What is the optimal outcome for evaluating the triage Systems? Insights from a prospective observational study

Background: Currently, there is no universally accepted gold standard outcome for assessing the effectiveness of the Triage Systems. This study aimed to comprehensively evaluate and compare various outcomes utilized in triage studies. Methods: A prospective observational study was conducted at the Emergency Department (ED) of Merano Hospital from June 1 to December 31, 2023. We assessed the predictive capability of the Manchester Triage System (MTS) across multiple outcomes using areas under the receiver operating characteristic curve (AUROC), along with their corresponding 95% confidence intervals (95% CI), and frequency distributions. Results: The MTS demonstrated strong performance concerning the most objective outcomes, such as mortality (at 72 h: AUROC 0.914; 95 %CI: 0.815-1; at 7 days: 0.845; 95 %CI: 0.729-0.965; at 30 days: 0.794; 95 %CI: 0.706-0.881), admission to the intensive care unit (0.831; 95 %CI: 0.763-0.899), and need for life-saving interventions (0.870; 95 %CI: 0.806-0.934). Additionally, outcomes such as urgency status and clinical priority, as judged by physicians, exhibited excellent performance and optimal frequency distribution. Conclusions: The performance of the MTS varied significantly depending on the specific outcome under evaluation. Currently, no single outcome appears superior to others, nor does any seem poised to serve as a potential gold standard for the assessment of triage systems. It is advisable for dedicated working groups to convene and reach a consensus on the most effective outcomes for evaluating the performance of MTS and other triage systems. This should be accomplished through a systematic, standardized, and transparent approach, grounded in the best available evidence.