The association between emergency department length of stay and hospital length of stay: an observational multi-centre cohort study.

Prolonged emergency department (ED) length of stay (LOS) is associated with ED crowding which is linked to mortality in healthcare systems with relatively long ED LOS. We hypothesized that even in systems with shorter ED LOS, prolonged ED LOS is also associated with increased hospital LOS, particularly in older and urgently triaged patients. This study assesses the association between ED LOS and hospital LOS ≥ 3 days in patients older and younger than 70 years, categorized by triage urgency. Observational multicentre cohort study including all hospitalized ED patients from the Netherlands Emergency department Evaluation Database (NEED), stratified by age and triage category. The NEED contains data from seven EDs of two tertiary care centres and four urban hospitals. Multivariable logistic regression analyses were employed to calculate Adjusted Odds Ratios (AOR) for the association between ED LOS and hospital LOS ≥ 3 days, adjusting for confounders. Of the 718,358 patients 258,636 adults were hospitalized. Median ED LOS of hospitalized patients was 3.30 h (95% CI 3.30-3.31), while median hospital LOS was 3.0 (95% CI 2.98-3.02) days; 12,511 patients (2%) died. Patients with ED LOS of 4-8 and > 8 h had AORs for hospital LOS ≥ 3 days of 1.39 (95% CI 1.36-1.41) and 1.58 (95% CI 1.50-1.66), respectively, compared to patients with ED LOS < 4 h. In the Dutch healthcare system, which has a relatively short ED LOS, prolonged ED LOS is associated with an increased hospital LOS. This association appears to be more pronounced in patients who are younger and triaged less urgent.