['The early resuscitation occurs in the emergency department (ED) where intensive care unit protocols do not always extend and monitoring capabilities vary. Our hypothesis is that increased ED length of stay (LOS) leads to increased hospital mortality in patients not undergoing immediate surgical intervention.', 'We examined all trauma activation admissions from January 2002 to July 2009 admitted to the Trauma Service (n = 3,973). Exclusion criteria were as follows: patients taken to the operating room within the first 2 hours of ED arrival, nonsurvivable brain injury, and ED deaths. Patients spending >5 hours in the ED were not included in the analysis because of significantly lower acuity and mortality.', 'Patients spent a mean of 3.2 hours ± 1 hour in the ED during their initial evaluation. Hospital mortality increases for each additional hour a patient spends in the ED, with 8.3% of the patients staying in the ED between 4 hours and 5 hours ultimately dying (p = 0.028). ED LOS measured in minutes is an independent predictor of mortality (odds ratio, 1.003; 95% confidence interval, 1.010-1.006; p = 0.014) when accounting for Injury Severity Score, Revised Trauma Score, and age. Linear regression showed that a longer ED LOS was associated with anatomic injury pattern rather than physiologic derangement.'] Is emergency department length of stay an independent predictor of hospital mortality in trauma activation patients?