Economic and caregiver impact of Alzheimer's disease across the disease spectrum: a cohort study.

BACKGROUND: Alzheimer's disease (AD) substantially increases health-related costs. This study investigates direct medical costs and characterizes the caregiver burden across AD stages. METHODS: This study analyzed data from the French Primary Health Insurance Fund claims database and reflected this public payer perspective. Outpatients (N = 1998) visiting a memory clinic at Lyon University Hospital in France between 2014 and 2019 were included. Real healthcare costs (ie, ambulatory medicine, paramedical care, pharmaceutical treatment, public and private hospital stays, and medical transportation) were collected for patients 1 year prior to the date of the first memory visit and 2 years following the first visit (reference year: 2019). Patients were grouped based on a clinical diagnosis of cognitively normal with a subjective cognitive complaint (SCC), all-cause mild cognitive impairment (MCI), or AD dementia. The severity of AD dementia was defined by the Mini-Mental State Examination score. Caregiver burden was measured using the mini Zarit Burden Interview. A generalized linear model was used for statistical analyses. Other patient nonmedical and indirect costs and caregiver costs were not included. RESULTS: The study sample included patients with SCC (n = 640), MCI (n = 630), mild (n = 212), moderate (n = 256), or moderately severe/severe AD dementia (n = 260). One year after the first consultation, mean total costs were higher with progressive cognitive deficit, with little difference between dementia groups (SCC = €8028; MCI = €9758; mild AD dementia = €10,558; moderate AD dementia = €10,544; moderately severe/severe AD dementia = €10,345; P < .001). Public hospital stays comprised the majority of direct medical costs during the first semester following the visit (49.4% of the total costs), regardless of the severity of cognitive deficit. Caregiver burden increased with the severity of cognitive deficit (P < .0001). CONCLUSIONS: Direct medical costs and caregiver burden rose from SCC to AD dementia; in patients with AD dementia, the direct medical costs increased over the 2 years after the first consultation. These results, in conjunction with data from other care components, will be critical to elucidate the potential economic value of a therapeutic intervention that slows AD progression.

Estimating Progression Rates Across the Spectrum of Alzheimer's Disease for Amyloid-Positive Individuals Using National Alzheimer's Coordinating Center Data.

INTRODUCTION: Published estimates of Alzheimer's disease (AD) progression do not capture the full disease continuum. This study provides transition probabilities of individuals with amyloid-ß (Aß+) pathology across the disease continuum. METHODS: Patient-level longitudinal data from the National Alzheimer's Coordinating Center were used to estimate progression rates. Progression rates through five clinically defined AD stages-asymptomatic, mild cognitive impairment due to AD (MCI-AD), mild AD dementia, moderate AD dementia, severe AD dementia-and death were measured as transition probabilities. Rates were assessed in "incident" patients who recently entered the stage, controlling for covariates. Transition probabilities were generated from multinomial logit regression models that predicted an individual's health state as a function of health state at the previous visit and adjusted for time between initial and follow-up visits, age, sex, years of education, and concomitant symptomatic AD medications. RESULTS: Annual transition probabilities to more severe dementia stages for surviving incident Aß+ patients were as follows: asymptomatic to MCI-AD, 40.8%; MCI-AD to mild AD dementia or worse, 21.8%; mild AD dementia to moderate AD dementia or worse, 35.9%; moderate AD dementia to severe AD dementia, 28.6%. Transition probabilities to less severe dementia stages were: 5.3% annual reversion from MCI-AD to asymptomatic, 3.0% mild AD dementia to MCI-AD, 1.8% moderate AD dementia to mild AD dementia, and 1.3% for severe AD dementia to moderate AD dementia. CONCLUSIONS: These transition probabilities reflect the full continuum of AD progression in Aß+ individuals and can be used to assess the impact of treatment on expected transitions.