View source for Triage

{{Short description|Emergency medical process}}
{{About|the concept of triage as it occurs in medical emergencies and disasters}}
{{multiple image
| perrow            = 2
| total_width       = 300
| image1            = Mölndals sjukhus provtagningstält 2020.jpg
| alt1              = Triage tent set up outside of a Swedish Hospital
| image2            = DN-SD-04-12743.JPEG
| alt2              = A triage area outside the US Pentagon building following [[9/11]].
| image3            = Australian medic conducts triage in the shade of a tree. Pakistan 2010. Photo- Australian Government (10674887523).jpg
| alt3              = Australian medic conducts triage in the shade of a tree. Pakistan 2010.
| image4            = "Forward Triage", circa 1952 edited and recropped.jpg
| alt4              = A Hospital Corpsman prepares a wounded Marine for evacuation from a forward aid station in the Yanggu area.
| image5            = Misawa Air Base conducts mass casualty exercise 120830-N-VZ328-005.jpg
| alt5              = An U.S. Air Force emergency responder from the 35th Medical Group evacuates a simulated casualty during a major accident response exercise at Misawa Air Base.
| image6            = U.S. Air Force Capt. Jennilyn Estell, right, a dentist with the 374th Dental Squadron, guides Senior Airman Fausto Rojas, a simulated patient with the 374th Medical Support Squadron, to a decontamination area 111104-F-PM645-070.jpg
| alt6              = U.S. Air Force Capt. Jennilyn Estell, right, a dentist with the 374th Dental Squadron, guides Senior Airman Fausto Rojas, a simulated patient with the 374th Medical Support Squadron, to a decontamination area
| footer            = From top-left to bottom-right:<br />[[COVID-19]] triage tent outside of a Swedish Hospital<br />[[9/11]] triage station outside of [[the Pentagon]]<br />[[2010 Pakistan floods]] triage station under a tree<br />[[Korean War]] triage station in modern [[South Korea]]<br /> Mass casualty drill at [[Misawa Air Base]] <br /> [[CBRN]] triage drill at [[Yokota Air Base]]
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In medicine, '''triage''' ({{IPAc-en|ˈ|t|r|iː|ɑː|ʒ}}, {{IPAc-en|t|r|i|ˈ|ɑː|ʒ}}; {{IPA|fr|tʁiaʒ|lang}}) is a process by which care providers such as [[Health professional|medical professionals]] and those with [[first aid]] knowledge determine the order of priority for providing treatment to injured individuals<ref name="Robertson-Steel_2006" /> and/or inform the [[rationing]] of limited supplies so that they go to those who can most benefit from it.<ref>{{Cite journal | vauthors = Muensterer OJ, Gianicolo EA, Paul NW |date=January 2021 |title=Rationing and triage of scarce, lifesaving therapy in the context of the COVID-19 pandemic: a cross-sectional, social media-driven, scenario-based online query of societal attitudes |url=https://journals.lww.com/ijsgh/fulltext/2021/01010/rationing_and_triage_of_scarce,_lifesaving_therapy.4.aspx |journal=IJS Global Health |language=en-US |volume=4 |issue=1 |pages=e47 |doi=10.1097/GH9.0000000000000047 |s2cid=220847218 |issn=2576-3342|doi-access=free }}</ref> Triage is usually relied upon when there are more injured individuals than available care providers (known as a [[mass casualty incident]]), or when there are more injured individuals than supplies to treat them.<ref name="Iserson_2007" />

The methodologies of triage vary by institution, locality, and country but have the same universal underlying concepts.<ref name="World Health Organization_2008" /> In most cases, the triage process places the most [[Major trauma|injured]] and most able to be helped as the first priority, with the most [[Terminal illness|terminally injured]] the last priority (except in the case of reverse triage).<ref name="van Ruler_2022" /> Triage systems vary dramatically based on a variety of factors, and can follow specific, measurable metrics, like [[Trauma Screening Questionnaire|trauma scoring systems]], or can be based on the medical opinion of the provider.<ref name="Petridou-2008" /> Triage is an imperfect practice, and can be largely subjective, especially when based on general opinion rather than a score.<ref name="Xiang-2014" /><ref name="Turégano-Fuentes-2008" /> This is because triage needs to balance multiple and sometimes contradictory objectives simultaneously, most of them being fundamental to personhood: likelihood of death, efficacy of treatment, patients' remaining lifespan, ethics, and religion.{{TOC limit|2}}

== Etymology and origin ==
The term ''triage'' comes directly from [[French language|French]] {{lang|fr|triage}}, meaning the action of picking or sorting,<ref>{{cite OED|triage|8063675021}}</ref> it itself coming from the [[Old French]] verb {{wikt-lang|fr|trier}}, meaning to separate, sort, shift, or select; with {{wikt-lang|fr|trier}} in turn came from [[late Latin]] tritare, to grind.<ref>{{cite web |title=Merriam-Webster Online Dictionary |url=http://www.merriam-webster.com/dictionary/triage |access-date=2008-12-05}}</ref> Although the concept existed much earlier, at least as far back as the reign of [[Maximilian I, Holy Roman Emperor|Maximillian I]],<ref name="Cueni_2020">{{cite news | vauthors = Cueni C |date=27 November 2020 |title=Triage in Zeiten der Corona-Pandemie – Claude Cueni |language=de-CH |work=Blick |agency=Kirche und Leben |url=https://www.blick.ch/meinung/kolumnen/kolumne-geschichte-ueber-die-triage-in-der-corona-pandemie-lizenz-zum-sterben-id16215543.html |access-date=29 January 2022}}</ref> it was not until the 1800s that the Old French trier was used to describe the practice of triage.<ref>{{cite journal | vauthors = Nakao H, Ukai I, Kotani J | title = A review of the history of the origin of triage from a disaster medicine perspective | journal = Acute Medicine & Surgery | volume = 4 | issue = 4 | pages = 379–384 | date = October 2017 | pmid = 29123897 | pmc = 5649292 | doi = 10.1002/ams2.293 }}</ref> That year, [[Baron Dominique-Jean Larrey]], the [[Surgeon|Surgeon in Chief]] of [[Napoleon|Napoleon's]] [[Imperial Guard (Napoleon I)|Imperial Guard]] laid the groundwork for what would eventually become modern triage<ref name="Robertson-Steel_2006">{{cite journal | vauthors = Robertson-Steel I | title = Evolution of triage systems | journal = Emergency Medicine Journal | volume = 23 | issue = 2 | pages = 154–155 | date = February 2006 | pmid = 16439754 | doi = 10.1136/emj.2005.030270 | pmc = 2564046 }}</ref> introducing the concept of "treat[ing] the wounded according to the observed gravity of their injuries and the urgency for medical care, regardless of their rank or nationality".<ref name="pmid16850154">{{cite journal | vauthors = Skandalakis PN, Lainas P, Zoras O, Skandalakis JE, Mirilas P | title = "To afford the wounded speedy assistance": Dominique Jean Larrey and Napoleon | journal = World Journal of Surgery | volume = 30 | issue = 8 | pages = 1392–9 | date = August 2006 | pmid = 16850154 | doi = 10.1007/s00268-005-0436-8 | s2cid = 42597837 }}</ref>

== Concepts in triage ==
=== Simple triage ===
Simple triage is usually used in a scene of an accident or "[[mass-casualty incident]]" (MCI), in order to sort patients into those who need critical attention and immediate transport to a secondary or tertiary care facility to survive, those who require low-intensity care to survive, those who are uninjured, and those who are deceased or will be so imminently.<ref>{{cite book | vauthors = Hanfling D, Lang CR | chapter = Chapter 166 - Aircraft Crash Preparedness and Response |date=2006-01-01| title = Disaster Medicine |pages=829–833 | veditors = Ciottone GR, Anderson PD, Der Heide EA, Darling RG  |place=Philadelphia |publisher=Mosby |language=en |isbn=978-0-323-03253-7 }}</ref> In the United States, this most commonly takes the form of the [[Simple triage and rapid treatment|START]] triage model, in Canada, the CTAS model, and in Australia the ATS model.<ref name="Yancey_2023">{{cite book | vauthors = Yancey CC, O'Rourke M | chapter = Emergency Department Triage |date=2023 | chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK557583/ | title = StatPearls |access-date=2023-05-06 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=32491515 }}</ref> Assessment often begins with asking anyone who can walk to walk to a designated area, labeling them the lowest priority, and assessing other patients from there.<ref name="Yancey_2023" /> Upon completion of the initial assessment by the care provider, which is based on the so-called [[ABC (medicine)|ABCDE approach]],<ref name="World Health Organization_2008" /><ref name="Thim_2012">{{cite journal | vauthors = Thim T, Krarup NH, Grove EL, Rohde CV, Løfgren B | title = Initial assessment and treatment with the Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach | journal = International Journal of General Medicine | volume = 5 | pages = 117–121 | date = January 2012 | pmid = 22319249 | pmc = 3273374 | doi = 10.2147/IJGM.S28478 | doi-access = free }}</ref> patients are generally labelled with their available information, including "patient’s name, gender, injuries, interventions, care-provider IDs, casualty triage score, and an easily visible overall triage category".<ref>{{cite book | vauthors = Foley E, Reisner AT | chapter = Chapter 54 - Triage | veditors = Ciottone GR |title=Ciottone's Disaster Medicine | year = 2016 | doi = 10.1016/B978-0-323-28665-7.00054-6 |publisher = Elsevier Inc. |language=en | isbn = 978-0-323-28665-7 | pages = 339–340 }}</ref>

==== ABCDE Assessment ====
{{Main|ABC (medicine)}}

An ABCDE assessment (other variations include ABC,<ref>{{Cite web | vauthors = Schimelpfenig T |title=ABCs of Wilderness Medicine: The Initial Assessment |url=http://blog.nols.edu/2019/07/30/wilderness-medicine-abcs |access-date=2023-05-12 | location = Lander, WY | publisher = National Outdoor Leadership School (NOLS ) | work = blog.nols.edu |language=en-us}}</ref> ABCD,<ref>{{cite journal | vauthors = Livingston EH, Passaro EP | title = Resuscitation. Revival should be the first priority | journal = Postgraduate Medicine | volume = 89 | issue = 1 | pages = 117–20, 122 | date = January 1991 | pmid = 1985304 | doi = 10.1080/00325481.1991.11700789 }}</ref> ABCDEF,<ref>{{Cite book |title=UK Ambulance Services Clinical Practice Guidelines 2013 |publisher=[[National Health Service]] |year=2013 |isbn=9781859593639}}</ref> and many others, including those localized to non-English) is rapid patient assessment designed to check bodily function in order of importance.<ref name="Thim_2012" />
{| class="wikitable"
|+ABCDE Assessment Example<ref name="Thim_2012" />
!Letter
!Term
!Meaning
|-
|A
|Airway
|Checking for airway obstruction
|-
|B
|Breathing
|Checking if the patient is breathing and if the breathing is normal
|-
|C
|Circulation
|Checking to see if the heart rate and capillary refill time is normal
|-
|D
|Disability
|Checking the patient’s alertness, awareness, and response to painful stimuli
|-
|E
|Exposure
|Checking the patient for trauma, bleeding, temperature, and other skin signs
|}

==== Tags ====
{{Main|Triage tag}}
[[File:Triage 041105 big.jpg|thumb|Many triage systems use triage tags with specific formats]]
[[File:ET Light Picture 352 X 240.jpg|thumb|Emergency Triage (E/T) Lights – particularly useful at night or under adverse conditions]]

A [[triage tag]] is a premade label placed on each patient that serves to accomplish several objectives:
* identify the patient.
* bear record of assessment findings.
* identify the priority of the patient's need for medical treatment and transport from the emergency scene.
* track the patients' progress through the triage process.
* identify additional hazards such as contamination.

Triage tags take a variety of forms.  Some countries use a nationally standardized triage tag,<ref>{{cite journal |vauthors=Idoguchi K, Mizobata Y, etal |title=Usefulness of Our Proposed Format of Triage Tag |journal=Journal of Japanese Association for Acute Medicine |volume=17 |issue=5 |pages=183–91 |year=2006 |doi=10.3893/jjaam.17.183 |doi-access=free }}</ref> while in other countries commercially available triage tags are used, which vary by jurisdictional choice.<ref>{{cite journal | vauthors = Nocera A, Garner A | title = Australian disaster triage: a colour maze in the Tower of Babel | journal = The Australian and New Zealand Journal of Surgery | volume = 69 | issue = 8 | pages = 598–602 | date = August 1999 | pmid = 10472919 | doi = 10.1046/j.1440-1622.1999.01643.x | url = http://www.ema.gov.au/www/emaweb/rwpattach.nsf/VAP/(084A3429FD57AC0744737F8EA134BACB)~Australian_disaster_triage.pdf/$file/Australian_disaster_triage.pdf | access-date = 2010-04-12 | url-status = dead | archive-url = https://web.archive.org/web/20110314034438/http://www.ema.gov.au/www/emaweb/rwpattach.nsf/VAP/(084A3429FD57AC0744737F8EA134BACB)~Australian_disaster_triage.pdf/$file/Australian_disaster_triage.pdf | archive-date = 2011-03-14 }}</ref> In some cases, international organizations also have standardized tags, as is the case with [[NATO]].<ref name="United States Marine Corps" /> The most commonly used commercial systems include the METTAG,<ref>{{cite web|url=http://www.mettag.com/|title=METTAG Corporate website|access-date=2008-12-05|archive-date=2019-03-28|archive-url=https://web.archive.org/web/20190328180133/https://www.mettag.com/|url-status=dead}}</ref> the SMARTTAG,<ref>{{cite web|url=http://www.tsgassociates.co.uk/English/Civilian/products/smart_tag.htm|title=Smart Triage Tag | work = TSG Associates Corporate website |access-date=2008-12-05 |url-status=dead |archive-url= https://web.archive.org/web/20081120030204/http://www.tsgassociates.co.uk/English/Civilian/products/smart_tag.htm |archive-date=2008-11-20}}</ref> E/T LIGHT<ref>{{cite web|url = http://www.nationaldefensemagazine.org/archive/2010/December/Pages/MilitaryMedics,FirstRespondersGuidedBySimpleLight.aspx|title = Military Medics, First Responders Guided By Simple Light|date = December 2010| vauthors = Beidel E | work = National Defense |publisher = National Defense Industrial Association | location = Arlington, VA |access-date = 2011-02-03|archive-url = https://web.archive.org/web/20110131074100/http://www.nationaldefensemagazine.org/archive/2010/December/Pages/MilitaryMedics,FirstRespondersGuidedBySimpleLight.aspx|archive-date = 2011-01-31|url-status = dead}}</ref> and the CRUCIFORM systems.<ref>{{cite book | vauthors = Lakha R, Moore T |title=Tolley's handbook of disaster and emergency management |publisher=Elsevier |location=Amsterdam |year=2006 |isbn=978-0-7506-6990-0 }}</ref>  More advanced tagging systems incorporate special markers to indicate whether or not patients have been contaminated by hazardous materials, and also tear off strips for tracking the movement of patients through the process.<ref>{{Cite web |title=Mass Casualty START Triage and the SMART Tag System |url=https://asprtracie.hhs.gov/technical-resources/resource/4082/mass-casualty-start-triage-and-the-smart-tag-system |access-date=2023-05-06 | work =  Administration for Strategic Preparedness and Response (ASPR) | publisher = U.S. Department of Health and Human Services }}</ref>

=== Advanced triage ===
{{Hatnote|For classifications, see the specific section for that topic}}

In advanced triage, those with advanced training, such as doctors, nurses and paramedics make further care determinations based on more in-depth assessments, and may make use of advanced diagnostics like [[CT scan]]s.<ref>{{Cite journal | vauthors = Masoumi G |title=Simple and advanced triage in occurrence of natural disasters and examine the role of volunteers |url=https://www.academia.edu/28749033 |journal=International Journal of Current Life Sciences}}</ref> This can also be a form of secondary triage, where the evaluation occurs at a secondary location like a hospital,<ref>{{cite book | vauthors = Haller HL, Wurzer P, Peterlik C, Gabriel C, Cancio LC | chapter = 5 - Burn Management in Disasters and Humanitarian Crises |date=2018-01-01 | title = Total Burn Care | edition = Fifth  |pages=36–49.e2 | veditors = Herndon DN  |publisher=Elsevier |language=en |isbn=978-0-323-47661-4 }}</ref> or after the arrival of more qualified care providers.

=== Reverse triage ===
There are a three primary concepts referred to as reverse triage. The first is concerned with the discharge of patients from hospital often to prepare for an incoming mass casualty.<ref name="Pollaris_2016" /> The second concept of Reverse Triage is utilized for certain conditions such as lightning injuries, where those appearing to be dead may be treated ahead of other patients, as they can typically be resuscitated successfully.<ref name="van Ruler_2022">{{cite journal | vauthors = van Ruler R, Eikendal T, Kooij FO, Tan EC | title = A shocking injury: A clinical review of lightning injuries highlighting pitfalls and a treatment protocol | journal = Injury | volume = 53 | issue = 10 | pages = 3070–3077 | date = October 2022 | pmid = 36038387 | doi = 10.1016/j.injury.2022.08.024 | s2cid = 251661429 | doi-access = free | hdl = 2066/288478 | hdl-access = free }}</ref> The third is the concept of treating the least injured, often to return them to functional capability. This approach originated in the military, where returning combatants to the theatre of war may lead to overall victory (and survivability).<ref name="Pollaris_2016">{{cite journal | vauthors = Pollaris G, Sabbe M | title = Reverse triage: more than just another method | journal = European Journal of Emergency Medicine | volume = 23 | issue = 4 | pages = 240–247 | date = August 2016 | pmid = 26479736 | doi = 10.1097/MEJ.0000000000000339 | s2cid = 23551247 | url = https://lirias.kuleuven.be/handle/123456789/519402 | url-access = subscription }}</ref>

=== Undertriage and overtriage ===
'''Undertriage''' is underestimating the severity of an illness or injury.  An example of this would be categorizing a Priority 1 (Immediate) patient as a Priority 2 (Delayed) or Priority 3 (Minimal). The rate of undertriage generally varies by the location of the triage, with a 2014 review of triage practices in emergency rooms finding that in-hospital undertriaging occurred 34% of the time in the United States,<ref name="Xiang-2014">{{cite journal | vauthors = Xiang H, Wheeler KK, Groner JI, Shi J, Haley KJ | title = Undertriage of major trauma patients in the US emergency departments | journal = The American Journal of Emergency Medicine | volume = 32 | issue = 9 | pages = 997–1004 | date = September 2014 | pmid = 24993680 | doi = 10.1016/j.ajem.2014.05.038 }}</ref> while reviews of pre-hospital triage finding undertriage rates of 14%.<ref>{{cite journal | vauthors = Lokerman RD, Waalwijk JF, van der Sluijs R, Houwert RM, Leenen LP, van Heijl M | title = Evaluating pre-hospital triage and decision-making in patients who died within 30 days post-trauma: A multi-site, multi-center, cohort study | journal = Injury | volume = 53 | issue = 5 | pages = 1699–1706 | date = May 2022 | pmid = 35317915 | doi = 10.1016/j.injury.2022.02.047 | s2cid = 247240059 | doi-access = free }}</ref>

'''Overtriage''' is the overestimating of the severity of an illness or injury.  An example of this would be categorizing a Priority 3 (Minimal) patient as a Priority 2 (Delayed) or Priority 1 (Immediate). Acceptable overtriage rates have been typically up to 50% in an effort to avoid undertriage.  Some studies suggest that overtriage is less likely to occur when triaging is performed by hospital medical teams, rather than paramedics or EMTs.<ref name="Turégano-Fuentes-2008">{{cite journal | vauthors = Turégano-Fuentes F, Pérez-Díaz D, Sanz-Sánchez M, Ortiz Alonso J | title = Overall Asessment of the Response to Terrorist Bombings in Trains, Madrid, 11 March 2004 | journal = European Journal of Trauma and Emergency Surgery | volume = 34 | issue = 5 | pages = 433–441 | date = October 2008 | pmid = 26815987 | doi = 10.1007/s00068-008-8805-2 | s2cid = 13657747 }}</ref>

=== Telephone triage ===
In telephone triage, care providers like [[nurses]] assess symptoms and medical history, and make a care recommendation over the [[phone]].<ref>{{cite journal | vauthors = Wheeler SQ, Greenberg ME, Mahlmeister L, Wolfe N | title = Safety of clinical and non-clinical decision makers in telephone triage: a narrative review | journal = Journal of Telemedicine and Telecare | volume = 21 | issue = 6 | pages = 305–322 | date = September 2015 | pmid = 25761468 | doi = 10.1177/1357633x15571650 | s2cid = 23049229 }}</ref> A review of available literature found that these services provide accurate and safe information about 90% of the time.<ref>{{cite journal | vauthors = Huibers L, Smits M, Renaud V, Giesen P, Wensing M | title = Safety of telephone triage in out-of-hours care: a systematic review | journal = Scandinavian Journal of Primary Health Care | volume = 29 | issue = 4 | pages = 198–209 | date = December 2011 | pmid = 22126218 | pmc = 3308461 | doi = 10.3109/02813432.2011.629150 }}</ref>

=== Palliative care ===
In triage, [[palliative care]] takes on a wider applicability, as some conditions which may be survivable outside of extreme circumstances become unsurvivable due to the nature of a mass casualty incident.<ref>{{cite journal | vauthors = Matzo M, Wilkinson A, Lynn J, Gatto M, Phillips S | title = Palliative care considerations in mass casualty events with scarce resources | journal = Biosecurity and Bioterrorism | volume = 7 | issue = 2 | pages = 199–210 | date = June 2009 | pmid = 19635004 | doi = 10.1089/bsp.2009.0017 }}</ref> For these patients, as well as those who are deemed to be unsavable, palliative care can mean the difference of a painful death, and a relatively peaceful one.<ref name="Arya_2020">{{cite journal | vauthors = Arya A, Buchman S, Gagnon B, Downar J | title = Pandemic palliative care: beyond ventilators and saving lives | journal = CMAJ | volume = 192 | issue = 15 | pages = E400–E404 | date = April 2020 | pmid = 32234725 | doi = 10.1503/cmaj.200465 | pmc = 7162443 }}</ref> During the [[COVID-19 pandemic]] issues of palliative care in triage became more obvious as some countries were forced to deny care to large groups of individuals due to lack of supplies and [[ventilator]]s.<ref name="Arya_2020" /><ref>{{Cite journal | vauthors = Misek R, ((The National Catholic Bioethics Center)) |date=2022 |title=The Injustice of Categorical Exclusions during Triage |url=http://www.pdcnet.org/oom/service?url_ver=Z39.88-2004&rft_val_fmt=&rft.imuse_id=ncbq_2022_0022_0003_0495_0507&svc_id=info:www.pdcnet.org/collection |journal=The National Catholic Bioethics Quarterly |volume=22 |issue=3 |pages=495–507 |doi=10.5840/ncbq202222345 |s2cid=254707340 |issn=1532-5490|url-access=subscription }}</ref>

=== Evacuation ===
In the field, [[Casualty evacuation|evacuation]] of all casualties is the ultimate goal,<ref>{{cite journal | vauthors = Xie T, Liu XR, Chen GL, Qi L, Xu ZY, Liu XD | title = Development and application of triage and medical evacuation system for casualties at sea | journal = Military Medical Research | volume = 1 | issue = 1 | pages = 12 | date = 2014-06-01 | pmid = 25722870 | pmc = 4340638 | doi = 10.1186/2054-9369-1-12 | doi-access = free }}</ref> so that the site of the incident can ultimately be cleared, if necessary investigated, and eventually rendered safe. Additional considerations must be made to avoid overwhelming local resources,<ref>{{cite journal | vauthors = Pinkert M, Lehavi O, Goren OB, Raiter Y, Shamis A, Priel Z, Schwartz D, Goldberg A, Levi Y, Bar-Dayan Y | display-authors = 6 | title = Primary triage, evacuation priorities, and rapid primary distribution between adjacent hospitals--lessons learned from a suicide bomber attack in downtown Tel-Aviv | journal = Prehospital and Disaster Medicine | volume = 23 | issue = 4 | pages = 337–341 | date = August 2008 | pmid = 18935948 | doi = 10.1017/S1049023X00005975 | s2cid = 10929982 }}</ref> and in some extreme cases, this can mean evacuating some patients to other countries.

=== Alternative care facilities ===
Alternative care facilities are places that are set up for the care of large numbers of patients, or are places that could be so set up. Examples include schools, sports stadiums, and large camps that can be prepared and used for the care, feeding, and holding of large numbers of victims of a mass casualty or other type of event.<ref>{{cite web|url=http://www.phac-aspc.gc.ca/publicat/sars-sras/naylor/8-eng.php|title=Chapter 8: Clinical and Public Health Systems Issues Arising from the Outbreak of Sars in Toronto (Public Health Agency of Canada website)|access-date=2008-12-05|date=2004-11-08|archive-url=https://web.archive.org/web/20081206185742/http://www.phac-aspc.gc.ca/publicat/sars-sras/naylor/8-eng.php|archive-date=2008-12-06|url-status=dead}}</ref>  Such improvised facilities are generally developed in cooperation with the local hospital, which sees them as a strategy for creating surge capacity.  While hospitals remain the preferred destination for all patients, during a mass casualty event such improvised facilities may be required in order to divert low-acuity patients away from hospitals in order to prevent the hospitals becoming overwhelmed.

== Pre-modern history of triage ==
[[File:Edwin Smith Papyrus v2.jpg|thumb|A page of the Edwin Smith Papyrus]]

=== The Edwin Smith Papyrus ===
The general concept was first described in a 17th-century BCE [[Ancient Egypt|Egyptian]] document, the [[Edwin Smith Papyrus]].<ref name="pmid20697750">{{cite journal | vauthors = van Middendorp JJ, Sanchez GM, Burridge AL | title = The Edwin Smith papyrus: a clinical reappraisal of the oldest known document on spinal injuries | journal = European Spine Journal | volume = 19 | issue = 11 | pages = 1815–1823 | date = November 2010 | pmid = 20697750 | pmc = 2989268 | doi = 10.1007/s00586-010-1523-6 }}</ref> Discovered in 1862, outside of modern-day [[Luxor, Egypt]],<ref>{{cite journal | vauthors = Stiefel M, Shaner A, Schaefer SD | title = The Edwin Smith Papyrus: the birth of analytical thinking in medicine and otolaryngology | journal = The Laryngoscope | volume = 116 | issue = 2 | pages = 182–188 | date = February 2006 | pmid = 16467701 | doi = 10.1097/01.mlg.0000191461.08542.a3 | s2cid = 35256503 | doi-access = free }}</ref> the Edwin Smith Papyrus contains descriptions of the assessment and treatment of a multitude of medical conditions, and divides injuries into three categories:

# "A medical condition I can heal"<ref name="pmid20697750" />
# "A medical condition I intend to fight with."<ref name="pmid20697750" />
# "A medical condition that cannot be healed."<ref name="pmid20697750" />

=== The Holy Roman Empire ===
During the reign of Emperor [[Maximilian I, Holy Roman Emperor|Maximilian I]], during wartime, a policy was implemented where soldiers were prioritized over all others in hospitals, and the sickest soldiers received treatment first.<ref name="Cueni_2020" />

== Modern history of triage ==
[[File:Larrey's Flying Ambulance.jpg|thumb|Larrey's "flying ambulance" design.]]

=== Napoleonic triage ===
Modern triage grew out of the work of [[Baron Dominique-Jean Larrey]] and [[Pierre-François Percy]] during the reign of [[Napoleon]]. Larrey in particular introduced the concept of a "flying [[ambulance]]" (flying in this case meaning rapidly moving) or in its native French, [[History of the ambulance|Ambulance Volante]].<ref name="Robertson-Steel_2006" />

=== World War I ===
In 1914, [[Antoine Depage]] developed the five-tiered ''Ordre de Triage'', a triage system which set specific benchmarks on evacuation, described staged evacuation.<ref>{{Cite web | author = WSJ com News Graphics |title=World War I Centenary: Triage |url=https://online.wsj.com/ww1/triage |access-date=2023-05-26 |website=The Wall Street Journal |language=en}}</ref><ref name="Pollock-2008">{{cite journal | vauthors = Pollock RA | title = Triage and management of the injured in world war I: the diuturnity of antoine de page and a belgian colleague | journal = Craniomaxillofacial Trauma & Reconstruction | volume = 1 | issue = 1 | pages = 63–70 | date = November 2008 | pmid = 22110790 | pmc = 3052731 | doi = 10.1055/s-0028-1098965 }}</ref> [[France|French]] and [[Belgium|Belgian]] [[physician|doctors]] began using these concepts to inform the treatment of casualties at [[aid station]]s behind the front.<ref>{{Cite web | vauthors = Thompson G |title=Battlefield Medicine: Triage-Field Hospital Section |url=https://www.kumc.edu/school-of-medicine/academics/departments/history-and-philosophy-of-medicine/archives/wwi/essays/military-medical-operations/triage-field-hospital-section.html |access-date=2023-05-26 |website=Kansas University Medical Center |language=en-us}}</ref><ref name="Pollock-2008" /> Those responsible for the removal of the wounded from a battlefield or their care afterwards would divide the victims into three categories:<ref name="Iserson_2007">{{cite journal | vauthors = Iserson KV, Moskop JC | title = Triage in medicine, part I: Concept, history, and types | journal = Annals of Emergency Medicine | volume = 49 | issue = 3 | pages = 275–281 | date = March 2007 | pmid = 17141139 | doi = 10.1016/j.annemergmed.2006.05.019 }}</ref><ref>{{cite journal | vauthors = Chipman M, Hackley BE, Spencer TS | title = Triage of mass casualties: concepts for coping with mixed battlefield injuries | journal = Military Medicine | volume = 145 | issue = 2 | pages = 99–100 | date = February 1980 | pmid = 6768037 | doi = 10.1093/milmed/145.2.99 }}</ref>

* Those who are likely to live, regardless of what care they receive;
* Those who are unlikely to live, regardless of what care they receive;
* Those for whom immediate care may make a positive difference in outcome.

From that delineation, aid workers would follow the ''Ordre de Triage'':

==== First Order of Triage ====
[[File:A ward in the 2nd Australian Casualty Clearing Station near Steenvoorde.jpg|thumb|Casualty Clearing Station as described in the Second Order of Triage]]

In the first order of triage, the injured would be evacuated to clearing stations in the night, when darkness offered maximum protection from the [[German Empire|German forces]].<ref name="Pollock-2008" /><ref name="Lewis-2013">{{Cite web | vauthors = Lewis CH |date=2013-12-15 |title=Triage and Trauma Medicine in United States Military History – Health & Medicine in American History |url=https://lewiscar.sites.grinnell.edu/HistoryofMedicine/uncategorized/triage-and-trauma-medicine-in-united-states-military-history/ |access-date=2023-05-26 |language=en}}</ref>

==== Second Order of Triage ====
Once at a casualty clearing station, wounds were dressed,<ref name="Lewis-2013" /> and anyone requiring immediate surgical intervention was placed in a cart and brought immediately to an ambulance pickup area. If the wounded could wait, they would be evacuated by ambulance during the night.<ref name="Pollock-2008" />

==== Third Order of Triage ====
Ambulances, driven by [[YMCA]] and [[American Red Cross]] trained drivers then removed the casualties to [[Mobile Army Surgical Hospital|mobile surgical centers]], called ''postes avances des hospitaux du front'' or outposts of the frontline hospitals.<ref name="Pollock-2008" /><ref name="Lewis-2013" />

==== Fourth Order of Triage ====
At the mobile surgical hospitals, the most severe cases were treated, specifically those who were likely to die before reaching a permanent, more equipped hospital. Anyone who could survive the trip was transported to a farther away, often costal, hospital.<ref name="Pollock-2008" /><ref name="Lewis-2013" />

==== Fifth Order of Triage ====
Upon reaching a permanent hospital, casualties received appropriate care to treat all of their injuries.<ref name="Pollock-2008" /><ref name="Lewis-2013" />

=== World War II ===
By the onset of World War II, American and British forces had adopted and adapted triage, with other global powers doing the same.<ref name="www.sciencemuseum.org.uk">{{Cite web |title=Medicine in the war zone {{!}} Science Museum |url=https://www.sciencemuseum.org.uk/objects-and-stories/medicine/medicine-war-zone |access-date=2023-05-26 |website=www.sciencemuseum.org.uk |language=en}}</ref><ref name="Katoch-2010">{{cite journal | vauthors = Katoch R, Rajagopalan S | title = Warfare Injuries: History, Triage, Transport and Field Hospital Setup in the Armed Forces | journal = Medical Journal, Armed Forces India | volume = 66 | issue = 4 | pages = 304–308 | date = October 2010 | pmid = 27365730 | pmc = 4919805 | doi = 10.1016/S0377-1237(10)80003-6 }}</ref> The increased availability of airplanes allowed rapid evacuation to a hospital outside of the warzone to become a part of the triage process.<ref name="www.sciencemuseum.org.uk" /><ref name="Katoch-2010" /> Although the basic practices remained the same as in World War I, with initial evacuation to an aid station, followed by transitions to higher levels of care, and eventual admission to a permanent hospital, more advanced care was provided at each stage, and the mindset of treating only what was absolutely necessary fell away.<ref>{{cite journal | vauthors = Baker MS | title = Creating order from chaos: part I: triage, initial care, and tactical considerations in mass casualty and disaster response | journal = Military Medicine | volume = 172 | issue = 3 | pages = 232–236 | date = March 2007 | pmid = 17436764 | doi = 10.7205/MILMED.172.3.232 | s2cid = 44317599 | doi-access = free }}</ref> Although triage almost certainly occurred in the days after the [[atomic bombings of Hiroshima and Nagasaki]], the pandemonium caused by the attack left records of such action non-existent until after the fifth day, at which point they are largely without historical use.<ref>{{cite book | vauthors =  Leaning J | collaboration = Institute of Medicine (US) Steering Committee for the Symposium on the Medical Implications of Nuclear War | chapter = Burn and Blast Casualties: Triage in Nuclear War |date=1986 | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK219175/ | title = The Medical Implications of Nuclear War |access-date=2023-05-26 |publisher=National Academies Press (US) |language=en | veditors = Solomon F, Marston RQ }}</ref> 

=== The Texas City disaster (1947) ===
[[File:Txcitydisaster5storybuilding.jpg|thumb|A destroyed rubber factory from the Texas City Disaster]]

In 1947, the [[Texas City Disaster]] occurred when the SS ''Grandcamp'' exploded in [[Texas City, Texas]], killing 600 people and injuring thousands more.<ref>{{Cite web | vauthors = Barnes M |title=Texas history: A witness to one of America's worst human-made disasters |url=https://www.statesman.com/story/news/history/2020/04/17/texas-history-witness-to-one-of-americas-worst-human-made-disasters/1335171007/ |access-date=2023-05-26 |website=Austin American-Statesman |language=en-US}}</ref> The entire fire department was killed in the blast, and what followed was a massive informal triage of the victims.<ref name="Wall-2015">{{Cite journal | vauthors = Wall BM |date=2015 |title=Disasters, Nursing, and Community Responses: A Historical Perspective |journal=Nursing History Review |language=en |volume=23 |issue=1 |pages=11–27 |doi=10.1891/1062-8061.23.11 |pmid=25272474 |s2cid=219207043 |issn=1062-8061|doi-access=free }}</ref> Drug stores, clinics, and homes were opened as makeshift triage stations. As the city has no hospital, they had to evacuate casualties to area facilities, including those in [[Galveston, Texas|Galveston]] and [[Houston]],<ref name="Wall-2015" /> with at least one doctor relying on skills he had learned in World War II to inform care decisions.<ref>{{Cite web | vauthors = Barnes M |title=Texas history: Readers relive the horrors of the 1947 Texas City Disaster |url=https://www.statesman.com/story/news/history/2020/05/08/texas-history-readers-relive-horrors-of-1947-texas-city-disaster/1227001007/ |access-date=2023-05-27 |website=Austin American-Statesman |language=en-US}}</ref>

=== The Korean War ===
The [[Korean War]] saw the advent of the tiered triage, wherein care providers sorted people into categories defined ahead of time.<ref name=":1">{{Cite journal |last1=Nocera |first1=Antony |last2=Garner |first2=Alan |title=An Australian Mass Casualty Incident Triage System for the Future Based Upon Triage Mistakes of the Past: The Homebush Triage Standard |date=August 1999 |url=http://doi.wiley.com/10.1046/j.1440-1622.1999.01644.x |journal=ANZ Journal of Surgery |language=en |volume=69 |issue=8 |pages=603–608 |doi=10.1046/j.1440-1622.1999.01644.x |pmid=10472920 |issn=1445-1433|url-access=subscription }}</ref> These categories, immediate, delayed, minimal and expectant are still the basis for most triage systems today.<ref name=":1" /> The time period was also marked by improvements in medical understanding, including shock, which allowed effective interventions to be administered earlier in the Triage process, which in turn significantly improved outcomes.<ref name=":2">{{Cite journal |last=Mitchell |first=Glenn W. |date=September 2008 |title=A Brief History of Triage |url=https://www.cambridge.org/core/product/identifier/S1935789300001270/type/journal_article |journal=Disaster Medicine and Public Health Preparedness |language=en |volume=2 |issue=S1 |pages=S4–S7 |doi=10.1097/DMP.0b013e3181844d43 |pmid=18769265 |s2cid=11093773 |issn=1935-7893|url-access=subscription }}</ref> At the same time, [[Mobile Army Surgical Hospital]]s (MASH) were introduced along with helicopters for evacuation. These helicopters, however were used for evacuation only, and care was not provided in the air during the evacuation.<ref name="United States Marine Corps" /> These advances reduced fatalities for injured soldiers by up to 30%, and changed the nature of battlefield medicine significantly.<ref name=":2" />

=== The Vietnam War ===
The conditions of the [[Vietnam War]] drove further development on the concepts created during the Korean War. Advances in helicopters allowed the introduction of the first helicopter medics, who were able to provide [[fluid resuscitation]], and other interventions mid-flight.<ref name=":2" /> This made it so that the average time from injury to definitive care was less than two hours.<ref name="United States Marine Corps" /> This evolution also flowed into the everyday life, with air ambulances emerging in the civilian world by the mid-1960's.<ref name=":2" /> The use of triage in emergency departments and ambulance services also quickly followed.<ref name="United States Marine Corps" />

=== The World Trade Center bombing (1993) ===
In 1993, the north tower of the [[1993 World Trade Center bombing|World Trade Center was bombed]], in a plot with a similar intended outcome as the later [[September 11 attacks|September 11th attacks]].<ref>{{Cite web |title=February 26, 1993 Commemoration |url=https://www.911memorial.org/connect/commemoration/February26-1993 |website=9/11 Memorial & Museum}}</ref> While search, rescue and triage operations immediately following were ordinary, the attack itself represented one of the first terrorist attacks affecting the United States directly. The fact that the U.S. was no longer seen as untouchable, along with the later [[Oklahoma City bombing]] in 1995, and the September 11th attack lead to long term changes in triage practices to be more focused on operational safety and the risk of secondary attacks designed to kill care providers.<ref>{{Cite journal |last=Eckstein |first=Marc |date=August 1999 |title=The Medical Response to Modern Terrorism: Why the "Rules of Engagement" Have Changed |journal=Annals of Emergency Medicine |language=en |volume=34 |issue=2 |pages=219–221 |doi=10.1016/S0196-0644(99)70232-5|pmid=10424924 |doi-access=free }}</ref>

=== Matsumato sarin attack (1994) ===
In June 1994, emergency crews began responding to calls related to symptoms of toxic gas exposure in a neighborhood. Without proper [[personal protective equipment]], more than 253 residents were evacuated and 50 were hospitalized.<ref>{{Cite journal |last1=Kulling |first1=Per E. J. |last2=Lorin |first2=Henry |date=March 1999 |title=KAMEDO — A Swedish Disaster Medicine Study Organization |url=https://www.cambridge.org/core/product/identifier/S1049023X0002851X/type/journal_article |journal=Prehospital and Disaster Medicine |language=en |volume=14 |issue=1 |pages=25–33 |doi=10.1017/S1049023X0002851X |pmid=10537595 |s2cid=12078694 |issn=1049-023X|url-access=subscription }}</ref> 20 vehicles were called to the scene, and a mobile operating center was setup nearby, likely within the zone of contamination. Unaware of the presence of Sarin, triage was performed following the standard system of the time, which ultimately resulted in eight care givers experiencing mild sarin poisoning, and an unknown amount of additional staff experiencing general malaise.<ref name=":3">{{Cite journal |last1=Okudera |first1=Hiroshi |last2=Morita |first2=Hiroshi |last3=Iwashita |first3=Tomomi |last4=Shibata |first4=Tatsuhiko |last5=Otagiri |first5=Tetsutaro |last6=Kobayashi |first6=Shigeaki |last7=Yanagisawa |first7=Nobuo |date=September 1997 |title=Unexpected nerve gas exposure in the city of Matsumoto: Report of rescue activity in the first sarin gas terrorism |url=https://linkinghub.elsevier.com/retrieve/pii/S0735675797902011 |journal=The American Journal of Emergency Medicine |language=en |volume=15 |issue=5 |pages=527–528 |doi=10.1016/S0735-6757(97)90201-1|pmid=9270397 |url-access=subscription }}</ref>

At the time, no decontamination procedures or gas masks were available for incidents involving contaminants. In response, the [[Japan Self-Defense Forces]] created a decontamination team, which was then instrumental to the response of the Tokyo subway sarin attack which occurred only seven months later.<ref name=":3" />

=== Triage in the present day ===
As medical technology has advanced, so have modern approaches to triage, which are increasingly based on scientific models. The categorizations of the victims are frequently the result of triage scores based on specific [[physiological]] assessment findings. Some models, such as the [[Simple triage and rapid treatment|START]] model may be [[algorithm]]-based. As triage concepts become more sophisticated, and to improve patient safety and quality of care, several human-in-the-loop decision-support tools have been designed on top of triage systems to standardize and automate the triage process (e.g., eCTAS, [[NHS 111]]) in both [[hospitals]] and the field.<ref>{{cite web| url = https://hospitalnews.com/digital-tools-and-virtual-care-in-emergency-services/| title = Digital tools and virtual care in emergency services| date = 25 September 2020}}</ref> Moreover, the recent development of new [[machine learning]] methods offers the possibility to learn optimal triage policies from data and in time could replace or improve upon expert-crafted models.<ref>{{cite arXiv | vauthors = Buchard A, Bouvier B |eprint=2003.12828 |title=Learning medical triage from clinicians using Deep Q-Learning  |date=2020 |class=cs.AI }}</ref>

==Specific triage systems and methods <span class="anchor" id="Specific systems"></span> ==
[[File:13049 2012 Article 483 Fig2 HTML.svg|thumb|Vital signs defining the color-coded triage. RR: [[respiratory rate]]; SpO2: [[Oxygen saturation (medicine)|saturation of peripheral oxygen]] (pulse oximetry); HR: [[heart rate]]; GCS: [[Glasgow Coma Scale|Glasgow Coma Score]]; Tp: temperature. Abnormal vital signs are strong predictors for intensive care unit admission and in-hospital mortality in adults triaged in the emergency department.]]
[[File:Triagemexico.jpg|thumb|A triage sign at a Mexican emergency department indicating the waiting time for patients based on the severity of their condition]]

Most simply, the general purpose of triage is to sort patients by level of acuity to inform care decisions; so that the most people possible can be saved.<ref>{{Cite book |title=Leadership During a Pandemic: What your municipality can do |publisher=[[USAID]] |year=2011}}</ref> Although a multitude of systems, color codes, codewords, and categories exist to help direct it, in all cases, triage follows the same basic process.<ref name="World Health Organization_2008">{{Cite book |url=https://www.ncbi.nlm.nih.gov/books/NBK143755/ |title=Triage and emergency assessment |date=2008 |publisher=World Health Organization |language=en}}</ref><ref>{{Cite web |title=What is the triage procedure? |url=https://www.msf-me.org/media-centre/news-and-stories/what-triage-procedure |access-date=2023-05-09 |website = Medecins Sans Frontieres - Middle East |language=en}}</ref> In all systems, patients are first assessed for injuries,<ref name="World Health Organization_2008" /><ref name="Burstein_2007" /> then, they are categorized based on the severity of those injuries.<ref name="World Health Organization_2008" /> Although the number of categories differs from system to system, all have at least three in common; high severity, low severity, and deceased. Some systems involve features like scoring systems, such as the [[Revised Trauma Score]],<ref name="Petridou-2008">{{Citation | vauthors = Petridou ET, Antonopoulos CN, Alexe DM |title=Injuries, Epidemiology of |date=2008-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780123739605001866 |encyclopedia=International Encyclopedia of Public Health |pages=609–625 | veditors = Heggenhougen HK |access-date=2023-05-10 |place=Oxford |publisher=Academic Press |language=en |doi=10.1016/b978-012373960-5.00186-6 |isbn=978-0-12-373960-5 |url-access=subscription }}</ref> the [[Injury Severity Score]],{{citation needed|date=June 2023}} and the Trauma and Injury Severity Score, the latter of which has been shown to be most effective at determining outcome.{{citation needed|date=June 2023}}

=== Triage systems by methodology ===
==== S.T.A.R.T. model ====
{{Main|Simple triage and rapid treatment}}

S.T.A.R.T. (Simple Triage and Rapid Treatment) is a simple triage system that can be performed by lightly trained lay and emergency personnel in emergencies.<ref name="Burstein_2007">{{cite book |url=https://archive.org/details/disastermedicine00hoga |title=Disaster medicine |vauthors=Burstein JL, Hogan D |publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins |year=2007 |isbn=978-0-7817-6262-5 |location=Philadelphia |page=[https://archive.org/details/disastermedicine00hoga/page/n40 25] |url-access=limited}}</ref> It was developed at Hoag Hospital in [[Newport Beach, California]] for use by emergency services in 1983.<ref name="chemm.hhs.gov">{{Cite web |title=START Adult Triage Algorithm - CHEMM |url=https://chemm.hhs.gov/startadult.htm#more |access-date=2023-05-12 |website=chemm.hhs.gov}}</ref>

Triage separates the injured into four groups:<ref name="chemm.hhs.gov" />

* The ''expectant'' who are beyond help
* The injured who can be helped by ''immediate'' transportation
* The injured whose transport can be ''delayed''
* Those with ''minor'' injuries who need help less urgently

Triage also sets priorities for evacuation and transport as follows:<ref name="chemm.hhs.gov" />

* ''Deceased'' are left where they fell.  These include those who are not breathing and repositioning their airway efforts were unsuccessful.
* ''Immediate'' or Priority 1 (red) evacuation to a medical facility as they need advanced medical care at once or within one hour. These people are in critical condition and would die without immediate assistance.
* ''Delayed'' or Priority 2 (yellow) can have their medical evacuation delayed until all ''immediate'' people have been transported. These people are in stable condition but require medical assistance.
* ''Minor'' or Priority 3 (green) are not evacuated until all ''immediate'' and ''delayed'' persons have been evacuated.  These will not need advanced medical care for at least several hours. Continue to re-triage in case their condition worsens. These people are able to walk and may only need [[bandages]] and [[antiseptic]].

==== JumpSTART triage ====
{{Main|JumpSTART triage}}

The JumpSTART pediatric triage MCI triage tool is a variation of the S.T.A.R.T. model. Both systems are used to sort patients into categories at [[mass casualty incident]]s (MCIs). However, JumpSTART was designed specifically for triaging children in disaster settings. Though JumpSTART was developed for use in children from infancy to age 8, where age is not immediately obvious, it is used in any patient who appears to be a child (patients who appear to be young adults are triaged using START).<ref name="x2">{{cite web |author=<!--Staff writer(s); no by-line.--> |date=June 25, 2011 |title=JumpSTART Pediatric Triage Algorithm |url=https://chemm.nlm.nih.gov/startpediatric.htm |url-status=dead |archive-url=https://web.archive.org/web/20160326102436/https://chemm.nlm.nih.gov/startpediatric.htm |archive-date=March 26, 2016 |access-date=February 9, 2016 |website=Chemical Hazards Emergency Medical Management |publisher=United States Department of Health and Human Services}}</ref>

=== Triage systems by country ===
==== Australia and New Zealand ====
In hospital settings, Australia and New Zealand rely on the ''Australasian Triage Scale'' (abbreviated ''ATS'' and formally known as the ''National Triage Scale'').<ref name="ethics">{{cite journal |vauthors=Aacharya RP, Gastmans C, Denier Y |year=2011 |title=Emergency department triage: an ethical analysis |journal=[[BMC Emergency Medicine]] |volume=11 |page=16 |doi=10.1186/1471-227X-11-16 |pmc=3199257 |pmid=21982119 |doi-access=free }}</ref><ref>{{cite journal |date=November 2000 |title=Policy on the Australasian Triage Scale |url=http://www.acem.org.au/media/policies_and_guidelines/P06_Aust_Triage_Scale_-_Nov_2000.pdf |url-status=dead |journal=Australasian College for Emergency Medicine |archive-url=https://web.archive.org/web/20120322001312/http://www.acem.org.au/media/policies_and_guidelines/P06_Aust_Triage_Scale_-_Nov_2000.pdf |archive-date=2012-03-22 |access-date=2011-12-10}}</ref><ref>{{Cite web |title=ACEM - Triage |url=https://acem.org.au/Content-Sources/Advancing-Emergency-Medicine/Better-Outcomes-for-Patients/Triage |access-date=2023-05-10 |website=acem.org.au}}</ref> The scale has been in use since 1994.<ref name="modern">{{cite journal |vauthors=Christ M, Grossmann F, Winter D, Bingisser R, Platz E |date=December 2010 |title=Modern triage in the emergency department |journal=[[Deutsches Ärzteblatt International]] |volume=107 |issue=50 |pages=892–98 |doi=10.3238/arztebl.2010.0892 |pmc=3021905 |pmid=21246025}}</ref> The scale consists of 5 levels, with 1 being the most critical (resuscitation), and 5 being the least critical (nonurgent).<ref name="ethics" />

{| class="wikitable sortable"
|+Australasian Triage Scale
!Level
!Description
!Should be seen by provider within
|-
|1
|Resuscitation
|0 minutes
|-
|2
|Emergency
|10 minutes
|-
|3
|Urgent
|30 minutes
|-
|4
|Semi-Urgent
|60 minutes
|-
|5
|Nonurgent
|120 minutes
|}

In field settings, various standardized triage systems are used, and there is no area wide standard.<ref>{{cite journal | vauthors = Field K, Norton I | title = Australian triage tags: a prospective, randomised cross-over trial and evaluation of user preference | journal = Emergency Medicine Australasia | volume = 24 | issue = 3 | pages = 321–328 | date = June 2012 | pmid = 22672173 | doi = 10.1111/j.1742-6723.2012.01573.x | s2cid = 25074668 }}</ref>

==== Canada ====
In 1995, the CAEP Triage and Acuity scale was launched in Canada relying on a simplified version of the Australian National Triage Scale.<ref>{{Cite web |date=June 1999 |title=A Uniform Triage Scale in Emergency Medicine: Information Paper |url=https://www.acep.org/siteassets/uploads/uploaded-files/acep/clinical-and-practice-management/resources/administration/triagescaleip.pdf |publisher=[[American College of Emergency Physicians]]}}</ref> This scale used three categories, emergent, urgent, and non-urgent.<ref>{{Cite web |date=2012 |title=The Canadian Triage and Acuity Scale: Education Manual |url=https://caep.ca/wp-content/uploads/2017/06/module_1_slides_v2.5_2012.pdf |access-date=10 May 2023 |publisher=The Canadian Association of Emergency Physicians}}</ref> This scale was deprecated in 1999 with the introduction of the Canadian Triage and Acuity Scale (CTAS),<ref>{{Cite web |date=November 2013 |title=The Canadian Triage and Acuity Scale: Combined Adult/Paediatric Educational Program Participants Manual |url=http://ctas-phctas.ca/wp-content/uploads/2018/05/participant_manual_v2.5b_november_2013_0.pdf |access-date=10 May 2023 |publisher=Canadian Association of Emergency Physicians}}</ref> which is used across the country to sort incoming patients.<ref>{{cite web |title=Canadian Triage and Acuity Scale (Canadian Association of Emergency Physicians website) |url=http://www.caep.ca/template.asp?id=B795164082374289BBD9C1C2BF4B8D32 |url-status=dead |archive-url=https://web.archive.org/web/20081210093457/http://www.caep.ca/template.asp?id=B795164082374289BBD9C1C2BF4B8D32 |archive-date=2008-12-10 |access-date=2008-12-02}}</ref>  The system categorizes patients by both injury and physiological findings, and ranks them by severity from 1–5 (1 being highest).<ref name="jhas22">{{cite journal | vauthors = Alghalyini B, Shakir IM, Wahed MM, Babar SM, Mohamed MS |date=30 June 2022 |title=Does SARI Score Predict COVID-19 Positivity? A Retrospective Analysis of Emergency Department Patients in a Tertiary Hospital |url=https://www.thieme-connect.de/products/ejournals/pdf/10.1055/s-0042-1748806.pdf |journal=Journal of Health and Allied Sciences |volume=13 |issue= |pages=077–082 |doi=10.1055/s-0042-1748806 |s2cid=250189262 |access-date=1 July 2022}}</ref>  The model is not currently used for mass casualty triage, and instead the START protocol and METTAG triage tags is used.<ref>{{cite web |title=METTAG Triage Tags |url=http://www.mettag.com/ |url-status=dead |archive-url=https://web.archive.org/web/20190328180133/https://www.mettag.com/ |archive-date=2019-03-28 |access-date=2008-12-02}}</ref>

{| class="wikitable sortable"
|+Canadian Triage and Acuity Scale (CTAS)
!Level
!Description
!Should be seen by provider within
|-
|1
|Resuscitation
|0 minutes
|-
|2
|Emergency
|15 minutes
|-
|3
|Urgent
|30 minutes
|-
|4
|Less Urgent
|60 minutes
|-
|5
|Non Urgent
|120 minutes
|}

==== France ====
In [[France]], the Prehospital triage in case of a disaster uses a multi-tier scale:

* ''Décédé'' (deceased), or ''urgence dépassée'' (beyond urgency)<ref name="Franceinfo_2018">{{Cite web |date=2018-12-13 |title=Attentats : que signifient "urgence absolue" ou "pronostic vital engagé" ? |url=https://www.francetvinfo.fr/sante/soigner/attentats-que-signifient-urgence-absolue-ou-pronostic-vital-engage_3098925.html |access-date=2023-05-10 |website=Franceinfo |language=fr-FR}}</ref>
* ''Extrême urgence (extreme urgency):'' requiring care within a half hour.<ref name="La Nouvelle République du Centre-Ouest_2017">{{Cite news |date=7 February 2017 |title=Extrême, absolue, relative comment trier les urgences |language=French |work=[[La Nouvelle République du Centre-Ouest]] |url=https://www.lanouvellerepublique.fr/deux-sevres/extreme-absolue-relative-comment-trier-les-urgences}}</ref> 
* ''Urgence absolue'' (absolute urgency):<ref name="Carli_2003">{{cite journal | vauthors = Carli P, Telion C, Baker D | title = Terrorism in France | journal = Prehospital and Disaster Medicine | volume = 18 | issue = 2 | pages = 92–99 | date = June 2003 | pmid = 15074489 | doi = 10.1017/S1049023X00000820 | s2cid = 31853138 }}</ref> requiring care within an hour.<ref name="La Nouvelle République du Centre-Ouest_2017" />
* ''Urgence relative'' (relative urgency):<ref name="Carli_2003" /> requiring care, but not immediately.<ref name="La Nouvelle République du Centre-Ouest_2017" />
* ''Blessé léger'' (slightly injured)<ref name="Franceinfo_2018" />
* ''Impliqué'' (involved, but not directly injured)<ref name="Franceinfo_2018" />
This triage is performed by a [[physician]] called ''médecin trieur'' (sorting medic).<ref>{{cite book | vauthors = Hoyt DL, Wilson WJ, Grande CM  |title=Trauma |publisher=Informa Healthcare |year=2007 |isbn=978-0-8247-2919-6 }}</ref><ref>{{cite journal | vauthors = Hamada SR, Gauss T, Duchateau FX, Truchot J, Harrois A, Raux M, Duranteau J, Mantz J, Paugam-Burtz C | display-authors = 6 | title = Evaluation of the performance of French physician-staffed emergency medical service in the triage of major trauma patients | journal = The Journal of Trauma and Acute Care Surgery | volume = 76 | issue = 6 | pages = 1476–1483 | date = June 2014 | pmid = 24854319 | doi = 10.1097/TA.0000000000000239 | s2cid = 3405705 }}</ref>

==== Germany ====
The German triage system uses four color codes:<ref name="Franke_2020">{{cite journal | vauthors = Franke A, Bieler D, Friemert B, Hoth P, Pape HC, Achatz G | title = Terrorist incidents: strategic treatment objectives, tactical diagnostic procedures and the estimated need of blood and clotting products | journal = European Journal of Trauma and Emergency Surgery | volume = 46 | issue = 4 | pages = 695–707 | date = August 2020 | pmid = 32676714 | pmc = 7364295 | doi = 10.1007/s00068-020-01399-w }}</ref>

{| class="wikitable"
|+German Triage System<ref name="Franke_2020" />
!Category
!Meaning
!Action
!Examples
|-
|'''{{legend inline|red|Category TI}}'''
|Acute, life-threatening condition
|Immediate, highest priority treatment
|Arterial lesions, internal haemorrhage, major amputations
|-
|'''{{legend inline|yellow|Category T2}}'''
|Severe injury requiring urgent treatment
|Rapid transport and treatment
|Minor amputations, flesh wounds, fractures and dislocations
|-
|'''{{legend inline|green|Category T3}}'''
|Minor injury or no injury
|Physician examination, clearance and discharge as soon as possible
|Minor lacerations, sprains, abrasions
|-
|'''{{legend inline|black|Deceased}}'''
|Already [[Death|dead]], or expectant
|No/low priority. Identification, guarding and evacuation as possible
|Death, injuries not compatible with life
|}

In addition, also the "Manchester" triage system has been introduced in Germany as well as in its German speaking neighbour countries: in Germany itself in 2004, in [[Austria]] in 2009, and in German speaking parts of [[Switzerland]] in 2011 (see also [[w:de:Manchester-Triage-System|Manchester-Triage-System (in German)]].

==== Hong Kong ====
In [[Hong Kong]], triage in accident and emergency departments is performed by experienced [[registered nurse]]s, and patients are divided into five triage categories: ''Critical'', ''Emergency'', ''Urgent'', ''Semi-urgent'' and ''Non-urgent''.<ref>{{cite web
 | title = Guide to Accident & Emergency (A&E) Service
 | publisher = Hospital Authority
 | url = http://www.ha.org.hk/visitor/ha_visitor_index.asp?Content_ID=10051&Lang=ENG&Dimension=100&Parent_ID=10042
 | access-date = 2012-11-29
 | archive-url = https://web.archive.org/web/20120908014449/http://www.ha.org.hk/visitor/ha_visitor_index.asp?Content_ID=10051&Lang=ENG&Dimension=100&Parent_ID=10042
 | archive-date = 2012-09-08
 | url-status = dead
 }}</ref> In mass casualty incidents, the [[START triage]] system is used.<ref>{{Cite journal | vauthors = Tingleung L |date=2020 |title=Disaster response approach in Hong Kong |url=http://html.rhhz.net/SYXKZZ/1596268862640-1973378719.htm |journal=Journal of Practical Shock |volume=4 |issue=3 |pages=186–192}}</ref><ref>{{Cite web | vauthors = Kwok-leung S |date=2013 |title=Disaster Response From Scene to Hospitals |url=https://www3.ha.org.hk/haconvention/hac2013/proceedings/downloads/PS1.1.pdf}}</ref>

==== Japan ====
In [[Japan]], the triage system is mainly used by health professionals. The categories of triage, in corresponding color codes, are:

* '''{{legend inline|red|Category I}}''': Used for viable victims with potentially life-threatening conditions.
* '''{{legend inline|Yellow|Category II}}''': Used for victims with non-life-threatening injuries, but who urgently require treatment.
* '''{{legend inline|Green|Category III}}''': Used for victims with minor injuries that do not require ambulance transport.
* '''{{legend inline|Black|Category 0}}''': Used for victims who are dead, or whose injuries make survival unlikely.

==== Portugal ====
In [[Portugal]], the "Manchester" triage protocol is used. <ref>[https://www.grupoportuguestriagem.pt/grupo-portugues-triagem/protocolo-triagem-manchester/ ''Sistema de Triagem de Manchester''; Grupo Português de Triagem.] Retrieved 2025-05-02.</ref>

{| class="wikitable sortable"
|+Portuguese Triage Protocol
!Level
!Description
!Should be seen by provider within
|-
|'''{{legend inline|red|1}}'''
|Emergency
|0 minutes; needs immediate treatment
|-
|'''{{legend inline|orange|2}}'''
|Highly urgent
|10 minutes; needs practically immediate treatment
|-
|'''{{legend inline|yellow|3}}'''
|Urgent
|60 minutes; needs fast treatment, but can wait
|-
|'''{{legend inline|green|4}}'''
|Less Urgent
|120 minutes; may wait or be forwarded to other medical services
|-
|'''{{legend inline|blue|5}}'''
|Not Urgent
|240 minutes; may wait or be forwarded to other medical services
|}

==== Singapore ====
All public hospitals in Singapore use the Patient Acuity Category Scale (PACS) to triage patient in Emergency Departement. PACS is a symptom-based differential diagnosis approach that triages patients according to their presenting complaints and objective assessments such as vital signs and Glasgow Coma Scale, allowing acute patients to be identified quickly for treatment. PACS classifies patients into four main categories: P1, P2, P3, and P4.<ref name="Fong_2018">{{cite journal | vauthors = Fong RY, Glen WS, Mohamed Jamil AK, Tam WW, Kowitlawakul Y | title = Comparison of the Emergency Severity Index versus the Patient Acuity Category Scale in an emergency setting | journal = International Emergency Nursing | volume = 41 | pages = 13–18 | date = November 2018 | pmid = 29887281 | doi = 10.1016/j.ienj.2018.05.001 | s2cid = 47014585 }}</ref>

{| class="wikitable sortable"
|+ Patient Acuity Category Scale<ref name="Fong_2018" />
|-
! Category (Priority Level)
! Category Name 
! Description
! Example
|-
| P1 
| Critically ill and requires resuscitation
| State of cardiovascular collapse or in imminent danger of collapse and require immediate medical attention.
| Multiple major trauma, head injury with loss of consciousness, shortness of breath, unconsciousness from any cause
|-
| P2 
| Major emergency 
| unable to walk and are in some form of distress, appear stable on initial examination, and are not in imminent danger of collapse, requires very early attention
| Chest pain, major limb fractures, major joint dislocations, spinal cord injury, trunk injury with stable vital signs
|-
| P3 
| Minor emergency
| able to walk, have mild to moderate symptoms and require early treatment
| All sprains, mild constant abdominal pain, fever with cough for several days, insect stings or animal bites (not in severe distress), superficial injuries with or without mild bleeding, minor head injury (alert, no vomiting), foreign object in ear, nose, or throat, urinary tract infections, headaches.
|-
| P4 
| Nonemergency 
| Old injury or condition that has been present for a long time.
| Chronic lower back pain, high cholesterol, acne.
|}

In mass casualty incidents, the [[START triage]] system is used.<ref>{{cite journal | vauthors = Maruhashi T, Takeuchi I, Hattori J, Kataoka Y, Asari Y | title = The Tsukui (Japan) Yamayuri-en Facility Stabbing Mass-Casualty Incident | journal = Prehospital and Disaster Medicine | volume = 34 | issue = 2 | pages = 203–208 | date = April 2019 | pmid = 30957735 | doi = 10.1017/S1049023X19000128 | s2cid = 102349890 }}</ref><ref>{{Cite journal | vauthors = Suzuki Y, Tsujiguchi T, Sakamoto M, Ito K, Tokonami S, Kashiwakura I |title=Current Situation of Triage Methods for Exposed Patients in the Acute Phase of a Nuclear Disaster |url=https://www.jstage.jst.go.jp/article/radiatenvironmed/9/1/9_41/_pdf |journal=Radiation Environment and Medicine}}</ref>

==== Spain ====
In [[Spain]], there are two models which are the most common found in hospitals around the country:

* The Sistema Estructurado de Triaje (SET), which is an adaptation of the Model Andorrà de Triatge (MAT). The system uses 650 reasons for medical appointment in 32 symptomatic categories, that together with some patient information and basic exploratory data, classifies the emergency within 5 levels of urgency.     
* The "Manchester", based on the system with the same name in the UK,<ref>{{cite journal | vauthors = Azeredo TR, Guedes HM, Rebelo de Almeida RA, Chianca TC, Martins JC | title = Efficacy of the Manchester Triage System: a systematic review | journal = International Emergency Nursing | volume = 23 | issue = 2 | pages = 47–52 | date = April 2015 | pmid = 25087059 | doi = 10.1016/j.ienj.2014.06.001 }}</ref> use 51 reasons for consultation. Through some yes/no questions, addressed in a diagram, it classifies the emergency in 5 severities.
In mass casualty incidents, the ''Modelo Extrahospitalario de Triaje Avanzado'' (META)/Advanced Triage Out of Hospital Model system is used.<ref>{{cite journal | vauthors = Castro Delgado R, Gan RK, Cabrera García V, Arcos González P | title = Sensitivity and Specificity of Spanish Prehospital Advanced Triage Method (META) | journal = Prehospital and Disaster Medicine | volume = 37 | issue = 3 | pages = 321–326 | date = June 2022 | pmid = 35379369 | doi = 10.1017/S1049023X22000504 | s2cid = 247954532 | doi-access = free }}</ref><ref name="Arcos González_2016">{{cite journal | vauthors = Arcos González P, Castro Delgado R, Cuartas Alvarez T, Garijo Gonzalo G, Martinez Monzon C, Pelaez Corres N, Rodriguez Soler A, Turegano Fuentes F | display-authors = 6 | title = The development and features of the Spanish prehospital advanced triage method (META) for mass casualty incidents | journal = Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine | volume = 24 | issue = 1 | pages = 63 | date = April 2016 | pmid = 27130042 | pmc = 4850631 | doi = 10.1186/s13049-016-0255-y | doi-access = free }}</ref> META is a seven-stage system, classifying patients as: Red 1st, Red 2nd, Red 3rd, Yellow 1st, Yellow 2nd, Green, and Deceased.<ref name="Arcos González_2016" /> The system aligns with the ABCDE framework.

{| class="wikitable"
|+Advanced Triage Out-of-Hospital Model/''Modelo Extrahospitalario de Triaje Avanzado'' (META)<ref name="Arcos González_2016" />
!Category
!Meaning
|-
|'''{{legend inline|red|Red 1st}}'''
|Compromised airway
|-
|'''{{legend inline|red|Red 2nd}}'''
|Not breathing, or abnormally breathing
|-
|'''{{legend inline|red|Red 3rd}}'''
|[[Asystole]], [[arrhythmia]], or hemorrhage
|-
|'''{{legend inline|Yellow|Yellow 1st}}'''
|Injury requiring urgent care
|-
|'''{{legend inline|Yellow|Yellow 2nd}}'''
|Injury requiring delayed care
|-
|'''{{legend inline|Green|Green}}'''
|Mildly or non-injured
|-
|'''Deceased'''
|Dead
|}

==== United Kingdom ====
In April 2023, the [[National Health Service|NHS]] and [[Ambulance services in England|ambulance services]] adopted two new triage tools to be used in [[major incident]]s, replacing the NASMeD Triage Sieve.<ref name="Vassallo_2022">{{cite journal | vauthors = Vassallo J, Moran CG, Cowburn P, Smith J | title = New NHS Prehospital Major Incident Triage Tool: from MIMMS to MITT | journal = Emergency Medicine Journal | volume = 39 | issue = 11 | pages = 800–802 | date = November 2022 | pmid = 36244685 | doi = 10.1136/emermed-2022-212569 | pmc = 9613863 }}</ref><ref name=":0">{{Cite web |title=NHS England » Major incident triage tools |url=https://www.england.nhs.uk/long-read/major-incident-triage-tools/ |access-date=2023-05-12 |website=www.england.nhs.uk}}</ref> These new tools resulted from a multi-stakeholder review led by the NHS but its implementation became more urgent after the Manchester Arena Inquiry made it a monitored recommendation for the NHS and National Ambulance Resilience Unit to adopt.<ref name="Vassallo_2022" /><ref>{{Cite web |date=November 2022 |title=Report of the Public Inquiry into the Attack on Manchester Arena on 22nd May 2017 - Volume 2-II |url=https://files.manchesterarenainquiry.org.uk/live/uploads/2022/11/03141957/MAI-Volume-2-Part-ii.pdf |access-date=21 February 2023 |website=Manchester Arena Inquiry |vauthors=Saunders J |archive-date=21 February 2023 |archive-url=https://web.archive.org/web/20230221090424/https://files.manchesterarenainquiry.org.uk/live/uploads/2022/11/03141957/MAI-Volume-2-Part-ii.pdf |url-status=dead }}</ref>

===== Ten Second Triage Tool =====
The Ten Second Triage Tool (TST) was introduced as a way for all emergency services, including the police and fire service, to assess and prioritise mass casualties to provide lifesaving intervention.<ref name=":0" /> The tool allows for rapid assessment by removing the need to measure physiological vital signs focusing on what the emergency responder can see.<ref name=":0" /><ref>{{Cite web |title=NHS England » Ten Second Triage tool |url=https://www.england.nhs.uk/long-read/ten-second-triage-tool/ |access-date=2023-06-08 |website=www.england.nhs.uk}}</ref>

* '''{{legend inline|red|P1}}''' – Patients who have catastrophic bleeding, a penetrating injury or those who are unconscious
* '''{{legend inline|Gold|P2}}''' – Patients who are unable to walk but are conscious
* '''{{legend inline|Green|P3}}''' – Patients who are able to walk
* '''{{legend inline|grey|Not Breathing}}''' – Patients who are not breathing (this replaces the deceased category)

===== NHS Major Incident Triage Tool =====
The Major Incident Triage Tool (MITT) serves as the more advanced triage tool for emergency medial responders to triage casualties.<ref name=":0" /> The tool, derived from the Modified Physiological Triage Tool, can be used on both adults and children, and also includes the assessment of physiological vital signs.<ref name=":0" /><ref>{{Cite web |title=NHS England » NHS Major Incident Triage Tool (MITT) |url=https://www.england.nhs.uk/long-read/nhs-major-incident-triage-tool-mitt/ |access-date=2023-06-08 |website=www.england.nhs.uk}}</ref>

* '''{{legend inline|red|P1}}''' – Life-threatening injury 
* '''{{legend inline|Gold|P2}}''' – Unconscious but breathing
* '''{{legend inline|Green|P3}}''' – Non-life-threatening injury
* '''{{legend inline|black|Dead}}''' – No signs of life or non-survivable injury

==== United States ====
A multitude of triage systems exist in the United States, and there is no national standard.<ref>{{cite journal | vauthors = Christian MD | title = Triage | journal = Critical Care Clinics | volume = 35 | issue = 4 | pages = 575–589 | date = October 2019 | pmid = 31445606 | pmc = 7127292 | doi = 10.1016/j.ccc.2019.06.009 }}</ref> Among local, regional, state, and interstate systems, the [[Simple triage and rapid treatment|START triage method]] is most commonly used.<ref name="Yancey_2023" />

===== United States Armed Forces =====
The U.S. armed forces utilize a four-stage system,<ref name="United States Marine Corps">{{Cite web |title=FMSO 107 CONDUCT TRIAGE |url=https://www.trngcmd.marines.mil/Portals/207/Docs/FMTBE/Student%20Materials/FMSO%20Manual/107.pdf |publisher=[[United States Marine Corps]]}}</ref> A battlefield situation, care providers rank casualties for precedence, treat those who they can safely, and transport casualties who need it to a higher level of care, either a [[Forward surgical teams|Forward Surgical Team]] or [[Combat Support Hospital]].<ref>{{Cite book |title=ATP 4-02.5: Casualty Care |publisher=[[United States Department of the Army]] |year=2013}}</ref>

The triage categories (with corresponding color codes), in order of priority, are:<ref name="United States Marine Corps" /><ref>{{cite web|url=http://www.armystudyguide.com/content/powerpoint/First_Aid_Presentations/triage-2.shtml|title=US Army Study Guide|access-date=2008-12-04|archive-url=https://web.archive.org/web/20080914193002/http://www.armystudyguide.com/content/powerpoint/First_Aid_Presentations/triage-2.shtml|archive-date=2008-09-14|url-status=dead}}</ref>

{| class="wikitable"
|+U.S. Armed Forces Triage Categories<ref name="United States Marine Corps" />
!Category
!Description
!Conditions
|-
|'''{{legend inline|red|Immediate}}'''
|Life-threatening injury
|Airway or breathing issues, hemorrhage
|-
|'''{{legend inline|Gold|Delayed}}'''
|Potentially life-threatening injury
|Shock, Fractures and dislocations, abdominal, spinal, thoracic, or head injuries, uncomplicated major burns
|-
|'''{{legend inline|Green|Minimal}}'''
|Not life-threatening injuries
|Cuts, bruises, abrasions, small bone fractures, minor burns, strains/sprains, frostbite
|-
|'''{{legend inline|Black|Expectant}}'''
|Non-survivable injuries
|Cardiac arrest, massive head or brain trauma, Second or third degree burns over 70% or more of body
|}

== Limitations of current practices ==
Notions of mass casualty triage as an efficient rationing process of determining priority based upon injury severity are not supported by research, evaluation and testing of current triage practices, which lack scientific and methodological bases. START and START-like (START) triage that use color-coded categories to prioritize provide poor assessments of injury severity and then leave it to providers to subjectively order and allocate resources within flawed categories.<ref name="Lindsey_2005">{{cite journal | vauthors = Lindsey J | title = New triage method considers available resources | journal = JEMS: A Journal of Emergency Medical Services | volume = 30 | issue = 7 | pages = 92–94 | date = July 2005 | pmid = 16027670 | doi = 10.1016/S0197 | doi-broken-date = 1 November 2024 | url = http://saccotriage.com/pdf/JEMS_7_05_New_Triage_v2.pdf | archive-url = https://web.archive.org/web/20160304054034/http://saccotriage.com/pdf/JEMS_7_05_New_Triage_v2.pdf | archive-date = 2016-03-04 }}</ref> Some of these limitations include:

* lacking the clear goal of maximizing the number of lives saved, as well as the focus, design and objective methodology to accomplish that goal (a protocol of taking the worst Immediate – lowest chances for survival – first can be statistically invalid and dangerous)<ref name="Lindsey_2005" /><ref name="Lerner_2008">{{cite journal | vauthors = Lerner EB, Schwartz RB, Coule PL, Weinstein ES, Cone DC, Hunt RC, Sasser SM, Liu JM, Nudell NG, Wedmore IS, Hammond J, Bulger EM, Salomone JP, Sanddal TL, Markenson D, O'Connor RE | display-authors = 6 | title = Mass casualty triage: an evaluation of the data and development of a proposed national guideline | journal = Disaster Medicine and Public Health Preparedness | volume = 2 | issue = Suppl 1  | pages = S25–S34 | date = September 2008 | pmid = 18769263 | doi = 10.1097/DMP.0b013e318182194e | s2cid = 8262943 | doi-access = free }}</ref>
* using trauma measures that are problematic (e.g., capillary refill)<ref name="Lerner_2008" /> and grouping into broad color-coded categories that are not in accordance with injury severities, medical evidence and needs. Categories do not differentiate among injury severities and survival probabilities, and are invalid based on categorical definitions and evacuation priorities
* ordering (prioritization) and allocating resources subjectively within Immediate and Delayed categories, which are neither reproducible nor scalable, with little chance of being optimal<ref name="Lindsey_2005" />
* not considering/addressing size of incident, resources, and injury severities and prioritization within its categories<ref name="Lindsey_2005" /><ref name="Lerner_2008" /> – e.g., protocol does not change whether 3, 30 or 3,000 casualties require its use, and regardless of available resources to be rationed
* not considering differences in injury severities and survival probabilities between types of trauma (blunt versus penetrating, etc.) and ages
* resulting in inconsistent tagging and prioritizing/ordering of casualties and substantial overtriage

Research indicates there are wide ranges and overlaps of survival probabilities of the Immediate and Delayed categories, and other START limitations. The same physiologic measures can have markedly different survival probabilities for blunt and penetrating injuries. For example, a START Delayed (second priority) can have a survival probability of 63% for blunt trauma and a survival probability of 32% for penetrating trauma with the same physiological measures – both with expected rapid deterioration, while a START Immediate (first priority) can have survival probabilities that extend to above 95% with expected slow deterioration. Age categories exacerbate this. For example, a geriatric patient with a penetrating injury in the Delayed category can have an 8% survival probability, and a pediatric patient in the Immediate category can have a 98% survival probability. Issues with the other START categories have also been noted.<ref name="Lerner_2008" /> In this context, color-coded tagging accuracy metrics are not scientifically meaningful.

Poor assessments, invalid categories, no objective methodology and tools for prioritizing casualties and allocating resources, and a protocol of worst first triage provide some challenges for emergency and disaster preparedness and response. These are clear obstacles for efficient triage and resource rationing, for maximizing savings of lives, for best practices and National Incident Management System (NIMS) compatibilities,<ref name="thirteen">{{cite web | work = US Department of Homeland Security. | title = National Incident Management System. | date = December 2008 | url = http://www.fema.gov/national-incident-management-system }}</ref><ref name="Villani_2007">{{cite web | vauthors = Villani D | work = Department of Public Safety, Okaloosa County, Florida. | title = Letter to FEMA asking if START and STM are NIMS compatible. | date = September 2007 | url = http://saccotriage.com/pdf/Florida_official_letter_toFEMA.pdf | archive-url = https://web.archive.org/web/20160303233313/http://saccotriage.com/pdf/Florida_official_letter_toFEMA.pdf | archive-date=2016-03-03 }}</ref><ref name="Fluman_2007">{{cite web | vauthors = Fluman A | title = FEMA Letter to Dino Villani, former State of Florida EMS Director, summarizing FEMA Evaluation and Testing Program of STM NIMS compatibilities and operational effectiveness and suitability. | date = December 2007 | url = http://saccotriage.com/pdf/FEMAresponseNIMS.pdf | archive-url = https://web.archive.org/web/20160304053929/http://saccotriage.com/pdf/FEMAresponseNIMS.pdf | archive-date=2016-03-04 }}</ref> and for effective response planning and training.

Inefficient triage also provides challenges in containing health care costs and waste. [[Field triage]] is based upon the notion of up to 50% overtriage as being acceptable. There have been no cost-benefit analyses of the costs and mitigation of triage inefficiencies embedded in the healthcare system. Such analyses are often required for healthcare grants funded by taxpayers, and represent normal engineering and management science practice. These inefficiencies relate to the following cost areas:

* tremendous investment in time and money since [[September 11 attacks|9/11]] to develop and improve responders' triage skills<ref name="Lerner_2008" />
* cited benefits from standardization of triage methodology, reproducibility and interoperability,<ref name="Lerner_2008" /> and NIMS compatibilities
* avoided capital costs for taxpayer investment in additional EMS and trauma infrastructure<ref name="Brown_2006">{{cite news | vauthors = Brown D | title = Crisis Seen in Nation's ER Care. | newspaper = The Washington Post | date = June 2006 | url = https://www.washingtonpost.com }}</ref>
* wasteful daily resource utilization and increased operating costs from acceptance of substantial levels of overtriage
* prescribed values of a statistical life<ref name="Appelbaum_2011">{{Cite news | vauthors = Appelbaum B |date=2011-02-16 |title=As U.S. Agencies Put More Value on a Life, Businesses Fret |language=en-US |work=The New York Times |url=https://www.nytimes.com/2011/02/17/business/economy/17regulation.html |access-date=2023-02-17 |issn=0362-4331}}</ref> and estimated savings in human lives that could reasonably be expected using evidence-based triage practices
* ongoing performance improvements<ref name="thirteen" /> that could reasonably be expected from a more objective optimization-based triage system and practices

== Ethical considerations ==
Because treatment is intentionally delayed or withheld from individuals under this system, triage has ethical implications that complicate the decision-making process. Individuals involved in triage must take a comprehensive view of the process to ensure fidelity, veracity, justice, autonomy, and beneficence are safeguarded.<ref name="pmid16001601">{{cite journal | vauthors = Repine TB, Lisagor P, Cohen DJ | title = The dynamics and ethics of triage: rationing care in hard times | journal = Military Medicine | volume = 170 | issue = 6 | pages = 505–509 | date = June 2005 | pmid = 16001601 | doi = 10.7205/milmed.170.6.505 }}</ref>

Ethical implications vary between different settings and the type of triage system employed, culminating in no single gold-standard approach to triage. Emergency departments are advised to preemptively plan strategies in attempts to mitigate the emotional burden on these triage responders.<ref>{{cite journal | vauthors = Hick JL, Hanfling D, Cantrill SV | title = Allocating scarce resources in disasters: emergency department principles | journal = Annals of Emergency Medicine | volume = 59 | issue = 3 | pages = 177–187 | date = March 2012 | pmid = 21855170 | doi = 10.1016/j.annemergmed.2011.06.012 | doi-access = free }}</ref> While doing so, [[standards of care]] must be maintained to preserve the safety of both patients and providers.

There is widespread agreement among [[ethicist]]s that, in practice, during the [[COVID-19 pandemic]] triage should prioritize "those who have the best chance of surviving" and follow guidelines with strict criteria that consider both short-term and long-term survivability.<ref>{{cite journal | vauthors = Joebges S, Biller-Andorno N | title = Ethics guidelines on COVID-19 triage-an emerging international consensus | journal = Critical Care | volume = 24 | issue = 1 | pages = 201 | date = May 2020 | pmid = 32375855 | pmc = 7202791 | doi = 10.1186/s13054-020-02927-1 | doi-access = free }}</ref> Likewise, the triage of other health services has been adjusted during the pandemic to limit resource strain on hospitals.

=== Utilitarian approach and critique ===
Under the utilitarian model, triage works to maximize the survival outcomes of the most people possible. This approach implies that some individuals may likely suffer or die, in order for the majority to survive. Triage officers must allocate limited resources and weigh an individual's needs along with the needs of the population as a whole.

Some ethicists argue the utilitarian approach to triage is not an impartial mechanism, but rather a partial one that fails to address the social conditions that prevent optimal outcomes in marginalized communities, rendering it a practical but inadequate means of distributing health resources.<ref name="pmid29933511">{{cite journal | vauthors = Okorie N | title = Partiality, impartiality and the ethics of triage | journal = Developing World Bioethics | volume = 19 | issue = 2 | pages = 76–85 | date = June 2019 | pmid = 29933511 | doi = 10.1111/dewb.12201 | s2cid = 49387832 }}</ref>

=== Special population groups ===
There is wide discussion regarding how VIPs and celebrities should be cared for in the emergency department. It is generally argued that giving special considerations or deviating from the standard [[Medical guideline|medical protocol]] for VIPs or celebrities is unethical due to the cost to others. However, others argue that it may be morally justifiable as long as their treatment does not hinder the needs of others after assessing overall fairness, quality of care, privacy, and other ethical implications.<ref>{{cite journal | vauthors = Geiderman JM, Malik S, McCarthy JJ, Jagoda A | title = The care of VIPs in the emergency department: Triage, treatment and ethics | journal = The American Journal of Emergency Medicine | volume = 36 | issue = 10 | pages = 1881–1885 | date = October 2018 | pmid = 30238911 | doi = 10.1016/j.ajem.2018.07.009 | s2cid = 52310367 }}{{Dead link|date=October 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

=== Proposed frameworks in conflict ===
A variety of logistical challenges complicate the triage and ultimate provision of care in conflict situations. Humanitarian actors acknowledge challenges like disruptions in food and medical supply chains, lack of suitable facilities, and existence of policies that prohibit administration of care to certain communities and populations as elements that directly impede the successful delivery of care.<ref name = "Broussard_2019" /> The logistical realities of humanitarian emergencies and conflict situations threatens the bioethical principle of beneficence, the obligation to act for the benefit of others.<ref name = "Broussard_2019">{{Cite journal| vauthors = Broussard G, Rubenstein LS, Robinson C, Maziak W, Gilbert SZ, DeCamp M |date=2019-09-05|title=Challenges to ethical obligations and humanitarian principles in conflict settings: a systematic review|journal=Journal of International Humanitarian Action|volume=4|issue=1|pages=15|doi=10.1186/s41018-019-0063-x|s2cid=201838587|issn=2364-3404|doi-access=free}}</ref>

=== Technical challenges of triage in conflict settings ===
To address the ethical concerns that underpin triage in conflict situations and [[humanitarian crises]], new triage frameworks and classification systems have been suggested that aim to uphold [[human rights]]. Scholars have argued that new frameworks must prioritize informed consent and rely on established medical criteria only in order to respect the human rights considerations set forth by the [[Geneva Convention]] of 1864 and the [[Universal Declaration of Human Rights]],<ref name="pmid11367943">{{cite journal | vauthors = Domres B, Koch M, Manger A, Becker HD | title = Ethics and triage | journal = Prehospital and Disaster Medicine | volume = 16 | issue = 1 | pages = 53–58 | date = 2001 | pmid = 11367943 | doi = 10.1017/s1049023x00025590 | s2cid = 36211479 }}</ref> but no comprehensive triage model has been adopted by international bodies.

=== Veterinary triage===
[[Veterinarian|Emergency veterinarian]] Jessica Fragola wrote in 2022 about the ethics of animal triage. She said that pressures on veterinarians having been exacerbated by staffing shortages that resulted from the COVID-19 pandemic, coupled with growth in spending on [[veterinary care]] and on [[pet insurance]].<ref>{{Cite web|url=https://www.newsday.com/opinion/commentary/pet-care-veterinary-care-animal-er-p06697|title=Pets need vets: Be kind to both|website=Newsday|date=February 7, 2022| vauthors = Fragola J }}</ref>

== See also ==
{{Portal|Medicine|Philosophy|COVID-19}}
<!-- Please keep entries in alphabetical order & add a short description [[WP:SEEALSO]] -->
* [[Combat stress reaction]]
* [[Glasgow coma scale]]
* [[Hospital emergency codes]]
* [[Mass decontamination]]
* [[Remote patient monitoring]]
* [[Wilderness first aid]]
<!-- Please keep entries in alphabetical order -->

== References ==
{{Reflist}}

== External links ==
* {{Wiktionary inline|triage}}
* {{Commons category-inline|Triage}}

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{{EMSworld}}
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[[Category:Triage| ]]
[[Category:Emergency management]]
[[Category:First aid]]
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[[Category:Intensive care medicine]]