Canadian Triage and Acuity Scale (CTAS) Proficiency in High-volume Emergency Settings: A Scoping Review

Abstract

Background: Triage decision-making (TDM) using the Canadian Triage and Acuity Scale (CTAS) is critical in high-volume emergency departments (EDs), but nurse experience and work environment factors may influence CTAS proficiency. Objective: To map and synthesize evidence on how nurse experience and work environment affect CTAS proficiency in high-volume EDs. Methods: Following JBI guidelines and PRISMA-ScR, we searched PubMed, CINAHL, Scopus, Web of Science, and Google Scholar (2000–September 2025). Inclusion criteria: studies of adult ED triage nurses (Population), TDM/CTAS proficiency (Concept), and high-volume EDs (>50,000 visits/year or NEDOCS ≥100) (Context). Data from 28 studies were thematically synthesized. Results: Tenure >5 years was associated with 15–30% accuracy gains for urgent cases (Levels 2–3), supported by intuitive reasoning (System 1). However, cognitive biases (e.g., centrality bias, kappa 0.65–0.72) limited reliability. Overcrowding and nurse-to-patient ratios >4:1 increased errors by 12–18%, with under-triage reaching 41.5% during surges. Electronic aids improved reliability by approximately 0.10 kappa but could not eliminate systemic strain. Conclusions: CTAS proficiency depends on both individual expertise and supportive work environments. Debiasing training, workload caps, and better electronic support are needed. Major gaps include lack of longitudinal studies and underrepresentation of low-resource settings.