Methodology for creating a novel cardiac arrest registry using the Trinetx electronic health record database.

Background: Care in the hospital, post-arrest care, is a crucial component of out-of-hospital cardiac arrest (OHCA) management, but current OHCA databases contain limited post-arrest care data. To address this, we present the methodology for assembling a multicenter, real-world post-arrest care research registry using the Trinetx database. Methods: We queried the Trinetx research database (01/01/2000-02/19/2025), a federated database of electronic health record data from over 100 healthcare organisations in the US and internationally, to identify OHCAs from ICD codes for cardiac arrest related to emergency department (ED) visits. To define our cohort of patients eligible to receive post-arrest care, we identified OHCAs that survived to admission based on having a temporally associated inpatient encounter (based on encounter type/Current Procedure Terminology codes) or an ED visit lasting >24 h. We defined survival to discharge as 1) having an encounter after the hospitalisation and 2) having a death date after the end of the hospitalisation. We report patient characteristics and the number of clinical variables available in each data table for the cohort. Results: We identified 222,868 OHCAs and included 88,753 patients (39.8%) who survived to admission. The median age was 65, 60.3% were male, and 59.8% were White. Survival to discharge rate was 48.5%. The database contained 188,038,385 clinical data points: 40,868,707 vital signs, 52,145,594 labs, 17,781,035 procedures, 72,575,389 medication administrations, and 4,667,660 diagnoses. Conclusion: Using Trinetx real-world data, it is possible to create a multicentre, OHCA post-arrest care database with a substantial number of clinical variables, enabling novel post-arrest care research.