The Tsukui (Japan) Yamayuri-en Facility Stabbing Mass-Casualty Incident

INTRODUCTION

In July 2016, a mass-casualty stabbing attack took place at a facility for disabled persons located in Sagamihara City (Kanagawa Prefecture, Japan). The attack resulted in 45 casualties, including 19 deaths. The study hospital dispatched physicians to the field and admitted multiple casualties. This report aimed to review the physicians' experiences and to provide insights for the formulation of response measures for similar incidents in the future.

REPORT

This incident involved 30 emergency teams and 12 fire department teams, including those from neighboring fire departments. Five physicians from three medical institutions, including the study hospital, entered the field. The Simple Triage and Rapid Treatment (START) method was used on the field. The final field triage category count was: 20 red, four yellow, two green, and 19 black tags. All the casualties (n = 26) except for the 19 black tag casualties were transported to one of six neighboring medical institutions.The median age of the transported casualties was 41 years (interquartile range [IQR] = 35.5 - 42.0). Three casualties (21.4%) were in hemorrhagic shock on arrival at the hospital. Twelve patients had multiple cervical stab wounds (median four wounds; IQR = 3.75 - 6.0). A total of 91.7% of these stab wounds were in mid-neck Zone II region. Of the 12 patients with cervical stab wounds, four (33.3%) required emergency surgery, and the rest were sutured on an out-patient basis. One patient had already been sutured on the field. All patients requiring emergency surgery had deep wounds, including those of the carotid vein, thyroid gland, nerves, and the trachea. Eight of the casualties were hospitalized at the study institution. Five of them were admitted to the intensive care unit. There were no deaths among the casualties transported to the hospitals.

CONCLUSION

Regional core disaster medical hospitals must take on a central role, particularly in the case of local disasters. Horizontal communication and interactions should be reinforced by devising protocols and conducting joint training for effective inter-department collaborations on the field.Maruhashi, T, Takeuchi, I, Hattori, J, Kataoka, Y, Asari, Y. The Tsukui (Japan) Yamayuri-en facility stabbing mass-casualty incident. Prehosp Disaster Med. 2019;34(2):203-208.

START versus SALT Triage: Which is Preferred by the 21st Century Health Care Student?

IntroductionWhile the art and science of disaster triage continue to evolve, the education of the US health care student in matters pertaining to disaster preparedness and response remains stifled. Unfortunately, these students will be assuming major decision-making responsibilities regarding catastrophes that will be complicated by climate change, nuclear threats, global terrorism, and pandemics. Meanwhile, Sort, Assess, Life-Saving Interventions, Treatment, and/or Transport (SALT) triage is being advocated over the globally popular Simple Triage and Rapid Treatment (START) algorithm for multiple reasons: (1) it's an all-hazard approach; (2) it has four medical interventions; and (3) it has an additional triage color for victims with non-survivable injuries.Hypothesis/ProblemAs present-day threats become more ominous and health care education emphasizes the needs of vulnerable populations and palliative care, the authors hypothesize that, when given a choice, health care students will prefer SALT triage.

METHODS

A convenience sample of 218 interprofessional, disaster-naïve health care students received just-in-time, unbiased education on both START and SALT triage systems. Students then completed a survey asking them to decide which triage system they believe would be most effective in their community.

RESULTS

A total of 123 health care students (56.4%) preferred SALT while 95 (43.6%) preferred START; however, only the physician assistant students showed a statistically significantly preference (28 versus six, respectively; P=.042). Interestingly, there was also a statistically significant difference in preference by gender (Chi-square=5.02; P=.025) of the observed distribution versus expected distribution in SALT and START. The females preferred SALT (61.0%) while the males preferred START (55.9%).Among those who preferred START, START being easier to learn was the most important reason cited. Among those who preferred SALT, the most important reason cited was that the number of patient triage categories seemed more logical, comprehensible, and consistent with traditional medical care.

CONCLUSION

While SALT's preference among females and physician assistant students was based on the addition of medical interventions and the provision of palliative care, START's preference was related to expediency. Based on this research, incorporating disaster concepts into US health care students' curricula encourages thoughtful consideration among the future health care leaders about the most effective approach to triage care. It is critical that further research be completed to determine, without reservation, which triage system will not only save the most lives but provide the most humane care to victims.Fink BN, Rega PP, Sexton ME, Wishner C. START versus SALT triage: which is preferred by the 21st century health care student? Prehosp Disaster Med. 2018;33(4):381-386.

Comparison of Electronic Versus Manual Mass-Casualty Incident Triage

IntroductionMass-casualty incidents (MCIs) easily overwhelm a health care facility's human and material resources through the extraordinary influx of casualties. Efficient and accurate triage of incoming casualties is a critical step in the hospital disaster response.Hypothesis/ProblemTraditionally, triage during MCIs has been manually performed using paper cards. This study investigated the use of electronic Simple Triage and Rapid Treatment (START) triage as compared to the manual method.

METHODS

This observational, crossover study was performed during a live MCI simulation at an urban, Canadian, Level 1 trauma center on May 26, 2016. Health care providers (two medical doctors [MDs], two paramedics [PMs], and two registered nurses [RNs]) each triaged a total of 30 simulated patients - 15 by manual (paper-based) and 15 by electronic (computer-based) START triage. Accuracy of triage categories and time of triage were analyzed. Post-simulation, patients and participating health care providers also completed a feedback form.

RESULTS

There was no difference in accuracy of triage between the electronic and manual methods overall, 83% and 80% (P=1.0), between providers or between triage categories. On average, triage time using the manual method was estimated to be 8.4 seconds faster (P<.001) for PMs; and while small differences in triage times were observed for MDs and RNs, they were not significant. Data from the participant feedback survey showed that the electronic method was preferred by most health care providers. Patients had no preference for either method. However, patients perceived the computer-based method as "less personal" than the manual triage method, but they also perceived the former as "better organized."

CONCLUSION

Hospital-based electronic START triage had the same accuracy as hospital-based manual START triage, regardless of triage provider type or acuity of patient presentations. Time of triage results suggest that speed may be related to provider familiarity with a modality rather than the modality itself. Finally, according to patient and provider perceptions, electronic triage is a feasible modality for hospital triage of mass casualties. Further studies are required to assess the performance of electronic hospital triage, in the context of a rapid surge of patients, and should consider additional efficiencies built in to electronic triage systems. This study presents a framework for assessing the accuracy, triage time, and feasibility of digital technologies in live simulation training or actual MCIs. BolducC, MaghrabyN, FokP, LuongTM, HomierV. Comparison of electronic versus manual mass-casualty incident triage. Prehosp Disaster Med. 2018;33(3):273-278.

Introduction of Pediatric Physiological and Anatomical Triage Score in Mass-Casualty Incident

BACKGROUND

Triage has an important role in providing suitable care to the largest number of casualties in a disaster setting, but there are no secondary triage methods suitable for children. This study developed a new secondary triage method named the Pediatric Physiological and Anatomical Triage Score (PPATS) and compared its accuracy with current triage methods.

METHODS

A retrospective chart review of pediatric patients under 16 years old transferred to an emergency center from 2014 to 2016 was performed. The PPATS categorized the patients, defined the intensive care unit (ICU)-indicated patients if the category was highest, and compared the accuracy of prediction of ICU-indicated patients among PPATS, Physiological and Anatomical Triage (PAT), and Triage Revised Trauma Score (TRTS).

RESULTS

Among 137 patients, 24 (17.5%) were admitted to ICU. The median PPATS score of these patients was significantly higher than that of patients not admitted to ICU (11 [IQR: 9-13] versus three [IQR: 2-4]; P<.001). The optimal cut-off value of the PPTAS was six, yielding a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 95.8%, 86.7%, 60.5%, and 99.0%. The area under the receiver-operating characteristic curve (AUC) was larger for PPTAS than for PAT or TRTS (0.95 [95% CI, 0.87-1.00] versus 0.65 [95% CI, 0.58-0.72]; P<.001 and 0.79 [95% CI, 0.69-0.89]; P=.003, respectively). Regression analysis showed a significant association between the PPATS and the predicted mortality rate (r2=0.139; P<.001), ventilation time (r2=0.320; P<.001), ICU stay (r2=0.362; P<.001), and hospital stay (r2=0.308; P<.001).

CONCLUSIONS

The accuracy of PPATS was superior to other methods for secondary triage of children. Toida C , Muguruma T , Abe T , Shinohara M , Gakumazawa M , Yogo N , Shirasawa A , Morimura N . Introduction of pediatric physiological and anatomical triage score in mass-casualty incident. Prehosp Disaster Med. 2018;33(2):147-152.

Use of a Novel, Portable, LED-Based Capillary Refill Time Simulator within a Disaster Triage Context

Introduction A simple, portable capillary refill time (CRT) simulator is not commercially available. This device would be useful in mass-casualty simulations with multiple volunteers or mannequins depicting a variety of clinical findings and CRTs. The objective of this study was to develop and evaluate a prototype CRT simulator in a disaster simulation context.

METHODS

A CRT prototype simulator was developed by embedding a pressure-sensitive piezo crystal, and a single red light-emitting diode (LED) light was embedded, within a flesh-toned resin. The LED light was programmed to turn white proportionate to the pressure applied, and gradually to return to red on release. The time to color return was adjustable with an external dial. The prototype was tested for feasibility among two cohorts: emergency medicine physicians in a tabletop exercise and second year medical students within an actual disaster triage drill. The realism of the simulator was compared to video-based CRT, and participants used a Visual Analog Scale (VAS) ranging from "completely artificial" to "as if on a real patient." The VAS evaluated both the visual realism and the functional (eg, tactile) realism. Accuracy of CRT was evaluated only by the physician cohort. Data were analyzed using parametric and non-parametric statistics, and mean Cohen's Kappas were used to describe inter-rater reliability.

RESULTS

The CRT simulator was generally well received by the participants. The simulator was perceived to have slightly higher functional realism (P=.06, P=.01) but lower visual realism (P=.002, P=.11) than the video-based CRT. Emergency medicine physicians had higher accuracy on portrayed CRT on the simulator than the videos (92.6% versus 71.1%; P<.001). Inter-rater reliability was higher for the simulator (0.78 versus 0.27; P<.001).

CONCLUSIONS

A simple, LED-based CRT simulator was well received in both settings. Prior to widespread use for disaster triage training, validation on participants' ability to accurately triage disaster victims using CRT simulators and video-based CRT simulations should be performed. Chang TP , Santillanes G , Claudius I , Pham PK , Koved J , Cheyne J , Gausche-Hill M , Kaji AH , Srinivasan S , Donofrio JJ , Bir C . Use of a novel, portable, LED-based capillary refill time simulator within a disaster triage context. Prehosp Disaster Med. 2017;32(4):451-456.

First Responder Accuracy Using SALT after Brief Initial Training

BACKGROUND

Mass-casualty incidents (MCIs) present a unique challenge with regards to triage as patient volume often outweighs the number of available Emergency Medical Services (EMS) providers. A possible strategy to optimize existing triage systems includes the use of other first responder groups, namely fire and police, to decrease the triage time during MCIs, allowing for more rapid initiation of life-saving treatment and prioritization of patient transport. Hypothesis First-year primary care paramedic (PCP), fire, and police trainees can apply with similar accuracy an internationally recognized MCI triage tool, Sort, Assess, Life-saving interventions, Treatment/transport (SALT), immediately following a brief training session, and again three months later.

METHODS

All students enrolled in the PCP, fire, and police foundation programs at two community colleges were invited to participate in a 30-minute didactic session on SALT. Immediately following this session, a 17-item, paper-based test was administered to assess the students' ability to understand and apply SALT. Three months later, the same test was given to assess knowledge retention.

RESULTS

Of the 464 trainees who completed the initial test, 364 (78.4%) completed the three month follow-up test. Initial test scores were higher (P<.05) for PCPs (87.0%) compared to fire (80.2%) and police (68.0%) trainees. The mean test score for all respondents was higher following the initial didactic session compared to the three month follow-up test (75% vs 64.7%; Δ 10.3%; 95% CI, 8.0%-12.6%). Three month test scores for PCPs (75.4%) were similar to fire (71.4%) students (Δ 4.0%; 95% CI, -2.1% to 10.1%). Both PCP and fire trainees significantly outperformed police (57.8%) trainees. Over-triage errors were the most common, followed by under-triage and then critical errors, for both the initial and follow-up tests.

CONCLUSIONS

Amongst first responder trainees, PCPs were able to apply the SALT triage tool with the most accuracy, followed by fire, then police. Over-triage was the most frequent error, while critical errors were rare.

Primary Triage in a Mass-casualty Event Possesses a Risk of Increasing Informational Confusion: A Simulation Study Using Shannon's Entropy

Introduction Primary triage in a mass-casualty event setting using low-visibility tags may lead to informational confusion and difficulty in judging triage attribution of patients. In this simulation study, informational confusion during primary triage was investigated using a method described in a prior study that applied Shannon's Information Theory to triage. Hypothesis Primary triage using a low-visibility tag leads to a risk of informational confusion in prioritizing care, owing to the intermingling of pre- and post-triage patients. It is possible that Shannon's entropy evaluates the degree of informational confusion quantitatively and improves primary triage.

METHODS

The Simple Triage and Rapid Treatment (START) triage method was employed. In Setting 1, entropy of a triage area with 32 patients was calculated for the following situations: Case 1 - all 32 patients in the triage area at commencement of triage; Case 2 - 16 randomly imported patients to join 16 post-triage patients; Case 3 - eight patients imported randomly and another eight grouped separately; Case 4 - 16 patients grouped separately; Case 5 - random placement of all 32 post-triage patients; Case 6 - isolation of eight patients of minor priority level; Case 7 - division of all patients into two groups of 16; and Case 8 - separation of all patients into four categories of eight each. In Setting 2, entropies in the triage area with 32 patients were calculated continuously with each increase of four post-triage patients in Systems A and B (System A - triage conducted in random manner; and System B - triage arranged into four categories).

RESULTS

In Setting 1, entropies in Cases 1-8 were 2.00, 3.00, 2.69, 2.00, 2.00, 1.19, 1.00, and 0.00 bits/symbol, respectively. Entropy increased with random triage. In Setting 2, entropies of System A maintained values the same as, or higher than, those before initiation of triage: 2.00 bits/symbol throughout the triage. The graphic waveform showed a concave shape and took 3.00 bits/symbol as maximal value when the probability of each category was 1/8, whereas the values in System B showed a linear decrease from 2.00 to 0.00 bits/symbol.

CONCLUSION

Informational confusion in a primary triage area measured using Shannon's entropy revealed that random triage using a low-visibility tag might increase the degree of confusion. Methods for reducing entropy, such as enhancement of triage colors, may contribute to minimizing informational confusion. Ajimi Y , Sasaki M , Uchida Y , Kaneko I , Nakahara S , Sakamoto T . Primary triage in a mass-casualty event possesses a risk of increasing informational confusion: a simulation study using Shannon's entropy. Prehosp Disaster Med. 2016;31(5):498-504.

You Can't Make a Silk Purse Out of a Sow's Ear: Time to Start Again with MCI Triage

Horne S , Nutbeam T . You can't make a silk purse out of a sow's ear: time to start again with MCI triage. Prehosp Disaster Med. 2016;31(4):459-460.

First Responder Accuracy Using SALT during Mass-casualty Incident Simulation

INTRODUCTION

During mass-casualty incidents (MCIs), patient volume often overwhelms available Emergency Medical Services (EMS) personnel. First responders are expected to triage, treat, and transport patients in a timely fashion. If other responders could triage accurately, prehospital EMS resources could be focused more directly on patients that require immediate medical attention and transport.

HYPOTHESIS

Triage accuracy, error patterns, and time to triage completion are similar between second-year primary care paramedic (PCP) and fire science (FS) students participating in a simulated MCI using the Sort, Assess, Life-saving interventions, Treatment/Transport (SALT) triage algorithm.

METHODS

All students in the second-year PCP program and FS program at two separate community colleges were invited to participate in this study. Immediately following a 30-minute didactic session on SALT, participants were given a standardized briefing and asked to triage an eight-victim, mock MCI using SALT. The scenario consisted of a four-car motor vehicle collision with each victim portrayed by volunteer actors given appropriate moulage and symptom coaching for their pattern of injury. The total number and acuity of victims were unknown to participants prior to arrival to the mock scenario.

RESULTS

Thirty-eight PCP and 29 FS students completed the simulation. Overall triage accuracy was 79.9% for PCP and 72.0% for FS (∆ 7.9%; 95% CI, 1.2-14.7) students. No significant difference was found between the groups regarding types of triage errors. Over-triage, under-triage, and critical errors occurred in 10.2%, 7.6%, and 2.3% of PCP triage assignments, respectively. Fire science students had a similar pattern with 15.2% over-triaged, 8.7% under-triaged, and 4.3% critical errors. The median [IQR] time to triage completion for PCPs and FSs were 142.1 [52.6] seconds and 159.0 [40.5] seconds, respectively (P=.19; Mann-Whitney Test).

CONCLUSIONS

Primary care paramedics performed MCI triage more accurately than FS students after brief SALT training, but no difference was found regarding types of error or time to triage completion. The clinical importance of this difference in triage accuracy likely is minimal, suggesting that fire services personnel could be considered for MCI triage depending on the availability of prehospital medical resources and appropriate training.

Accuracy, Efficiency, and Inappropriate Actions Using JumpSTART Triage in MCI Simulations

INTRODUCTION

Using the pediatric version of the Simple Triage and Rapid Treatment (JumpSTART) algorithm for the triage of pediatric patients in a mass-casualty incident (MCI) requires assessing the results of each step and determining whether to move to the next appropriate action. Inappropriate application can lead to performance of unnecessary actions or failure to perform necessary actions. Hypothesis/Problem To report overall accuracy and time required for triage, and to assess if the performance of unnecessary steps, or failure to perform required steps, in the triage algorithm was associated with inaccuracy of triage designation or increased time to reach a triage decision.

METHODS

Medical students participated in an MCI drill in which they triaged both live actors portraying patients and computer-based simulated patients to the four triage levels: minor, delayed, immediate, and expectant. Their performance was timed and compared to intended triage designations and a priori determined critical actions.

RESULTS

Thirty-three students completed 363 scenarios. The overall accuracy was 85.7% and overall mean time to assign a triage designation was 70.4 seconds, with decreasing times as triage acuity level decreased. In over one-half of cases, the student omitted at least one action and/or performed at least one action that was not required. Each unnecessary action increased time to triage by a mean of 8.4 seconds and each omitted action increased time to triage by a mean of 5.5 seconds. Discussion Increasing triage level, performance of inappropriate actions, and omission of recommended actions were all associated with increasing time to perform triage.

Comparison of Computerized Patients versus Live Moulaged Actors for a Mass-casualty Drill

INTRODUCTION

Multiple modalities for simulating mass-casualty scenarios exist; however, the ideal modality for education and drilling of mass-casualty incident (MCI) triage is not established. Hypothesis/Problem Medical student triage accuracy and time to triage for computer-based simulated victims and live moulaged actors using the pediatric version of the Simple Triage and Rapid Treatment (JumpSTART) mass-casualty triage tool were compared, anticipating that student performance and experience would be equivalent.

METHODS

The victim scenarios were created from actual trauma records from pediatric high-mechanism trauma presenting to a participating Level 1 trauma center. The student-reported fidelity of the two modalities was also measured. Comparisons were done using nonparametric statistics and regression analysis using generalized estimating equations.

RESULTS

Thirty-three students triaged four live patients and seven computerized patients representing a spectrum of minor, immediate, delayed, and expectant victims. Of the live simulated patients, 92.4% were given accurate triage designations versus 81.8% for the computerized scenarios (P=.005). The median time to triage of live actors was 57 seconds (IQR=45-66) versus 80 seconds (IQR=58-106) for the computerized patients (P<.0001). The moulaged actors were felt to offer a more realistic encounter by 88% of the participants, with a higher associated stress level.

CONCLUSION

While potentially easier and more convenient to accomplish, computerized scenarios offered less fidelity than live moulaged actors for the purposes of MCI drilling. Medical students triaged live actors more accurately and more quickly than victims shown in a computerized simulation.

Recent advances in medical device triage technologies for chemical, biological, radiological, and nuclear events

In 2010, the US Food and Drug Administration (Silver Spring, Maryland USA) created the Medical Countermeasures Initiative with the mission of development and promoting medical countermeasures that would be needed to protect the nation from identified, high-priority chemical, biological, radiological, or nuclear (CBRN) threats and emerging infectious diseases. The aim of this review was to promote regulatory science research of medical devices and to analyze how the devices can be employed in different CBRN scenarios. Triage in CBRN scenarios presents unique challenges for first responders because the effects of CBRN agents and the clinical presentations of casualties at each triage stage can vary. The uniqueness of a CBRN event can render standard patient monitoring medical device and conventional triage algorithms ineffective. Despite the challenges, there have been recent advances in CBRN triage technology that include: novel technologies; mobile medical applications ("medical apps") for CBRN disasters; electronic triage tags, such as eTriage; diagnostic field devices, such as the Joint Biological Agent Identification System; and decision support systems, such as the Chemical Hazards Emergency Medical Management Intelligent Syndromes Tool (CHEMM-IST). Further research and medical device validation can help to advance prehospital triage technology for CBRN events.

A modified simple triage and rapid treatment algorithm from the New York City (USA) Fire Department

INTRODUCTION

The objective of this study was to determine if modification of the Simple Triage and Rapid Treatment (START) system by the addition of an Orange category, intermediate between the most critically injured (Red) and the non-critical, non-ambulatory injured (Yellow), would reduce over- and under-triage rates in a simulated mass-casualty incident (MCI) exercise.

METHODS

A computer-simulation exercise of identical presentations of an MCI scenario involving a 2-train collision, with 28 case scenarios, was provided for triaging to two groups: the Fire Department of the City of New York (FDNY; n=1,347) using modified START, and the Emergency Medical Services (EMS) providers from the Eagles 2012 EMS conference (Lafayette, Louisiana USA; n=110) using unmodified START. Percent correct by triage category was calculated for each group. Performance was then compared between the two EMS groups on the five cases where Orange was the correct answer under the modified START system.

RESULTS

Overall, FDNY-EMS providers correctly triaged 91.2% of cases using FDNY-START whereas non-FDNY-Eagles providers correctly triaged 87.1% of cases using unmodified START. In analysis of the five Orange cases (chest pain or dyspnea without obvious trauma), FDNY-EMS performed significantly better using FDNY-START, correctly triaging 86.3% of cases (over-triage 1.5%; under-triage 12.2%), whereas the non-FDNY-Eagles group using unmodified START correctly triaged 81.5% of cases (over-triage 17.3%; under-triage 1.3%), a difference of 4.9% (95% CI, 1.5-8.2).

CONCLUSIONS

The FDNY-START system may allow providers to prioritize casualties using an intermediate category (Orange) more properly aligned to meet patient needs, and as such, may reduce the rates of over-triage compared with START. The FDNY-START system decreases the variability in patient sorting while maintaining high field utility without needing computer assistance or extensive retraining. Comparison of triage algorithms at actual MCIs is needed; however, initial feedback is promising, suggesting that FDNY-START can improve triage with minimal additional training and cost.

A Simple Graphical Method for Quantification of Disaster Management Surge Capacity Using Computer Simulation and Process-control Tools

INTRODUCTION

Surge capacity, or the ability to manage an extraordinary volume of patients, is fundamental for hospital management of mass-casualty incidents. However, quantification of surge capacity is difficult and no universal standard for its measurement has emerged, nor has a standardized statistical method been advocated. As mass-casualty incidents are rare, simulation may represent a viable alternative to measure surge capacity. Hypothesis/Problem The objective of the current study was to develop a statistical method for the quantification of surge capacity using a combination of computer simulation and simple process-control statistical tools. Length-of-stay (LOS) and patient volume (PV) were used as metrics. The use of this method was then demonstrated on a subsequent computer simulation of an emergency department (ED) response to a mass-casualty incident.

METHODS

In the derivation phase, 357 participants in five countries performed 62 computer simulations of an ED response to a mass-casualty incident. Benchmarks for ED response were derived from these simulations, including LOS and PV metrics for triage, bed assignment, physician assessment, and disposition. In the application phase, 13 students of the European Master in Disaster Medicine (EMDM) program completed the same simulation scenario, and the results were compared to the standards obtained in the derivation phase.

RESULTS

Patient-volume metrics included number of patients to be triaged, assigned to rooms, assessed by a physician, and disposed. Length-of-stay metrics included median time to triage, room assignment, physician assessment, and disposition. Simple graphical methods were used to compare the application phase group to the derived benchmarks using process-control statistical tools. The group in the application phase failed to meet the indicated standard for LOS from admission to disposition decision.

CONCLUSIONS

This study demonstrates how simulation software can be used to derive values for objective benchmarks of ED surge capacity using PV and LOS metrics. These objective metrics can then be applied to other simulation groups using simple graphical process-control tools to provide a numeric measure of surge capacity. Repeated use in simulations of actual EDs may represent a potential means of objectively quantifying disaster management surge capacity. It is hoped that the described statistical method, which is simple and reusable, will be useful for investigators in this field to apply to their own research.