Abstract DP009: Neighborhood environmental burden and incident stroke and stroke severity: the Brain Attack Surveillance in Corpus Christi (BASIC) Project, 2022-2024

Background: Aspects of neighborhood environment, such as socioeconomic status, air pollution, walkability, and extreme heat, are associated with stroke incidence and severity. Less is known about cumulative and interactive effects of a range of neighborhood environmental features. We evaluated the associations of neighborhood social and environmental burden with incident stroke and initial stroke severity and whether these associations differed by ethnicity. Method: All first-ever Mexican American (MA) and Non-Hispanic White (NHW) stroke cases between 2022-2024 in the Brain Attack Surveillance in Corpus Christi Project across 78 census tracts were included (n=1,215). Stroke severity was measured by National Institute of Health Stroke Severity (NIHSS) score. Census-tract level social vulnerability index (SVI) and environmental burden index (EBI) data came from the CDC in 2022 ( Table 1 ). Cumulative environmental burden was calculated by summing the ranks of SVI and EBI and converting to a percentile score ranging from 0-1 (larger →higher burden). Data on population at risk of stroke by census tracts were from the US Census. Poisson and linear regressions were used to estimate unadjusted and age-sex-ethnicity adjusted associations between three environmental burden indices and their interaction and incident stroke rates and NIHSS score, respectively, accounting for clustering within census tracts. Results: High cumulative burden (index>0.75) existed in 15 tracts ( Figure 1 ). Similar distributions were found for SVI and EBI. Higher SVI was associated with higher incident stroke rates in the fully adjusted model ( Table 2 ), overall (90 th vs 10 th percentile RR 1.32, 95% CI 1.03, 1.69) and among MAs (RR 1.53, 95% CI 1.08, 2.16). Higher EBI was associated with lower incident stroke rates among NHWs (RR 0.78, 95% CI 0.61, 0.99) but not MAs. A multiplicative interaction between SVI and EBI was found (P=0.02) in the full sample. In neighborhoods with high EBI (90 th percentile), higher SVI was associated with higher stroke rates (RR 2.62, 95% CI 1.59, 4.32) but not in neighborhoods with low EBI. No significant association between environmental burden and NIHSS was found. Conclusion: Neighborhood social environmental burden was associated with higher incident stroke rates, particularly among MAs and neighborhoods with high natural and built environment burden. Findings suggest the importance of neighborhood social and environmental burdens in primary prevention of stroke.