Factors that predict emergency department length of stay in analysis of national data

Objective This study used a nationwide database to identify and analyze factors that influence emergency department (ED) length of stay (LOS) and improve the efficiency of emergency care. Methods This retrospective study analyzed data from the National Emergency Department Information System (NEDIS) database in Korea: 25,578,263 ED visits from 2018 to 2022. Patient demographics, clinical characteristics, and ED operational variables were examined. Univariate and multivariate logistic regression analyses were used to assess the associations between the variables and prolonged ED LOS, defined as 6 hours or more. Results Among the 25,578,263 patients, the median ED LOS was 2.1 hours (interquartile range, 1.050–3.830 hours), with 12.6% experiencing a prolonged ED LOS. Elderly patients (aged ≥65 years) were significantly more likely than younger patients 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 emergency medical services (aOR, 1.093; 95% CI, 1.077–1.108) also had high odds of prolonged LOS. Conversely, pediatric patients had a low likelihood of extended stay (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), was strongly associated with prolonged LOS. Conclusion Prolonged ED LOS is influenced by a combination of patient demographics, clinical severity, and systemic factors. Targeted interventions for older adults, severe illness, and operational inefficiencies such as hospital transfers are essential for reducing ED LOS and improving overall emergency care delivery.