PRECEPT-OHCA: prehospital evaluation of confidence and practice in the treatment of out-of-hospital cardiac arrest across Australia, the United Kingdom, and New Zealand: a cross-sectional study protocol.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) has poor survival. Resuscitation guidelines recommend consideration of reversible causes, commonly termed the "4 Hs and 4 Ts", but prehospital constraints may limit clinicians' ability to identify or exclude them. This study will assess clinicians' confidence in identifying reversible causes, team composition, and perceived barriers to improving OHCA outcomes. METHODS: This international, multicentre, cross-sectional survey will recruit prehospital clinicians across Australia, New Zealand and the United Kingdom. It will be disseminated through prehospital and emergency medicine organisations using email links and QR codes. The questionnaire assesses respondent characteristics, team composition, equipment and medication availability, and confidence in ruling in and ruling out each reversible cause using a five-point Likert scale. Structured and free-text items examine service practices and barriers. From an estimated population of 54,874 clinicians, at least 382 responses are required. The primary outcome is clinicians' perceived confidence in identifying reversible causes. Secondary outcomes include service-level standard operating procedures, use of clinical adjuncts, and perceived barriers. Analyses will include descriptive statistics, Mann-Whitney U, Kruskal-Wallis and chi-squared tests, with thematic content analysis of free-text responses. DISCUSSION: The study will describe international variation in prehospital OHCA practice and assess how adjuncts, including point-of-care ultrasound, may support identification of reversible causes. Self-reported confidence may not reflect diagnostic accuracy or clinical performance. ETHICS AND DISSEMINATION: Ethics approval was granted by the Southern Adelaide Local Health Network Human Research Ethics Committee [2025/HRE00367] and the UK Health Research Authority [IRAS: 346781]. Findings will be published and presented at conferences.