Introduction
All communities experience occasions during which large numbers of people assemble in public or private spaces for the purpose of celebrating or participating in musical, sporting, cultural, religious, political, or other events. Collectively, these events are referred to as “mass gatherings.” From a medical perspective, a mass gathering is defined as an event involving the gathering of individuals or crowds during which emergency responses may be delayed due to limited access.Reference Arbon1-Reference Milsten, Maguire, Bissell and Seaman5
Large crowds require dedicated first aid, medical, and other health-related services at a presentation rate that is higher than that for the surrounding, local population.Reference Hodgetts and Cooke4 There is great variability within and between mass gatherings. The crowd size, weather, event duration, crowd members’ age and behaviour, topography, event-specific hazards, use of alcohol or drugs, and whether attendees are participants or spectators will vary substantially between events.Reference Arbon1, Reference Milsten, Maguire, Bissell and Seaman5, Reference Enock and Jacobs6 At any mass gathering, this complex interplay of factors affects the patient presentation rate (PPR), the acuity, and the case mix.
Triage is a complex process and is one means of determining which patients most need access to limited resources. The process of triage takes many forms, depending on the context. It may be divided into triage systems used in prehospital settings (ie, at the side of a road, in a field of combat) and those used in a fixed location (ie, emergency department, military field hospital). For example, during a mass-casualty incident (MCI) in which health care needs (ie, number of seriously ill or injured patients) exceed available resources to provide the health care required (ie, personnel or bed-spaces to provide care), triage is the process of sorting patients with the goal of identifying life-threats and saving the maximum number of people.Reference Jenkins, McCarthy and Sauer7 Similarly, in a hospital setting triage is used to determine the right location for the right patient at the right timeReference Murray, Bullard and Grafstein8 as opposed to using a “first-come, first-served” approach that ignores time-critical clinical presentations.Reference Wuerz, Travers, Gilboy, Eitel, Rosenau and Yazhari9 Emergency departments function on a “worst-come, first-served” principle.
Mass Gatherings as Unique Populations
Mass gatherings present a unique set of challenges for health care professionals. Mass gathering settings differ in several important ways from other prehospital settings. First, there currently is limited knowledge and understanding with regard to the factors that shape PPRs during mass-gathering events.Reference Arbon2 Systematically collected data regarding acuity and the range of clinical presentations have the potential to shape planning for medical services.Reference Finch, Valuri and Ozanne-Smith10 Second, there is great variability in the on-site medical capacity between events in relation to both available equipment and medical team expertise and composition (eg, availability of automatic external defibrillators, basic vs. advanced life support, first aid only vs. full medical team).Reference Feldman, Lukins, Verbeek, MacDonald, Burgess and Schwartz11 Third, PPRs—the number of people who present with an illness or injury per 1,000 attendees or participants—vary between events. No reliable, validated model currently exists to predict PPR for an event prospectively.Reference Arbon, Bridgewater and Smith3, Reference Zeitz, Schneider, Jarrett and Zeitz12 Accordingly, at any given event there may be hundreds of patients presenting in a very short period of time (e.g., at the finish line of a marathon); some will require resuscitation, but the majority simply will need to be streamlined to the appropriate service or level of care.Reference Robertson-Steel13
Fourth, mass gatherings may involve high PPRs, and critically ill patients may be encountered.Reference Delaney and Drummond14 Mass-gathering events generate an increased injury and illness burden. A higher incidence of injury occurs at mass gatherings than is expected from general population statistics.Reference Arbon1 Fifth, at many mass gatherings there is overuse of drugs and/or alcohol.Reference Erickson, Koenigsberg and Bunney15 However, existing prehospital (field) triage systems focus primarily on ensuring that individuals with traumatic injuries receive timely, appropriate care,Reference Jenkins, McCarthy and Sauer7, Reference Robertson-Steel13, Reference Bond, Kortbeek and Preshaw16-Reference Sharma18 making these systems imperfect instruments for use in the mass gathering context. Sixth, the literature regarding mass gatherings often has been written from the perspective of care providers who are employed in acute care settings. Health promotion and illness prevention, as well as other central tenets of public health theory, may not be the focus.
Finally, by their very nature, mass-gathering events have the potential to become mass-casualty incidents (MCIs)Reference Delaney and Drummond14 that require multiple, local and regional agencies to work together. This makes a common language of paramount importance.Reference Robertson-Steel13 Thus, any triage system used in this context must be effective and efficient in both a mass-gathering medicine (MGM) tent/clinic setting and in a field/disaster setting. Together, these challenges make mass gatherings different from other prehospital settings. Existing triage tools may fail to address the needs of individuals who are injured or become ill while attending mass-gathering events.
Triage—State of the Art
The quality of evidence regarding the effectiveness of triage systems varies substantially. Because of the difficulties in doing field research during a disaster, only a small amount of research has been performed in relation to the use of prehospital triage systems in this setting. In contrast, much research has been done in relation to the use and efficacy of triage in emergency departments, where individuals presenting for treatment often are competing for limited resources. Canadian researchers have made substantial contributions to the literature with regard to emergency department triage systems.Reference Murray, Bullard and Grafstein8, Reference Bullard, Unger, Spence and Grafstein19-Reference Field and Lantz23 However, virtually no research has been done to develop, test, and prospectively validate an effective triage approach for use during mass gatherings.
The authors of this article are members of the Mass Gathering Medicine Interest Group (MGMIG), within the Department of Emergency Medicine at the University of British Columbia. Faculty, learners, and other volunteers are involved in the provision of medical support for mass gatherings. After more than two decades of experience providing care at mass-gathering events, the authors are seeking a triage and acuity scoring system appropriate for both mass gatherings and MCIs. Unfortunately, existing triage systems (particularly prehospital triage systems) are biased toward traumatic injuries, and usually fail to incorporate mitigating factors such as alcohol and drug use and environmental exposures, which are important factors at mass gatherings. Moreover, a substantial amount of over-triage occurs when using existing prehospital systems, which at times leads to the misallocation of limited resources.
Mass-gathering medical care providers also deliver services that include health promotion, injury prevention, and customer service at the events; these activities are not captured by any of the currently described triage or acuity scoring systems. No existing triage tool meets the needs for a mass gathering. Hence, a review of the available literature with regard to currently used triage systems, in general, is provided. A triage system is proposed for use during mass gatherings and also, if required, in a mass-casualty or disaster scenario, should such an event occur in these settings.
Methods
A review of the literature on mass gatherings and triage systems, both prehospital and in-hospital, was conducted. Three databases were utilized: (1) EBSCO (EBSCO Publishing, Ipswich, Massachusetts USA, www.ebsco.com); (2) OVID (Ovid Technologies, Inc., New York, New York USA, www.ovid.com); and (3) PubMed (National Center for Biotechnology Information, US National Library of Medicine, Bethesda, Maryland USA, www.pubmed.com). The search terms “triage,” “prehospital triage,” “field triage,” “acuity scoring,” “acuity scales,” “mass gatherings,” “mass-casualty incidents,” and “disaster triage” were used. Abstracts were reviewed by two team members, and relevant articles were obtained and reviewed by the team. Articles selected for in-depth review had to be: written in English; published in a peer-reviewed journal; focused on the development and testing of a triage scale or scales for use in the context of humans; and tested in the field (in vivo).
This synthesis underpins a larger project that includes a central registry for mass-gathering events. The registry supports collection of a wide variety of data such as patient presentations rates, event characteristics, and a host of other variables that, in turn, facilitate longitudinal data collection. The intention of this registry is to facilitate comparisons between events from year to year and between different types of events that encompass different risk factors. Acuity is one important data element of patient presentations that must be captured and quantified for the purposes of measurement and comparison. Further information about the Mass Gathering Medicine Online Registry Project may be found at http://www.ubcmgm.ca/registry.
Based on the findings of the present analysis of currently available triage systems and the needs for an additional system for use during mass-gathering events and MCIs, suggestions for a new system were developed.
Results
A medical research librarian was consulted regarding search strategies. The search terms described above, for the years 1985-2010, yielded thousands of references. To narrow the search, key words were systematically deleted from the overall search when a review of the abstracts revealed articles not directly relevant to the research question. For example, the search term “acuity scoring” yielded abstracts about tools used to measure acuity (often in an intensive care setting) and to predict mortality and morbidity in the context of a given disease or disorder (eg, stroke). The search term “mass-casualty incident” yielded >1,100 citations, only a small portion of which dealt with triage systems. In the end, approximately 40 articles were reviewed in depth and the results are summarized below.
Overview of Triage Systems
During the past two decades, triage systems have been standardized in a number of countries and both prehospital (also known as “primary” or “field” triage) and hospital/emergency department (ED) (also known as “secondary”) triage systems are in widespread use.Reference FitzGerald, Jelinek, Scott and Gerdtz24 The former systems focus on sorting the sickest patients from among mass casualties using parallel triage (ie, groups of patients are the unit of analysis), whereas the latter focus on sorting the sickest using serial triage (ie, one patient at a time).
Although originally used to sort the injured according to the severity of injuries, during the present decade triage systems have evolved to serve multiple purposes related to acuity determination, human resource planning, resource allocation, and quality assurance. Formally, triage systems provide data regarding acuity for a certain population (eg, patients presenting to the emergency department). These systems also provide a mechanism for prioritizing patients in a situation where the demand for health care resources exceeds the availability of required resources at a moment in time. Triage systems may be used as a way to quantify workload (although this was not an intended use), predict resource consumption,Reference Ma, Gafni and Goldman22, Reference Elshove-Bolk, Mencl, van Rijswijck, Simons and van Vugt25 measure quality of care (eg, waiting times),Reference Jimenez, Murray and Beveridge26 and/or to support funding requests for additional staff.Reference J Murray27, Reference Anderson, Zaric, Dreyer, Carter and McLeod28 Informally, triage systems serve as a common language for health care professionals to abbreviate descriptions of acuity for communication among team members.
Triage System Limitations
Despite decades of common usage and the ongoing efforts of researchers to develop and refine triage tools, there are a number of persistent limitations discussed in the literature (Table 1). Limitations may be grouped into three main themes. First, given the challenges of research in the field, there is a relative dearth of high-level evidence with regard to prehospital triage. Second, the evidence that is available only infrequently addresses unique populations (eg, children) or nontraditional settings (eg, mass gatherings in developing nations), although this slowly is changing. Third, prehospital triage scales may be inefficient and ineffective due to the variety of reasons listed in Table 1, including the current lack of both standardization and the ability to capture changes in patient status over time.
Table 1 General Limitations of Existing Triage Systems
Triage and Acuity Scoring System for Mass Gatherings
Creating effective triage approaches for high-consequence events has been identified as an important focus of research.Reference Rothman, Hsu, Kahn and Kelen29 A triage system for mass gatherings must be: (1) Versatile—the system must be useful across the full spectrum of patient presentations ranging from mass-casualty incidents (parallel triage) to “business as usual” (serial triage). In particular, such a system must capture all of the work done on-scene in relation to medical support during which transport is averted, as well as capturing services such as prevention, over-the-counter medication requests, and the myriad of other non-urgent care requests that constitute (at least anecdotally) the majority of the work of the medical team during events that are well-planned and executed; (2) Simple—the system must be quick to learn and easy to apply, by individuals from a wide variety of health care backgrounds; (3) Evolving—the system takes into account acuity at the initial call and again upon discharge. Of necessity, there must be a way to differentiate between the initial “call out” (ie, security calls for medical assessment for a “collapse/unconscious patient” who is assigned a high acuity score), from actual acuity when assessed by members of the medical team and discharged (ie, when the diagnosis is known, the case turns out to be a minor intoxication and is assigned a correspondingly low acuity score). Conversely, a patient initially may be triaged as a simple medication request (eg, “do you carry any Benadryl [diphenhydramine]?”) and given a low triage acuity score (TAS), but then progresses to anaphylaxis, with a high discharge acuity score (DAS). Capturing one or the other, in isolation, will provide a biased view of the population serviced by the medical team. The change between TAS and DAS represents an important area of research regarding the impact of the medical team on individual cases; (4) Supportive of Communication—the system must be supportive of communication between providers on-site and between levels of care (eg, mass casualty incident/disaster, prehospital, hospital);Reference Armstrong, Frykberg and Burris30 and (5) Practical—the triage system considers business implications. The volume of service provided at an event might have an impact on the budget for similar or subsequent events, as well as for equipment and staff. The system used must enable staff to quantify acuity so that event planners and medical team members have accurate information upon which to base current and future decisions about resource allocation and budget.
Only one article was identified that described the use of a scale-based scoring system specifically designed for use during a mass-gathering event. The authors developed and retrospectively applied the Drug-Rock Injury Severity Score (DRISS) to the patient encounters during five rock music concerts involving 250,000 spectators.Reference Erickson, Koenigsberg and Bunney15 The triage system used a combination of anatomical and physiological indicators as well as features of the patient history—specifically drug and alcohol use—that were applied retrospectively. Interestingly, additional points were assigned for treatment required (eg, restraints, cardiac monitor). The higher the score, the more acute was the presentation. The DRISS never was prospectively applied and validated. Essentially, the DRISS functioned as a discharge acuity score that was useful in terms of measuring acuity retrospectively, but it is unknown whether the tool had the ability to capture the complexity of the initial patient presentations. In a slightly different take on triage during mass gatherings, Salhanick and colleagues,Reference Salhanick, Sheahan and Bazarian31 created an algorithm for use by paramedics to make decisions about whether or not to transport a patient to the hospital. The system involved a list of categories of common illnesses/injuries such as “burns,” “lacerations,” and “asthma.” Each category included clear criteria for transfer. The strengths of this approach include a sensitivity of 100% for detecting cases that require transport and a specificity of 90%. The weaknesses of this approach include the resulting over-triage and the fact that the content of the algorithm was necessarily brief, and therefore, not inclusive of the full range of injuries and illness with which individuals might present.
Other than in the articles discussed above, few authors have written about triage systems for use during mass gatherings. With regard to mass gatherings that turn into mass-casualty incidents, the literature is sparse and consists primarily of opinion.Reference Delaney and Drummond14
Proposed Solution
Acknowledging that there is no need to add to the proliferation of triage systems that differ in important ways, confuse providers, and make communication between levels of care more difficult, there exists an opportunity to build on the strengths of existing systems, and to make adaptations for triage during mass gatherings.
In developing a triage system for use at mass gatherings, disruptions of physiology alone will not identify every critically ill individualReference Subbe, Slater, Menon and Gemmell32 and may result in a medical bias because victims of trauma may have normal vital signs and subsequently evolve into an unstable condition.Reference Gottschalk, Wood, DeVries, Wallis and Bruijns33 Similarly, anatomical changes alone will not identify every critically ill individual. The weakness of a mechanism-of-injury-based system is that this approach results in considerable over-triage.Reference Gottschalk, Wood, DeVries, Wallis and Bruijns33
Additionally, no current triage system takes into account the unique features of a population attending mass gatherings, specifically the use (or overuse) of recreational drugs and/or alcohol and/or environmental exposures. Importantly, the triage and acuity scoring system must acknowledge that the majority of patients seen at mass-gathering events are not critically ill; ideally they should provide some opportunity for capturing the type of intervention required (eg, minor wound care, blister management, sunscreen, bug spray, ear plugs, or over-the-counter medication requests). There is a substantial gap in the literature for describing and classifying the service and care provided to individuals in the minor spectrum of presentation. Not capturing the lowest acuity services provided on-site due to absent or inadequate charting represents a lost opportunity to fully document and understand the role of the medical team at a mass gathering.
Triage ought to be, at minimum, a two-stage process due to the fact that an individual's status can change over time, evolving into a more serious (or less serious) clinical presentationReference Gottschalk, Wood, DeVries, Wallis and Bruijns33 that also must capture the nature of the work for event planners. Finally, any system used must be effective for both serial triage and parallel triage.
This project currently is in the second of three phases. The first phase included the literature review and creation of the University of British Columbia Mass Gathering Medical (UBC MGM) Triage Acuity Scale/Discharge Acuity Scale (TAS/DAS); the second phase involves retrospective application of the tool in the context of a series of clinical cases that occurred during events held during the previous event season; and, the third phase will involve prospective testing.
The TAS/DAS is based on the most widely used disaster triage system, simple triage and rapid treatment (START)34 that employs a common, color-based system, and the Canadian Triage Acuity Scale (CTAS)Reference Murray, Bullard and Grafstein8, Reference Bullard, Unger, Spence and Grafstein19 that employs several clinical modifiers. Development, modification, and simplification are ongoing. The START disaster triage system is physiology-based and uses four color categories: black (deceased or expectant); red (emergent, resuscitation); yellow (urgent); and green (minor). Addition of a fifth color, white (dispensary), captures any patient interaction for services, such as any request that a patient normally would take care of independently at home (eg, band aids, sunscreen, contact lens removal, simple over-the-counter medications) and that does not require medical assessment or intervention.
Recognizing that a physiology-based system has limitations, indicators were extracted from the CTAS; then, two modifiers that captured the strengths of other triage systems were added and applied specifically to the mass-gathering situation. Thus, “mechanism of injury” and the “use of recreational drugs and/or alcohol” were chosen as modifiers.
The last phase of testing will include validation of the scale and determination of inter-observer reliability using retrospective data collected through the UBC MGM Online Registry Project.Reference Lund, Turris, Gutman and Louis35 Finally, prospective validation, evaluation, and dissemination of the results are planned for 2012 and 2013.
Summary and Conclusions
In the practice context of mass gatherings, a triage scale that is reliable, valid, and easy to use by a wide variety of providers is essential. No existing system meets the needs of those providing medical support for mass gatherings. The MGM TAS/DAS is proposed as an approach to triage and discharge acuity categorization during mass gatherings, during which large numbers of patients may present in surges, for assessment and treatment.
The adaptation of a familiar and widely used triage acuity system for the unique environment of a mass gathering represents an opportunity to streamline care for those attending mass gatherings. Use of a rigorously tested triage system in this context may improve data collection for researchers and event planners between and across different types of events. Such an adaptation could increase the consistency of nomenclature thereby improving communication between health care professionals. Looking into the future, use of a common triage system for mass gatherings has the potential to allow comparisons between municipal, provincial, and national populations and between data sets from different MGM patient registries.
Acknowledgments
The authors acknowledge Ms. Kerrie Lewis, EMR, LPN, for her participation and careful review of several drafts of the manuscript and work on deriving the new tool; Dr. Samuel Gutman for his commitment to the highest quality of care at mass-gathering events and his participation in the derivation of a triage and discharge acuity scoring tool; and Dr. Erin Morley who contributed early in the process in relation to the literature review.
Abbreviations
- CTAS:
Canadian Triage Acuity Scale
- DAS:
discharge acuity score
- DRISS:
Drug-Rock Injury Severity Score
- EMS:
Emergency Medical Services
- MCI:
mass-casualty incident
- MGM:
mass-gathering medicine
- PPR:
patient presentation rate
- START:
simple triage and rapid treatment
- TAS:
triage acuity score
