Prehospital data in the dark: a scoping review of the widening gap between EMS demand and the evidence to meet it

Prehospital emergency medical services generate data at unprecedented scale, yet the scientific evidence base underpinning this field remains thin relative to operational activity. This scoping review examines the challenges of prehospital data utilisation and research conduct, explores methodological limitations of the existing literature, considers the challenge of linking prehospital data to in-hospital outcomes, and discuss the economic and structural case for investment in prehospital research capacity. A structured literature search was conducted across PubMed/MEDLINE combining MeSH terms and free-text keywords across three conceptual domains: prehospital EMS systems, electronic health records and data infrastructure, and health services research capacity and evidence generation. The search was updated in May 2025. An integrated EMS systems audit examined publicly available annual reports and operational data from 15 EMS systems selected randomly to explore research output reporting practices within EMS systems. Prehospital research is constrained by the operational environment, ethical and governance complexity, fragmented data systems, absence of linkage infrastructure, inadequate funding mechanisms that remains underdeveloped in most services. The updated search retrieved 1,886 records; after duplicate removal and title/abstract screening, 11 peer-reviewed studies meeting the eligibility criteria were included. None of the 15 EMS systems audited reported research output as a formal key performance indicator, with the sole exception of Denmark. Publications per 100,000 patient contacts ranged from 3.65 in the USA to 0.40 in Saudi Arabia. Addressing the prehospital evidence gap requires coordinated investment at organisational, national, and international levels in the technical, institutional, and cultural conditions that enable scientific research. The cost of operating without an adequate evidence base is reflected in the resource allocation decisions made by services.