Jul 27, 2023 - Health

Alzheimer's prevalence, mapped

Estimated share of older adults with Alzheimer's disease dementia
Data: Dhana, et al., 2023, “Prevalence of Alzheimer’s disease dementia in the 50 U.S. states and 3,142 counties”; Map: Kavya Beheraj/Axios

The Eastern and Southeastern U.S. have the country's highest prevalence of Alzheimer's disease, per a new study.

Why it matters: It's critical for public health officials, policymakers and others to have a clear look at the number of Alzheimer's cases in a given area, the authors say — in part because caring for those with the disease cost an estimated $321 billion nationwide last year, much of which came via Medicare and Medicaid.

Details: For the study, published in the journal Alzheimer's & Dementia, researchers estimated the rates of Alzheimer's disease among adults age 65 or older in a given area based on demographic risk factors, including age, sex and race/ethnicity.

  • They used data from the Chicago Health and Aging Project (a population-based study examining Alzheimer's risk factors), plus population estimates from the CDC's National Center for Health Statistics.

What they found: Maryland (12.9%), New York (12.7%) and Mississippi (12.5%) topped the list of U.S. states ranked by estimated number of Alzheimer's cases among older adults.

  • California (719,700), Florida (579,900) and Texas (459,300) have the highest estimated number of older residents with Alzheimer's — though of course those are also the most populous states overall.

What they're saying: "These estimates could help public health officials to understand the burden of disease (e.g., demand for caregiver counseling and institutional care) at the county and state levels and develop adequate strategies for identifying and caring for people with [Alzheimer's]," the authors write.

Yes, but: The researchers caution that their approach is incomplete, as demographic-based risk factors can only tell part of the picture.

  • Other risk factors — including cardiovascular health and lifestyle — also play a role, but "such data are unavailable at the county level, and we cannot incorporate them into our estimates," they write.
Go deeper