Access to physician-based HEMS in the UK: progress, patchwork or postcode lottery?

Background

Imagine you are a severely injured patient in the UK at three o’clock in the morning. Whether a physician-led prehospital team arrives may depend not just on clinical need, but on geography, time of day and the funding model of the service operating in your region.

Prehospital critical care in the UK has evolved rapidly over the last 15 years. Physician/paramedic Helicopter Emergency Medical Services (HEMS) teams now deliver interventions that once lived exclusively in emergency departments and operating theatres. Training pathways have been established, trauma networks have expanded and the professional identity of prehospital emergency medicine is now clear.

Yet the system has grown in a uniquely British way. Unlike many NHS services, HEMS provision is largely, though not entirely, charity funded. That has allowed innovation and local development, but it has also meant that national direction is limited. There is no single commissioning body dictating where bases should be located, what hours must be covered or which interventions should be universally available.

Some national standards exist. For example, NICE guidance around timely prehospital emergency anaesthesia implies expectations about response capability. But these are very different from the operational targets and key performance indicators (KPIs) that NHS organisations work under. Ambulance services and emergency departments operate within a framework of mandated performance metrics; HEMS charities, by contrast, develop organically according to local priorities, fundraising success and regional culture. Their relationships with NHS organisations vary too. Some are entirely independent, with their own CQC registration and inspections, others are more closely linked to their regional ambulance service for governance and admin, others are embedded as part of thje NHS prehospital care services. Basically, it’s very very different to what we see. inother aspects of the UK health services.

Thias week Macdonald and colleagues have looked at the provision of HEMS in 2024 and mapped out the variety, and perhaps the lack of equity for PHEM services in the UK.

The abstract is below, but as always our advice is to go read the paper yourself and come to your own conclusions.

Abstract

Background Physician-based prehospital teams provide advanced critical care services in the UK (eg, prehospital anaesthesia). The last review of such teams in 2009, which included England, Wales and Northern Ireland, reported only one physician-based prehospital team available 24/7. Helicopter Emergency Medical Services (HEMS) across the UK offer paid physician-based teams, while other organisations may provide physician-based teams on a voluntary ad hoc basis. The primary aim of this study was to determine if access to a physician-based HEMS team has changed in the past 12 years.

Methods An online survey was distributed to all UK HEMS organisations in January 2024. The primary outcome measure was the number of physician-based teams operated by HEMS in 2024 and the operational hours of such teams. Secondary outcomes included interventions offered by HEMS teams and any additional medical teams offered (eg, paramedic only).

Results All 21 HEMS responded. The number of potentially available physician-based HEMS teams has increased from 11 in England, Wales and Northern Ireland in 2009 to 28 in 2024, with two services in Scotland (total=30). HEMS providing consistent 24/7 physician-based prehospital teams increased from one (5.9%) in 2009 to 11 (52.4%) in 2024. The East of England has the highest 24/7 availability, with Northern Ireland, South West England and Northern England the least. Within physician-based teams, variation remains in advanced interventions available—for example, 19 services (90.4%) offer blood transfusion while only one (4.7%) offers resuscitative balloon occlusion of the aorta. Only one service is completely government funded; the others are funded by charity alone or a combination of charity and government sources.

Conclusion Both geographical and temporal variations in access to a physician-based HEMS remain across the UK, although there has been improvement since 2009. However, within this provision, variation exists in terms of interventions provided such as the provision of blood products.

What kind of study is this?

This is a national service analysis based on a structured online survey of all UK HEMS organisations. Twenty-one services responded, giving a comprehensive overview of the current landscape. The study is observational and descriptive; it maps provision rather than measuring outcomes. The authors focus on physician-based teams, defined as those with a doctor present on more than 95% of shifts. Availability is explored at specific times of day, which allows the paper to demonstrate diurnal variation rather than presenting an overly simplistic summary of operating hours. There is some controversy about this as there are some highly effective paramedic (CCP) only teams, but in the UK at least a doctor is required for the full range of PHEM interventions (there may be a couple of exceptions, but in general this is the case).

Importantly, the study examines not just clinical capability but also funding and organisational structure. That context matters. When a service is predominantly charity-funded, expansion or overnight coverage may depend as much on donor support as on national workforce planning.

Tell me about what was studied

The authors studied services rather than patients. Each UK HEMS organisation provided information about team configuration, operating hours, interventions offered and dispatch processes. The survey also explored whether other critical care assets existed within regions, such as advanced paramedics or voluntary responders.

This systems-level approach shows how unevenly structured the UK’s prehospital environment is. NHS ambulance trusts operate under nationally agreed frameworks, whereas HEMS charities exist alongside them with varying degrees of integration. Some regions have tightly embedded physician-led services; others rely more heavily on advanced paramedic models or ground-based teams.

Population density was used as a proxy for clinical demand, which is not perfect as different populations have different health needs, and more rural areas may have different needs for transport as compared to urban. However, as a blunt tool it seems reasonable.

What was measured in this study

The primary outcomes focused on availability: how many physician-based teams exist, when they operate and how access varies geographically and temporally. Particular attention was paid to overnight coverage where we know that there are limitations nationally. Night shifts are harder to staff, more expensive and workload is less so the ‘value’ of them may be considered differently.

Secondary outcomes included advanced interventions offered, dispatch models, helicopter use in darkness and funding arrangements. The authors also gathered information on additional prehospital resources, though these were not analysed in depth. By asking respondents to report availability at specific time points during weekdays and weekends, the study gives a snap shot of what happens across the UK, I like this approach.

Location of UK Air Ambulances from https://www.airambulancesuk.org/about-us/air-ambulance-charities/

What are the main results?

The data show clear growth in physician-based HEMS provision since 2009, but also reveal ongoing variation.

Physician-based teams increased from 11 in 2009 to 30 across the UK in 2024.
Eleven of 21 services now provide consistent 24/7 physician-based coverage.
Regional disparities persist, with many areas lacking overnight provision.
Funding remains predominantly charitable, with only one fully government-funded service, 8 combined funding and 12 fully charity.
Advanced procedural capability varies between teams.
- Blood transfusion (red blood cells, fresh frozen plasma or whole blood) 19/21
  Regional anaesthesia 17/21
  Arterial line 16/21
  Lateral canthotomy 16/21 (1 service dependent on individual clinician skill)
  Dried plasma (or alternative) 8/21
  Resuscitative balloon occlusion of aorta (REBOA) for trauma 1/21
They also reported BASICS schemes as operating in some regions at level 2/3 (as my own scheme does on a voluntary basis)

The maps presented in the paper illustrate how availability drops overnight in several regions, emphasising the reality that access to advanced prehospital care is not guaranteed at all times. I can’t reproduce them here, but they are worth a look if you can get the full paper. They show a significant North/South divide with the South East/East of England having far more availability than the North and other regions.

This link gives a preview to the maps…..https://share.google/kI7jVmWVDcx9ePvKv

What becomes apparent is that growth has occurred in a decentralised fashion. Some regions have expanded significantly, while others are some distance behind. This variation is not surprising when services rely heavily on local fundraising and charitable governance rather than national commissioning frameworks.

Can we believe the results?

The study’s strengths lie in its national scope and complete response rate. It provides one of the clearest snapshots of UK physician-based HEMS provision in over a decade. The focus on diurnal variation is particularly useful, highlighting that patients access to PHEM is very variable based on time and geography.

However, there are limitations. The data are self-reported, meaning that capability may be interpreted differently between services, and it tells us what people think they do/could do, but not necessarilly what they actually ‘usually’ do. The study also assumes that increased availability equates to improved patient outcomes, that’s probably true, and there evidence for this is getting better, but it is an assumpttion and not tested here.

The broader context of funding deserves attention. When services operate largely outside NHS commissioning structures, variability is almost inevitable. Unlike NHS ambulance trusts, which are held to nationally defined KPIs, HEMS charities are not bound by uniform performance metrics. The requirement to deliver timely PHEA provides some shared direction, but it is far less prescriptive than the performance frameworks governing emergency departments or ambulance response times. There is work going on in this area though, The NHRAF is a national group of air ambulance researchers who are working together to develop KPIs and other metrics that will hopefully develop this over time. I am on that group and they are doing great work.

The flip side is that a lack of central direction may foster innovation and local autonomy as it’s easy to be agile when not constrained, but that can lead to inequjity. The study highlights variation in advanced interventions and operating hours that might be difficult to justify if the services were centrally commissioned within a single national framework. Again though, the flip side is that national comissioning might lead to stagnation and barriers to progress, for example LAA is pushing ahead with ECPR, which would no doubt have been blocked by a national commissioning body.

Another limitation is the exclusion of the wider prehospital ecosystem. Advanced paramedics and voluntary responders contribute significantly to patient care, yet their activity is not fully captured. Without understanding how these assets interact with HEMS, it is difficult to assess true access to advanced prehospital interventions available to patients. This study approaches the question of who has access to HEMS, but from a patient perspective they don’t need a helicopter, they need a skill set and expertise and systems that provide life saving interventions. HEMS can do that (variably as we have seen in this study), but they don’t hold thise skills exclusively. A wider study would look at these elements across all services, but in truth I stiull think it would show significant inequity for high level interventions such as PHEA and surgical procedures.

You should also look at a paper in Scandianavian Journal of Trauma and Crtitical Care by McHenry et al., that demonstrates the inverse care law for HEMS and from a health economics perspective. That showed that the most need and most deprived areas have the lowest access. So even more evidence of inequity.

What does this mean for prehospital care?

For clinicians, probably not that much. This paper does not provide new evidence about how to manage patients or which interventions improve outcomes. What it does challenge is the assumption that growth alone will produce equity. If physician-based HEMS remains largely charity-funded, national consistency may remain elusive. The NHS operates within a framework of targets, accountability and central oversight. HEMS services, by contrast, evolve according to local priorities and financial sustainability. The future is uncertain. National standards, such as expectations around timely PHEA, provide a shared vision, but without mandated KPIs or commissioning frameworks, variation will persist. Whether that variation represents healthy diversity or unacceptable inequity is as much a philosophical question as a clinical one.

Perhaps it’s worth considering an analogy. If I have a myocardial infarction tomorrow at 3am I will get the same or very similar care wherever I am in the UK. In some remote or rural areas that’s tricky, but networks have come together to try and mitigate those challenges. If at 3am tomorrow I get hit by a bus and suffer life threatening injuries, my initial prehospital resuscitation will be significantly determined by where I am, and by the time of day/night. Is that disparity acceptable?

Summary

This is a really interesting snapshot by Macdonald and colleagues of HEMS provision in the UK. The number of teams has increased and overnight availability has improved but access remains uneven, shaped by geography, operational models and funding structures. The predominantly charitable nature of UK HEMS has enabled remarkable growth, but it has also resulted in a system with limited national direction. While some shared standards exist, they are very different from the KPIs and accountability frameworks that govern NHS services. The result is a patchwork of provision that continues to evolve organically rather than strategically.

I don’t see any strategic direction changes anytime soon. Air Ambulances are working together to develop KPIs etc. but these will not be binding, and it’s likely that the current variability will remain for some time to come.

References

Macdonald S, Grier G, Goodsman D, Morton S. Access to physician-based Helicopter Emergency Medical Services in the UK: a service analysis in 2024. Emerg Med J. 2026;0:1–7.
Hyde P, Mackenzie R, Ng G, et al. Availability and utilisation of physician-based pre-hospital critical care support to the NHS ambulance service in England, Wales and Northern Ireland. Emerg Med J. 2012;29:177–81.
Bourn S, Turner J, Raitt J, et al. Geo-temporal provision of pre-hospital emergency anaesthesia by UK Helicopter Emergency Medical Services. Br J Anaesth. 2020;124:571–8.
Beaumont O, Lecky F, Bouamra O, et al. Helicopter and ground emergency medical services transportation to hospital after major trauma in England. Trauma Surg Acute Care Open. 2020;5:e000508.
Fritz CL, Thomas SA, Galvagno SM Jr, et al. Survival benefit of helicopter scene response for patients with an injury severity score ≥9: a systematic review and meta-analysis. Prehosp Emerg Care. 2024;28:841–50.
Simon Carley, “BASICS, NWPCCC and EPHC. St Emlyn’s,” in St.Emlyn’s, August 20, 2023, https://www.stemlynsblog.org/basics-nwpccc-and-ephc-st-emlyns/.
UK Air Ambulances https://www.airambulancesuk.org/about-us/air-ambulance-charities/
McHenry, R.D., Leech, C., Barnard, E.B.G. et al. Equity in the provision of helicopter emergency medical services in the United Kingdom: a geospatial analysis using indices of multiple deprivation. Scand J Trauma Resusc Emerg Med 32, 73 (2024). https://pubmed.ncbi.nlm.nih.gov/39164775/