LAUSR

Key Points Question What is the rate of emergency department (ED) mistriage, and what patient and visit characteristics are associated with mistriage? Findings In a cohort study of 5 315 176 adult ED encounters across 21 hospitals, mistriage occurred in an estimated one-third of encounters, and the sensitivity to identify a critically ill patient was 66%. Key patient sociodemographic and clinical characteristics were associated with mistriage. Meaning These findings suggest that development of more data-driven, standardized triage processes may limit critical undertriage, optimize resource allocation, and promote more equitable care in EDs.