N. Ewen Wang

Cost-Effectiveness of Helicopter Versus Ground Emergency Medical Services for Trauma Scene Transport in the United States

STUDY OBJECTIVE We determine the minimum mortality reduction that helicopter emergency medical services (EMS) should provide relative to ground EMS for the scene transport of trauma victims to offset higher costs, inherent transport risks, and inevitable overtriage of patients with minor injury. METHODS We developed a decision-analytic model to compare the costs and outcomes of helicopter versus ground EMS transport to a trauma center from a societal perspective during a patients lifetime. We determined the mortality reduction needed to make helicopter transport cost less than

Evaluating the Use of Existing Data Sources, Probabilistic Linkage, and Multiple Imputation to Build Population-based Injury Databases Across Phases of Trauma Care

100,000 and

The Affordable Care Act Reduces Emergency Department Use By Young Adults: Evidence From Three States

50,000 per quality-adjusted life-year gained compared with ground EMS. Model inputs were derived from the National Study on the Costs and Outcomes of Trauma, National Trauma Data Bank, Medicare reimbursements, and literature. We assessed robustness with probabilistic sensitivity analyses. RESULTS Helicopter EMS must provide a minimum of a 15% relative risk reduction in mortality (1.3 lives saved/100 patients with the mean characteristics of the National Study on the Costs and Outcomes of Trauma cohort) to cost less than

Characteristics of pediatric trauma transfers to a level i trauma center: implications for developing a regionalized pediatric trauma system in california.

100,000 per quality-adjusted life-year gained and a reduction of at least 30% (3.3 lives saved/100 patients) to cost less than

The trade-offs in field trauma triage: a multiregion assessment of accuracy metrics and volume shifts associated with different triage strategies.

50,000 per quality-adjusted life-year. Helicopter EMS becomes more cost-effective with significant reductions in patients with minor injury who are triaged to air transport or if long-term disability outcomes are improved. CONCLUSION Helicopter EMS needs to provide at least a 15% mortality reduction or a measurable improvement in long-term disability to compare favorably with other interventions considered cost-effective. Given current evidence, it is not clear that helicopter EMS achieves this mortality or disability reduction. Reducing overtriage of patients with minor injury to helicopter EMS would improve its cost-effectiveness.

Variability in Pediatric Utilization of Trauma Facilities in California: 1999 to 2005

OBJECTIVES The objective was to evaluate the process of using existing data sources, probabilistic linkage, and multiple imputation to create large population-based injury databases matched to outcomes. METHODS This was a retrospective cohort study of injured children and adults transported by 94 emergency medical systems (EMS) agencies to 122 hospitals in seven regions of the western United States over a 36-month period (2006 to 2008). All injured patients evaluated by EMS personnel within specific geographic catchment areas were included, regardless of field disposition or outcome. The authors performed probabilistic linkage of EMS records to four hospital and postdischarge data sources (emergency department [ED] data, patient discharge data, trauma registries, and vital statistics files) and then handled missing values using multiple imputation. The authors compare and evaluate matched records, match rates (proportion of matches among eligible patients), and injury outcomes within and across sites. RESULTS There were 381,719 injured patients evaluated by EMS personnel in the seven regions. Among transported patients, match rates ranged from 14.9% to 87.5% and were directly affected by the availability of hospital data sources and proportion of missing values for key linkage variables. For vital statistics records (1-year mortality), estimated match rates ranged from 88.0% to 98.7%. Use of multiple imputation (compared to complete case analysis) reduced bias for injury outcomes, although sample size, percentage missing, type of variable, and combined-site versus single-site imputation models all affected the resulting estimates and variance. CONCLUSIONS This project demonstrates the feasibility and describes the process of constructing population-based injury databases across multiple phases of care using existing data sources and commonly available analytic methods. Attention to key linkage variables and decisions for handling missing values can be used to increase match rates between data sources, minimize bias, and preserve sampling design.

Variation in Prehospital Use and Uptake of the National Field Triage Decision Scheme

The Affordable Care Act (ACA) extended eligibility for health insurance for young adults ages 19-25. This extension may have affected how young adults use emergency department (ED) care and other health services. To test the impact of the ACA on how young adults used ED services, we used 2009-11 state administrative records from California, Florida, and New York to compare changes in ED use in young adults ages 19-25 before and after the ACA provision was implemented with changes in the same period for people ages 26-31 (the control group). Following implementation of the ACA provision, the younger group had a decrease of 2.7 ED visits per 1,000 people compared to the older group--a relative change of -2.1 percent. The largest relative decreases were found in women (-3.0 percent) and blacks (-3.4 percent). This relative decrease in ED use implies a total reduction of more than 60,000 visits from young adults ages 19-25 across the three states in 2011. When we compared the probability of ever using the ED before and after implementation of the ACA provision, we found a minimal decrease (-0.4 percent) among the younger group compared to the older group. This suggests that the change in the number of visits was driven by fewer visits among ED users, not by changes in the number of people who ever visited the ED.

Predictors of hospitalization after an emergency department visit for California youths with psychiatric disorders.

BACKGROUND since California lacks a statewide trauma system, there are no uniform interfacility pediatric trauma transfer guidelines across local emergency medical services (EMS) agencies in California. This may result in delays in obtaining optimal care for injured children. OBJECTIVES this study sought to understand patterns of pediatric trauma patient transfers to the study trauma center as a first step in assessing the quality and efficiency of pediatric transfer within the current trauma system model. Outcome measures included clinical and demographic characteristics, distances traveled, and centers bypassed. The hypothesis was that transferred patients would be more severely injured than directly admitted patients, primary catchment transfers would be few, and out-of-catchment transfers would come from hospitals in close geographic proximity to the study center. METHODS this was a retrospective observational analysis of trauma patients ≤ 18 years of age in the institutional trauma database (2000-2007). All patients with a trauma International Classification of Diseases, 9th revision (ICD-9) code and trauma mechanism who were identified as a trauma patient by EMS or emergency physicians were recorded in the trauma database, including those patients who were discharged home. Trauma patients brought directly to the emergency department (ED) and patients transferred from other facilities to the center were compared. A geographic information system (GIS) was used to calculate the straight-line distances from the referring hospitals to the study center and to all closer centers potentially capable of accepting interfacility pediatric trauma transfers. RESULTS of 2,798 total subjects, 16.2% were transferred from other facilities within California; 69.8% of transfers were from the catchment area, with 23.0% transferred from facilities ≤ 10 miles from the center. This transfer pattern was positively associated with private insurance (risk ratio [RR] = 2.05; p < 0.001) and negatively associated with age 15-18 years (RR = 0.23; p = 0.01) and Injury Severity Score (ISS) > 18 (RR = 0.26; p < 0.01). The out-of-catchment transfers accounted for 30.2% of the patients, and 75.9% of these noncatchment transfers were in closer proximity to another facility potentially capable of accepting pediatric interfacility transfers. The overall median straight-line distance from noncatchment referring hospitals to the study center was 61.2 miles (IQR = 19.0-136.4), compared to 33.6 miles (IQR = 13.9-61.5) to the closest center. Transfer patients were more severely injured than directly admitted patients (p < 0.001). Out-of-catchment transfers were older than catchment patients (p < 0.001); ISS > 18 (RR = 2.06; p < 0.001) and age 15-18 (RR = 1.28; p < 0.001) were predictive of out-of-catchment patients bypassing other pediatric-capable centers. Finally, 23.7% of pediatric trauma transfer requests to the study institution were denied due to lack of bed capacity. CONCLUSIONS from the perspective an adult Level I trauma center with a certified pediatric intensive care unit (PICU), delays in definitive pediatric trauma care appear to be present secondary to initial transport to nontrauma community hospitals within close proximity of a trauma hospital, long transfer distances to accepting facilities, and lack of capacity at the study center. Given the absence of uniform trauma triage and transfer guidelines across state EMS systems, there appears to be a role for quality monitoring and improvement of the current interfacility pediatric trauma transfer system, including defined triage, transfer, and data collection protocols.

Gunshot injuries in children served by emergency services

BACKGROUND: National benchmarks for trauma triage sensitivity (>=95%) and specificity (>=50%) have not been rigorously evaluated across broad populations of injured patients. We evaluated the impact of different field triage schemes for identifying seriously injured patients across a range of sensitivity values. Impact metrics included specificity and number of undertriaged and overtriaged patients compared with current triage practices. METHODS: This was a retrospective cohort study of injured children and adults transported by 48 emergency medical service (EMS) agencies to 105 hospitals in 6 regions of the Western United States from 2006 through 2008. Hospital outcomes were probabilistically linked to EMS records through trauma registries, state discharge databases, and state emergency department databases. The primary outcome was an Injury Severity Score (ISS) of 16 or greater. We evaluated 40 field predictor variables, including 31 current field triage criteria, using classification and regression tree analysis and cross‐validation to generate estimates for sensitivity and specificity. RESULTS: A total of 89,261 injured patients were evaluated and transported by EMS providers during the 3‐year period, of whom 5,711 (6.4%) had ISS of 16 or greater. As the 95% sensitivity target for triage was approached (from the current value of 87.5%), decision tree complexity increased, specificity decreased (from 62.8% to 18.7%), and the number of triage‐positive patients without serious injury doubled (67,927 vs. 31,104). Analyses restricted to children and older adults were similar. The most consistent modification to the current triage algorithm to increase sensitivity without a major decrease in specificity was altering the Glasgow Coma Scale (GCS) score cutoff point from 13 or less to 14 or less (sensitivity increase to 90.4%). CONCLUSION: Reaching the field triage sensitivity benchmark of 95% would require a large decrease in specificity (increase in overtriage). A 90% sensitivity target seems more realistic and may be obtainable by modest changes to the current triage algorithm. LEVEL OF EVIDENCE: Diagnostic test, level II.

Deciphering the Use and Predictive Value of “EMS Provider Judgment” in Out-of-Hospital Trauma Triage: A Multi-site, Mixed Methods Assessment

STUDY OBJECTIVE We identify geographic, system, and socioeconomic differences between injured children cared for within and outside of state-designated trauma centers. METHODS This was a nonconcurrent observational study of a population-based sample from the California Office of Statewide Health Planning and Development Public Patient Discharge Database 1999 to 2005. Patients were 1 to 14 years of age, with International Classification of Diseases, Ninth Revision (ICD-9) diagnostic codes indicative of trauma. Injury Severity Scores were calculated from ICD-9 codes and categorized into severity categories. Outcomes were hospitalization in a trauma or nontrauma center. RESULTS Children with severe injury who resided 0 to 10, 11 to 25, 26 to 50, and more than 50 miles from a trauma center were hospitalized in these centers at rates of 80.0%, 71.2%, 51.4%, and 28.5%, respectively. Children with severe injury who were living in a county with a trauma center were hospitalized in these centers at rates of 78.8%, whereas children living in a county without a trauma center were hospitalized in trauma centers at rates of 39.0%. Children with severe injury and public, private non-health maintenance organization (HMO), and HMO insurance were hospitalized in trauma centers at rates of 77.7%, 68.0%, and 55.4%, respectively. Age, injury severity, insurance type, residence in a county with a trauma center, and proximity to a trauma center were identified as predictors of trauma center utilization by logistic regression. CONCLUSION We demonstrate considerable variation in the utilization pattern of trauma specialty care for children with moderate and severe injuries. Children with HMO and private insurance are cared for less often in trauma centers than those with public insurance, even after adjustment for other variables. Increased distance to a trauma center, as well as lack of trauma center within a county, also decreases trauma center utilization. These results suggest that assessing trauma center utilization patterns in total populations of children may identify opportunities for improved referral policies and practices as part of a larger effort to ensure high-quality trauma care for all children in need.