Longitudinal Impact of Agitation and Aggression Symptoms on Societal Costs in Alzheimer's Disease: A Focus on Informal Care and Socioeconomic Disparities

Background To date, no longitudinal study has assessed the effect of agitation on societal costs—particularly informal care costs—over time in Alzheimer's Disease (AD) patients with Agitation and Aggression (A/A) symptoms. Objectives This study estimates the impact of A/A symptoms evolution on longitudinal care costs including informal care costs in moderate‐to‐severe AD, considering patient and caregiver socioeconomic characteristics. Design A longitudinal trajectory clustering method was used on this longitudinal, prospective, multicenter observational cohort study. Setting and Participants: 262 community‐dwelling and long‐term care facility (LTCF) patients of both sexes, aged 60 years and older, with clinically significant A/A symptoms were recruited from memory centers in southwest France. Methods Patients were followed for 12 months. A/A data was recorded by clinicians using the Neuropsychiatric Inventory (NPI‐c). Costs were estimated from a societal perspective, including healthcare and informal care, using the RUD questionnaire. K‐means longitudinal method identified A/A evolution profiles. Cost differences across A/A evolution profiles were analyzed using Generalized Linear Models. Results Two A/A evolution profiles were identified: mild symptoms at baseline with improvement (A) and moderate symptoms at baseline with limited improvement or stability (B). Annual costs were €22,959 in group A and €23,625 in group B excluding supervision, and €52,111 and €56,149, respectively, including supervision. In LTCF residents, higher A/A severity was associated with increased medical visits and medication costs, though overall cost differences were smaller. Informal care neared 70% of total costs for community‐dwelling patients, with supervision covering the majority of these costs. Conclusions Evolution of A/A symptoms significantly increases both healthcare and informal care costs, particularly in at‐home settings. Integrating systematic monitoring of behavioral symptoms into routine care would enable personalized, cost‐effective strategies. Informal care costs, often undervalued and overlooked in economic analyzes, underscores the need for improvement in resource allocation and quality of life, for both patients and caregivers. Clinical trial number NCT03554226