Overnight Stay in the Emergency Department and In-Hospital Mortality Among Elderly Patients: A 6-Year Follow-Up Italian Study

<b>Background/Objectives:</b> Due to challenges in securing hospital beds, elderly patients may face prolonged emergency department (ED) stays. Recent studies have highlighted an association between ED overnight stays (EDOSs) before admission and increased mortality. This study aimed to evaluate the potential impact of EDOSs on mortality among elderly patients awaiting a regular bed in a standard hospital ward. <b>Methods:</b> This monocentric, retrospective study included subjects ≥ 75 years who required urgent hospitalization between 2017 and 2022. Two groups were compared: patients hospitalized between 00:00 and 08:00 following an ED overnight stay (EDOS group), and those admitted directly to conventional medical units between 08:00 and 00:00 (Ward group). The primary outcome was in-hospital mortality 30 days after ED visit. <b>Results</b>: Among the 20,009 patients included (median age: 85 years [IQR: 80-89]), 3064 (15.3%) belonged to the EDOS group, while 16,945 (84.7%) were in the Ward group. In-hospital mortality occurred in 3020 cases (15.1%), with no significant differences observed between the groups. The variables identified by the logistic model as predictors of mortality included age > 85 years, Charlson Comorbidity Index (CCI) ≥ 5, National Early Warning Score (NEWS) > 6 at arrival, infectious diseases, respiratory diseases, and circulatory system diseases, yielding an accuracy of 0.700 ± 0.007. EDOS while awaiting inpatient beds was not a predictor of mortality. <b>Conclusions</b>: The results of our study did not show an association between mortality and EDOS, even when considering the large sample size collected over 6 years and the varying percentages of patients awaiting hospital beds.