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

introductionAlzheimer'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.

methodsA 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.

resultsIn 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.

conclusionThis 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.