Patient and disease characteristics before the start of etanercept
| JIA patients who never switch (n=227) | Switchers to a second agent (n=80)† | Switchers to a third agent (n=22)† | |
| Female | 155 (68) | 56 (70) | 17 (77) |
| Age at onset JIA (years) | 8.0 (3.9–11.4) | 5.1 (2.9–11.8) | 4.1 (2.9–10.9) |
| Disease duration before start etanercept (years)** | 3.2 (1.5–6.7) | 2.1 (1.0–4.3) | 1.4 (0.9–2.8) |
| Age at start etanercept (years)** | 13.0 (9.7–15.5) | 10.2 (6.2–13.8) | 8.2 (5.0–12.3) |
| Duration follow-up since start of etanercept (months)* | 29.4 (16.3–51.3) | 41.8 (25.6–69.2) | 57.1 (35.1–94.1) |
| Category JIA | |||
| Systemic-onset JIA** | 27 (12) | 24 (30) | 11 (50) |
| Polyarticular JIA RF negative | 92 (41) | 30 (38) | 5 (23) |
| Polyarticular JIA RF positive | 24 (11) | 5 (6) | 3 (14) |
| Oligoarticular JIA persistent | 9 (4) | 1 (1) | 0 (0) |
| Oligoarticular JIA extended | 45 (20) | 16 (20) | 3 (14) |
| Arthritis psoriatica | 17 (8) | 2 (3) | 0 (0) |
| Enthesitis-related arthritis | 13 (6) | 2 (3) | 0 (0) |
| Medication history before etanercept | |||
| Systemic glucocorticoids | 104 (46) | 50 (63) | 17 (77) |
| Methotrexate | 202 (89) | 70 (88) | 19 (86) |
| Other synthetic DMARD | 92 (41) | 32 (40) | 6 (27) |
| Disease activity at start of etanercept | |||
| VAS physician | 62 (47–72) | 60 (37–75) | 62 (37–79) |
| CHAQ score** | 1.4 (0.9–2.0) | 1.9 (1.2–2.4) | 2.1 (1.6–2.6) |
| VAS pain patient/parent | 57 (25–75) | 60 (34–78) | 74 (52–83) |
| VAS wellbeing patient/parent | 50 (27–74) | 58 (35–79) | 70 (50–92) |
| No of joints with arthritis | 8 (5–16) | 10 (7–17) | 11 (9–18) |
| No of joints with limited motion | 7 (3–13) | 6 (4–12) | 7 (4–11) |
| ESR | 18 (9–35) | 19 (7–38) | 23 (11–55) |
Numbers given are: absolute numbers (%) or median (IQR).
*p Value <0.0001 (switchers compared with patients who never switch, Mann-Whitney U test).
**p Value <0.05 adjusted for follow-up duration (switchers compared with patients who never switch, logistic regression analysis, p value based on Wald's test). Because of the non-normal distribution of disease duration before the start of etanercept a logarithmic transformation was used.
†Patients who switched to a third agent are also represented in the switchers to a second agent patient group.
CHAQ, child health assesment questionnaire; DMARD, diesease-modifying antiheumatic agent; ESR, erythrocyte sedimentation rate; JIA, juvenile idiopathic artritis; RF, rheumatoid factor; VAS, Visual analogue scale.