A Brief Look at the Current State of EMS Dispatch Triage in Ontario

*Photo Credit: Professional Paramedic Association of Ottawa (PPAO)

[This paper originally submitted as an assignment in my introduction to Quality, Patient Safety & Risk for my MScHQ program.]

Emergency Medical Services (EMS) is the provision of pre-hospital or out-of-hospital medical care and transportation, traditionally in emergency situations to anyone that asks for help (Calle, 1996). In recent years the system has felt performance pressure due to increased low acuity demand on limited resources (Infinger, 2013).  This demand has increased with an aging population demographic and positive public education on the use of an emergency phone number such as 911 in North America or 999 in the United Kingdom.  

While this system was originally designed for serious traumatic and medical emergencies (Thakore, 2002), todays modern system responds to requests for service and transport for all kinds of patients; from minor cuts and infections, vague prolonged symptoms, psychiatric issues and severe acute medical or traumatic conditions. There are estimates that up to 52% of patients do not require emergency assistance (Marks, 2002).  This demand has also placed pressure on hospital emergency departments as the default destination of ambulances (KCACC, 2019).

The historical objective was to respond to emergencies as fast as possible with a flat (static) deployment model; meaning that if you call the number the response will be the quick and reproducible for each response.  In light of the system demand on this deployment model, the potential of telephone medical triage as a means to manage risk and quality of care in EMS, has moved to the forefront as a solution in the modern approach (Shah, 2005).

The Kingston Central Ambulance Communications Centre (KCACC) is operated by the Kingston General Hospital (KGH) under contract to the Ontario Ministry of Health and Long Term Care – Emergency Health Services Branch (MOHLTC-EHSB) with a standardized delivery model and performance agreement with the Ministry of Health and Long Term Care (MOHLTC).  The current model uses an Ontario specific Dispatch Priority Card Index version two (DPCI-II) designed and developed by the MOH-EHSB (KCACC, 2019).

The specific issue observed and subject to this analysis is the use of the current medical dispatch triage system, DPCI-II which uses a static deployment model and little variability in dispatch triage assignment for level of response. Additionally, there are currently no alternatives to transporting patients to the emergency department. This is an important and complex issue because the static deployment model may no longer be sustainable with a lack of resources and the current model requiring all patients be transported to an emergency department. This demand and resource mismatch can increase risk and potentially harm patients.

The key strength within the current DPCI-II and deployment model is what is known as “over triage” (Shah, 2005) and reduced liability for the crown agency of Ontario.  This model is designed around ensuring that a critical medical condition is not missed by the dispatch triage algorithm.  As a result of over triage, a large number of events are considered to be high priority and require maximal resources be assigned (Shah, 2005).  This triage method as a strength, is based on theoretically reducing risk of under triaging severe patient conditions. These patients could otherwise be assigned a triage level that would require waiting for an ambulance and cause harm and resulting liability.  This model treats all requests for service as emergencies; with the majority at the highest level, reducing the perceived liability of the MOHLTC. The model sets standard expectations and retains simplified policy and operating guidelines, reducing decision making requirements of dispatch staff and potential for human error.

In the eyes of the MOHLTC, the reduced liability aspect has been the focus for many years (KCACC, 2019), this very focus appears to also be in contrast; potentially as the greatest weakness in the system due to the mounting system demands. Let’s consider a hypothetical hospital emergency department (ED) that triages with only two levels of priority, where approximately 80% of patients are all of the highest priority. This would essentially mean 80% of the patients would be on a first-come, first-served assessment and treatment basis; with limited available ED resources and no preference given to any particular medical problem.  This includes patients with immediate life threatening and reversible conditions. Such a model would appear to be chaotic and ineffective with high acuity patients waiting for assessment and treatment in the ED waiting room.  This is exactly how the Ontario MOHLTC manages dispatch triage and ambulance deployment.  Therefore, as an example, a person with shortness of breath from a self-declared anxiety episode would be dispatched as the same priority as an infant in cardiac arrest, with the closest ambulance assigned to the prior patient if that 911 request arose first and within minutes of one another. Without enough ambulances and without effective dispatch triage, there is a high likelihood that a critical patient will have to wait for an ambulance.

An opportunity exists to learn from international ambulance communication centres and look at emerging practices in dispatch medical triage and alternative patient dispositions (Infinger, 2013).  Industry accepted dispatch medical triage tools exists such as Advanced Medical Priority Dispatch SystemsTM (AMPDS; International Academies of Emergency Dispatch, Salt Lake City, UT). Such systems encompass a statistically and medically validated dispatch triage system with broader classifications of patient condition, that create a virtual telephone waiting room similar to a hospital emergency department waiting room (Studnek, 2012).  Such a system redefines which life-threatening emergencies require a rapid response and which medical conditions can appropriately wait while limited resources attend to the higher-level emergencies.  In addition, leading agencies using this system are employing alternative patient disposition opportunities such as telephone medical consultations, alternative urgent care destinations and in-home health care (Studnek, 2012). These agencies have shown a safe reduction in demand on ambulances with approximately one fourth still needing transport to an emergency department as the destination for 911 callers (Studnek, 2012).

Since the MOHTLC has ultimate responsibility and oversight of the ambulance communications system (Ambulance Act, 2019) the risk and liability remain with the crown agency and there is essentially no business competition as a government delivered service.  The key threat to the current model is not addressing the increasing demand through provision of increased resources or alternative deployment and delivery models.  Should status quo be allowed, the ambulance response times will continue to increase as well as secondary threats such as ambulance off-load delays (the inability to transfer care to the emergency department and make the ambulance available for the next response) will continue to increase (Infinger, 2013).  Further delays in ambulance response will potentially harm the highest priority patients in emergency situations.  Alternatively, should the MOHLTC act on this current threat they will be undertaking a massive change management project with all the potential risks and hazards of such a transition for critical infrastructure and people.

Due to limitations in the scope of this paper and complexity of the issue, the analysis looked only at my assessed primary strength, weakness, opportunity and threat presented by the current Kingston CACC dispatch triage system as described and observed on a site visit.

This paper does not present the complexity needed to fully address the issues at hand.  It is apparent that the Ontario MOHLTC dispatch triage system and deployment model has been in operation for a substantial period of time, with minimal change or consideration of international best practices or alternative validated triage systems.

I therefore take the position that the current MOHLTC DPCI-II dispatch triage system and regulations regarding patient disposition are a significant weakness and threat to the safety of patients in Ontario.  I see substantial opportunity to create a dynamic and efficient dispatch triage and deployment model in Ontario and Kingston CACC. Such a model could improve patient safety, reduce risk and still meet the MOHLTC requirements of liability protection.  This is an area that needs further study and validation in Canada to safely integrate a new model in the overall health care system.


Ambulance Act, R.S.O. 1990, c. A.19. (2019). Retrieved August 3, 2019, from https://www.ontario.ca/laws/statute/90a19?search=e+laws

Calle, P., Lagaert, L., & Buylaert, W. (1996). How to evaluate an emergency medical dispatch system and identify areas for improvement? European Journal of Emergency Medicine3, 187–190.

Infinger, A., Studnek, J. R., Hawkins, E., Bagwell, B., & Swanson, D. (2013). Implementation of Prehospital Dispatch Protocols That Triage Low-acuity Patients to Advice-line Nurses. Prehospital Emergency Care17(4), 481–485. https://doi.org/10.3109/10903127.2013.811563

Kingston CACC. (2019). Kingston Central Ambulance Communications Centre [Powerpoint slides & Presentation]

Marks, P. J., Daniel, T. D., Afolabi, O., Spiers, G., & Nguyen-Van-Tam, J. S. (2002). PREHOSPITAL CARE Emergency (999) calls to the ambulance service that do not result in the patient being transported to hospital: an epidemiological study. Emerg Med J19, 449–452. https://doi.org/10.1136/emj.19.5.449

Shah, M. N., Bishop, P., Brooke Lerner, E., Fairbanks, R. J., & Davis, E. A. (2005). Validation of Using EMS Dispatch Codes to Identify Low-Acuity Patients. Prehospital Emergency Care9(1), 24–31. https://doi.org/10.1080/10903120590891651

Studnek, J. R., Thestrup, L., Blackwell, T., & Bagwell, B. (2012). Utilization of Prehospital Dispatch Protocols to Identify Low-Acuity Patients. Prehospital Emergency Care16(2), 204–209. https://doi.org/10.3109/10903127.2011.640415

Thakore, S., McGugan, E. A., & Morrison, W. (2002). Emergency ambulance dispatch: is there a      case for triage?Journal of the Royal Society of Medicine 2002;126-129

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!