The NZ PHRM Society White Paper

The value and economic benefit of interprofessional doctor and paramedic prehospital clinical teams

The Aotearoa New Zealand Prehospital and Retrieval Medicine (PHRM) Society

February 2025

Executive summary

i)           Interprofessional doctor and paramedic clinical teams save lives. A recent meta-analysis demonstrates a 20% reduction in mortality in the setting of major trauma: https://pubmed.ncbi.nlm.nih.gov/39757222/

ii)          There is a significant cost benefit to New Zealanders through the implementation of interprofessional doctor and paramedic prehospital clinical teams. Using the New Zealand Transport Agency’s ‘Value of a Statistical Life’ methodology, we estimate system cost savings of over $300 million dollars per year: https://www.nzta.govt.nz/assets/resources/research/reports/698/698-monetised- benefits-and-costs-manual-mbcm-parameter-values.pdf

iii)        The increased interoperability of interprofessional doctor and paramedic prehospital clinical teams provides improved system efficiency. These interprofessional clinical teams bring a broad capability that can complete prehospital, interhospital (IHT/Retrieval), search and rescue (SAR) and major incident taskings

iv)        Interprofessional learning decreases clinical adverse events (as published in this New Zealand peer-reviewed research): https://pubmed.ncbi.nlm.nih.gov/37921751/

1. The opportunity to reduce prehospital trauma death in New Zealand 

There are a significant number of preventable prehospital deaths due to trauma in New Zealand.1 A high quality study using New Zealand’s (NZ) mortality collection, national minimum dataset, and coronial records by Lilley et al.1 estimated that there are approximately 1,200 prehospital deaths annually in NZ, four times the in-hospital death rate. In addition, Māori were 50% more likely to die prehospital compared to non-Māori, whereas there were no differences between Māori and non-Māori death rates in-hospital. The highest proportion of prehospital deaths occurred in rural settings, such as farms and forests, with 20 prehospital deaths for every in-hospital death. Over 90% of rural center deaths were prehospital, with a 15:1 prehospital-to-in-hospital death ratio, three times higher than urban centers.1 In their discussion, the authors noted that “The extension of hospital-based trauma systems into improved integrated equitable prehospital care would extend the benefits of secondary prevention for those with initially survivable trauma- related injuries”,1 and concluded that “These findings identify where improvements in prevention efforts are needed to reduce the substantive burden of prehospital fatal injury in New Zealand, serving to highlight the importance of strengthening both primary and secondary injury prevention efforts.”1

Kool et al.2 found that in New Zealand prehospital injury deaths eligible for injury severity score (ISS) scoring, (1,796), 196 (11%) were assessed to have had survivable injuries, 501 (28%) to have had potentially survivable injuries, and 1102 (61%) unsurvivable injuries. Head injuries were common (48% of survivable deaths and 80% in both potentially survivable and non-survivable deaths). Chest injuries were also common (37% survivable, 60% potentially survivable, 84% of unsurvivable). The authors concluded that “1 in 10 prehospital deaths are survivable and as such are likely to benefit from appropriate bystander first aid, improvements in the timeliness and the quality of prehospital care, and improved access to advanced level hospital care.”2

2. Interprofessional doctor-paramedic teams save lives 

A recently published systematic review and meta-analysis demonstrates the benefits of interprofessional doctor and paramedic prehospital care teams.3

In this meta-analysis of studies investigating trauma-specific mortality, interprofessional doctor-paramedic teams (compared to uni-professional paramedic-only crews) were associated with a significantly decreased mortality rate of 20% (95%CI 32% lower – 9% lower).

These findings are consistent with the Knapp et al.4 systematic review and meta-analysis, and Wilson et al.5 Additionally, available evidence suggests that interprofessional teams improve important surrogate outcomes in trauma care, such as intubation success rates.6-8 Importantly, whilst some studies demonstrate no difference in outcome between interprofessional teams and paramedic only crews (including some within the systematic review and meta-analysis), no studies demonstrate a worsened outcome.

3. Cost effectiveness 

The cost-effectiveness of prehospital interventions is generally not as well researched as preventative public health strategies and hospital-based care. In addition, there are several topics and subtopics to consider, such as the cost-effectiveness of using helicopters as a transport platform (versus ground-based transport platforms) as well as interprofessional teams versus paramedic-only crews (irrespective of transport platform). The focus here is on the latter.

Taylor et al.9 evaluated the cost-effectiveness of interprofessional teams transported by helicopter versus paramedic-only crews transported by road in New South Wales, Australia in 2012, and concluded that interprofessional teams were associated with improved mortality in trauma patients and was likely to be cost-effective in those who were most seriously injured and those who had a serious traumatic brain injury.

Ackermann et al.10 evaluated the cost-effectiveness of interprofessional teams transported by helicopter versus paramedic-only crews transported by road in Finland.1 They concluded that helicopter-based interprofessional teams were cost-effective compared to paramedic- only crews.

Whilst there are significant challenges extrapolating the specific findings of these studies to NZ because of the differences in systems and funding, the incremental cost per life year saved (LYS)/quality adjusted life year (QALY) of interprofessional teams over paramedic- only crews is substantially lower than the estimated value of statistical life (VOSL) in New Zealand, which is estimated at $12.5 million (2023). Using the VOSL framework, investment in interprofessional teams is highly likely to yield economic benefits greater than the implementation costs.

Estimates of the incremental cost difference of a PHRM doctor above the cost of a flight critical care paramedic is between $500,000 to $1 million per 24/7/365 roster line. Across six New Zealand aeromedical hubs, the incremental cost difference of a PHRM doctor is between $3 to 6 million dollars per year.

Economic impact models

I) As of April 2023, the statistical value of a life in New Zealand was set at NZ$12.5 million by the NZTA (New Zealand Transport Agency with input from the Accident Compensation Corporation). This value represents a significant increase from the previous figure of around $4.88 million (2021).

Meaning of "statistical value":

This figure is not meant to represent the actual worth of an individual life, but rather a monetary value assigned by the New Zealand Government to a statistical life lost when evaluating the cost-benefit of safety measures.

II)  In New Zealand, prehospital injury deaths are estimated to be around 1,200 per year. This is about four times the number of in-hospital injury deaths.

Definitions:

Injury Severity Score (ISS): Internationally validated classification based upon an anatomic scoring system (Abbreviated injury scale – AIS)

Survivable deaths: Injury Severity Score (ISS) < 25

Potentially survivable deaths: Injury Severity Score (ISS) 25-49

If we consider a more conservative model which uses historical costings from 2021, there is still over NZD $130 million dollars per year of cost benefit.

Annually, there are 1200 prehospital deaths per year in New Zealand. This new research demonstrates that interprofessional doctor and paramedic teams reduce mortality by approximately 20%. Applying this 20% mortality reduction to the 468 survivable or potentially survivable deaths per year (after applying as estimate of 30% of major trauma patients receiving care from aeromedical crews) could mean that an additional 28 lives could be saved annually by implementing interprofessional doctor-paramedic teams across the country. Given the value of a statistical life of $12.5 million, New Zealanders would be willing to pay $350 million dollars to prevent the loss of these 28 lives.

Treasury recommends a cost-benefit analysis (CBA) of healthcare investments (a social viewpoint) as opposed to taking a health system viewpoint, and the use of VSOL is consistent with a societal benefits approach to investment. This value of a statistical life methodology is used globally, with estimates ranging from NZD$4.5 million to 18.6 million per life.

4. Recommendations from prior reviews of the NZ air ambulance sector

There are three notable independent prior reviews of this sector in NZ done in 1996 (The “Cull report”),12 in 2008,13 and in 201714

The 1996 report included a recommendation that:

“The crewing requirement for air ambulance in first tier (Advanced Trauma Service) areas must be a minimum of a doctor, paramedic and/or an ambulance officer.”12

The 2008 report included a recommendation:

“Participation by suitably qualified and experienced doctors in primary retrievals where information received indicates that the patient’s condition means that the patient may benefit from the skills such a doctor would bring”.13

The (most recent) 2017 report included a recommendation that:

“NASO, [now Ambulance Team] in consultation with the Air Rescue Group, to nominate for each region, a single and centrally based, 24/7 medical staffed aeromedical (retrieval) capacity for scene (primary) response as well as inter- hospital transfers from “stabilising” hospitals. This will ensure a level of consistency across the regions of standards for inter-hospital transfers, and will replace locally based, ad hoc medical crewing arrangements. It will also rationalize and consolidate the number and location of emergency helicopters and fixed-wing air ambulances. In addition, it generates significant efficiencies and concentrates case numbers to specific locations, thus improving exposure, training and quality and safety of

retrieval services.”14

Independent reviews of the air ambulance sector for nearly 30 years have consistently recommended the implementation of interprofessional teams involving a doctor.

5. Conclusions and feedback

There is a significant opportunity to reduce prehospital deaths in New Zealand.

The best available evidence suggests that interprofessional doctor and paramedic teams compared to uniprofessional paramedic-only teams are associated with a clinically significant reduction in deaths from major trauma.

Interprofessional doctor and paramedic teams represent a significant economic benefit when using the VOSL framework.

Reviews of the air ambulance sector (nationally and internationally) have concluded for over 30 years that interprofessional prehospital teams involving doctors should be implemented nationally.

We value your constructive feedback on this white paper.

info@phrm.nz

5. References 

1.          Lilley R, Kool B, Davie G, de Graaf B, Dicker B. Opportunities to prevent fatalities due to injury: a cross-sectional comparison of prehospital and in-hospital fatal injury deaths in New Zealand. Aust N Z J Public Health. Jun 2021;45(3):235-241. doi:10.1111/1753- 6405.13068

2.          Kool B, Lilley R, Davie G, et al. Potential survivability of prehospital injury deaths in New Zealand: a cross-sectional study. Inj Prev. May 23 2020;doi:10.1136/injuryprev-2019- 043408

3.          Lavery MD, Aulakh A, Christian MD. 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. Scand J Trauma Resusc Emerg Med. Jan 6 2025;33(1):1. doi:10.1186/s13049-024-01298-8

4.          Knapp J, Haeske D, Boettiger BW, et al. Influence of prehospital physician presence on survival after severe trauma: systematic review and meta-analysis. Journal of Trauma and Acute Care Surgery. 2019;87(4):978-989.

5.          Wilson SL, Gangathimmaiah V. Does prehospital management by doctors affect outcome in major trauma? A systematic review. J Trauma Acute Care Surg. Nov 2017;83(5):965-974. doi:10.1097/TA.0000000000001559

6.          Crewdson K, Lockey D, Røislien J, Lossius HM, Rehn M. The success of pre-hospital tracheal intubation by different pre-hospital providers: a systematic literature review and meta-analysis. Critical Care. 2017;21:1-10.

7.          Fouche PF, Stein C, Simpson P, Carlson JN, Doi SA. Nonphysician out-of-hospital rapid sequence intubation success and adverse events: a systematic review and meta- analysis. Annals of emergency medicine. 2017;70(4):449-459. e20.

8.          Garner AA, Bennett N, Weatherall A, Lee A. Success and complications by team composition for prehospital paediatric intubation: a systematic review and meta-analysis. Critical Care. 2020;24:1-15.

9.          Taylor C, Jan S, Curtis K, et al. The cost-effectiveness of physician staffed Helicopter Emergency Medical Service (HEMS) transport to a major trauma centre in NSW, Australia. Injury. Nov 2012;43(11):1843-9. doi:10.1016/j.injury.2012.07.184

10.       Ackermann A, Pappinen J, Nurmi J, Nordquist H, Torkki P. The Estimated Cost- Effectiveness of Physician-Staffed Helicopter Emergency Medical Services Compared to Ground-Based Emergency Medical Services in Finland. Air Med J. May-Jun 2024;43(3):229-

235. doi:10.1016/j.amj.2023.12.006

11.       Zealand" TAAoN. 2024 sees lowest rate of road deaths since the 1920s. https://www.aa.co.nz/about/newsroom/media-releases/safety/2024-sees-lowest-rate-of- road-deaths-since-the-1920s/

12.       A National Air Ambulance Network for New Zealand (1996).

13.       Report of the Air Ambulance Reference Group to the ACC and Health Ministers (2008).

  14.        New Zealand Trauma System Review (2017).