Study Estimates Dementia Burden for Older U.S. Adults

The first nationally representative study of cognitive impairment in more than 20 years found that nearly 1 in 10 US adults over the age of 65 have dementia.

The study, led by researchers at Columbia University and with participation by scientists from the University of Michigan, also found that another 22% had mild cognitive impairment. People with dementia and mild cognitive impairment are older, less educated, and more likely to be racialized as Black or Hispanic. Men and women have similar rates of dementia and mild cognitive impairment.

Dementia and mild cognitive impairment are known to be common in the United States, but there have been few accurate and up-to-date measures of national prevalence.

“Because the HCAP study is part of a nationally representative long-term health and retirement study, these data not only show the current dementia burden, but also the trends in dementia burden over the coming decades. Cyrus Sturgis, co-author of the study and research professor at the UM Medical School, Institute for Social Research, and Veterans Affairs Ann Arbor Health Care System, said Kenneth Langa “It is especially important to follow these trends given that COVID and other recent changes in population health may impact dementia risk in the coming decades.”

This study was published in the journal JAMA Neurology.

35% of people in their 90s have dementia

This study is based on data from 3,500 individuals from the Harmonized Cognitive Assessment Protocol (HCAP) project, part of UM’s nationally representative Health and Retirement Study (HRS). Between 2016 and 2017, each participant completed a comprehensive set of neuropsychological tests and in-depth interviews used to develop algorithms for diagnosing dementia or mild cognitive impairment. Did.

Rates of dementia and mild cognitive impairment rose sharply with age, with 3% of people aged 65-69 having dementia and rising to 35% of people aged 90 and over.

Such data are used to understand the causes, costs, and consequences of dementia and mild cognitive impairment in the United States, and to inform policies aimed at reducing their impact on patients, families, and public programs. It is important. ”

Jennifer J. Manly, lead author of the study and Professor of Neurology and Neuropsychology at Columbia University’s Gertrude H. Sergievsky Center and Taub Institute for Research in Aging and Alzheimer’s Disease

“Cognitive impairment is projected to increase significantly in the coming decades as baby boomers live longer and older, impacting individuals, families and programs that provide care and services to people with dementia. increase.”

The economic impact of dementia, including unpaid family care, is estimated at $257 billion annually in the US and $800 billion globally.

Disparities in cognitive impairment are driven by exposure to structural and social inequalities

Unlike previous large studies of dementia in the United States, participants in the new study were representative of older adults, and researchers were able to assess national dementia by age, race, ethnicity, gender, and education. and mild cognitive impairment prevalence.

Data show that there is a disproportionate burden of dementia among older adults who identify as black or African American, and mild cognitive impairment among older adults who identify as Hispanic. , indicating that both categories of cognitive impairment exist among those who had less access to education.

David Weir, a research professor at ISR’s Research Center, is a principal investigator at HRS and co-author of the current study.

“Large, diverse, and nationally representative population studies are essential to identify the types of disparities shown here,” Weir said. “This study caps off more than a decade of his developing methods to bring powerful diagnostic tools out of the clinic and into the masses.”

Langa is the principal investigator of the HCAP study. Weir and Langa are co-investigators of the HCAP International Network. Langa, Weir, and co-workers developed the HCAP protocol prior to its implementation in the United States in 2016 as part of HRS.

The HRS HCAP project is also part of an international research network on dementia, using the same research protocol to collect comparable data on dementia from 15 countries around the world. This will allow researchers to measure and compare the current and next decade’s burden of dementia in low-, middle- and high-income countries.

Other contributors are: Richard N. Jones (Brown University Warren Alpert Medical School); Lindsay H. Ryan, Ryan McCammon, Steven G. Heeringa (University of Michigan); and Deborah A. Levine (University of Michigan and Veterans Affairs Center, Clinical Management Studies, Ann Arbor).