Details of the PREVENT-JIA group and the respective BiKeR control patients
| Characteristics | ITT analysis Patients who reached I1 under medication | Primary statistical analysis Patients who stopped therapy following I1 | ||
| PREVENT-JIA | BiKeR (matched) | PREVENT-JIA | BiKeR | |
| n=100* | n=100† | n=91‡ | n=118§ | |
| Female, No. (%) | 69 (69) | 69 (69) | 60 (66) | 74 (63) |
| Male, No. (%) | 31 (31) | 31 (31) | 31 (34) | 44 (37) |
| Age at disease onset, median (range), years | 6.0 (<1–15.0) | 6.1 (<1–14.3) | 7.0 (<1–15.0) | 5.9 (<1–14.2) |
| Duration from therapy start to inactive disease, median (range), years | 1.7 (<1–11.8) | 1.5 (<1–12.4) | 1.7 (<1–11.8) | 1.9 (<1–12.4) |
| Age at I1, median (range), years | 10.8 (3.0–17.5) | 11.2 (2.1–19.0) | 11.0 (3.0–17.5) | 11.7 (2.5–17.5) |
| Disease duration at I1, median (range), years | 3.3 (<1–15.3) | 3.5 (1.4–13.8) | 3.4 (<1–15.3) | 3.9 (1.3–13.8) |
| JIA subtype, No. (%) | ||||
| Oligoarthritis (extended) | 21 (21) | 21 (21) | 19 (21) | 35 (30%) |
| Polyarthritis, negative rheumatoid factor | 59 (59) | 62 (62) | 54 (59) | 47 (40) |
| Polyarthritis, positive rheumatoid factor | 2 (2) | 2 (2) | 2 (2) | 5 (4) |
| Systemic-onset juvenile idiopathic arthritis | 4 (4) | 1 (1) | 3 (3) | 4 (3) |
| Enthesitis-related arthritis | 6 (6) | 8 (8) | 6 (7) | 10 (8) |
| Psoriasis arthritis | 7 (7) | 5 (5) | 6 (7) | 11 (9) |
| Other | 1 (1) | 1 (1) | 1 (1) | 6 (5) |
| Final therapy, No. (%) | ||||
| csDMARD, no bDMARDs | 79 (79) | 79 (79) | 72 (79) | 33 (28) |
| bDMARDs±csDMARD | 21 (21) | 21 (21) | 19 (21) | 85 (72) |
*PREVENT-JIA patients who reached the first intervention time point I1.
†Of the 430 eligible patients from the BiKeR registry who reached clinical remission on medication, remained inactive for at least further 6 months on medication and reached the corresponding first intervention time point I1, 100 patients were selected so that the JIA subtype and the type of final therapy of a pair of individual PREVENT-JIA and BiKeR patients matched exactly (final therapy type 1: csDMARD without additional bDMARDs, type 2: bDMARDs with or without additional csDMARD), and the duration of therapy matched as well as possible (duration from treatment start until inactive disease on stable medication).
‡PREVENT-JIA patients who stopped treatment within the 1 year intervention phase.
§A number of 118 eligible patients from the BiKeR registry reached the corresponding first intervention time point I1 and stopped treatment within a 1 year period corresponding to the intervention phase of the PREVENT-JIA study.
bDMARD, biological DMARD; BiKeR, Biologika in der Kinderrheumatologie ; csDMARDs, conventional synthetic disease-modifying anti-rheumatic drugs; ITT, intention-to-treat ; JIA, juvenile idiopathic arthritis .