Health Disparities
Area Deprivation as a Modifier of Racial and Income-Based Disparities in Stroke Risk: A Population-Based Analysis Jiajun Luo* Jiajun Luo Briseis Aschebrook-Kilfoy
Background: Prior research has consistently shown that minority populations and lower-income groups experiencing a higher burden. However, less is known about how broader contextual factors, such as neighborhood-level deprivation, interact with individual characteristics to exacerbate or mitigate these disparities. This study investigates the interaction between area deprivation, race, and household income in determining stroke risk in the US.
Methods: The study used data from the All of Us Research Program. Participants aged above 35 and with valid data on electronic health records (EHR), household income, and race/ethnicity identity were included for analysis. Stroke incidence was measured based on EHR records. Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval for stroke according to racial/ethnic and household income groups.
Results: A total of 178,026 participants were included in this study. Race/ethnicity and household income were significantly associated with stroke incidence (Table). When stratified by area deprivation index, the associations of race and ethnicity were strengthened in the high-deprivation area (non-Hispanic Black: HR=2.21, 95% CI: 1.73-2.82), nonetheless, became null in the low-deprivation area (non-Hispanic Black: HR=0.99, 95% CI: 0.75-1.30). The difference was significant (P for interaction <0.01). The associations of household income were also more pronounced in the high-deprivation area (≥100k: HR=0.61, 95% CI: 0.43-0.87) compared to the low-deprivation area (≥100k: HR=0.73, 95% CI: 0.58-0.93).
Conclusion: The finding that racial and income-based disparities in stroke risk are only present in high-deprivation areas suggests that structural inequalities embedded in disadvantaged neighborhoods may amplify the effects of individual-level risk factors.
