Doubly marginalized: the interplay of racism and disability in outcomes for minoritized people with Down syndrome.

Background: Intersectionality, or the multidimensional influence of social identity and systems of power, may drive increased morbidity and mortality for adults of color with Down syndrome. We documented racial and ethnic differences in death and hospitalizations among Medicaid enrolled adults with Down syndrome and assessed interaction of racial-ethnic group and Down syndrome.

Methods: Our sample consisted of 119,325 adults with Down syndrome and >3.2 million adults without intellectual disability enrolled in Medicare at any point from 2011-2019. We calculated age-adjusted mortality and hospitalization rates by racial-ethnic group among those with Down syndrome. We examined additive interaction between Down syndrome and racial and ethnic group on mortality and hospitalization rates.

Results: Among those with Down syndrome, age-adjusted mortality rate did not differ between Black and White racial groups (rate ratio: 0.96, 95%CI: 0.92, 1.01) while mortality rate was lower for Pacific Islander (0.80), Asian (0.71), Native (0.77), and Mixed-race groups (0.50). Hospitalization rates were higher for all marginalized groups compared to the White group. When assessing the interaction between racial-ethnic group and Down syndrome, Black, Native Americans, and Mixed-race groups exhibited a negative additive interaction for mortality rate and all groups except Native Americans exhibited positive additive interaction for hospitalization.

Conclusions: Increased hospitalization rates for adults with Down syndrome from marginalized racial and ethnic groups suggest worse health and healthcare. Similar mortality rates across racial and ethnic groups may result from increased infant mortality rate in marginalized groups with Down syndrome leading to reduced mortality among those surviving to adulthood.