The global research landscape of emergency medical services in out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) remains a major cause of death, and emergency medical services (EMS) are central to recognition, resuscitation, transport, and linkage to post-arrest care. Although previous bibliometric studies have mapped the broader cardiac arrest and cardiopulmonary resuscitation literature, the intersection of EMS and OHCA warrants focused characterization. We performed a retrospective bibliometric analysis of records indexed in the Web of Science Core Collection from 1972 through June 2026. The search combined OHCA terms with terms for EMS, paramedics, and emergency medical technicians. Annual output, research categories, journals, authors, and countries were described. VOSviewer version 1.6.20 was used for author co-authorship, keyword co-occurrence, and cited-reference co-citation analyses. The search identified 3,005 records. Annual output increased markedly after 2010, peaked at 244 publications in 2021, and remained above 200 publications per year from 2022 to 2025; 130 records were indexed for the partial 2026 year. Emergency Medicine (1,745; 58.1%) and Critical Care Medicine (1,014; 33.7%) were the most frequently assigned Web of Science categories. Resuscitation published 694 records (23.1%). The United States had the greatest country-level output (1,022; 34.0%), followed by Japan (375; 12.5%) and Canada (281; 9.4%). The most prolific author was Shin SD (98 publications). Co-authorship mapping showed registry-centered regional communities, while keyword analysis yielded ten interpreted domains spanning epidemiology, resuscitation interventions, dispatch, registries, extracorporeal cardiopulmonary resuscitation, equity, and technology-related topics. Co-citation analysis identified four major intellectual communities. EMS-focused OHCA publications indexed in Web of Science show sustained output and international collaboration associated with established registries. Limited visibility of low- and middle-income settings within this database warrants further investigation. Equity, implementation, and digital and resuscitative technologies are potential areas for further research; the pooled network analysis does not establish their temporal growth.