Cost of Patients with Alzheimer's Disease in Spain According to Disease Severity.

Background: Alzheimer's disease (AD) has been associated with great healthcare and non-healthcare resource consumption. The aim of this study was to estimate the burden of AD in Spain according to disease severity from a societal perspective.

Methods: A self-administered questionnaire was designed by the researchers and completed by the informal caregivers of patients with AD, reporting data on themselves as caregivers and on the AD patients for whom they care. The patients' sociodemographic and clinical data, their healthcare and non-healthcare resource consumption in the previous 12 months, and the impact of the disease on labor productivity were compiled. Data collected on informal caregivers included sociodemographic data and the impact of caring for a person with AD on their quality of life and labor productivity. Costs were estimated by multiplying the number of consumed resources by their unit prices. The cost of informal care was assessed using the proxy good method, and labor productivity losses were estimated using the human capital method. Costs were estimated by disease severity and are presented per patient per year in 2021 euros (€).

Results: The study sample comprised 171 patients with AD aged 79.1 ± 7.4 years; 68.8% were female, time from diagnosis was 5.8 ± 4.1 years, diagnosis delay was 1.8 ± 2.3 years, and the mean Cumulative Illness Rating Scale-Geriatric (CIRS-G) total was score 8.2 ± 6.0. According to disease severity, 14% had mild cognitive impairment or mild AD, 43.9% moderate AD, and 42.1% severe AD. The average annual cost per patient was €42,336.4 in the most conservative scenario. The greatest proportion of this cost was attributed to direct non-healthcare costs (86%, €36,364.8), followed by direct healthcare costs (8.6%, €3647.1), social care costs (4.6%, €1957.1), and labor productivity losses (less than 1%, €367.4). Informal care was the highest cost item, representing 80% of direct non-healthcare costs and 69% of the total cost. The total direct non-healthcare cost and total cost were significantly higher in moderate to severe disease severities, compared to milder disease severity.

Conclusions: AD poses a substantial burden on informal caregivers, the national healthcare system, and society at large. Early diagnosis and treatment to prevent disease progression could reduce this economic impact.