摘要BACKGROUND: We aimed to explore the impact of the emergency department length of stay (EDLOS) on the outcome of trauma patients. METHODS: A retrospective study was conducted on all trauma patients requiring hospitalization between 2015 and 2019. Patients were categorized into 4 groups based on the EDLOS (<4 h, 4–12 h,12–24 h, and >24 h). Data were analyzed using Chi-square test (categorical variables), Student's t-test (continuous variables), correlation coefficient, analysis of variance and multivariate logistic regression analysis for identifying predictors of short EDLOS and hospital mortality. RESULTS: The study involved 7,026 patients with a mean age of 32.1±15.6 years. One-fifth of patients had a short EDLOS (<4 h) and had higher level trauma team T1 activation (TTA-1), higher Injury Severity Score (ISS), higher shock index (SI), and more head injuries than the other groups (P=0.001). Patients with an EDLOS >24 h were older (P=0.001) and had more comorbidities (P=0.001) and fewer deaths (P=0.001). Multivariate regression analysis showed that the predictors of short EDLOS were female gender, GCS, SI, hemoglobin level, ISS, and blood transfusion. The predictors of mortality were TTA-1 (odds ratio [OR]=4.081, 95％CI: 2.364–7.045), head injury (OR=3.920, 95％CI: 2.413–6.368), blood transfusion (OR=2.773, 95％CI: 1.668–4.609), SI (OR=2.132, 95％CI: 1.364–3.332), ISS (OR=1.077, 95％CI: 1.057–1.096), and age (OR=1.040, 95％CI: 1.026–1.054). CONCLUSIONS: Patients with shorter EDLOS had different baseline characteristics and hospital outcomes compared with patients with longer EDLOS. Patients with prolonged EDLOS had better outcomes; however, the burden of prolonged boarding in the ED needs further elaboration.