Baseline characteristics of patients in the effectiveness cohort
| Characteristic | Effectiveness cohort N=43 |
| Age at etanercept start, median (Q1, Q3), years | 10.0 (7.0, 13.0) |
| Sex, n (%) | |
| Female | 29 (67.4) |
| Male | 14 (32.6) |
| White, n (%) | 37 (86.0) |
| Disease duration at start of follow-up, median (Q1, Q3), years | 0.4 (0.1, 2.7) |
| Concomitant use of non-biologic therapy at start of follow-up, n (%) | 24 (55.8) |
| Methotrexate | 22 (51.2) |
| Leflunomide | 2 (4.7) |
| Sulfasalazine | 1 (2.3) |
| Concomitant use of oral glucocorticoid, n (%) | 3 (7.0) |
| Total number of joints with active arthritis* | |
| Available patients, n (%) | 42 (97.7) |
| Median (Q1, Q3) | 4.0 (2.0, 8.0) |
| Physician global assessment of disease activity* | |
| Available patients, n (%) | 39 (90.7) |
| Median (Q1, Q3) | 3.5 (2.5, 5.0) |
| Patient/parent global assessment of overall well-being* | |
| Available patients, n (%) | 30 (69.8) |
| Median (Q1, Q3) | 3.0 (1.0, 6.0) |
| ESR*, mm/hour | |
| Available patients, n (%) | 25 (58.1) |
| Median (Q1, Q3) | 8.0 (5.0, 25.0) |
| CRP*, mg/L | |
| Available patients, n (%) | 15 (34.9) |
| Median (Q1, Q3) | 0.5 (0.2, 0.7) |
| Active psoriasis skin lesions reported, n (%) | 12 (27.9) |
| Previous or current dactylitis at the CARRA Registry baseline visit | 18 (41.9) |
| Active uveitis*, n (%) | 0 (0) |
| Past uveitis, n (%) | 0 (0) |
| Morning stiffness*, n (%) | |
| None | 12 (27.9) |
| ≤ 15 min | 4 (9.3) |
| 16–60 min | 11 (25.6) |
| > 60 min | 9 (20.9) |
| Unknown | 7 (16.3) |
| cJADAS-10* | |
| Available patients, n (%) | 29 (67.4) |
| Median (Q1, Q3) | 10.0 (6.0, 10.0) |
| Active enthesitis at the study baseline visit | 9 (20.9) |
| Previous or current sacroiliitis at the study baseline visit | 10 (23.3) |
N=number of patients who met the criteria for the effectiveness cohort, that is, had a registry visit ±14 days from etanercept initiation, had uninterrupted etanercept use and had a 6-month or 12-month follow-up visit; n=number of patients with the characteristic.
*Disease activity data reflective of the visit that occurred within 14 days of etanercept initiation.
CARRA, Childhood Arthritis and Rheumatology Research Alliance; cJADAS-10, clinical Juvenile Arthritis Disease Activity Score 10-joint; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; Q1, quartile 1; Q3, quartile 3.