Do physician led prehospital teams improve outcomes

JC: Do physician led prehospital teams improve outcomes?

Background

Physicians in prehospital teams are an increasingly common sight in the UK and internationally (though notably rarely in the US). However, this has been controversial and widely debated as to whether it really makes a difference to patient outcomes. This article reviews a systematic review and meta-analysis by Lavery et al. that evaluates whether physician-led interprofessional teams offer better outcomes for critically ill or injured patients compared to care provided solely by paramedics. The focus is on interventions that combine senior clinical decision-making and advanced treatments while ensuring rapid hospital transport. The abstract is below, but as always please read the full paper yourself. One small note is that the paper talks about physician-led teams. I sort of understand this from the clinical perspective, but PHEM is so much more than the medicine and I think it’s much more of a collaborative/team approach as opposed to the doc leading the paramedics!

This study has been doing the rounds on social media as definitive proof of the advantage of physicians in prehospital teams. Here at St Emlyn’s, we are a bit more sceptical, and so a little more in-depth analysis is required.

Abstract

Introduction Over the past three decades, more advanced pre-hospital systems have increasingly integrated physicians into targeted roles, forming interprofessional teams. These teams focus on providing early senior decision-making and advanced interventions while also ensuring rapid transport to hospitals based on individual patient needs. This paper aims to evaluate the benefits of an inter-professional care model compared to a model where care is delivered solely by paramedics.
Methodology A meta-analysis and systematic review were conducted using the guidelines of PRISMA 2020. Articles were identified through a systematic search of three databases and snowballing references. A systematic review was conducted of articles that met the inclusion criteria, and a suitable subset was included in a meta-analysis. The survival and mortality outcomes from the studies were then pooled using the statistical software Review Manager (RevMan) Version 8.2.0.
Results Two thousand two hundred ninety-six articles were found from the online databases and 86 from other sources. However, only 23 articles met the inclusion criteria of our study. A pooled analysis of the outcomes reported in these studies indicated that the mortality risk was significantly reduced in patients who received pre-hospital care from interprofessional teams led by physicians compared with those who received care from paramedics alone (AOR 0.80; 95% CI [0.68, 0.91] p = 0.001). The survival rate of critically ill or injured patients who received pre-hospital care from interprofessional teams led by physicians was increased compared to those who received care from paramedics alone (AOR 1.49; 95% CI [1.31, 1.69] P < 0.00001).
Conclusions The results of our analysis indicate that the targeted deployment of interprofessional teams led by physicians in the pre-hospital care of critically ill or injured patients improves patient
outcomes.


What Kind of Study Is This?

This paper is a systematic review and meta-analysis, adhering to PRISMA 2020 guidelines. The authors conducted a thorough search across three databases, identified 2,382 articles, and ultimately included 23 studies. The studies spanned various countries and patient demographics, pooling data from 332,533 cases. Most studies were observational, with just one randomised controlled trial. This is important as it means that the quality of the studies is not as good as we would like. Observational studies are prone to significant bias, and especially so in papers looking at PHEM interventions as despatch decisions often mean that patient groups differ between physician and non-physician teams.

The authors have pooled the aORs from each study.


Tell Me About the Patients

The included studies focused on critically ill or injured patients requiring pre-hospital care. Patient categories included:

  • Those suffering major trauma.
  • Individuals with out-of-hospital cardiac arrest (OHCA).
  • Patients with severe injuries (e.g., traumatic brain injury).

This seems reasonable as they are the patients where advanced clinical interventions may make a difference, and it also reflects the sort of patients I go to within a service that has both doctor/CCP teams and CCP/CCP teams on different aircraft within the same system. The review incorporated both adult and paediatric populations, highlighting diversity in patient profiles and care needs.


What Were the Measured Outcomes in This Study?

The primary outcomes were:

  • Survival Outcomes: Survival to hospital discharge, 30-day survival, and one-year survival.
    • Subgroup analysis focused on conditions like trauma and OHCA.

What Are the Main Results?

  • Mortality Reduction: Patients cared for by physician-led teams had significantly lower mortality (Adjusted Odds Ratio [AOR] 0.80; 95% CI 0.68–0.91; p = 0.001).
  • Subgroup Analysis:
    • OHCA: Better outcomes, particularly in non-shockable rhythms.
    • Trauma: Increased survival rates compared to paramedic-only teams.

So, at face value, the review demonstrated the added value of physicians in complex, high-acuity cases.


Can we believe the results?

In terms of design, then a systematic review needs good methodology and good data to work with (with data being the quality of the papers included).

In terms of methods, it’s pretty good. There is a comprehensive search strategy and well described and robust analysis. So, mathematically, it seems fine, but I do have concerns about the quality of the data being used.

If we look across the included studies, there is only one RCT in the analysis (the rest are observational), there is a high heterogeneity between studies (I² = 73%), and limited evaluation of non-survival outcomes (e.g., cost-effectiveness, provider satisfaction). Inevitably, the reliance on observational studies introduces many potential biases. The authors did look at study quality using the Newcastle Ottawa Scale which indicated good quality for most studies, but the bottom line is that observational studies are likely to be biased thus I am uncertain as to how robust the results really are (much as I would like to believe them).

I also struggle to understand whether the results are clinically important. The study reports and pools adjusted odds ratios (aOR) and finds these to be statistically significant, but are they clinically important? To do this, we would need to have a good idea of the baseline event rate of the outcomes they are looking for, in this case, death. However, that data is not in the paper and is not in the supplementary material either. To find this, you would have to look at each individual paper yourself, which is time-consuming and difficult to achieve. This is something that happens a lot in systematic review papers and it drives me nuts (apologies if it’s in there somewhere, but I cannot find it). If you do go digging then you will find that mortality rates vary widely. For example, the Hamilton paper has a 2.7% difference for cardiac arrest, with a roughly 10% survival rate(the most heavily weighted paper in the analysis), but others survival rates of just 1.2% and so any intervention there, even if associated with a large odds ratio would be clinically much less significant and arguably not cost effective (something not covered in this paper, though relevant due to the cost of HEMS services).

The study also mentions that there are 332,726 patients included. The range of study size was considerable. For example one Japanese study examined a database of 372,365 patients and included 49,144 patients, subsequently included in the systematic review. Overall mortality in the doctor group was higher, but after adjustment for confounders the aOR showed benefit. This reversal of outcomes is something seen in other papers too, with crude mortality (OR) being higher in the HEMS/physician groups, but then reversing after adjustment for known confounders (the aOR shows benefit to physician teams). There a couple of concerns here. Either we can only find a benefit after statistical analysis for confounders (which is an acceptable method but not ideal), and/or the despatch criteria are such that we are not really comparing similar groups of patients. It is almost certainly the latter which makes any form of comparison complex.

It’s also important to note that the authors have analysed and pooled the adjusted odds ratios from the various studies as opposed to taking the original data and ensuring that it was all handled in a similar way. Inevitably, each study has variations in how it calculated its adjusted odds ratios. It might have been technically possible to perform a systematic review by pooling individual patient data, but that would be a far more complex task, and likely not possible in practice.

Finally, there is great variation in what constitutes a prehospital doctor and a paramedic between the different studies. That also relates to capabilities too. For example, here at St Emlyn’s we are increasingly interested in endovascular resuscitation in the PHEM environment which would certainly require a physician; this would also influence any potential benefits, costs and outcomes when attempting to extrapolate the data in this study.


Should We Change Practice Based on This Study?

Many would consider a physician/CCP model to be optimal for PHEM and there are strong practical arguments for this, as both professions bring complimentary skills and experience to the patient that are (IMHO) greater than the sum of their parts. So, I am biased in believing this approach to be the best already. This study provides evidence for improved patient outcomes with physician-led pre-hospital care, but the certainty of that finding could be better. The absence of high-quality randomised controlled trials is perhaps disappointing but not surprising. Performing an RCT of this question would be costly and ethically challenging and I don’t see it happening any time soon. So this level of evidence is probably as good as we will see. For those systems with established paramedic-led models this study will raise questions and they may consider whether patients may benefit from incremental integration of physicians, focusing on high-acuity scenarios like trauma and OHCA. That said, the evidence base for this remains relatively weak.


Summary

Lavery et al.’s review is a great paper that has involved a lot of work to summarise the state of evidence in 2025. At face value, it reinforces the value of physician-led interprofessional teams in pre-hospital emergency care, highlighting reductions in mortality and improvements in survival. However, the data available is itself of lower quality than we would like (that’s not the authors fault, as they have done the best they can with the data available). That means that any conclusion about the magnitude and importance of this effect seen is difficult to determine, and is likely very variable between different systems and health economies.


References

  1. Lavery, M. D., Aulakh, A., & Christian, M. D. (2025). Benefits of targeted deployment of physician-led interprofessional pre-hospital teams on the care of critically ill and injured patients: A systematic review and meta-analysis. Scandinavian Journal of Trauma, Resuscitation, and Emergency Medicine, 33(1). https://doi.org/10.1186/s13049-024-01298-8.
  2. Knapp, J., Häske, D., Böttiger, B. W., et al. (2019). Influence of pre-hospital physician presence on survival after severe trauma: Systematic review and meta-analysis. Journal of Trauma and Acute Care Surgery, 87(4), 978–989. https://doi.org/10.1097/TA.0000000000002425.
  3. Moors, X. R. J., van Lieshout, E. M. M., Verhofstad, M. H. J., et al. (2019). A physician-based helicopter emergency medical service was associated with an additional 2.5 lives saved per 100 dispatches of severely injured paediatric patients. Air Medical Journal, 38(4), 289–293. https://doi.org/10.1016/j.amj.2019.02.007.
  4. Fukuda, T., Ohashi-Fukuda, N., & Kukita, I. (2018). Association of pre-hospital advanced life support by physicians with survival after out-of-hospital cardiac arrest with blunt trauma following traffic collisions. JAMA Surgery, 153(6), e180674. https://doi.org/10.1001/jamasurg.2018.0674.
  5. Garner, A. A., Bennett, N., Lee, A., et al. (2020). Success and complications by team composition for pre-hospital paediatric intubation: A systematic review and meta-analysis. Critical Care, 24(1), 149. https://doi.org/10.1186/s13054-020-02863-x.
  6. Den Hartog, D., Romeo, J., Ringburg, A. N., et al. (2015). Survival benefit of physician-staffed helicopter emergency medical services assistance for severely injured patients. Injury, 46(7), 1281–1286. https://doi.org/10.1016/j.injury.2015.03.031.
  7. Hessefeldt, R., Steinmetz, J., & Buggeskov, K. (2013). Impact of a physician-staffed helicopter on a regional trauma system: A prospective controlled observational study. Acta Anaesthesiologica Scandinavica, 57(5), 660–668. https://doi.org/10.1111/aas.12089.
  8. Giannakopoulos, G. F., Kolodzinskyi, M. N., Boer, C., et al. (2013). Helicopter emergency medical services save lives: Outcome in a cohort of 1073 polytraumatized patients. European Journal of Emergency Medicine, 20(2), 79–85. https://doi.org/10.1097/MEJ.0b013e328356f4d7.
  9. Lyons, J., Gabbe, B. J., & Fry, R. J. (2021). Impact of a physician-critical care practitioner pre-hospital service in Wales on trauma survival: A retrospective analysis of linked registry data. Anaesthesia, 76(11), 1475–1481. https://doi.org/10.1111/anae.15517.
  10. Vianen, N. J., Maissan, I. M., Bramer, W. M., et al. (2022). Pre-hospital traumatic cardiac arrest: A systematic review and meta-analysis. European Journal of Trauma and Emergency Surgery, 48(4), 3357–3372. https://doi.org/10.1007/s00068-021-01816-9.
  11. Simon Carley, “Non-invasive or arterial pressure monitoring in PHEM?,” in St.Emlyn’s, September 29, 2024, https://www.stemlynsblog.org/non-invasive-or-arterial-pressure-monitoring-in-phem/.
  12. Simon Carley, “Intra-Arrest Arterial Blood Pressure and Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest.,” in St.Emlyn’s, November 22, 2024, https://www.stemlynsblog.org/intra-arrest-arterial-blood-pressure/.
  13. Simon Carley, “ECPR for refractory cardiac arrest,” in St.Emlyn’s, January 30, 2023, https://www.stemlynsblog.org/ecpr-for-refractory-cardiac-arrest/.
  14. Halden Hutchinson-Bazely, “Pre Hospital Extracorporeal CPR (ECPR) in the UK: The Sub30 study,” in St.Emlyn’s, January 2, 2025, https://www.stemlynsblog.org/sub30study/.
  15. Iain Beardsell, “Podcast – Prehospital eCPR with Alice Hutin at Tactical Trauma 2024,” in St.Emlyn’s, November 6, 2024, https://www.stemlynsblog.org/podcast-prehospital-ecpr/.
  16. Iain Beardsell, “The Annual ILCOR Update – what’s new in adult life support,” in St.Emlyn’s, November 11, 2023, https://www.stemlynsblog.org/the-annual-ilcor-update-whats-new-in-adult-life-support/.
  17. Simon Carley, “Podcast – REBOA with Zaf Qasim,” in St.Emlyn’s, November 14, 2019, https://www.stemlynsblog.org/reboa/.
  18. Simon Carley, “Selective aortic arch perfusion,” in St.Emlyn’s, December 30, 2023, https://www.stemlynsblog.org/selective-aortic-arch-perfusion/.
  19. Halden Hutchinson-Bazely, “Prehospital Partial Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) for Exsanguinating Subdiaphragmatic Hemorrhage,” in St.Emlyn’s, July 14, 2024, https://www.stemlynsblog.org/zone-1-partial-reboa/.

Cite this article as: Simon Carley, "JC: Do physician led prehospital teams improve outcomes?," in St.Emlyn's, January 27, 2025, https://www.stemlynsblog.org/physician-led-prehospital-teams/.

Thanks so much for following. Viva la #FOAMed

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