A new study offers the first-ever county-level estimates of Alzheimer’s disease in the United States.

It shows that the East and Southeast have the highest prevalence of Alzheimer’s dementia, which researchers said may owe in part to the higher percentages of older people, and Black and Hispanic residents in those regions.

The study covered all 3,142 U.S. counties.

“These new estimates add more granular data to our understanding of Alzheimer’s prevalence across the country,” said Kumar Rajan, a professor of internal medicine at Rush Medical College, in Chicago. “This information, in addition to raising awareness of the Alzheimer’s crisis in specific communities, may help public health programs better allocate funding, staffing and other resources for caring for people with Alzheimer’s and all other dementia.”

Data came from the Chicago Health and Aging Project and U.S. government population estimates.

The highest rates of Alzheimer’s, in counties with 10,000 or more seniors, were in Miami-Dade County, Fla.; Baltimore City, Md.; and Bronx County, N.Y., with 16.6% each.

Close behind were Prince George’s County, Md., at 16.1%; Hinds County, Miss., 15.5%; Orleans Parish, La., 15.4%; Dougherty County, Ga., 15.3%; Orangeburg County, Ca., 15.2%; and Imperial County, Ca. and El Paso County, Texas, each at 15%.

Age is a primary risk factor for Alzheimer’s. Older Black Americans are about twice as likely to have Alzheimer’s or other dementias as older white Americans. Older Hispanic adults are about 1.5 times as likely to have Alzheimer’s or other dementias as older white folks, the study authors noted.

“The estimates are based on cognitive and demographic characteristics,” Rajan said in an Alzheimer’s Association news release. “Alzheimer’s dementia is a multifactorial disease involving several risk characteristics that interact with demographic risk factors and ultimately contribute to the prevalence.”

About 6.7 million Americans are living with Alzheimer’s disease. The West and Southwest are projected to have the largest percentage increase between 2020 and 2025.

“Alzheimer’s prevalence estimates can help federal and state public health officials determine the burden on the health care system, and county-level estimates help us better understand and pinpoint areas of high risk and high need — where, for example, culturally sensitive health support and caregiver training services are needed,” said Matthew Baumgart, vice president of health policy for the Alzheimer’s Association. “As the prevalence of Alzheimer’s disease increases, so does the need for a larger workforce that is trained in diagnosing, treating and caring for those living with the disease.”

The findings were presented Sunday at the Alzheimer’s Association International Conference in Amsterdam, the Netherlands, and simultaneously published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

More information

The U.S. Centers for Disease Control and Prevention has more on Alzheimer’s disease.

SOURCE: Alzheimer’s Association, news release, July 17, 2023