Determinants of Severely Prolonged Emergency Department Stays Among Older Adults: A Retrospective Comparative Analysis.

Objective: Prolonged emergency department (ED) stays are linked to adverse outcomes in older adults. This study examined the clinical characteristics and determinants of severely prolonged ED stays in a large tertiary hospital in China. Methods: A retrospective cohort study was conducted at a tertiary hospital in Zhejiang Province, including 652 adult patients with ED boarding ≥ 72 h between January 1 and December 31, 2024. Patients were stratified into geriatric (≥ 60 years) and nongeriatric groups for descriptive comparison. Logistic regression analyses were performed to identify independent predictors of severely prolonged stays (> 96 h) among geriatric patients. Results: Among all included patients, 73.3% were geriatric. Compared with nongeriatric patients, older adults had significantly higher rates of multimorbidity and nutritional risk and were less likely to arrive at night. Multivariate analysis showed that advanced age, nighttime arrival, nutritional risk, and infection were independent risk factors for severely prolonged ED stays, while multidisciplinary consultation significantly reduced risk. Conclusion: Severely prolonged ED stays among older adults are driven by both patient-level vulnerabilities and system-level constraints. Early nutritional screening, timely infection management, and multidisciplinary collaboration may help reduce boarding time and optimize care for aging populations.