Increased prevalence, ER visits, and hospitalizations in medicare systemic lupus erythematosus patients living in socially vulnerable counties: A cross-sectional study.

Background: Systemic Lupus Erythematosus (SLE) disproportionately affects women, minorities, and individuals with low socioeconomic status. We hypothesized that counties with a higher percentage of disadvantaged individuals have a higher prevalence of SLE and increased acute hospital events, including emergency room (ER) visits and hospitalizations, among Medicare patients with SLE.

Methods: This cross-sectional study used the Centers for Disease Control and Prevention's Social Vulnerability Index (SVI) and Lupus Research Alliance's Lupus Index Medicare data. SLE was identified through Medicare fee-for-service administrative records from 2016 containing two or more ICD-10 codes for SLE. We examined SLE prevalence, acute hospital events, and their association with county-level SVI rankings.

Results: The study population was 89 % female and 69 % White, with 22 % Black. SVI ranking (r = 0.508) and its subthemes correlated with SLE prevalence, with socioeconomic status and household composition showing the strongest associations (R = 0.431 and R = 0.365, respectively). Similar but weaker correlations were seen between SVI and acute healthcare events, including ER visits and hospitalizations. Limitations include the cross-sectional design preventing longitudinal analysis, reliance on administrative data potentially introducing bias, and exclusion of counties with fewer than 10 SLE patients.

Conclusions: This is the first study linking county-level vulnerability to SLE prevalence and healthcare events in a Medicare SLE population. Findings suggest that social and environmental factors influence SLE risk and healthcare utilization, much like other chronic diseases. The modest association between location and hospital/ER events suggests that structural factors may act as barriers to optimal care and outcomes.