Abstract DP204: Prolonged Emergency Department Boarding and Delirium Incidence in Older Patients with Acute Ischemic Stroke

Introduction: Timeliness of acute and sub-acute stroke care are crucial for optimizing post-stroke recovery. We investigated whether emergency department (ED) boarding (i.e., holding admitted patients in the ED while awaiting an inpatient bed) was associated with incident delirium among older acute ischemic stroke (AIS) patients. Methods: Clinical data was abstracted for AIS patients (aged ≥70 years) treated in the ED at a 7-hospital stroke certified health system and subsequently admitted for an inpatient stay (Jan 2018 to Jul 2025). Patients initially held for observation or transferred to specialty units were excluded. ED boarding durations (wait times) were calculated using timestamps corresponding to when admit decisions were made and when patients ultimately departed the ED for an available bed. ED boarding was categorized as short (<2 hours), moderate (between 2-4 hours), or extended (4+ hours). Outcomes included positive delirium screens (via 12-hour assessments), which were distinguished as: 1) present-on-admission (D-POA) within 48 hours of inpatient arrival, or 2) hospital-acquired (HAD). Multivariable logistic regression was used to evaluate associations between ED boarding with D-POA or HAD, while accounting for stroke severity, treatment, patient acuity, and pertinent factors. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) are reported. Results: The overall cohort consisted of 7,214 AIS patients admitted from the ED (median age: 79.0 years; 56.9% female; median length of stay: 4.0 days) (Table 1). Prolonged ED boarding after admit decision was frequent, with a total of 4,130 (57.2%) having wait times over 2 hours. Proportionately, patients with short wait times presented with greater frequency of moderate to severe strokes than those with extended wait times (45.8% vs 40.8%); patients in serious to critical condition were also more frequent (8.5% vs 5.2%). Compared to patients with short ED boarding wait times, the odds of HAD were significantly increased for those with wait times of both moderate (aOR: 1.56, CI: 1.09-2.24) and extended duration (aOR: 1.81, CI: 1.28-2.59) (Figure 1). ED boarding was not associated with D-POA. Conclusions: Prolonged ED boarding is common and strongly associated with increased risks of in-hospital delirium. System-wide strategies to optimize hospital resources and minimize delays in care transitions are warranted to prevent further adverse events during the sub-acute phase of stroke recovery.