O05 Juvenile idiopathic arthritis is core business in adult rheumatology: the case for specialist services
Authors: Nock Rebecca J , Maxwell James R , Tattersall Rachel S 
Published: April 2021

Abstract
Background/Aims
Juvenile idiopathic arthritis (JIA) is a heterogenous, childhood-onset condition persisting into adulthood in over 50% of people. Recognition of JIA-specific features is poor in adult services, there are no validated disease activity scores for adults with JIA and specialist adult JIA clinics are rare; this leads to under-treatment of adults with JIA. Sheffield Teaching Hospitals (STH) has a mature transition service and well-established young adult clinic (YAC) for 16-25 year olds and older adults with JIA. Here, we evaluate the proportion of our adult rheumatology workload attributable to JIA, the prevalence of JIA subtypes and therapies utilised.
Methods
Outpatient attendances in STH rheumatology are coded by diagnosis. The evaluation period was 1.12.2018 to 27.2.2020. We evaluated the number and characteristics of patients in the JIA cohort, producing a database from coded diagnoses and patient records, and analysed this using Microsoft Excel. Local permission was granted.
Results
11,520 patients were seen in adult rheumatology in the evaluation period; 9,422 had a coded diagnosis of which 4,915 (52%) had inflammatory arthritis (IA). Assuming a proportional number of the 2,098 non-coded patients had IA (1,090), the adult IA cohort is estimated at 6,005. 304 patients (aged 17-72) with JIA were seen in adult rheumatology, accounting for 5% of the adult IA cohort. 280 (92%) were in the YAC, and 24 (8%) in general rheumatology. 31 (10%) patients had evidence of uveitis. The commonest subtypes of JIA were: 75 polyarticular (25%), 38 enthesitis related (13%) and 37 extended oligoarticular (12%). 64 (21%) patients had no subtype specified. Of the 233 (77%) JIA patients ever treated with methotrexate, 132 (57%) had discontinued due to inefficacy or adverse effects. 175 (58%) patients were on biologic treatment: the commonest therapies were adalimumab (40%, 70 patients) and etanercept (27%, 47 patients). There is evidence of diagnostic relabelling from JIA to other IA to access biologics not approved by NICE.
Conclusion
This evaluation uses real-world data, with some data loss due to absent coding, but shows JIA is a small proportion of adult rheumatology. This is a complex group with high biologic use, poor methotrexate tolerance and heterogenous disease phenotypes. Young adults experience specific challenges in adult services and require developmentally appropriate care, for which best evidence confirms young adult clinics are ideal. The majority of people with JIA are in a dedicated young adult service at STH. Biologics are used within NICE guidance, except for a minority where JIA is relabelled as IA to access additional biologics or due to independent funding requests. NICE guidance for JIA is outdated and restrictive. JIA is an adult disease in &gt; 50% and requires specialist services, further research to elucidate validated adult disease activity scores and wider education amongst adult rheumatologists.
Disclosure
R.J. Nock: None. J.R. Maxwell: Other; JRM has served on advisory boards for Abbvie, Pfizer, BMS and Lilly and has received speaking honoraria from Pfizer, BMS, Novartis and Lilly. R.S. Tattersall: Other; RST has received speaker fees and educational grants to attend meetings from UCB, AbbVie, Pfizer and Janssen.