease status according to the definition by Wallace et al. Remission off medication for ≥ 12 months. Inactive disease on medication for less than 6 months or inactive disease off medication for less than 12 months or remission on medication (inactive disease on medication for more than 6 months). Active disease flare or continuous active disease
bJIA category according to the International League of Associations for Rheumatology (ILAR) classification criteria