Abstract 100: In-Hospital Delirium and Long-Term Cognitive Outcomes Among Patients With Ischemic Stroke: A Population-Based Cohort Analysis

Abstract

Introduction: Evidence of association between delirium during initial hospitalization of ischemic stroke (IS) patients, and development of long-term mild cognitive impairment or dementia (MCID) is lacking. We examined the prospective incident risk of MCID among IS patients who experienced in-hospital delirium in a large multi-state population-based cohort. Methods: We utilized NY, CA, and FL (2005 - 2014) State Inpatient and Emergency Department Databases, and established a cohort by selecting MCID free patients with a primary diagnosis of IS (ICD-9: 433.x1, 434.x1, 436) during a 2yr period. Delirium during the initial IS event was tagged using a validated algorithm with high specificity for the confusion assessment method. The cohort was followed for MCID diagnoses. Patients that died within 90 days of initial IS event were excluded. We conducted time-to-event analyses and report cumulative incidence, 95% Confidence Interval (CI) and hazard ratios (HR) for risk of MCID among IS patients with and without delirium. Results: A total of 133,815 IS patients (age: 70.5, female: 51.7%, white: 65.5%) were followed for up to 8yrs, resulting in 357,500 person-years. Patients who experienced delirium were significantly older and had a higher comorbidity burden. A significantly smaller proportion of delirium patients underwent IV or IA thrombolysis. Cumulative incidence (95% CI) for development of MCID was significantly higher among delirium patients (9.01, 8.32 - 9.74) as compared to non-delirium patients (3.99, 3.93 - 4.06). Likewise, the HR for MCID among delirium patients was statistically significant (1.86, 1.71 - 2.02) in the fully adjusted Cox proportional model (Figure). Conclusion: In-hospital delirium was independently associated with a higher risk of developing MCID in this large population-based cohort. Further investigation is warranted to elucidate the mechanistic basis for the role of delirium in long-term cognitive decline among IS patients.