Performance of the medical priority dispatch system in correctly classifying out-of-hospital cardiac arrests as appropriate for resuscitation

Justin Yap; Jennie Helmer; Marc Gessaroli; Jacob Hutton; Laiba Khan; Frank Scheuermeyer; Nechelle Wall; Jennifer Bolster; Sean Van Diepen; Joseph Puyat; Michael Asamoah-Boaheng; Ron Straight; Jim Christenson; Brian Grunau

doi:10.1016/j.resuscitation.2022.11.001

Performance of the medical priority dispatch system in correctly classifying out-of-hospital cardiac arrests as appropriate for resuscitation

Resuscitation. 2022 Dec:181:123-131. doi: 10.1016/j.resuscitation.2022.11.001. Epub 2022 Nov 11.

Authors

Affiliations

¹ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; Faculty of Science, University of British Columbia, British Columbia, Canada. Electronic address: justinyap.ubc@gmail.com.
² British Columbia Resuscitation Research Collaborative, British Columbia, Canada; British Columbia Emergency Health Services, British Columbia, Canada; School of Population & Public Health, University of British Columbia, British Columbia, Canada.
³ British Columbia Emergency Health Services, British Columbia, Canada.
⁴ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; British Columbia Emergency Health Services, British Columbia, Canada; Faculty of Medicine, University of British Columbia, British Columbia, Canada.
⁵ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; Faculty of Science, University of British Columbia, British Columbia, Canada.
⁶ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; Department of Emergency Medicine, University of British Columbia and St. Paul's Hospital, British Columbia, Canada; Centre for Health Evaluation and Outcome Sciences, British Columbia, Canada.
⁷ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; British Columbia Emergency Health Services, British Columbia, Canada.
⁸ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; Division of Critical Care, University of Alberta, Alberta, Canada.
⁹ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; Centre for Health Evaluation and Outcome Sciences, British Columbia, Canada.
¹⁰ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; Department of Emergency Medicine, University of British Columbia and St. Paul's Hospital, British Columbia, Canada.
¹¹ British Columbia Resuscitation Research Collaborative, British Columbia, Canada; British Columbia Emergency Health Services, British Columbia, Canada; Department of Emergency Medicine, University of British Columbia and St. Paul's Hospital, British Columbia, Canada; Centre for Health Evaluation and Outcome Sciences, British Columbia, Canada.

PMID: 36375652
DOI: 10.1016/j.resuscitation.2022.11.001

Abstract

Background: Emergency dispatch centres receive emergency calls and assign resources. Out-of-hospital cardiac arrests (OHCA) can be classified as appropriate (requiring emergent response) or inappropriate (requiring non-emergent response) for resuscitation. We sought to determine system accuracy in emergency medical services (EMS) OHCA response allocation.

Methods: We analyzed EMS-assessed non-traumatic OHCA records from the British Columbia (BC) Cardiac Arrest registry (January 1, 2019-June 1, 2021), excluding EMS-witnessed cases. In BC the "Medical Priority Dispatch System" is used. We classified EMS dispatch as "emergent" or "non-emergent" and compared to the gold standard of whether EMS personnel decided treatment was appropriate upon scene arrival. We calculated sensitivity, specificity, and positive and negative predictive values (PPV, NPV), with 95% CI's.

Results: Of 15,371 non-traumatic OHCAs, the median age was 65 (inter quartile range 51-78), and 4834 (31%) were women; 7152 (47%) were EMS-treated, of whom 651 (9.1%) survived). Among EMS-treated cases 6923/7152 had an emergent response (sensitivity = 97%, 95% CI 96-97) and among EMS-untreated cases 3951/8219 had a non-emergent response (specificity = 48%, 95% CI, 47 to 49). Among cases with emergent dispatch, 6923/11191 were EMS-treated (PPV = 62%, 95% CI 61-62), and among those with non-emergent dispatch, 3951/4180 were EMS-untreated (NPV = 95%, 95% CI 94-95); 229/4180 (5.5%) with a non-emergent dispatch were treated by EMS.

Conclusion: The dispatch system in BC has a high sensitivity and moderate specificity in sending the appropriate responses for OHCAs deemed appropriate for treatment by paramedics. Future research may address strategies to increase system specificity, and decrease the incidence of non-emergent dispatch to EMS-treated cases.

Keywords: Dispatch; Heart arrest; Medical priority dispatch system; Out-of-hospital cardiac arrest.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Cardiopulmonary Resuscitation*
Emergency Medical Dispatch*
Emergency Medical Services*
Female
Humans
Male
Out-of-Hospital Cardiac Arrest* / therapy
Registries