The association between ethnicity, socioeconomic position and outcomes following initiation of TNF inhibitors in Juvenile Idiopathic Arthritis: Results from the UK JIA Biologics Register.

Abstract

Health outcomes in children and young people are known to vary by ethnicity and socioeconomic position. In juvenile idiopathic arthritis (JIA), it is unclear whether this relates to differential changes following one of the most common treatments, TNF-inhibitors (TNFi). This study investigated these factors, disease activity and treatment persistence following initial TNFi therapy in patients with JIA in the UK. Patients with non-systemic JIA in the UK JIA Biologic Register starting their first TNFi biologic were included. Outcomes included change in disease activity between start of TNFi and 6 months, measured by JADAS-71.Multivariable linear regression was used to assess the association between ethnicity or socioeconomic position and change in JADAS. Treatment persistence was analysed using Kaplan-Meier estimates. Cox proportional hazards models compared TNFi drug persistence by ethnic group and by socioeconomic position. A total of 1,641 patients were included; 67% female, 90% White ethnic group (6% Asian, 2% Black, 2% Mixed), 25% in the most deprived socioeconomic group. JADAS-71 improved for all ethnic and socioeconomic groups by 6 months, with no difference in improvement by group.The proportion of patients remaining on TNFi at 12 months (67%) and the likelihood of stopping was similar between all ethnic and socioeconomic groups. Outcomes following TNFi initiation are similar between ethnic and socioeconomic groups. Based on the results of this study, ethnicity and socioeconomic position do not appear to be associated with differential change in disease activity, and there is no evidence that the effects of socioeconomic position are moderated by ethnicity or vice versa.