Socioeconomic deprivation is associated with reduced response and lower treatment persistence with anti-tnf therapies in people with rheumatoid arthritis

Abstract Background/Aims Recent global health crises have highlighted the importance of socioeconomic (SE) inequalities and its influence on health provision and outcomes. The impact of SE deprivation on treatment of rheumatoid arthritis (RA) is understudied in contemporary biologic-treated populations. The aim of this study was to investigate the association between SE deprivation and outcomes of TNF inhibitor (TNFi) treatment. Methods Individuals commencing their first TNFi in the BSR Biologics Register for RA from 2001 to 2020 were included. SE deprivation was proxied using the Index of Multiple Deprivation (IMD), which measures relative deprivation of geographic areas. Using the participants' residential postcode, each individual was assigned a relative rank score and categorised into the 20% most deprived, middle 40%, and 40% least deprived; thresholds were chosen because IMD gives greater distinction within the most deprived areas. DAS28, low disease activity (LDA) and EULAR response at 6 months were compared using linear, logistic and ordinal logistic regression models with the 40% least deprived as referent. Risk of drug discontinuation was compared using Cox models. Models were first unadjusted, then adjusted for potential confounders and/or mediators, namely age, gender, baseline DAS28, BMI, HAQ, number of comorbidities, age at diagnosis, ever smoking status and rheumatoid factor status. Multiple imputation was used for missing data. Results 17,117 individuals were included (mean±SD age 56±12 years, 76% female), of whom 3002 (18%) were in the 20% most, 6999 (41%) in the middle 40%, and 7116 (41%) in the 40% least deprived groups (Table 1). The 20% most deprived group had higher DAS28 at 6 months (beta=0.30, 95%CI 0.22-0.37) and were less likely to achieve LDA (OR 0.76; 0.68-0.84) and EULAR response (OR 0.73; 0.67-0.80) in unadjusted models. They were also more likely to discontinue treatment (HR 1.19; 1.13-1.25). Adjusted estimates were broadly similar (Table 1). Conclusion SE deprivation is associated with reduced response to TNFi and increased risk of treatment discontinuation. Estimates were largely unchanged despite adjusting for potential mediators. SE inequality embodies a multitude of factors that can be intervened upon, including behaviours and biases of clinicians or institutes, which should be a focus of future research. Disclosure S. Zhao: None. L. Kearsley-Fleet: None. K. Rogers: None. K. Watson: None. A. Bosworth: None. J. Galloway: None. S.M. Verstappen: None. J.H. Humphreys: None. A. Barton: None. K.L. Hyrich: None.