‘Is the patient completely alert?’ – accuracy of emergency medical dispatcher determination of patient conscious state


emergency medical services
pre-hospital care
emergency dispatch
conscious state

How to Cite

Belcher J, Finn J, Whiteside A, Ball S. ‘Is the patient completely alert?’ – accuracy of emergency medical dispatcher determination of patient conscious state. Australasian Journal of Paramedicine [Internet]. 2021Jan.3 [cited 2023May28];18. Available from: https://ajp.paramedics.org/index.php/ajp/article/view/858



During emergency ambulance calls, one of the key issues assessed is the patient’s level of consciousness. An altered conscious state can be indicative of a need for a high priority response; however, the reliability of the resulting triage depends on how accurately alertness can be ascertained over the phone. This study investigated the accuracy of emergency medical dispatcher (EMD) determination of conscious state in emergency ambulance calls in Perth, Western Australia.


The study compared EMD determination of patient alertness based on the Medical Priority Dispatch System (MPDS), with conscious state as recorded by paramedics on arrival, for all emergency ambulance calls in a 1-year period in metropolitan Perth. Diagnostic accuracy was reported across the whole system and stratified by MPDS chief complaint.


There were 109,678 calls included for analysis. In terms of identifying patients as not alert, the overall positive predictive value was 6.62% and negative predictive value was 99.93%, with 10 times as many patients dispatched as not alert than found to be not alert at scene. Sensitivity was only 69.94%. There was significant variation in accuracy between chief complaints.


The study found high levels of inaccuracy between dispatch identification of not-alert patients, and what paramedics found on scene. While not-alert dispatch was 10 times more common than patients being determined not-alert on scene, only 70% of not-alert patients on scene were classified as such during dispatch. Further research is suggested into the factors that affect the accuracy of EMD determination of patient conscious state.



Andrew E, Jones C, Stephenson M, et al. Aligning ambulance dispatch priority to patient acuity: a methodology. Emerg Med Australas 2019;31:405-10. doi: 10.1111/1742-6723.13181

Eastwood K, Morgans A, Smith K, et al. A novel approach for managing the growing demand for ambulance services by low-acuity patients. Aust Health Rev 2016;40:378-84. doi: 10.1071/ah15134

Bohm K, Kurland L. The accuracy of medical dispatch - a systematic review. Scand J Trauma Resusc Emerg Med 2018;26:94. doi: 10.1186/s13049-018-0528-8

Yancey A, Clawson J. EMD position paper resource document. Ann Emerg Dispatch Response 2014;2(2).

Ball SJ, Williams TA, Smith K, et al. Association between ambulance dispatch priority and patient condition. Emerg Med Australas 2016;28:716-24.

Feldman MJ, Verbeek PR, Lyons DG, et al. Comparison of the medical priority dispatch system to an out-of-hospital patient acuity score. Acad Emerg Med 2006;13:954-60. doi: 10.1197/j.aem.2006.04.018

Hodell EM, Sporer KA, Brown JF. Which emergency medical dispatch codes predict high prehospital nontransport rates in an urban community? Prehosp Emerg Care 2014;18:28-34. doi: 10.3109/10903127.2013.825349

Hoikka M, Länkimäki S, Silfvast T, Ala-Kokko TI. Medical priority dispatch codes - comparison with national early warning score. Scand J Trauma Resusc Emerg Med 2016;24:142. doi: 10.1186/s13049-016-0336-y

Neely KW, Eldurkar JA, Drake MER. Do emergency medical services dispatch nature and severity codes agree with paramedic field findings? Acad Emerg Med 2000;7:174-80.

Sporer KA, Craig AM, Johnson NJ, Yeh CC. Does emergency medical dispatch priority predict delphi process-derived levels of prehospital intervention? Prehosp Disaster Med 2010;25:309-17.

Sporer KA, Youngblood GM, Rodriguez RM. The ability of emergency medical dispatch codes of medical complaints to predict ALS prehospital interventions. Prehosp Emerg Care 2007;11:192-8. doi: 10.1080/10903120701205984

Mosley I, Morphet J, Innes K, Braitberg G. Triage assessments and the activation of rapid care protocols for acute stroke patients. Australas Emerg Nurs J 2013;16:4-9. doi: https://doi.org/10.1016/j.aenj.2012.12.002

American College of Surgeons, Committee on Trauma. Advanced trauma life support: student course manual. Chicago, IL2018.

Umpierrez G, Korytkowski M. Diabetic emergencies - ketoacidosis, hyperglycaemic hyperosmolar state and hypoglycaemia. Nat Rev Endocrinol 2016;12:222-32. doi: http://dx.doi.org/10.1038/nrendo.2016.15

Kelly C, Upex A, Bateman D. Comparison of consciousness level assessment in the poisoned patient using the alert/verbal/painful/unresponsive scale and the Glasgow Coma Scale. Ann Emerg Med 2004;44:108-13.

Australian Government Department of Health and Ageing. Emergency triage education kit. Canberra: DoHA; 2009. Available at: https://acem.org.au/getmedia/c9ba86b7-c2ba-4701-9b4f-86a12ab91152/Triage-Education-Kit.aspx

International Academy of Emergency Medical Dispatch. Medical priority dispatch system QA guide v13. Salt Lake City: Priority Dispatch Corporation; 2016.

Belcher J, Finn J, Whiteside A, Ball SJ. Accuracy of call-taker assessment of patient level of consciousness: a systematic review. Australasian Journal of Paramedicine 2020;17. doi:10.33151/ajp.17.741

Bach A, Christensen EF. Accuracy in identifying patients with loss of consciousness in a police-operated emergency call centre – first step in the chain of survival. Acta Anaesthesiol Scand 2007;51:742-6. doi:10.1111/j.1399-6576.2007.01310.x

Radonić J, Gnjidić M, Matijanec M, Hochstädter D, Jasprica-Hrelec V. What is not revealed in the telephone call reporting "unconsciousness". Lijec Vjesn. 1995;117(Suppl 2):68-70.

Australian Bureau of Statistics. Regional population growth, Australia, 2017-18. Canberra: ABS; 2019.

St John Western Australia. Annual report 2018-2019. Available at: https://stjohnwa.com.au/docs/default-source/corporate-publications/annual-report-2019_v11_web.pdf?sfvrsn=6

Queensland Ambulance Service. Neurological assessment. Clinical Practice Manual 2016; p. 431-3.

American College of Surgeons Committee on Trauma. Advanced life support course for physicians. Chicago, IL: American College of Surgeons; 1993.

Clopper C, Pearson E. The use of confidence or fiducial limits illustrated in the case of the binomial. Biometrika 1934;26:404-13.

Yates D, Moore D, McCabe G. The practice of statistics. 1st edn. New York: W.H. Freeman; 1999.

Teasdale G, Jennett B. Assessment of coma and impaired consciousness. A practical scale. Lancet 1974;2:81-4.

Pereira VdC, Scott S, Nakano MU, et al. Caller’s ability to understand “responding normally” vs. “completely alert” key question in a Brazilian Portuguese version of an emergency medical dispatch protocol. Ann Emerg Dispatch Response 2019;7(2).

King County Emergency Medical Services Division. Criteria based dispatch: emergency medical dispatch guidelines 2010. Available at: www.emsonline.net/assets/CriteriaBasedDispatchGuidelines-Rev2010.pdf

Frazier A. Completely alert? The Journal of Emergency Dispatch. 2019. Available at: https://iaedjournal.org/completely-alert/

Clawson J. The holy grail of emergency medical dispatching. Ann Emerg Dispatch Response 2013;1(1).