Factors associated with the disposition of severely injured patients initially seen at non–trauma center emergency departments: disparities by insurance status.

Importance: Trauma is the leading cause of potential years of life lost before age 65 years in the United States. Timely care in a designated trauma center has been shown to reduce mortality by 25%. However, many severely injured patients are not transferred to trauma centers after initially being seen at non–trauma center emergency departments (EDs).
Objectives: To determine patient-level and hospital-level factors associated with the decision to admit rather than transfer severely injured patients who are initially seen at non–trauma center EDs and to ascertain whether insured patients are more likely to be admitted than transferred compared with uninsured patients.
Design, Setting, and Participants: Retrospective analysis of the 2009 Nationwide Emergency Department Sample. We included all ED encounters for major trauma (Injury Severity Score, >15) seen at non–trauma centers in patients aged 18 to 64 years. We excluded ED discharges and ED deaths. We quantified the absolute risk difference between admission vs transfer by insurance status, while adjusting for age, sex, mechanism of injury, Injury Severity Score, weekend admission and month of visit, and urban vs rural status and median household income of the home zip code, as well as annual ED visit volume and teaching status and US region.
Main Outcomes and Measures: Inpatient admission vs transfer to another acute care facility.
Results: In 2009, a total of 4513 observations from 636 non–trauma center EDs were available for analysis, representing a nationally weighted population of 19,312 non–trauma center ED encounters for major trauma. Overall, 54.5% in 2009 were admitted to the non–trauma center. Compared with patients without insurance, the adjusted absolute risk of admission vs transfer was 14.3% (95% CI, 9.2%-19.4%) higher for patients with Medicaid and 11.2% (95% CI, 6.9%-15.4%) higher for patients with private insurance. Other factors associated with admission vs transfer included severe abdominal injuries (risk difference, 15.9%; 95% CI, 9.4%-22.3%), urban teaching hospital vs non–teaching hospital (risk difference, 26.2%; 95% CI, 15.2%-37.2%), and annual ED visit volume (risk difference, 3.4%; 95% CI, 1.6%-5.3% higher for every additional 10,000 annual ED visits).
Conclusions and Relevance: Patients with severe injuries initially evaluated at non–trauma center EDs were less likely to be transferred if insured and were at risk of receiving suboptimal trauma care. Efforts in monitoring and optimizing trauma interhospital transfers and outcomes at the population level are warranted.