Global Societal Burden of Alzheimer’s Disease by Severity: a Targeted Literature Review

Abstract

Alzheimer’s disease (AD) is among the costliest of illnesses for the elderly, placing a significant burden on healthcare systems and caregivers. Despite the depth of evidence, reviews lack a holistic assessment of such costs, falling short of illustrating unmet medical needs. The objective of this review was to therefore characterize the total societal economic burden of AD, broken down by care setting and disease severity. A targeted literature search of systematic reviews, cost-of-illness, and observational studies published between 2013 and 2024 was conducted on MEDLINE and Embase to identify articles reporting the economic burden of AD. Grey literature was hand-searched. Both direct and indirect costs were assessed, including societal burdens not often reported by AD-specific cost-of-illness studies such as financial delinquencies. In total, 81 articles were reviewed in depth, including 20 systematic reviews and 61 studies or reports. Findings consistently demonstrated that societal costs of AD or dementia typically increased by at least 50% between consecutive severity levels, increasing with disease progression. Informal caregiving often comprised close to half of societal costs, regardless of care setting, disease severity, or region. While studies reporting costs of mild cognitive impairment (MCI) were limited, the economic burden reported for this stage was appreciable compared to mild AD. Evidence for the impact of AD, as early as MCI, on quality of life (e.g., emotional and mental strain) and personal financial management capabilities was also identified. This review provides a comprehensive overview, from studies spanning over more than a decade, of the substantial societal economic burden associated with AD, across cost categories, care settings, disease stages, and regions. This review may be used to inform health economic evaluations of novel interventions with potential to reduce the enormous and growing global economic burden of AD and dementia. This review presents a comprehensive overview on the last decade of key studies reporting societal costs related to Alzheimer’s disease (AD) and dementia globally. A strong focus was placed on assessing how costs, including those reflecting changes in day-to-day behaviors owing to memory deficits (e.g., deteriorating financial capabilities, getting lost in streets), vary by care setting and disease severity across regions. Across 81 studies, this review showed that indirect costs attributed to unpaid, informal caregiving represented a large proportion of total costs, often reaching close to 50% of the total societal burden, depending on stage of disease and region. Many studies reported a weekly rate of 60 h or more for informal caregiving time, and this increased when progressing from mild AD to more severe stages. Overall, total costs increased with progression from mild to severe disease, often by at least 1.5 × with long-term care costs becoming higher with moderate/severe AD. Costs related to the reduction in mental and emotional wellbeing of patients increased with disease severity, as did that of the caregiver, particularly in the mild-to-moderate stages of AD. The cost of financial scams increased by ₤194 from the mild-to-moderate AD stage. Furthermore, the large loss in tax payments to the government (up to €28,142) and reduced consumer spending over the lifetime of a patient with AD demonstrates the profound impact of the disease on public economics. Taken together, this study provides a complete viewpoint and framework for assessing total societal impact in economic evaluations of therapies targeted to slow disease progression of AD and dementia.

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