Development and validation of a mass casualty conceptual model

Hospital, health, and community burden after oil refinery fires, Richmond, California 2007 and 2012

INTRODUCTION

Emergency Departments experience a significant census burst after disasters. The aim of this study is to describe patient presentations at Emergency Departments in Contra Costa County, California following chemical release incidents at an oil refinery in 2007 and 2012. Specific areas of focus include hospital and community burden with an emphasis on disease classes.

METHODS

Searching 4 weeks before through 4 weeks after each event, Emergency Department abstracts identified patients living in Contra Costa County and seeking care there or in neighboring Alameda County. City and ZIP-code of residence established proximity to the refinery. This provided the following contrast groups: Event (2007, 2012), time (before, after), location (bayside, rest of county), and within bayside, warned or not warned to shelter in place. Using the Multi-Level Clinical Classification Software, we classified primary health groups recorded 4 weeks before and after the events, then summarized the data, calculated rates, and made tables, graphs, and maps to highlight findings.

RESULTS

Number of visits meeting selection criteria totalled 105020 records. Visits increased modestly but statistically significantly after the 2007 incident. After the 2012 incident, two Emergency Departments took the brunt of the surge. Censuses increased from less than 600 a week each to respectively 5719 and 3072 the first week, with the greatest number 2 days post-event. It took 4 weeks for censuses to return to normal. The most common diagnosis groups that spiked were nervous/sensory, respiratory, circulatory, and injury. Bayside communities had statistically significant increases in residents seeking care. Specifically, visits of residents in warned communities nearest the refinery increased by a factor of 3.7 while visits of residents in other nearby un-warned communities increased by a factor of 1.5.

CONCLUSIONS

The 2012 Emergency Department census peaked in the first week and did not return to normal for 4 weeks. Diagnoses changed to reflect conditions associated with reactions to chemical exposures. Surrounding communities and nearby hospitals experienced significant emergent burdens. In addition to changes from such events in patient diagnoses and community burden, the discussion highlights the long-term implications of failures to require adequate monitoring and warning systems and failures of health planning.

Identifying Factors That May Influence Decision-Making Related to the Distribution of Patients During a Mass Casualty Incident

OBJECTIVE

We aimed to identify and seek agreement on factors that may influence decision-making related to the distribution of patients during a mass casualty incident.

METHODS

A qualitative thematic analysis of a literature review identified 56 unique factors related to the distribution of patients in a mass casualty incident. A modified Delphi study was conducted and used purposive sampling to identify peer reviewers that had either (1) a peer-reviewed publication within the area of disaster management or (2) disaster management experience. In round one, peer reviewers ranked the 56 factors and identified an additional 8 factors that resulted in 64 factors being ranked during the two-round Delphi study. The criteria for agreement were defined as a median score greater than or equal to 7 (on a 9-point Likert scale) and a percentage distribution of 75% or greater of ratings being in the highest tertile.

RESULTS

Fifty-four disaster management peer reviewers, with hospital and prehospital practice settings most represented, assessed a total of 64 factors, of which 29 factors (45%) met the criteria for agreement.

CONCLUSIONS

Agreement from this formative study suggests that certain factors are influential to decision-making related to the distribution of patients during a mass casualty incident. (Disaster Med Public Health Preparedness. 2018;12:101-108).

Paramedic Application of a Triage Sieve: A Paper-Based Exercise

Introduction Triage is the systematic prioritization of casualties when there is an imbalance between the needs of these casualties and resource availability. The triage sieve is a recognized process for prioritizing casualties for treatment during mass-casualty incidents (MCIs). While the application of a triage sieve generally is well-accepted, the measurement of its accuracy has been somewhat limited. Obtaining reliable measures for triage sieve accuracy rates is viewed as a necessity for future development in this area.

OBJECTIVE

The goal of this study was to investigate how theoretical knowledge acquisition and the practical application of an aide-memoir impacted triage sieve accuracy rates.

METHOD

Two hundred and ninety-two paramedics were allocated randomly to one of four separate sub-groups, a non-intervention control group, and three intervention groups, which involved them receiving either an educational review session and/or an aide-memoir. Participants were asked to triage sieve 20 casualties using a previously trialed questionnaire.

RESULTS

The study showed the non-intervention control group had a correct accuracy rate of 47%, a similar proportion of casualties found to be under-triaged (37%), but a significantly lower number of casualties were over-triaged (16%). The provision of either an educational review or aide-memoir significantly increased the correct triage sieve accuracy rate to 77% and 90%, respectively. Participants who received both the educational review and aide-memoir had an overall accuracy rate of 89%. Over-triaged rates were found not to differ significantly across any of the study groups.

CONCLUSION

This study supports the use of an aide-memoir for maximizing MCI triage accuracy rates. A "just-in-time" educational refresher provided comparable benefits, however its practical application to the MCI setting has significant operational limitations. In addition, this study provides some guidance on triage sieve accuracy rate measures that can be applied to define acceptable performance of a triage sieve during a MCI. Cuttance G , Dansie K , Rayner T . Paramedic application of a triage sieve: a paper-based exercise. Prehosp Disaster Med. 2017;32(1):3-13.

A validation study of 5 triage systems using data from the 2005 Graniteville, South Carolina, chlorine spill

INTRODUCTION

Lack of outcomes-based research results in uncertainty about the effectiveness of any of the current triage systems in determining priority of care during actual chemical disasters. The purpose of this study was to determine whether the level of injury severity extrapolated from 5 triage systems correlated with actual injury severity outcomes of victims exposed to a chlorine disaster.

METHODS

Using secondary data analysis, data for 631 victims were merged, de-identified, and analyzed. Using logic models from the triage systems, the actual injury severity was compared with the extrapolated injury severity classifications.

RESULTS

Analysis showed weak to modest correlations between the extrapolated injury severity triage outcome classifications and the actual injury severity outcomes (Spearman correlation range 0.38 to 0.71, P < .0001). There was slight to fair agreement between the extrapolated injury severity triage outcome classifications and the actual injury severity outcomes (weighted κ = - 0.23 to 0.42).

DISCUSSION

The extrapolated injury severity triage outcome categories from the 5 triage systems did not agree with the actual injury severity categories. Oxygen saturation measured by pulse oximetry provides early indications and is very predictive of outcome severity in incidents involving irritant chemical exposures such as chlorine, and should be a part of a mass casualty protocol for any irritant chemical incident. Additional research is needed to identify the most sensitive clinical measures for triaging victims of toxic inhalation disasters.

The impact of adaptive capacity on disaster response and recovery: evidence supporting core community capabilities

INTRODUCTION

The aim of this study was to determine if a relationship exists between the development of adaptive capacity and disaster response and recovery outcomes. Hospitals and health care systems are a critical element in community planning for all phases of the disaster cycle. There is a lack of research, however, to validate the relationship between the development of these capabilities and improved response and recovery outcomes. Hypothesis/Problem Two hypotheses were formulated to address the research question. The first hypothesis argued that counties or parishes that developed adaptive capacity through pre-event planning, community engagement, training, and the use of national response frameworks would have improved response and recovery performance outcomes. The second hypothesis argued that adaptive capacity, along with response and recovery performance outcomes, predicts the trajectory of recovery progression.

METHODS

This study employed a quantitative cross-sectional survey methodology and existing community demographic data to explore the development of adaptive capacity and its ability to predict disaster response and recovery outcomes in communities affected by major disaster in 2011. A total of 333 counties and parishes were included in the final sample, providing a 95% confidence interval with a 5% margin of error. Data were analyzed using both descriptive and inferential statistics. Multiple, hierarchical, and robust regression were used to find the best fitting model. Multi-level modeling with random intercepts was used to control for the nesting effects associated with county, state, and the Federal Emergency Management Agency (FEMA) region sampling.

RESULTS

Descriptive results provide a baseline assessment of adaptive capacity development at the community level. While controlling for other variables, hypothesis testing revealed that pre-event planning, community engagement, full-scale exercises, and use of national frameworks predicated overall response and recovery performance outcomes (R 2 = .43; F 13,303 = 13.34; P < .001). In terms of recovery progression, pre-event planning, overall response and recovery performance outcome, total time of disruption, and percent of people below poverty were significant (R 2 = .15; F14,302 = 4.53; P < .001).

CONCLUSIONS

Establishment of empirical data provides communities with reinforcement to continue resilience-building activities at the local level. However, findings from this study suggest that only full-scale exercises were significant in improving response and recovery outcomes. Implications for re-evaluation of disaster training warrant further exploration.

Surveillance and epidemiology in natural disasters: a novel framework and assessment of reliability

OBJECTIVE

To create a framework and methodology for organizing relevant disaster epidemiology literature. The target audience for the framework is local public health practitioners conducting emergency surveillance in the setting of preparedness or response to natural disasters.

METHODS

The approach to developing the framework involved utilizing the public health and emergency management literature. It was created along four axes. The first was the type of natural disaster; second was according to phase of disaster cycle; third was the impact of the disaster (health, infrastructure, economic); and fourth was related to the main outcome of the study (ie. injuries or infectious diseases). A literature review was conducted and subsequently the current literature was utilized to perform a reliability test of the established framework, using two independent reviewers.

RESULTS

Using existing disaster classification systems and risk analysis tools, a framework was developed along the four axes. The final literature search resulted in 85 articles on surveillance in natural disaster settings. The majority of studies are on the subject of hurricanes with a catastrophic impact rating. The phase of testing reliability of the framework resulted in percent agreement of 74%.

CONCLUSIONS

A reliable framework was developed that enables local public health practitioners to easily access appropriate and previously utilized surveillance methods for a natural disaster emergency. This framework contributes to an evidence-informed approach to surveillance in natural disasters with public health impacts.

Gleaning data from disaster: a hospital-based data mining method to study all-hazard triage after a chemical disaster

OBJECTIVE

To describe the methods of evaluating currently available triage models for their efficacy in appropriately triaging the surge of patients after an all-hazards disaster.

DESIGN

A method was developed for evaluating currently available triage models using extracted data from medical records of the victims from the Graniteville chlorine disaster.

SETTING

On January 6, 2005, a freight train carrying three tanker cars of liquid chlorine was inadvertently switched onto an industrial spur in central Graniteville, SC. The train then crashed into a parked locomotive and derailed. This caused one of the chlorine tankers to rupture and immediately release ~60 tons of chlorine. Chlorine gas infiltrated the town with a population of 7,000.

PARTICIPANTS

This research focuses on the victims who received emergency care in South Carolina.

RESULTS

With our data mapping and decision tree logic, the authors were successful in using the available extracted clinical data to estimate triage categories for use in our study.

CONCLUSIONS

The methodology outlined in this article shows the potential use of well-designed secondary analysis methods to improve mass casualty research. The steps are reliable and repeatable and can easily be extended or applied to other disaster datasets.

A review of the literature on the validity of mass casualty triage systems with a focus on chemical exposures

INTRODUCTION

Mass casualty incidents (MCIs) include natural (eg, earthquake) or human (eg, terrorism or technical) events. They produce an imbalance between medical needs and resources necessitating the use of triage strategies. Triage of casualties must be performed accurately and efficiently if providers are to do the greatest good for the greatest number. There is limited research on the validation of triage system efficacy in determining the priority of care for victims of MCI, particularly those involving chemicals.

OBJECTIVE

To review the literature on the validation of current triage systems to assign on-site treatment status codes to victims of mass casualties, particularly those involving chemicals, using actual patient outcomes.

METHODS

The focus of this article is a systematic review of the literature to describe the influences of MCIs, particularly those involving chemicals, on current triage systems related to the on-site assignment of treatment status codes to a victim and the validation of the assigned code using actual patient outcomes.

RESULTS

There is extensive literature published on triage systems used for MCI but only four articles used actual outcome data to validate mass casualty triage outcomes including three for chemical events. Currently, the amount and type of data collected are not consistent or standardized and definitions are not universal.

CONCLUSIONS

Current literature does not provide needed evidence on the validity of triage systems for MCI in particular those involving chemicals. Well designed studies are needed to validate the reliability, sensitivity, and specificity of triage systems used for MCI including those involving chemicals.

Mental health triage tools for medically cleared disaster survivors: an evaluation by MRC volunteers and public health workers

OBJECTIVE

Psychological assessment after disasters determines which survivors are acutely distressed or medically compromised and what kind of assistance is needed (whether practical or psychological). A mental health triage tool can help direct more people to the appropriate type of help. The purpose of this study was to determine the effectiveness of the Fast Mental Health Triage Tool (FMHT) and the Alsept-Price Mental Health Scale (APMHS) among public health workers and Medical Reserve Corps (MRC) volunteers in conducting mental health triage. Both tools screen for ability to follow simple commands, chronic medical conditions, mental health conditions and services, occult injuries, and traumatic events in the past year. Both were designed for use in disasters where mental health resources are scarce and survivors are already medically triaged.

METHODS

Volunteers (n = 204) and workers (n = 66) were randomized into 3 groups, with 79 participating. Fifty-nine raters completed 20 each of 1180 mental health clinical vignettes of disaster survivors.

RESULTS

The survey presenting the vignettes was highly reliable at 0.771; the study model was parallel between baseline and treatment; and the interclass correlation among the raters was high at 0.852. Each rater triaged the same cases, but the rater was randomly assigned to use FMHT, APMHS, or no tool or scale. Between-subject effect for the tools used was significant (P = .039). The FMHT was significantly better than no tool in correct mental health triage, 67.3% to 51.5% (P = .028).

CONCLUSION

The incorporation of a temporal component should be evaluated for potential inclusion in existing mental health triage systems.