CJEM Infographic | Prehospital application of CTAS by EMS

In Infographics, Medical Concepts by Lily XiaoLeave a Comment

This month CanadiEM is featuring an article from the Canadian Journal of Emergency Medicine (CJEM) that looks at prehospital triaging by Emergency Medical Services (EMS).1 In Canadian emergency departments (ED), this process is traditionally performed by the triage nurse using the Canadian Triage Acuity Scale (CTAS). However, observational evidence suggests that it may reliably be implemented by paramedics in the prehospital setting.

To address this question, an observational cohort study was performed by Leeies et al. on patients transported to an ED in the Winnipeg Region. Specifically, CTAS scores assigned by EMS on arrival to the ED (CTASA) were compared to the initial and final CTAS scores assigned by a triage nurse (CTASI and CTASF). Interrater reliability between groups was subsequently assessed using a weighted kappa analysis. The results showed moderate agreement between CTASA and CTASI (κw = 0.437) with the CTAS scores being within one grade point in 84.3% of cases. Moderate agreement was also seen between CTASA and CTASF (κw = 0.452) with the CTAS scores being within one grade point in 86.5% of cases.

Overall, this study suggests that EMS providers can provide CTAS scores with moderate interrater reliability compared to ED triage nurses. Future studies are needed to determine the role of prehospital triage in EMS systems.

Download a PDF version of the infographic by clicking here.


Leeies M, Ffrench C, Strome T, Weldon E, Bullard M, Grierson R. Prehospital Application of the Canadian Triage and Acuity Scale by Emergency Medical Services. CJEM. 2017;19(1):26-31. [PubMed]
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Lily Xiao

Lily Xiao

Lily Xiao is a first year medial student at the University of Saskatchewan. She completed her undergraduate degree in Interdisciplinary Medical Sciences at The University of Western Ontario prior to her medical studies.
Lily Xiao

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Simon Huang

Simon Huang

Simon Huang is a PGY1 FRCP-EM resident at Dalhousie University. He is the Associate Social Media Editor for CJEM and is involved with infographic creation for the CanadiEM website.
Simon Huang
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