“Validity and accuracy of Manchester triage system with vignettes cases: A multicentric study”

Background Triage is a critical component of emergency department practice. Evaluating triage accuracy is essential for improving and standardizing triage practice. Clinical vignettes can simplify complex triage scenarios and highlight key variables. This study aimed to assess MTS accuracy as applied by triage nurses against an expert-panel reference standard.Methods We conducted a prospective, multicentre study from May 2024 to March 2025 across seven emergency departments in Spain. Forty validated real-case clinical vignettes were developed, and a panel of triage experts established the reference standard for priority level, flowchart and discriminator, each vignette contained all information necessary for triage. MTS version 3.6 was used. Accuracy was assessed overall and separately for each component.Results A total of 100 nurses participated (median age, 39.1 years). Overall accuracy was 75.98% (mean, 30.4; SD, 3.93), with 94.0% for flowchart, 80.3% for discriminator, and 83.5% for priority-level selection. Mean under-triage and over-triage rates were 10.1% and 6.3%, respectively. Nurses with >30 correctly classified vignettes had significantly more MTS experience. Specificity was 94.8% and NPV 95.9%. Interobserver agreement was substantial (Fleiss' κ = 0.681, 95% CI 0.614-0.759).Conclusion Trained nurses demonstrated good MTS accuracy, high specificity, and substantial interobserver agreement under standardized vignette-based conditions.