Delirium in Older Adults Presenting to the Emergency Department: Prevalence, Risk Factors, Management Strategies, and Hospital Utilization Outcomes.

Abstract

Despite the emergency department (ED) being a primary entry point for acutely ill older adults, delirium in this setting remains poorly characterized. This study aimed to determine ED delirium prevalence, identify associated patient characteristics in a diverse population, describe current ED management practices, and examine hospital utilization outcomes in a large, heterogeneous cohort. This multi-site retrospective cohort study analyzed 2,827 older adult patients (≥ 65 years) across three diverse EDs within a single integrated health system in the New York metropolitan area, identifying delirium via rigorous, validated in-depth chart review requiring evidence of acute change from baseline. Independent risk factors for ED delirium and hospital admission were identified via modified Poisson regression. Management strategies and 30-day hospital utilization outcomes were characterized. All analyses were stratified by control and intervention periods of a parent delirium screening trial. ED delirium prevalence was 16.0% (95% confidence interval: 14.6-17.4%), consistent across study periods and sites. The prevalence of delirium was 27.3% among hospitalized patients; 7.9% of all discharged patients had delirium. Independent risk factors included advanced age (adjusted relative risk, aRR = 1.01), dementia (aRR = 3.10), higher Charlson Comorbidity Index (aRR = 1.06), facility arrival (aRR = 1.28), and higher ED acuity (aRR = 3.85 for highest). Patients with delirium were more likely to receive physical restraints, psychoactive medications, and constant observation, but also safety precautions, family involvement, and palliative care consults (all p < 0.001). Delirium independently predicted hospital admission (aRR = 1.54) and was associated with higher 30-day readmissions (19% vs. 13%; p = 0.002). Approximately 1 in 6 older ED patients had delirium, including 7.9% who were discharged home. ED management involved both restrictive (restraints, psychoactive medications) and supportive (Goals-of-Care discussions, family involvement, safety precautions) strategies, though the latter remained underutilized. These findings underscore the critical need for standardized delirium screening, enhanced recognition, and supportive strategies.