International multi-center real world implementation trial to increase out-of-hospital cardiac arrest survival with a dispatcher-assisted cardio-pulmonary resuscitation package (Pan-Asian resuscitation outcomes study phase 2)

Background: Dispatcher-assisted CPR (DA-CPR) has the potential to deliver early bystander CPR (BCPR) and improve out-of-hospital cardiac arrest (OHCA) survival. This study in the Asia-Pacific evaluated the impact of a DA-CPR program on BCPR rates and survival. Methods: This was a three-arm, prospective, multi-national, population-based, community-level, implementation trial. Cases between January 2009 and June 2018 from the Pan-Asian Resuscitation Outcomes Study were included. Sites either implemented a comprehensive (with quality improvement tool) or a basic DA-CPR package, or served as controls. Primary outcome was survival-to-discharge/30th day post-arrest. Secondary outcomes were BCPR and favorable neurological outcome. A before-after comparison was made within each country; this before-after change was then compared across the three groups using logistic regression. Results: 170,687 cases were analyzed. Before-after comparison showed that survival to discharge was higher in the ‘implementation’ period in all three groups: comprehensive odds ratio (OR) 1.09, 95% confidence interval (CI; [1.0–1.19]); basic OR 1.14, 95% CI (1.08–1.2); and control OR 1.25, 95% CI (1.02–1.53). Comparing between groups, the comprehensive group had significantly higher change in BCPR (comprehensive vs control ratio of OR 1.86, 95% CI [1.66–2.09]; basic vs control ratio of OR 0.94, 95% CI [0.85–1.05]; and comprehensive vs basic ratio of OR 1.97, 95% CI [1.87–2.08]) and survival with favorable neurological outcome (comprehensive vs basic ratio of OR 1.2, 95% CI [1.04–1.39]). Conclusion: We evaluated the impact of a DA-CPR program across heterogeneous EMS systems and demonstrated that a comprehensive DA-CPR program had the most impact on BCPR and favorable neurological outcome.