Comparative study of ED mortality risk of US trauma patients treated at level I and level II vs nontrauma centers

• Published in: The American journal of emergency medicine 2015-09, Vol.33 (9), p.1158-1165
• Main Authors: Vickers, Brian P., BS, Shi, Junxin, MD, PhD, Lu, Bo, PhD, Wheeler, Krista K., MS, Peng, Jin, MD, MS, Groner, Jonathan I., MD, Haley, Kathryn J., MS, BSN, RN, Xiang, Huiyun, MD, MPH, PhD
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age; Chronic illnesses; Comorbidity; Comparative studies; Emergency; Emergency medical care; Emergency medical services; Emergency Service, Hospital; Female; Health risks; Humans; Injuries; Injury Severity Score; Logistic Models; Male; Medicaid; Medicare; Middle Aged; Mortality; Mortality risk; Risk Factors; Sensitivity analysis; Studies; Trauma; Trauma care; Trauma Centers; Triage; United States - epidemiology; Wounds and Injuries - mortality; Young Adult
• ISSN: 0735-6757; 1532-8171
• DOI: 10.1016/j.ajem.2015.05.010

Abstract Background Prior studies of undertriage have not made comparisons across multiple trauma levels. Methods Emergency department data was extracted from the Nationwide Emergency Department Sample for major trauma patients. We considered patients with moderate injuries (Injury Severity Score, ISS=16-24) and severe injuries (ISS=25-75) separately. Conditional logistic regression modeling was used to compare the odds of ED mortality for level I trauma centers (TC I) vs. nontrauma centers (NTC) and level II trauma centers (TC II) vs. NTC. An innovative 1:1:1 optimal matching (an extension of the traditional pair matching) was used to balance patient characteristics in three groups. To facilitate matching of all NTC patients, 3 subgroups were developed for ISS=16-24 and 2 subgroups for ISS=25-75. Sensitivity analyses were performed to assess the strength of the association between trauma center designation and ED mortality. Results For ISS=16-24, 2 of 3 subgroups had marginally significant reduced odds of ED mortality when properly triaged (TC I vs. NTC [T1:OR=0.63; 95%CI: 0.45 - 0.89, T2:OR=0.71;95%CI:0.51-0.99]). For ISS=25-75, both subgroups had significantly reduced odds of emergency department mortality when properly triaged (H1: TC I vs. NTC [OR=0.61; 95%CI: 0.50-0.74]; TC II vs. NTC [OR=0.49; 95%CI: 0.38 - 0.63]; H2: TC I vs. NTC [OR=0.50; 95%CI: 0.41 - 0.60]; TC II vs. NTC [OR=0.42; 95%CI: 0.33 - 0.53]). Conclusions for ISS 25-75 were robust to a hypothesized unobserved confounding variable as shown in sensitivity analysis. Conclusions Trauma patients with ISS≥25 received most benefit from proper triage. Efforts to reduce undertriage should focus on this population.