Alzheimer’s disease is most prevalent in the east and southeast, according to new research published Monday that seeks to map out the disease on a state and county level. 

The prevalence of Alzeheimer’s in those regions is closely tied to demographics and age.

Researchers are hoping that a better understanding of the geographic breakdown of the prevalence of the disease, however, can help officials make better decisions about allocating funds and make more targeted treatment plans to care for patients.

“Alzheimer’s disease and related dementias possess tremendous health, social, and economic burdens worldwide,” the report’s introduction said, noting that the cost of caring for people with Alzheimer’s disease was estimated to be at $321 billion in 2022 – which is about $50,000 per person – including $206 billion for Medicare and Medicaid.

“Therefore, to better plan the financial costs of caring for people with AD dementia across the United States, it is necessary to provide state-specific estimates of the number of people with AD dementia, that is, the disease’s prevalence,” the introduction read. 

The researchers used a dementia likelihood score to estimate the prevalence of the disease, using data from the U.S. Census data in combination with data from the thousands of participants in the Chicago Health and Aging Project, a population-based study. 

They mapped their likelihood score across demographic data for each of the 50 states and for 3,142 counties. They relied on statistics that showed the risk of Alzheimer’s increased “exponentially” with age; women had a risk 1.13 times higher than men; Black individuals were 2.5 times more at risk than white people; and Hispanic people were 1.73 times more at risk than white people; more years of schooling was also associated with lower odds of dementia.

The results indicated that the states with the highest estimated prevalence of Alzheimer’s disease were Maryland, (12.9 percent), New York (12.7 percent), Mississippi (12.5 percent), and Florida (12.5 percent). California and Illinois each had a high estimated prevalence of 12 percent. The study explained that Maryland’s high estimated prevalence is explained by its high population share of people more than 85 years old and by its high share of Black residents. 

The study noted that while demographics are important in determining the prevalence of dementia, other factors including lifestyle, diabetes and hypertension are important as well and can change the prevalence.