County-Level Association Between Social Vulnerability and Rheumatoid Arthritis-Related Mortality in the United States

Objectives: To evaluate associations between social vulnerability and rheumatoid arthritis (RA)-related mortality in the United States, with emphasis on domain-specific effects of the Social Vulnerability Index (SVI). Methods: We conducted a county-level ecological study of RA-related mortality from 2010 to 2019 using age-adjusted mortality rates and the Centers for Disease Control and Prevention SVI. Gamma regression models examined associations between RA mortality and overall SVI and four thematic domains, including socioeconomic status, household composition and disability, minority status and language, housing type and transportation by using both continuous and quartile-based measures. Results: Between 2010 and 2019, 354,280 deaths occurred among individuals with RA, corresponding to a mean age-adjusted mortality rate of 9.7 per 100,000 population. In multivariable analyses adjusting for all SVI domains, household composition and disability vulnerability demonstrated the strongest and most consistent positive association with mortality, with a dose-response relationship across quartiles. Housing type and transportation vulnerability showed a modest positive association. Minority status and language vulnerability was inversely associated with mortality, whereas socioeconomic vulnerability was not significant in continuous models but demonstrated an inverse association with mortality in quartile-based analyses. Conclusions: RA mortality is differentially associated with specific domains of social vulnerability rather than overall vulnerability burden. Household composition and disability represent clinically salient risk factors, demonstrating the relevance of functional status and caregiving context in RA outcomes. Domain-specific assessment of social vulnerability may enhance clinical risk stratification and inform more targeted, patient-centered RA management.