RescQ™: Study protocol for a feasibility pilot of structured support for bystanders/lay-rescuers following out-of-hospital cardiac arrest.

Worldwide, 3.8 million out-of-hospital cardiac arrests (OHCA) occur annually. RescQ™ is a 12-month, non-randomised, prospective feasibility pilot evaluating a structured support pathway for adult bystanders involved in out-of-hospital cardiac arrest of presumed medical or cardiac aetiology across Essex, United Kingdom. The pathway was developed to address the absence of a nationally standardised post-event support process for bystanders who witness, call emergency services, or assist with resuscitation. Attending ambulance clinicians offer brief on-scene signposting and register consenting adult bystanders through a dedicated digital application. Registration triggers a single text message or email linking to the RescQ™ website, which provides information on common physical and psychological reactions after involvement in cardiac arrest, coping strategies, lived-experience videos and sources of further support. Bystanders can self-refer to a liaison officer for structured supportive contact, psychological screening (using Clinical Outcomes in Routine Evaluation and the National Stressful Events Survey Short Scale), event-related discussion, signposting and onward referral where required. The primary outcome is feasibility, assessed through ambulance clinician uptake, bystander website access and acceptability to ambulance clinicians and bystanders. Secondary outcomes include digital engagement, psychological screening data, liaison officer activity, onward referral, satisfaction and service-delivery resource use. The project was reviewed by the West of Scotland Regional Ethics Committee and classified as a service evaluation. At the time of revised submission, the 12-month pilot has been completed, and data analysis is underway.