Background: Out-of-hospital cardiac arrest (OHCA) outcomes vary significantly across U.S. communities; however, systems of care factors that increase the likelihood of survival have not been well elucidated. The Enhancing Pre-Hospital Outcomes for Cardiac Arrest (EPOC) study is quantifying variation in the rate of sustained return of spontaneous circulation (ROSC) upon Emergency Department (ED) arrival across Michigan Emergency Medical Services (EMS) agencies as a first step to identifying ‘best practices’ in prehospital OHCA care.
Methods: Michigan Cardiac Arrest Registry to Enhance Survival (CARES) data for the years 2014-2016 was used. EMS agencies with 5+ arrests over the study years were included in the analysis. Using mixed-effects logistic regression, we calculated each agency’s reliability-adjusted sustained ROSC upon ED arrival; these rates were standardized across patient-, community-, and arrest-level characteristics.
Results: A total of 91 agencies covering >6.8 million lives met inclusion criteria. We included 14,219 OHCA patients with a mean age of 62.6, 40.0% female, and 18.2% with a shockable rhythm in the analyses. Across all agencies, the mean patient-standardized rate of sustained ROSC with pulse upon ED arrival was 25.3% (range, 6.1%-51.9%; IQR, 18.9%-31.2%). There were 14 agencies with patient-standardized rates and 95% CIs that exceeded the overall mean survival rate suggesting better-than-average outcomes while 16 agencies had rates and 95% CIs that were lower than the overall mean survival rate.