What have we learned from long-term studies in juvenile idiopathic arthritis? – Prediction, classification, transition.

Table 1 Patients in clinical remission off medication in adult juvenile idiopathic arthritis in long-term studies

Studies, country	n	Disease duration Years	Age at visit Years	CR^a %	Study design
Bertilsson, 2013 Sweden	86	17	n.a.	40^b	Prospective, population-based Diagnosis 1984-86
Selvaag, 2016 South-East Norway	176	30	39	59^c	Prospective, hospital-based Referral 1980-85
Oliveira-Ramos, 2016 Portugal	426	23	34	12	Cross-sectional, national register-based (“Reuma.pt register”), n = 355 retrospectively registered in adulthood
Dimopoulou, 2017 Greece	102 (302^d)	17	25	24 (47^d)	Retrospective, hospital-based (n = 102) + telephone interview of n = 205 lost-to follow-up. N = 74 diagnosed before 2000
Minden, 2019 Germany	701	14	23	11	Prospective register-based (“BiKeR/JUMBO registry”), selected to bDMARDs-treated individuals
Glerup, 2020 Nordic countries	434	18	24	33	Prospective, population-based (“Nordic JIA study”) Disease onset 1997–2000
Chhabra, 2020 Canada	247	6	17	47	Prospective, inception cohort (“ReACCH-Out cohort”) with retrospective long-term data collection. Diagnosis 2005–2020
Oliveira-Ramos, 2023 Portugal	361	20	29	15	Cross-sectional, national register-based (“Reuma.pt register”), selected to bDMARDs-treated individuals

CR clinical remission off medication, Reuma.pt Register Rheumatic Diseases Portuguese Registry, BiKer/JUMBO Biologika in der Kinderrheumatologie (BiKer) and Juvenile Arthritis Methotrexate/Biologics Long-Term Observation (JUMBO) registers, bDMARDs biologic diseasemodifying anti-rheumatic drugs, JIA juvenile idiopathic arthritis, ReACCH-Out Research in Arthritis in Canadian Children Emphasizing Outcomes inception cohort
^aAccording to the Wallace 2004 and/or ACR provisiona criteria 2011 unless otherwise commented
^bEULAR definition of remission: Inactive disease off medication for ≥ 2 years
^cIncluding 69% assessed only by questionnaires (CR at 15-year follow-up and no history of flare assessed by questionnaire after 23 and 30 years)
^dIncluding n = 205 lost to follow-up and assessed only by telephone interview

ISSN: 1546-0096