The Epidemiology of Emergency Department Trauma Discharges in the United States.

Objective Injury related morbidity and mortality is an important emergency medicine and public health challenge in the United States (US). Here we describe the epidemiology of traumatic injury presenting to US emergency departments, define changes in types and causes of injury among the elderly and the young, characterize the role of trauma centers and teaching hospitals in providing emergency trauma care, and estimate the overall economic burden of treating such injuries. Methods We conducted a secondary retrospective, repeated cross-sectional study of the Nationwide Emergency Department Data Sample (NEDS), the largest all-payer emergency department survey database in the US. Main outcomes and measures were survey-adjusted counts, proportions, means, and rates with associated standard errors, and 95% confidence intervals. We plotted annual age-stratified emergency department discharge rates for traumatic injury and present tables of proportions of common injuries and external causes. We modeled the association of Level 1 or 2 trauma center care with injury fatality using a multi-variable survey-adjusted logistic regression analysis that controlled for age, gender, injury severity, comorbid diagnoses, and teaching hospital status. Results There were 181,194,431 (standard error, se = 4234) traumatic injury discharges from US emergency departments between 2006 and 2012. There was an average year-to-year decrease of 143 (95% CI -184.3, -68.5) visits per 100,000 US population during the study period. The all-age, all-cause case-fatality rate for traumatic injuries across US emergency departments during the study period was 0.17% (se = 0.001). The case-fatality rate for the most severely injured averaged 4.8% (se = 0.001), and severely injured patients were nearly four times as likely to be seen in Level 1 or 2 trauma centers (relative risk = 3.9 (95% CI 3.7, 4.1)). The unadjusted risk ratio, based on group counts, for the association of Level 1 or 2 trauma centers with mortality was RR = 4.9 (95% CI 4.5, 5.3), however, after accounting for gender, age, injury severity and comorbidities, Level 1 or 2 trauma centers were not associated with an increased risk of fatality (odds ratio = 0.96 (0.79, 1.18)). There were notable changes at the extremes of age in types and causes of emergency department discharges for traumatic injury between 2009 and 2012. Age-stratified rates of diagnoses of traumatic brain injury increased 29.5% (se = 2.6) for adults older than 85, and increased 44.9% (se = 1.3) for children younger than 18. Firearm related injuries increased 31.7% (se = 0.2) in children five years and younger. The total inflation-adjusted cost of emergency department injury care in the US between 2006 and 2012 was $99.75 billion (se = 0.03). Conclusions Emergency departments are a sensitive barometer of the continuing impact of traumatic injury as an important cause of morbidity and mortality in the US. Level 1 or 2 trauma centers remain a bulwark against the tide of severe trauma in the US. But, the types and causes of traumatic injury in the US are changing in consequential ways, particularly at the extremes of age, with traumatic brain injuries and firearm-related trauma presenting increased challenges. This article is protected by copyright. All rights reserved.