b'Early Defibrillation With more than 15% of OHCAs occuring in public locations, the role of public access AEDs and community training have a large role to play in early defibrillation. However, the application of AEDs by bystanders remains relatively low, occurring after only 11.7% of public arrests.In 2023, 29.9% (n=41,736) of CARES patients were defibrillated in the field. Among these patients, 5.4% were initially defibrillated by a bystander, while 20.4% and 74.2% were first defibrillated by a first responder or EMS personnel, respectively.Reducing delays to defibrillation leads to improved outcomes for patients in a shockable rhythm. Unadjusted outcomes for this subset of patients vary based on who performed the first defibrillation (Figure 15). The proportion of OHCA patients surviving to hospital discharge when first defibrillated by a bystander with an AED was 47.1%, compared to 25.8% of patients first shocked by a first responder and 27.9% by responding EMS personnel.60% 60% 60%47% 43% 44% 45% 47%40%26% 28%20%0%Bystander AED First Responder Responding EMS Sustained ROSC Survived to admission Survived to dischargeFigure 15. Unadjusted survival outcomes by who performed first defibrillation in the population with a shockable presenting rhythm.38 39'