Predictive Factors of Emergency Department Length of Stay: Analyzing National Emergency Department Data.

OBJECTIVE: This study aimed to identify and analyze the factors influencing Emergency Department Length of Stay (ED LOS) using a nationwide database to improve emergency care efficiency. METHODS: This retrospective study utilized data from the National Emergency Department Information System (NEDIS) in South Korea, covering 25,578,263 ED visits from 2018 to 2022. Patient demographics, clinical characteristics, and ED operational variables were examined. The study employed univariate and multivariate logistic regression analyses to assess the association between these factors and prolonged ED LOS, defined as six hours or more. RESULTS: Among the 25,578,263 patients included, median ED LOS was 2.1 hours (interquartile range [IQR], 1.050 - 3.830 hours), with 12.6% experienced a prolonged ED LOS. Elderly patients (aged ≥ 65 years) were significantly more likely to experience prolonged ED LOS (adjusted odds ratio [aOR]: 1.415, 95% confidence interval [CI]: 1.411-1.419). Patients transferred from other hospitals (aOR: 1.469, 95% CI: 1.463-1.474) and those arriving by 119 ambulances (aOR: 1.093, 95% CI: 1.077-1.108) also had higher odds of prolonged LOS. Conversely, pediatric patients had a lower likelihood of extended stays (aOR: 0.682, 95% CI: 0.678-0.686). Severe illness, including sepsis (aOR: 1.324, 95% CI: 1.311-1.340) and COVID-19 infection (aOR: 1.413, 95% CI: 1.399-1.427), were strongly associated with prolonged LOS. CONCLUSION: Prolonged ED LOS is influenced by a combination of patient demographics, clinical severity, and systemic factors. Targeted interventions focusing on older adults, severe illness, and operational inefficiencies, such as hospital transfers, are essential for reducing ED LOS and improving overall emergency care delivery.