July 18, 2023 – The highest rates of Alzheimer’s disease occur in the East and Southeast parts of the United States, according to a new analysis.
It is the first time that the prevalence of Alzheimer’s disease has been reported at the county level, the authors of the analysis stated. Topping the list were Miami-Dade County in Florida, Baltimore in Maryland, Bronx County in New York, and Prince George’s County in Maryland. In all of those places, at least 16% of people ages 65 years and older were estimated to have Alzheimer’s disease, which is the most common type of dementia.
The higher rates were explained by demographic factors used to make the estimates, the researchers wrote, such as areas that have large populations of people age 85 or older.
The findings were published Monday in Alzheimer’s & Dementia, the journal of the Alzheimer’s Association, and also presented at the organization’s annual conference taking place this week in Amsterdam.
The researchers used a multi-step approach to arrive at their conclusions. First, they looked at cognitive test scores from another study for more than 10,000 people ages 65 and older living in the Chicago area, and estimated the likelihood that the people had Alzheimer’s disease. They then looked at the estimated rate of Alzheimer’s among the Chicago-area people based on demographic factors like age, race, gender, and education level. Finally, those demographic-based rates were combined with data from the National Center for Health Statistics and from the U.S. Census Bureau.
The study focused on demographic risk factors because previous research has shown them to be predictors of Alzheimer’s disease and other types of dementia.
“These new estimates add more granular data to our understanding of Alzheimer’s prevalence across the country,” researcher and Rush Medical College professor Kumar B. Rajan, PhD, said in a statement. “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.”
Besides looking at places based on the proportion of people who have Alzheimer’s disease, the researchers also looked at which counties may have the greatest total number of people living with the disease. They estimated that the top of the list included Los Angeles County in California, Cook County in Illinois, Maricopa County in Arizona, and Miami-Dade County.