Socioeconomic deprivation is associated with reduced response and lower treatment persistence with TNF inhibitors in rheumatoid arthritis

Abstract

Objective To investigate the association between socioeconomic deprivation and outcomes following TNF inhibitor (TNFi) treatment. Methods Individuals commencing their first TNFi in the British Society for Rheumatology Biologics Register for RA (BSRBR-RA) and Biologics in RA Genetics and Genomics Study Syndicate (BRAGGSS) cohort were included. Socioeconomic deprivation was proxied using the Index of Multiple Deprivation and categorised as 20% most deprived, middle 40%, 40% least deprived. DAS28-derived outcomes at 6 months (BSRBR-RA) and 3 months (BRAGGSS) were compared using regression models with the least deprived as referent. Risks of all-cause and cause-specific drug discontinuation were compared using Cox models in the BSRBR-RA. Additional analyses adjusted for lifestyle factors (e.g. smoking, BMI) as potential mediators. Results 16 085 individuals in the BSRBR-RA were included (mean age 56 years, 76% female), of whom 18%, 41% and 41% were in the most, middle and least deprived groups. Of 3459 included in BRAGGSS (mean age 57, 77% female), proportions were 22%, 36%, 41%, respectively. The most deprived group had 0.3-unit higher 6-month DAS28 (95%CI 0.22–0.37) and were less likely to achieve low disease activity (OR 0.76; 0.68–0.84) in unadjusted models. Results were similar for 3-month DAS28 (beta = 0.23, 95%CI 0.11–0.36) and low disease activity (OR 0.77; 0.63–0.94). The most deprived were more likely to discontinue treatment (HR 1.18; 1.12–1.25), driven by ineffectiveness rather than adverse events. Adjusted estimates were generally attenuated. Conclusion Socioeconomic deprivation is associated with reduced response to TNFi. Improvements in determinants of health other than lifestyle factors are needed to address socioeconomic inequities.