Elsevier

Injury

Volume 53, Issue 6, June 2022, Pages 1746-1755
Injury

Review
Improving ambulance dispatch triage to trauma: A scoping review using the framework of development and evaluation of clinical prediction rules

https://doi.org/10.1016/j.injury.2022.03.020Get rights and content

Highlights

  • Ambulance dispatch algorithms are clinical prediction rules, aiming to identify patients at high or low risk of adverse outcomes

  • Most trauma dispatch algorithms in use were rule-based or rule-based with specialist human review.

  • Few derivation or validation studies were followed by an impact study and few impact studies had been preceded by a derivation or validation phase

  • Low acuity Medical Priority Dispatch System codes may predict patients not requiring advanced life support, but dedicated studies are needed

  • Clinician review of dispatch may improve advanced trauma team dispatch, but this has been studied in helicopter emergency medical services only

Abstract

Objective

Ambulance dispatch algorithms should function as clinical prediction rules, identifying high acuity patients for advanced life support, and low acuity patients for non-urgent transport. Systematic reviews of dispatch algorithms are rare and focus on study types specific to the final phases of rule development, such as impact studies, and may miss the complete value-added evidence chain. We sought to summarise the literature for studies seeking to improve dispatch in trauma by performing a scoping review according to standard frameworks for developing and evaluating clinical prediction rules.

Methods

We performed a scoping review searching MEDLINE, EMBASE, CINAHL, the CENTRAL trials registry, and grey literature from January 2005 to October 2021. We included all study types investigating dispatch triage to injured patients in the English language. We reported the clinical prediction rule phase (derivation, validation, impact analysis, or user acceptance) and the performance and outcomes measured for high and low acuity trauma patients.

Results

Of 2067 papers screened, we identified 12 low and 30 high acuity studies. Derivation studies were most common (52%) and rule-based computer-aided dispatch was the most frequently investigated (23 studies). Impact studies rarely reported a prior validation phase, and few validation studies had their impact investigated. Common outcome measures in each phase were infrequent (0 to 27%), making a comparison between protocols difficult. A series of papers for low acuity patients and another for pediatric trauma followed clinical prediction rule development. Some low acuity Medical Priority Dispatch System codes are associated with the infrequent requirement for advanced life support and clinician review of computer-aided dispatch may enhance dispatch triage accuracy in studies of helicopter emergency medical services.

Conclusions

Few derivation and validation studies were followed by an impact study, indicating important gaps in the value-added evidence chain. While impact studies suggest clinician oversight may enhance dispatch, the opportunity exists to standardize outcomes, identify trauma-specific low acuity codes, and develop intelligent dispatch systems.

Section snippets

Background

The speed and accuracy of Emergency Medical Services (EMS) dispatch to the injured patient is important for optimizing patient outcomes [1,2]. Dispatch delays to motor vehicle accidents in the United States increase mortality for both urban and rural patients [3,4], and a retrospective review of prehospital trauma deaths in Victoria, Australia, identified dispatch as the most common area for systems improvement [5].

EMS dispatch often relies on humans integrating a mixture of structured and

Materials and methods

This scoping review was prepared according to the PRISMA-ScR guidelines [23]. The protocol was registered on the Open Science Framework before data extraction (https://osf.io/yprzs).

Results

The four databases and six grey literature searches yielded 2689 records. The study selection process is outlined in Fig. 1. Forty-four studies met the final inclusion criteria. Two of these investigated dispatch cancellation only and are discussed in the supplementary material, leaving 42 studies. The majority were derivation studies (21 of 42 (60%)), half of which were internal validity (12 of 21). One-quarter were either validation (10 studies) or impact (10 studies). One study was

Discussion

We performed a scoping review of ambulance dispatch triage to injured patients using a framework for development and evaluation of clinical prediction rules to summarize the types of algorithms and outcomes considered at derivation, validation and impact analysis phases. We found derivation studies to be the most common, and these rarely carried through to impact analysis. Similarly, only two studies on impact were based on previously published work. We also found few common outcomes for

Declarations of interest

None.

Acknowledgments

We would like to thank Dr. Ian Ferguson and Dr. Ilana Delroy-Buelles for their review of the original draft. Matthew Miller is supported in his PhD by an Australian Commonwealth Government Research Training Program (RTP) scholarship.

References (72)

  • E Lee et al.

    Estimate of mortality reduction with implementation of advanced automatic collision notification

    Traffic Inj Prev

    (2017)
  • N Sinclair et al.

    Clinician tasking in ambulance control improves the identification of major trauma patients and pre-hospital critical care team tasking

    Injury

    (2018)
  • L Tollinton et al.

    Enhancing predictions of patient conveyance using emergency call handler free text notes for unconscious and fainting incidents reported to the London Ambulance Service

    Int J Med Inform

    (2020)
  • P Ferri et al.

    Deep ensemble multitask classification of emergency medical call incidents combining multimodal data improves emergency medical dispatch

    Artificial Intelligence in Medicine

    (2021)
  • M Fernandes et al.

    Clinical Decision Support Systems for Triage in the Emergency Department using Intelligent Systems: a Review

    Artificial Intelligence in Medicine

    (2020)
  • R Pfeifer et al.

    Are Pre-hospital Trauma Deaths Preventable? A Systematic Literature Review

    World J Surg

    (2019)
  • S Gupta et al.

    Third delay in traumatic brain injury: time to management as a predictor of mortality

    J Neurosurg

    (2019)
  • JP Byrne et al.

    Association Between Emergency Medical Service Response Time and Motor Vehicle Crash Mortality in the United States

    JAMA surgery

    (2019)
  • H Pham et al.

    Faster on-scene times associated with decreased mortality in Helicopter Emergency Medical Services (HEMS) transported trauma patients

    Trauma Surg Acute Care Open

    (2017)
  • The Medical Priority Dispatch System

    International Academies of Emergency Dispatch

    (Sept 2020)
  • Can EMDs Using MPDS Safely Identify Low-Acuity Illness and Injury?

    Annals of Emergency Dispatch Editorial Team. Website.

    (Dec, 2017)
  • A Infinger et al.

    Implementation of prehospital dispatch protocols that triage low-acuity patients to advice-line nurses

    Prehosp Emerg Care

    (2013)
  • S Munro et al.

    A novel method of non-clinical dispatch is associated with a higher rate of critical Helicopter Emergency Medical Service intervention

    Scandinavian journal of trauma, resuscitation and emergency medicine

    (2018)
  • F Dami et al.

    Prehospital triage accuracy in a criteria based dispatch centre

    BMC Emerg Med

    (2015)
  • SCL Lee et al.

    Emergency medical dispatch services across Pan-Asian countries: a web-based survey

    BMC Emerg Med

    (2020)
  • HK Wesson et al.

    Trauma systems in Kenya: a qualitative analysis at the district level

    Qual Health Res

    (2015)
  • J Seblova et al.

    Prehospital emergency care systems in Europe - EuSEM prehospital section survey 2016.[letter]

    Eur J Emerg Med

    (2018)
  • Public Safety Answering Points - 2021 Global Edition

    European Emergency Number Association. Website.

    (Feb 2022)
  • LE Cowley et al.

    Methodological standards for the development and evaluation of clinical prediction rules: a review of the literature

    Diagn Progn Res

    (2019)
  • ST Adams et al.

    Clinical prediction rules

    BMJ

    (2012)
  • K Eastwood et al.

    Secondary triage in prehospital emergency ambulance services: a systematic review

    Emerg Med J

    (2015)
  • AN Ringburg et al.

    Validity of helicopter emergency medical services dispatch criteria for traumatic injuries: a systematic review

    Prehosp Emerg Care

    (2009)
  • K Bohm et al.

    The accuracy of medical dispatch - a systematic review

    Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine

    (2018)
  • AC Tricco et al.

    PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation

    Ann Intern Med

    (2018)
  • JM Clark et al.

    Improving the translation of search strategies using the Polyglot Search Translator: a randomized controlled trial

    J Med Libr Assoc

    (2020)
  • R Alizadeh et al.

    Impact of trauma dispatch algorithm software on the rate of missions of emergency medical services

    Trauma monthly

    (2012)
  • Cited by (0)

    View full text