SEVERITY OF AGITATION IN ALZHEIMER'S DISEASE: PROPORTION OF INDIVIDUALS TRANSITIONING TO LONG-TERM RESIDENTIAL CARE USING US NATIONAL ALZHEIMER'S COORDINATING CENTER DATA

Abstract

Introduction Agitation is among the most common behavioral symptoms of dementia and poses a major challenge for the treatment and management of individuals with dementia. A few studies have shown agitation may be an important predictor of institutionalization; however, these studies were limited to very small sample sizes and focused on behavioral symptoms in general. This study aimed to assess the rate of institutionalization by agitation severity level in patients with dementia. Methods A retrospective cohort analysis was undertaken using the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS), comprising data from 39 past and present Alzheimer's Disease Centers across the United States supported by the National Institute on Aging/National Institute of Health. Eligible individuals had dementia due to Alzheimer's disease, were not institutionalized as of the index date, and had known information on key variables (including residence status) as of the index date and the following annual visit. Agitation severity level was assessed using reported scores per the Neuropsychiatric Inventory Questionnaire (NPI-Q), a behavioral assessment scale. More specifically, agitation was defined per the NPI-Q agitation/aggression scale, where 1=mild (noticeable, but not a significant change), 2= moderate (significant, but not a dramatic change), and 3=severe (very marked or prominent; a dramatic change). Patients with no agitation at any time were included in the “No agitation cohort”. For each patient in the “No agitation cohort”, one visit was randomly selected among all of the patient's visits during which a score on the NPI-Q for the agitation domain was recorded, and the date of the selected visit was defined as the index date. Patients with at least one visit with a score greater than 0 on the agitation domain of the NPI-Q at any time were included in the “Agitation cohort” and classified in the Mild, Moderate, or Severe cohort based on their score on the agitation domain of the NPI-Q as of their index date. For each patient, one visit was randomly selected among all of the patient's visits where a score greater than 0 on the NPI-Q for the agitation domain was recorded, and the date of the selected visit was defined as the index date. Entropy balancing was used to reweight baseline characteristics of individuals included in the “Agitation cohort” and those in the “No agitation cohort” based on age; gender; race; ethnicity; education; primary language; marital status; blood pressure (systolic and diastolic); resting heart rate; active depression; and Clinical Dementia Rating, Geriatric Depression Scale, Modified Hachinski Ischemia Scale, and Functional Activities Questionnaire scores. Institutionalization rates were assessed among balanced cohorts at the first annual visit following the index date. Results A total of 4,344 individuals met the sample selection criteria for the study, of whom 2,798 (64%) were classified as having agitation per the NPI-Q agitation/aggression scale and 1,546 (36%) were in the “No agitation cohort”. Among patients in the balance cohort, 50% were female, 82% were white, and the mean age was 75.2 years ± 9.7. The proportion of patients by agitation severity level at index was 62.2% with mild agitation, 29.5% with moderate agitation, and 8.3% with severe agitation. The risk of transitioning to long-term care over a 12-month period was 4.78% for no agitation, 7.84% for mild agitation, 8.19% for moderate agitation, and 10.13% for severe agitation. Conclusions Study findings support increasing rates of long-term residential placement as agitation progresses which is interlinked with the natural disease progression. To our knowledge, this is one of the few studies reporting rates of institutionalization by agitation severity level, underscoring a need for research and innovation in a prevalent yet underserved condition. This research was funded by Otsuka Pharmaceutical Development & Commercialization, Inc. Lundbeck LLC