Association of Modifiable Risk Factors Measured With the Brain Care Score and Incident Stroke in the REGARDS Cohort

Abstract

OBJECTIVES: Stroke disproportionately affects Black individuals in the United States. We aimed to assess differences between Black and White individuals in the associations between health-related behaviors, measured with the Brain Care Score (BCS; a tool encompassing 12 modifiable risk factors), and incident stroke. METHODS: We analyzed data from REGARDS, a prospective US cohort of Black and White adults aged 45 years or older. Participants who were stroke free at baseline with complete BCS data were included. We assessed the BCS (range: 0-21; higher indicating healthier behaviors) and its associations with incident stroke in Black vs White individuals. Cox proportional hazard models were stratified by race (Black vs White) and adjusted for demographics and socioeconomic factors. Effect sizes were compared using Z-statistics. RESULTS: Among 10,861 participants (30.6% Black, 57.4% female, mean age: 63.2 years), 696 strokes occurred over a median of 15.9 years. A five-point higher BCS was associated with lower stroke risk in both groups, with larger magnitude among Black vs White individuals (HR: 0.47 [95% CI 0.36-0.61] vs 0.75 [95% CI 0.62-0.92]; Z-statistic p value = 0.0045). DISCUSSION: The BCS is associated with incident stroke in a biracial US cohort and shows larger effect sizes within Black compared with White individuals, suggesting that BCS improvement may yield greater stroke prevention benefits for Black populations.