Objective: To examine the independent and interdependent effects of race and social determinants of health (SDoH) and risk of all-cause and cardiovascular disease (CVD) mortality in the US.
Data source/study design: Secondary analysis of pooled data for 252,218 participants of the 2006-2018 National Health Interview Survey, linked to the National Death Index.
Methods: Age-adjusted mortality rates (AAMR) were reported for non-Hispanic White (NHW) and non-Hispanic Black (NHB) individuals overall, and by quintiles of SDoH burden, with higher quintiles representing higher cumulative social disadvantage (SDoH-Qx). Survival analysis was used to examine the association between race, SDoH-Qx, and all-cause and CVD mortality.
Findings: AAMRs for all-cause and CVD mortality were higher for NHB and considerably higher at higher levels of SDoH-Qx, however, with similar mortality rates at any given level of SDoH-Qx. In multivariable models, NHB experienced 20-25% higher mortality risk relative to NHW (aHR = 1.20-1.26); however, no association was observed after adjusting for SDoH. In contrast, higher SDoH burden was associated with up to nearly threefold increased risk of all-cause (aHR, Q5 vs Q1 = 2.81) and CVD mortality (aHR, Q5 vs Q1 = 2.90); the SDoH effect was observed similarly for NHB (aHR, Q5:all-cause mortality = 2.38; CVD mortality = 2.58) and NHW (aHR, Q5:all-cause mortality = 2.87; CVD mortality = 2.93) subgroups. SDoH burden mediated 40-60% of the association between NHB race and mortality.
Conclusions: These findings highlight the critical role of SDoH as upstream drivers of racial inequities in all-cause and CVD mortality. Population level interventions focused on addressing adverse SDoH experienced by NHB individuals may help mitigate persistent disparities in mortality in the US.
Keywords: All-cause mortality; Cardiovascular mortality; Mortality; Race; Racial disparities; Social determinants of health.
© 2023. W. Montague Cobb-NMA Health Institute.