Increasing risk of stroke with increased climate vulnerability: Assessing stroke burden and access to health care according to the climate vulnerability index in the United States

Background

Climate change-related worsening air quality and temperature extremes are linked to increased incidence of stroke. Stroke disproportionately impacts people living with higher risk of climate-related exposures and adverse health outcomes. This is an ecological study to examine the association between stroke, climate-related risks, and distance to comprehensive stroke centers (CSC) using the U.S. Climate Vulnerability Index (CVI).

Methods

CDC PLACES data was used to obtain stroke prevalence rates for 73,057 census tracts. CVI was used as measure of climate vulnerability. Maps and linear regression analyses evaluated the association between CVI score and stroke prevalence, and CVI score and distance to CSCs. Data were further stratified by CVI subdomains, regions, and historically-redlined communities.

Results

As CVI score increased, the odds of stroke also increased (OR 1.11, 95% CI [1.10 - 1.11]). The Southeast and Midwest regions had the highest odds of stroke (OR 1.14). The social-economic, infrastructure, and baseline health CVI subdomains were the most important factors in determining stroke risk. Additionally, census tracts with the highest CVI score were 2.67 times farther away from a CSC than those census tracts in the 50th percentile. In our analysis of metropolitan Atlanta, neighborhoods subjected to historical redlining clearly overlapped with high CVI-stroke prevalence census tracts.

Conclusions

Increased CVI score was associated with increased stroke burden and farther CSC distance. The most important contributing factors the social-economic, health, and infrastructure subdomains, highlighting the need to address these underlying conditions and improve health resources as the worsening climate crisis threatens to exacerbate disparities in already at-risk populations.