PROJECT SUMMARY / ABSTRACT Adults aged 65 and older represent ~23 million (18%) annual Emergency Department (ED) visits. Delirium, an acute, fluctuating change in cognition with numerous modifiable and nonmodifiable risk factors, is prevalent in up to 35% of older adults in the ED. However, the incidence and time course of ED delirium is currently unknown. Prevention is the only effective treatment, yet only 40% of delirium cases in hospitalized older adults can be prevented, making prediction and early recognition of patients at-risk of incident delirium – such as in the ED – vital. Unfortunately, ED providers fail to recognize up to 83% of delirium cases, which can lead to significant downstream consequences, such as ED revisits, falls, and hospitalizations. Thus, there is a critical need to identify older adults at highest-risk of delirium in the ED to facilitate early interventions. The overall objective of this proposal is to establish the incidence, time course, and risk factors of delirium during the ED stay, which is a critical prerequisite for implementing effective delirium prevention and management interventions. We will achieve this objective with the following three aims: (1) Determine the incidence and time course of ED delirium with validated detection tools, (2) Identify modifiable and nonmodifiable risk factors of incident ED delirium, and (3) Examine existing risk stratification screening instruments for incident ED delirium. We propose a prospective cohort study of older adults ≥65yo in a Level 1 accredited Geriatric ED. We will collect delirium and other cognitive impairment screenings on all patients ≥65yo at ED admission to establish baseline cognitive status. During the ED stay, patients will be screened for delirium at regular intervals to determine the incidence and time course of ED delirium. For admitted patients, delirium will continue to be assessed once per nursing shift during inpatient hospitalization. Using electronic health record data, we will examine modifiable and nonmodifiable risk factors for delirium in the ED and within 24- and 48- hrs of admission. Further, we will assess if recommended geriatric risk stratification instruments can predict incident ED delirium. Consistent with the goals of the “National Institute on Aging: Strategic Directions for Research, 2020-2025”, findings from this proposal will improve our understanding of the aging brain and its impact on the prevention, progression, and prognosis of ED delirium. Specifically, this work will have a positive impact on Geriatric ED care by identifying a subset of older adults at-risk for delirium. We will also establish the rate and risk factors for incident ED delirium, which will be the first steps in preventive strategies. During the award period, the candidate will acquire specific skills in aging research and benefit from interdisciplinary mentorship by accomplished geriatrics clinician-investigators. This study will serve as the basis for a K-award application by providing the groundwork and infrastructure for evaluating future delirium prevention and management strategies.

PROJECT NARRATIVE Delirium, an acute, fluctuating change in cognition with significant downstream consequences, is present in up to 35% of older adults in the Emergency Department (ED), but the incidence (number of patients developing delirium in the ED, versus those with delirium prior to ED visit) and time course are currently unknown. Prevention is the only effective treatment for delirium, requiring early identification of patients at-risk of developing delirium in the ED, but up to 83% of ED providers fail to recognize delirium cases, often due to lack of screening. We propose to tackle the first steps towards developing preventive and management strategies for delirium in the ED — that is, determining its incidence and time course, identifying the most relevant risk factors, and evaluating geriatric risk assessment instruments for ED delirium.