EM · Australasian Triage Scale
The Australasian Triage Scale — categories, validity, reliability and the under-triaged patient
Also known as Australasian Triage Scale · ATS · Emergency triage · Five-level triage scale · Triage nurse assessment · Under-triage and over-triage · Time-to-treatment threshold · Triage validity and reliability · Inter-rater agreement (weighted kappa) · Did not wait
The Australasian Triage Scale (ATS) — the five-level urgency scale used across Australian and New Zealand emergency departments, jointly endorsed by ACEM and the Australian College of Nursing. The five categories with their maximal acceptable times to clinical treatment (ATS 1 immediately, 2 within 10 minutes, 3 within 30 minutes, 4 within 60 minutes, 5 within 120 minutes); construct and criterion validity (ATS category predicts mortality, admission, ICU and resource use — Doherty’s stepwise inpatient mortality); reliability and inter-rater agreement measured by weighted kappa (fair-to-moderate, ~0.3–0.6, never perfect, best at the extremes); the triage nurse’s role and scope of practice (brief assessment, category allocation, first-line measur…
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Meet the patient
A 58-year-old man walks into triage with 40 minutes of central crushing chest pain, diaphoresis and nausea. He is anxious, pale, BP 148/92, HR 104, pain 8 out of 10. The triage nurse allocates him a number and the clock starts. The number she allocates will decide whether he is in a resuscitation bay within minutes or in a waiting room chair.[1]
This is the single most consequential minute of his ED stay. Two questions govern the triage decision, and they govern every triage decision: how quickly must this patient be seen? (the category answers) and is there a deranged vital sign that overrides how well he looks? (the physiological discriminator answers). Hold those two questions and the whole scale slots into place.[1]
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- [1]Gerdtz M. Australian triage nurses' decision-making and scope of practice Aust J Adv Nurs, 2000.PMID 11878360
- [2]Gerdtz MF, Bucknall TK. Triage nurses' clinical decision making. An observational study of urgency assessment J Adv Nurs, 2001.PMID 11529955
- [3]Considine J, LeVasseur SA, Charles A Development of physiological discriminators for the Australasian Triage Scale Accid Emerg Nurs, 2002.PMID 12568450
- [4]Doherty SR, Hore CT, Curran SW. Inpatient mortality as related to triage category in three New South Wales regional base hospitals Emerg Med (Fremantle), 2003.PMID 14631700
- [5]Considine J, LeVasseur SA, Villanueva E The Australasian Triage Scale: examining emergency department nurses' performance using computer and paper scenarios Ann Emerg Med, 2004.PMID 15520712
- [6]Richardson DB. Increase in patient mortality at 10 days associated with emergency department overcrowding Med J Aust, 2006.PMID 16515430
- [7]Gerdtz MF, Bucknall TK Influence of task properties and subjectivity on consistency of triage: a simulation study J Adv Nurs, 2007.PMID 17445021
- [8]Cooke MW, Jinks S. Does the Manchester triage system detect the critically ill? J Accid Emerg Med, 1999.PMID 10353042
- [9]van der Wulp I, van Stel HF. Reliability and validity of the Manchester Triage System in a general emergency department patient population in the Netherlands: results of a simulation study Emerg Med J, 2008.PMID 18573959
- [10]van Veen M, Moll HA Reliability and validity of triage systems in paediatric emergency care Scand J Trauma Resusc Emerg Med, 2009.PMID 19712467
- [11]Gerdtz MF, Considine J, Sands N, et al. Factors influencing consistency of triage using the Australasian Triage Scale: implications for guideline development Emerg Med Australas, 2009.PMID 19682012
- [12]Forero R, McCarthy S, Hillman K. Prevalence of morphine use and time to initial analgesia in an Australian emergency department Emerg Med Australas, 2008.PMID 18377403
- [13]Blake DF, Dissanayake DB, Hay RM, et al. 'Did not waits': a regional Australian emergency department experience Emerg Med Australas, 2014.PMID 24708003