Comparison of the Canadian Triage and Acuity Scale and Emergency Severity Index for Predicting Clinical Outcomes in Emergency Department Patients: A Prospective Cohort Study

Chanikarn Mapairoje; Parinya Tianwibool

doi:10.12982/BSCM.2026.55

Authors

Chanikarn Mapairoje Department of Emergency Medicine, Faculty of Medicine, Chiang Mai University. Thailand
Parinya Tianwibool Department of Emergency Medicine, Faculty of Medicine, Chiang Mai University. Thailand https://orcid.org/0000-0002-9643-8773

DOI:

https://doi.org/10.12982/BSCM.2026.55

Keywords:

accuracy, Canadian Triage and Acuity Scale , Emergency Severity Index , hospitalization rates, 24-hour mortality rate, resource utilization, emergency department

Abstract

Objective This study aimed to assess the accuracy of CTAS and ESI and examine their correlations with hospitalization rates, 24-hour mortality, and resource utilization.

Methods: A prospective cohort study collected CTAS and ESI data from patients at the Maharaj Nakorn Chiang Mai Hospital Emergency Department (ED) between January and June 2018.

Results: A total of 413 patients were included. Higher triage severity was associated with increased hospitalization rates and higher 24-hour mortality (p < 0.05). Resource utilization in the ED also tended to be higher for patients with more severe triage levels (p < 0.05), with the exception of specific procedures such as defibrillation, external pacing, intramuscular drug administration, and complex procedures. There was good statistical agreement between CTAS and ESI triage levels (weighted kappa = 0.67).

Conclusion: Both CTAS and ESI levels correlate with hospitalization rates and 24-hour mortality. Resource utilization in the ED increases with higher triage severity levels. The good agreement between CTAS and ESI triage levels suggests that the two systems perform comparably in emergency severity assessments.

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