Association of Race and Social Determinants of Health With Exacerbations in Generalized Myasthenia Gravis.

Introduction/aims: While racial/ethnic disparities exist across many disease states, their influence on the risk of adverse clinical outcomes in large populations of generalized myasthenia gravis (gMG) patients has not been extensively studied. This study assessed the association between race/ethnicity and MG exacerbation risk and examined the potential role of social determinants of health (SDOH).

Methods: This retrospective cohort study utilized data from HealthVerity; a large, de-identified, US insurance claims database. Eligible patients were adults with gMG (≥ 2 MG diagnosis code claims, excluding patients with only ophthalmologic specialist visits on/before index date). Inverse probability of treatment weighting using baseline variables was constructed with multinomial distribution for race/ethnicity (Asian/Black/Hispanic/White). Incidence rate ratio (IRR) for ≥ 1 MG exacerbation (defined as an inpatient episode with MG as admitting diagnosis) during follow-up was assessed using a generalized estimating equations model, using "White" as the reference. A subset of patients was linked with SDOH variables by residential ZIP code (income-per-capita and percentage of population without health insurance coverage) using the Agency for Healthcare Research and Quality database, and MG exacerbation risk adjusted.

Results: Of 10,981 gMG patients, 5147 had linked SDOH data. Weighted risk of MG exacerbations was significantly higher among Black versus White patients (IRR 1.21; 95% confidence interval 1.05-1.39). The association remained after controlling for income and/or health insurance coverage.

Discussion: Potential racial disparities exist in the occurrence of MG exacerbations. Further investigation of potential drivers is warranted. At-risk populations should be a focus for healthcare and patient support provision.