“…[1][2][3][4][5] Five-level triage scales have been developed in recent years, including the Australasian Triage Scale (ATS, Australia and New Zealand), the Canadian Triage and Acuity Scale (CTAS, Canada), the Manchester Triage System (MTS, United Kingdom [UK]), and the Emergency Severity Index (ESI, United States). [6][7][8] Like the three-level triage models, the ATS, CTAS, and MTS are based on the urgency of patients' conditions and seek to answer the question, ''How long can patients wait?'' Research has shown the ATS and the CTAS to be reliable, and the ATS has also been validated with clinical outcomes.…”