Abstract 257: Adherence to the Termination Recommendations in the Universal Termination of Resuscitation Rule and Survival After Out-of-hospital Cardiac Arrest

Abstract

Introduction: Survival after out-of-hospital cardiac arrest (OHCA) varies across emergency medical services (EMS) systems, but the EMS practices that contribute to the outcome variation are unclear. We evaluated the association between EMS agency variation in adherence to the termination recommendations in the Universal Termination of Resuscitation (TOR) rule and survival after OHCA. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry, a prospective multicenter OHCA registry in North America. We included adults (≥ 18 years) with OHCA for whom EMS providers attempted resuscitation from 2011 through 2015. The main exposure was proportion of patients meeting the Universal TOR rule (not EMS-witnessed arrest, no return of spontaneous circulation prior to transport, and no shock delivery prior to transport) among those who had prehospital TOR at the level of EMS agency. We categorized EMS agencies into quartiles based on the adherence to the Universal TOR rule. Our primary outcome was survival to hospital discharge. We used multilevel modified Poisson regression model, including patient-level and EMS-level covariates with patients nested within EMS agencies. Results: We included 43,656 EMS-treated OHCAs from 112 EMS agencies. The median adherence to the Universal TOR rule was 75.6% (interquartile range [IQR] 67.5-83.7) across EMS agencies. Compared with patients resuscitated at EMS agencies in the quartile of the lowest adherence (median adherence 62.5% [IQR 58.9-65.7]), survival to hospital discharge was inversely associated with treatment at EMS agencies in the second quartile (median adherence 72.6% [IQR 70.2-74.7]) (adjusted risk ratio [aRR] 0.83, 95% confidence interval [CI] 0.71-0.96), the third quartile (median adherence 80.6% [IQR 78.5-81.9]) (aRR 0.71, 95% CI 0.60-0.85), and the fourth quartile (median adherence 90.6% [IQR 86.2-93.7]) (aRR 0.68, 95% CI 0.58-0.80). Conclusions: In this large cohort study of adult patients with OHCA, we observed variation in the adherence to the Universal TOR rule’s termination recommendations across EMS agencies, and an association between higher EMS-level adherence and worse survival to hospital discharge after OHCA.