Effect of a resuscitation quality improvement programme on outcomes from out-of-hospital cardiac arrest

Background: Many emergency medical service (EMS) agencies are implementing programmes to improve the quality and performance of resuscitation. We sought to examine the impact of a resuscitation quality improvement programme on outcomes following OHCA. Methods: An interrupted time-series analysis of adult OHCA patients of medical aetiology. Patients treated after the implementation of a high-performance cardiopulmonary resuscitation (CPR) intervention between February 2019 and January 2020 were compared to historical controls between January 2015 and January 2019. The effect of the intervention on the risk-adjusted odds of survival were examined using logistic regression models, with and without adjustment for temporal trends. Results: A total of 8270 and 2330 patients were treated in the control and intervention periods, respectively. Patients in the intervention period were older and less likely to arrest in public, present with an initial shockable rhythm, and receive mechanical CPR. After adjustment for arrest factors and temporal trends, there was a significant increase in the level of monthly survival to hospital discharge (AOR 1.50; 95% CI: 1.10, 2.04; p = 0.01), event survival (AOR 1.34; 95% CI: 1.09, 1.65; p = 0.006) and return of spontaneous circulation (AOR 1.38; 95% CI: 1.14, 1.65; p = 0.001). After removing the non-significant temporal trend, there was a 33% increase (AOR 1.33; 95% CI: 1.11, 1.58; p = 0.002) in the risk-adjusted odds of survival over the 12-month intervention period. The average marginal effect of the intervention resulted in 8.7 (95% CI: 3.2, 14.1) additional survivors per million population. Conclusion: A resuscitation quality improvement programme consisting of high-performance CPR was associated with a significant increase in survival following OHCA.