Abstract Body (Do not enter title and authors here): Background: A growing body of evidence highlights the role of structural racism, or the ways in which societies foster racial discrimination through mutually reinforcing systems, on cardiovascular outcomes. This study aimed to better understand this relationship using historic structural racism (historic redlining) and a novel measure of contemporary structural racism (structural racism effect index) on life expectancy, accounting for distribution of race across counties in the US.

Methods: After combining census tract level data, the final analytic sample consisted of 15,190 census tracts across 157 counties, within 50 states including DC. Historic structural racism was defined as historic redlining using the Home Owners’ Loan Corporation (HOLC) neighborhood grades (score between 1=best and 4=redlined). Contemporary structural racism was defined using the structural racism effect index (SREI), a summary score of nine domains (built environment, criminal justice, education, employment, housing, income/poverty, social cohesion, transportation, and wealth). Life expectancy was based on the National Center for Health Statistics’ US Small-area Life Expectancy Estimates Project using 2010-2015 data. Structural equation modeling in Stata v17 was used to investigate direct and indirect relationships between race, historic structural racism, contemporary structural racism, and life expectancy in the US.

Results: Mean life expectancy was 77.3 years and 26.7% of the US population within each census tract was Black/African American. Historic redlining (-0.06, p<0.001), contemporary structural racism (-0.61, p<0.001), and proportion of the census tract reporting Black race (-0.21, p<0.001) were directly associated with decreased life expectancy. Historic redlining was indirectly associated with decreased life expectancy via the pathway of contemporary structural racism (0.19, p<0.001). Black race was indirectly associated with decreased life expectancy through both more exposure to historic redlining (0.18, p<0.001) and higher levels of contemporary structural racism (0.56, p<0.001).

Conclusion: Structural racism, measured using historic or contemporary measures, is associated with decreased life expectancy. Contemporary structural racism is a stronger relationship for the pathway through which Black race is associated with lower life expectancy and is a pathway through which historic residential redlining influences life expectancy.