Neuropsychiatric symptoms in patients with dementia and the longitudinal costs of informal care in the Cache County population

Abstract

IntroductionSeverity of dementia and neuropsychiatric symptoms contribute to increasing informal care costs. We examined which neuropsychiatric symptoms subdomains (NPS-SD) were associated with informal costs in a population-based sample. MethodsDementia progression and informal costs (2015 dollars) were estimated from the Cache County Dementia Progression Study. Overall NPS and specific NPS-SD were assessed with the Neuropsychiatric Inventory. Generalized Estimating Equations (GEE with gamma-distribution/log-link) modeled the relationship between NPS-SDs and informal cost trajectories. ResultsTwo hundred eighty participants (52.1% female; age M = 85.67, SD = 5.60) exhibited an adjusted cost increase of 5.6% (P = .005), 6.4% (P < .001), 7.6% (P = .030), and 13% (P = .024) for every increasing Neuropsychiatric Inventory unit in psychosis-SD, affective-SD, agitation/aggression-SD, and apathy-SD, respectively. An increase in each unit of apathy was associated with a 2% annual decrease in costs (P = .040). DiscussionWe extend our prior work on informal costs and dementia severity by identifying NPS-SD associated with informal costs. Interventions targeting NPS-SD may lower informal costs.