Factors associated with emergency department length of stay and in-hospital mortality in critically ill patients admitted to the intensive care unit from the emergency department: a nationwide analysis

Background: Prolonged emergency department length of stay (EDLOS) in critically ill patients leads to adverse outcomes, including an increased mortality risk. This nationwide study investigated patient and hospital characteristics associated with prolonged EDLOS and in-hospital mortality in adult patients admitted from the emergency department (ED) to the intensive care unit (ICU). Methods: We conducted a retrospective cohort study using data from the National Emergency Department Information System. Prolonged EDLOS was defined as an EDLOS of 6 h or more. We constructed multivariate logistic regressions to model the effects of patient and hospital variables as predictors of prolonged EDLOS and in-hospital mortality risk. Results: : Between 2016 and 2019, 657,622 adult patients were admitted to the ICU from the ED, representing 2.4% of all ED presentations. The median EDLOS of the overall study population was 3.3 h (interquartile range, 1.9–6.1 h). In total, 25.3% of patients had prolonged EDLOS. Patient characteristics associated with prolonged EDLOS included night-time ED presentation, assignment of initial triage to less urgency, and one or more comorbidities. Hospital characteristics associated with prolonged EDLOS included a higher number of staffed beds and a higher ED level. Prolonged EDLOS was associated with in-hospital mortality after adjustment for selected confounders (adjusted odds ratio,1.18; 95% confidence interval CI, 1.16–1.20). Patient characteristics associated with in-hospital mortality included age ≥ 65 years, transferred-in, mechanical ventilation in the ED, assignment of initial triage to more urgency, and one or more comorbidities. Hospital characteristics associated with in-hospital mortality included a lower number of staffed beds and a lower ED level. Conclusions: : In this nationwide analysis, 25.3% of critically ill patients admitted to the ICU from the ED had a prolonged EDLOS, which in turn was significantly associated with an increased in-hospital mortality risk. Hospital characteristics were also associated with prolonged EDLOS and in-hospital mortality, including the number of staffed beds and the ED level.