Accuracy of emergency department triage using the Emergency Severity Index and independent predictors of under-triage and over-triage in Brazil: a retrospective cohort analysis

TLDR

Emergency department triage prioritizes care for critically ill patients, but triage errors can increase morbidity and mortality. The study aimed to quantify under‑ and over‑triage rates by nurses using the Emergency Severity Index in Brazil and to identify factors independently associated with each. A single‑center retrospective cohort of 96,071 encounters compared initial ESI scores to physician‑assigned gold‑standard scores, validated by chi‑square analysis, and used multivariate logistic regression to identify predictors, finding 16,426 (≈17 %) triage assignments were inaccurate. Under‑triage was linked to higher admission and critical outcomes, while over‑triage was associated with lower rates; independent predictors of under‑triage included advanced age, vital‑sign derangements, and certain chief complaints, whereas hypertension and allergic complaints predicted over‑triage, highlighting substantial mis‑triage despite training.

Abstract

Emergency department (ED) triage is performed to prioritize care for patients with critical and time-sensitive illness. Triage errors create opportunity for increased morbidity and mortality. Here, we sought to measure the frequency of under- and over-triage of patients by nurses using the Emergency Severity Index (ESI) in Brazil and to identify factors independently associated with each.This was a single-center retrospective cohort study. The accuracy of initial ESI score assignment was determined by comparison with a score entered at the close of each ED encounter by treating physicians with full knowledge of actual resource utilization, disposition, and acute outcomes. Chi-square analysis was used to validate this surrogate gold standard, via comparison of associations with disposition and clinical outcomes. Independent predictors of under- and over-triage were identified by multivariate logistic regression.Initial ESI-determined triage score was classified as inaccurate for 16,426 of 96,071 patient encounters. Under-triage was associated with a significantly higher rate of admission and critical outcome, while over-triage was associated with a lower rate of both. A number of factors identifiable at time of presentation including advanced age, bradycardia, tachycardia, hypoxia, hyperthermia, and several specific chief complaints (i.e., neurologic complaints, chest pain, shortness of breath) were identified as independent predictors of under-triage, while other chief complaints (i.e., hypertension and allergic complaints) were independent predictors of over-triage.Despite rigorous and ongoing training of ESI users, a large number of patients in this cohort were under- or over-triaged. Advanced age, vital sign derangements, and specific chief complaints-all subject to limited guidance by the ESI algorithm-were particularly under-appreciated.