Expanded physician-led air ambulance services are improving access to advanced prehospital care across the UK, yet important regional and overnight gaps highlight ongoing challenges in delivering equitable lifesaving treatment.
Study: Access to physician-based Helicopter Emergency Medical Services in the UK: a service analysis in 2024. Image Credit: Jaromir Chalabala / Shutterstock
In a recent study published in the Emergency Medicine Journal, researchers evaluated national access to physician-based Helicopter Emergency Medical Services (HEMS) in the United Kingdom and assessed how availability and advanced interventions vary across regions and time.
Background
When a person suffers severe trauma or sudden critical illness, minutes can mean the difference between life and death. In the United Kingdom, advanced lifesaving interventions, such as prehospital emergency anesthesia, can be delivered only by physician-based prehospital teams; however, access to this level of care is often inconsistent across regions.
A national review in 2009 revealed that round-the-clock physician-led HEMS services were extremely rare. Since then, trauma networks, training pathways, and service delivery models have evolved substantially. This raises a critical question: has access to physician-based prehospital care improved for patients regardless of where or when emergencies occur? Evaluating whether progress has translated into equitable and reliable national coverage remains essential.
About the Study
A national service analysis was conducted using an online survey distributed to all HEMS services operating across the United Kingdom. The survey was circulated between January and March 2024 to medical and operational leads within each service. One response per service was permitted, with follow-up clarification obtained where discrepancies arose. Participation was voluntary and uncompensated.
For classification purposes, a physician-based HEMS team was defined as one in which a physician was present on more than 95 percent of operational shifts. Teams that did not meet this threshold were included in overall service counts but excluded from analyses of advanced prehospital care capability. Data collected included funding structures, staffing models, dispatch operations, working hours, and the range of interventions provided.
To enable regional comparisons, respondents reported service availability at standardized weekday and weekend time points during both daytime and overnight hours. Population density data were used as a proxy for clinical demand, based on publicly available national statistics. Primary outcomes focused on the number and operational coverage of physician-based teams, while secondary outcomes examined intervention availability and the presence of additional prehospital critical care resources.
Study Results
All 21 HEMS services operating in the United Kingdom responded to the survey, providing complete national coverage.
The analysis estimated an increase from 11 physician-based teams in 2009 to approximately 30 teams in 2024, representing a roughly 2.7-fold increase, including services in Scotland. This reflects a substantial expansion in potential access to advanced prehospital care.
Despite this progress, round-the-clock availability remained uneven. In 2024, approximately half of the services provided continuous 24-hour physician-based coverage. This marked an improvement from 2009, when only one service operated at this level, yet significant regional gaps persisted. The East of England demonstrated the highest overnight availability, while Northern Ireland, South West England, and parts of Northern England lacked consistent overnight physician coverage.
Some services ceased operations in the early evening, whereas others remained active into the early morning. Not all services routinely operated aircraft overnight; some relied instead on ground-based response vehicles.
Population-adjusted access also varied significantly. Nationally, the ratio was approximately 0.63 HEMS teams per million people, including all teams, not only physician-based units. Availability tended to be higher in less densely populated regions and lower in major urban centers such as London. These disparities highlight how geography, population distribution, service configuration, and dispatch practices shape real-world access.
All physician-based teams were capable of delivering advanced Level 3 prehospital interventions, including prehospital emergency anesthesia, surgical airways, thoracostomies, amputations, resuscitative thoracotomies, and resuscitative hysterotomies. However, the availability of other advanced procedures varied. Most teams carried blood products; many provided regional anesthesia and arterial line placement; fewer offered dried plasma; and only one service reported the capability to perform resuscitative balloon occlusion of the aorta.
Beyond HEMS, all regions reported access to additional prehospital critical care assets. These included paramedic-led teams capable of delivering intermediate-level interventions and volunteer physician responders affiliated with the British Association for Immediate Care. Funding models differed substantially, with most services relying partly or entirely on charitable funding, whereas only one service was fully supported by government funding. The study did not directly test causal links between funding structure and service availability.
Conclusions
Access to physician-based HEMS in the United Kingdom has improved markedly over the past decade, with more teams and greater overnight coverage than previously reported. Nevertheless, access to advanced prehospital care continues to depend strongly on geography and time of day.
Persistent variation in operating hours, intervention availability, and funding models raises concerns about equity of access. Given evidence suggesting potential survival benefits in some contexts, alongside acknowledged uncertainty, these findings highlight the need for coordinated national policy, sustainable funding mechanisms, and system-wide planning to ensure that advanced prehospital critical care is available to all patients who need it, regardless of location or timing. The authors note that this survey alone cannot fully characterize access to all prehospital critical care resources nationwide.