Healthcare Utilization and Cost Burden Associated with Depression among Patients with Alzheimer’s Disease - A Retrospective Cohort Analysis

Abstract

Background: Alzheimer’s disease (AD) is the most common cause of dementia in the United States. Patients with AD have increased use of healthcare services, including more frequent high-cost events like hospitalizations and emergency department (ED) visits, compared to cognitively normal individuals. Neuropsychiatric symptoms are more common in individuals with AD than in the general population. Many patients exhibit symptoms consistent with depression, such as mood changes, social withdrawal, apathy, and suicidal ideation. Additionally, individuals with AD and comorbid depression tend to show more severe neuropathological changes, including greater accumulation of tau, amyloid, and vascular pathology, compared to those without depression. Depression and its related symptoms in AD patients contribute to greater caregiver burden, higher fall risk, and a greater likelihood of requiring costly interventions such as skilled nursing care and early institutionalization. To our knowledge, no studies have looked at the associated healthcare burden of comorbid depression among patients with AD. Objective: In this study, we compared AD patients with depression to AD patients without depression with respect to patient characteristics, healthcare resource utilization, and costs to characterize the healthcare burden. Methods: We performed a retrospective cohort study using MarketScan® health insurance claims data. AD patients with depression within three years of AD diagnosis and AD patients without depression were identified between January 1st, 2017, and December 31st, 2022, and followed for up to one year after their depression or proxy diagnosis. AD controls were matched 6:1 to AD with depression cases. The primary outcomes of interest were all-cause healthcare resource utilization and expenditures during the follow-up period. Results: In the 12-month follow-up, patients with AD and comorbid depression had substantially higher healthcare costs and utilization compared to those without depression. Adjusted models showed significantly higher total costs (+$13,089; 95% CI: $11,623, $14,554) and greater utilization, including more ED visits, office visits, drug claims, inpatient days, and hospital admissions, all of which were statistically significant. Conclusion: The results of this study suggest that the financial burden following depression diagnosis in AD patients is substantial. These findings highlight the need for more effective treatments that can mitigate the resource use and economic burden in the management of depression among this vulnerable population. There is a clear unmet need for properly managing depression in patients with underlying AD.