Admission rates and outcomes of elderly patients in emergency department observation units. A Spanish multicentre study

Background: Emergency Department Observation Units (EDOUs) provide short-term treatment and monitoring for patients who require further evaluation. EDOUs may help reduce unnecessary hospital admissions in elderly adults, but their selection criteria and impact on outcomes remain unclear. The study, thus, aimed to identify clinical factors associated with using EDOUs in patients aged ≥65 years and to evaluate the relationship between EDOU care and short-term clinical outcomes. Methods: We analysed data from the Emergency Department and Elder Needs (EDEN) cohort, which included all emergency department visits by patients aged ≥65 years across 48 Spanish hospitals during seven days. We divided patients into two groups: those managed in an EDOU (EDOU group) and those managed without observation care (non-EDOU group). We examined demographic and clinical characteristics, emergency diagnoses, and 30-day outcomes. Multivariable logistic regression identified factors independently associated with EDOU use and subsequent outcomes. Results: Among 23,955 visits, 6393 (26.7%) involved EDOU management. Patients in the EDOU group were more likely to be ≥80 years and to present with tachypnoea, bradycardia, a Glasgow Coma Scale score <15, and anaemia. These variables showed significant independent associations with EDOU care. Compared to the non-EDOU group, the EDOU group had higher rates of hospital admission (adjusted odds Ratio (aOR) = 2.4; 95% confidence interval (CI): 2.0–2.8) and 30-day readmission (aOR = 1.6; 95% CI: 1.2–2.3), but similar rates of 30-day ED revisit, prolonged hospital stay, and mortality. Patient selection varied across centres and often lacked standardized protocols. Conclusions: EDOU care for elderly adults in Spanish emergency departments typically involves patients with greater clinical complexity. Although associated with higher hospital admission and readmission rates, EDOU use did not correlate with worse short-term outcomes. These findings support the need for standardized EDOU admission criteria in geriatric populations.

Emergency department; Observation unit; Older adults; Geriatric emergency care; Hospital admission; Short-term outcomes

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