Abstract
Sociodemographic factors, such as socioeconomic status and ethnicity, have been shown to associate with outcomes across many diseases. This analysis aims to investigate the association between outcomes over the first 6 months following initiation of methotrexate, ethnicity, and socioeconomic status, in children and young people with juvenile idiopathic arthritis (JIA).
Patients with JIA who started methotrexate between 01/2004 and 11/2017 and were registered in the UK JIA Biologics Register at the point of starting methotrexate were identified. The primary outcome was the mean change in Juvenile Arthritis Disease Activity Score (JADAS) between baseline and 6 months of follow-up. Multivariable linear regression was used to assess the association between ethnicity (grouped as White, Mixed, Asian and Black) or relative deprivation (using quintiles of the Index of Multiple Deprivation, IMD), and change in JADAS, adjusted for age, gender, baseline JADAS and ILAR category. Multiple imputation was used to handle missing covariate and outcome data.
830 patients (median age 9 years; 69% female; 87% White ethnic group, 3% Mixed, 8% Asian, 2% Black; 20% in most deprived quintile) were included (Table). Six months after starting methotrexate, mean change in JADAS was -10.7 units (95% CI -11.6, -9.9), indicating overall improvement. Compared to those with White ethnicity, children with Black ethnicity experienced an overall lesser mean improvement in JADAS of 6.1 units (95% CI 0.8, 11.4). There was no significant difference observed in change in JADAS between those living in lesser deprived areas compared to those from the most deprived areas (-1.1 units [95% CI -2.6, 0.3]).
This analysis using observational data has shown an association between ethnicity and improvements in disease activity in the first 6 months following start of methotrexate in children and young people with JIA. Whilst small sample sizes limit robust conclusions, research should continue into understanding why these differences in outcomes are observed, such that interventions to improve outcomes for all children and young people with JIA can be implemented.
R.P. Beesley: None. L. Kearsley-Fleet: None. E. Baildam: None. M.W. Beresford: None. S. Douglas: None. T.R. Southwood: None. K.L. Hyrich: None. J.H. Humphreys: None.
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