Effectiveness of a community based out-of-hospita cardiac arrest (OHCA) interventional bundle: Results of a pilot study

Background: 70% of Out-of-hospital cardiac arrests (OHCA) in Singapore occur in residential areas, and are associated with poorer outcomes. We hypothesized that an interventional bundle consisting of Save-A-life (SAL) initiative (cardiopulmonary resuscitation (CPR)/automated external defibrillator (AED) training and public-housing AED installation), dispatcher-assisted CPR (DA-CPR) program and myResponder (mobile application) will improve OHCA survival. Methods: This is pilot data from initial implementation of a stepped-wedge, before-after, real-world interventional bundle in six selected regions. Under the SAL initiative, 30,000 individuals were CPR/AED trained, with 360 AEDs installed. Data was obtained from Singapore's national OHCA Registry. We included all adult patients who experienced OHCA in Singapore from 2011 to 2016 within study regions, excluding EMS-witnessed cases and cases due to trauma/drowning/ electrocution. Cases occurring before and after intervention were allocated as control and intervention groups respectively. Survival was assessed via multivariable logistic regression. Results: 1241 patients were included for analysis (Intervention: 361: Control: 880). The intervention group had higher mean age (70 vs 67 years), survival (3.3% [12/361] vs. 2.2% [19/880]), pre-hospital return of spontaneous circulation (ROSC) (9.1% [33/361] vs 5.1% [45/880]), bystander CPR (63.7% [230/361] vs 44.8% [394/880]) and bystander AED application (2.8% [10/361] vs 1.1% [10/880]). After adjusting for age, gender, race and significant covariates, the intervention was associated with increased odds ratio (OR) for survival (OR 2.39 [1.02-5.62]), pre-hospital ROSC (OR 1.94 [1.15-3.25]) and bystander CPR (OR 2.29 [1.77-2.96]). Conclusion: The OHCA interventional bundle (SAL initiative, DA-CPR, myResponder) significantly improved survival and is being scaled up as a national program.