Abstract
BACKGROUND: Immediate cardiopulmonary resuscitation and early defibrillation are key determinants of survival after out-of-hospital cardiac arrest (OHCA). Public access defibrillation (PAD) remains inconsistently implemented, with major gaps in automated external defibrillator (AED) availability, integration and use. This study aimed to identify and prioritise barriers and enablers to PAD implementation and to highlight emerging deployment models for future research. METHODS: During the third International Community First Responder Symposium (April 2024, Hinterzarten, Germany), 46 experts from 14 countries participated in a structured RAND-UCLA Appropriateness Method consensus study. In moderated discussions, participants identified barriers and enablers to PAD, which were grouped into four thematic fields: availability and accessibility, usability and awareness, technological and systemic aspects, and financial and maintenance concerns. Nine statements were formulated and rated on a 9-point Likert scale; strong consensus was defined a priori as a median ≥ 7 with ≥ 80% of ratings in the 7-9 range. RESULTS: All nine statements met criteria for strong consensus. Key barriers included limited 24/7 AED access, poor coverage in residential areas, lack of centralised, real-time AED registries, insufficient public training and awareness, legal concerns for lay responders, patchy integration with emergency medical services, and device and maintenance costs. Key enablers comprised mandatory AED registration and live mapping, community training, legal protection for lay users, equipping police and fire services with AEDs within a "nearest vehicle" strategy, and improved data sharing between AEDs and hospitals. Experts also highlighted innovative deployment concepts, including use of postal and transport fleets, Vertical Take off and Landing drones, predictive positioning models and low-cost device designs. CONCLUSION: This international consensus study underscores the need for coordinated policy, robust AED registries, widespread training and multi-tier response models to improve PAD implementation. The identified priorities and innovative deployment strategies offer an agenda for future system development.