Expanded physician-led air ambulance services are improving access to advanced prehospital care across the United Kingdom, yet important regional and overnight gaps highlight ongoing challenges in delivering equitable lifesaving treatment.
Background
When a person suffers severe trauma or sudden critical illness, every minute is crucial. In the UK, advanced interventions like prehospital emergency anesthesia are typically delivered by physician-led prehospital teams. However, access to this specialized care isn’t uniform across the country.
A national review conducted in 2009 revealed that round-the-clock physician-led Helicopter Emergency Medical Services (HEMS) were rare. Since then, trauma networks, training programs, and service delivery models have evolved. A key question has been whether these changes have translated into improved and equitable access to physician-based prehospital care, regardless of location or time of day.
About the Study
Researchers recently conducted a national service analysis to evaluate access to physician-based HEMS across the UK. An online survey was distributed to all HEMS services operating in the country between January and March 2024. Medical and operational leads within each service were invited to participate, with one response permitted per service. Clarification was sought where inconsistencies arose. Participation was voluntary.
A physician-based HEMS team was defined as one with a physician present on more than 95 percent of operational shifts. Teams not meeting this threshold were included in overall service counts but excluded from analyses of advanced prehospital care capabilities. Data collected included funding structures, staffing models, dispatch operations, working hours, and the range of interventions provided.
To facilitate regional comparisons, respondents reported service availability at standardized weekday and weekend time points, both during the day and overnight. Population density data were used to estimate clinical demand, based on publicly available national statistics. The primary outcomes focused on the number and operational coverage of physician-based teams, while secondary outcomes examined the availability of interventions and additional prehospital critical care resources.
Study Results
All 21 HEMS services operating in the UK responded to the survey, providing complete national coverage.
The analysis showed an increase from 11 physician-based teams in 2009 to approximately 30 teams in 2024, representing a roughly 2.7-fold increase. This indicates a substantial expansion in potential access to advanced prehospital care.
Despite this progress, 24-hour availability remained inconsistent. In 2024, roughly half of the services provided continuous, round-the-clock physician-based coverage. While an improvement from 2009, when only one service operated at this level, 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 reduced operations in the early evening, while others remained active into the early morning. Not all services routinely used aircraft overnight, with some relying on ground-based response vehicles.
Population-adjusted access also varied considerably. Nationally, the ratio was approximately 0.63 HEMS teams per million people, including all teams. Availability tended to be higher in less densely populated regions and lower in major urban centers like London. These disparities highlight the influence of geography, population distribution, service configuration, and dispatch practices on 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 resources. 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, while only one service was fully supported by government funding. The study did not directly assess the relationship between funding structure and service availability.
Conclusions
Access to physician-based HEMS in the UK has improved significantly over the past decade, with more teams and greater overnight coverage than previously reported. However, access to advanced prehospital care continues to depend heavily on geographic location and time of day.
Persistent variations in operating hours, intervention availability, and funding models raise concerns about equitable access. Given evidence suggesting potential survival benefits in certain situations, these findings underscore 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 acknowledge that this survey alone cannot fully characterize access to all prehospital critical care resources nationwide.
