Abstract 283: Estimating the Impact of Bystander Interventions on Disability-Adjusted Life Years Following Adult Out-of-Hospital Cardiac Arrest in the United States

Abstract

Background: Disability-adjusted life years (DALY) are a common public health metric used to consistently estimate and compare disease burden. The impact of bystander interventions on DALY following out-of-hospital cardiac arrest (OHCA) is unknown. Our objective was to estimate the effect of bystander CPR (B-CPR) and bystander AED (B-AED) application on DALY following OHCA in the United States (U.S.). Methods: DALY were calculated as the sum of years of life lost (YLL) and years lived with disability (YLD) using all adult non-traumatic EMS-treated OHCA from the national CARES database for 2016. A multivariable linear regression model was constructed for effect estimation with DALY values as the outcome and standard Utstein variables as independent variables. Marginal effect estimates for B-CPR and B-AED were derived in models that used all independent variables as main effects. A sensitivity analysis included interaction terms. The analysis for B-CPR was limited to bystander witnessed events. The B-AED analysis was limited to public OHCA events. The marginal effects on DALY were used to derive national estimates of life years saved. Results: A total of 19,324 OHCA cases met study inclusion criteria. The provision of B-CPR was associated with an absolute mean decrease of -0.36 DALY; 95% CI (-0.44, -0.27) per OHCA, when compared to cases without B-CPR (p<0.001). When extrapolated to a national level, the cumulative effect of B-CPR resulted in an estimated 25,317 healthy life years saved; 95% CI (19,342, 31,292). Bystander AED application was associated with a mean reduction of -0.32 DALY; 95% CI (-0.41, -0.23) per OHCA (p<0.001). The cumulative effect of B-AED application was an estimated 22,755 healthy life years saved 95% CI (16292, 29218). From a regression model that incorporated interaction effects, B-CPR with defibrillation was associated with an estimated 74,758; 95% CI (58511, 91004) healthy life years saved. Conclusion: Bystander interventions are associated with a decrease in DALY following adult OHCA. These results highlight the importance of national bystander CPR and AED education and surveillance.