Improving survival from out-of-hospital cardiac arrest (OHCA) is a global health priority. Without immediate recognition, provision of good quality cardiopulmonary resuscitation and early defibrillation, the chances of survival from OHCA are negligible. Ireland has a heterogeneous settlement pattern, ranging from villages to one-off housing in rural areas, and from small towns to inner-city communities. Serving a national population with geographic inequalities in a resource constrained environment is a critical challenge for the National Ambulance Service (NAS). The reality is that the challenge of reaching OHCA victims on time, every time cannot be met by NAS alone. Community response is an important but unquantified component to meeting this challenge. Many community responses have been developed in Ireland over the years involving General Practitioners (GPs), lone off-duty ambulance personnel, community first responder (CFR) groups, county fire services and rapid response groups in discrete, mainly rural, areas. Ireland is one of three European countries with a long-established OHCA register, but does not include data that explicitly describes the contribution of community response to OHCA. The aim of the project is to investigate the challenges to effective community response in Ireland and to embed data on community response in routine Irish clinical data collection for OHCA. We will review international best practice on the community response role in OHCA (including the role of automated external defibrillator (AED) registers), and consult with key stakeholders on the barriers to community response development, how best to integrate the role of community response in OHCA and how to record such a role. It is envisaged that this project will provide information that can inform support services for community response in Ireland. It will result in the development of a reliable recording process, providing data that can reliably evaluate the impact of community responders on OHCA outcome in Ireland.