Abstract 262: Mediating Factors Between Community Race/Ethnicity and Initial Shockable Rhythm

Abstract

Background: Initial shockable rhythm is an important predictor of favorable out-of-hospital cardiac arrest (OHCA) outcomes. While patients from minoritized communities suffer from lower rates of initial shockable rhythm, the reason for this disparity is not known. Hypothesis: OHCA characteristics contribute to disparities in initial shockable rhythm. Methods: We performed a retrospective study of the 2014-2021 Texas Cardiac Arrest Registry to Enhance Survival, including adult, non-traumatic OHCAs. Linked to census tract data, we stratified OHCAs based on having a majority of a race/ethnicity: >50% White, >50% Black, and >50% Hispanic/Latino. To evaluate if initial shockable rhythm impacts outcome disparities, we compared logistic regression models between race and OHCA outcomes: 1) unadjusted, 2) adjusted for bystander CPR (bCPR), and 3) adjusted for initial rhythm. Using structural equation modeling, we then performed a mediation analysis between race/ethnicity, OHCA characteristics, and shockable rhythm, reporting the mediations proportions. Results: We included 39,596 OHCAs, 16,702 White, 5,461 Black, and 17,433 Hispanic. The rate of shockable rhythm was 19.0% for White, 14.3% for Black, and 14.6% for Hispanic. Odds of favorable neurologic outcome were lower for Black (OR 0.5, 95% CI 0.4-0.6) and Hispanic (OR 0.6, 95% CI 0.6-0.7). While adjusting for bCPR did not change these odds, adjusting for shockable rhythm increased odds for Black (OR 0.6, 95% CI 0.5-0.7) and Hispanic (OR 0.7, 95% CI 0.6-0.8). On mediation analysis, the proportion of initial shockable rhythm mediated for Black census tract were: age>65 (-7.3%), male gender (6.8%), public location (6.9%), healthcare facility location (-17.2%), bystander witnessed (19.2%), bCPR (4.3%), and bystander AED (6.4%). The proportion mediated for Hispanic census tract were: age>65 (-4.8%), male gender (0.5%), public location (-4.0%), healthcare location (-13.5%), bystander witnessed (20.8%), bCPR (8.7%), and bystander AED (6.2%). Conclusion: Bystander witnessed arrest was the most significant mediator of shockable rhythm for OHCA in Black and Hispanic communities, while bCPR was a modest mediator of shockable rhythm for Hispanic OHCA victims.