The "Strategies for Defibrillation during Out-of-Hospital Cardiac Arrest" (STRAT-DEFI) trial is an investigator-initiated, individually randomized, 3-group clinical trial comparing standard anterior-lateral pad positioning with anterior-posterior positioning and double sequential defibrillation during adult out-of-hospital cardiac arrest.

Inclusion Criteria:

1. Out-of-hospital cardiac arrest
2. Age ≥ 18 years
3. ≥ 1 manual defibrillation attempt by emergency medical services
4. Shockable rhythm as the last known rhythm
5. Two manual defibrillators present on-site

Exclusion Criteria:

1. Blunt trauma, penetrating trauma, or burn injury suspected to be the cause of the cardiac arrest
2. Prior enrollment in the trial
3. Posterior pad placement not deemed possible by on-site clinician

De-identified data. All relevant trial-related documents, including the protocol, data dictionary, and the main statistical code, will be shared along with the data.

After publication of the last results (i.e., 1-year follow-up), all de-identified individual patient data will be made available for data sharing as allowed within Danish law. There will be no predetermined end date for the data sharing.

Data will be available for any research purpose to all interested parties who have approval from an independent review committee if required and who have a methodological sound proposal as determined by the steering committee of the current trial. Only the methodological qualities and not the purpose or objective of the proposal will be considered. Interested parties will be able to request the data by contacting the principal investigator.