Abstract A138: Nighttime Interruptions and Hospital-Acquired Delirium among Older Patients with Acute Ischemic Stroke: Analysis of Overnight Clinical Workflow Impacts on Patient Restfulness and Outcomes

Introduction: Achieving restfulness in the hospital environment is increasingly recognized as a patient-centered goal. We investigated whether clinical workflow-related nighttime interruptions impact hospital-acquired delirium (HAD) and discharge outcomes among older acute ischemic stroke (AIS) patients. Methods: We analyzed AIS patients aged ≥ 70 years across 7 stroke-certified hospitals (Jan 2018 to Jul 2025). Inclusion criteria were absence of delirium on admission and 2+ nights of hospital stay. Nighttime interruptions (10PM to 5AM) were extracted from EMR entries related to documentation of imaging, lab draws, medication administration, vital measurements, and hygiene care. A restful night was defined as 4+ uninterrupted hours. Overall restfulness was scaled for the hospital visit (percentage of total nights considered restful) and categorized as high (>75% restful nights), moderate (50-75%), or low (<50%). Outcomes included HAD (via routine 12-hour screening) as well as discharge to skilled nursing or long-term care (SNF/LTAC). For all analyses, patients were tracked from inpatient admission to the first HAD or discharge event. Only night shifts with reasonable rest opportunity were considered. Associations between nighttime interruptions and outcomes were evaluated using multivariable logistic regression (accounting for pertinent stroke features). Adjusted odds ratios (OR) and 95% confidence intervals (CI) are reported. Results: A total of 5,043 older AIS patients met criteria (median age: 77.0 years; 53.7% female; median length of stay: 3.0 days). Over 75% of participants experienced low restfulness, among whom 26.2% had a moderate to severe stroke and 15.2% developed HAD (Table 1). Compared to those achieving high restfulness, patients experiencing the least restfulness had over 7-fold higher odds of HAD (aOR: 7.16, CI: 3.61-16.90) and over 6-fold higher odds of discharge to SNF/LTAC (aOR: 6.25, CI: 3.26-13.90) (Figure 1). Furthermore, even achieving moderate levels of restfulness was still associated with sustained risks of HAD (aOR: 3.03, CI: 1.40-7.59) and SNF/LTAC discharge (aOR: 3.82, CI: 1.86-8.94). Conclusions: Nighttime interruptions are significantly associated with increased delirium incidence as well as discharge to institutionalized care. Strategies aimed at optimizing overnight clinical workflows (such as clustered care) may help hospitalized patients achieve adequate rest and yield benefits in post-stroke recovery trajectories.