Researchers from the Centers for Disease Control and Prevention (CDC) say the prevalence of Alzheimer’s disease and related dementias (ADRD) will increase some 178% among all Americans aged 65 years and older by 2060, but Hispanic, African American and other racial and ethnic groups will see the fastest growing rates.
They say the study of 28 million Medicare recipients fills a critical research gap because estimates of the future burden of ADRD in the U.S. population by age, sex, race and ethnicity did not exist before now.
Researchers showed that although the main risk factor for ADRD is age, race and ethnicity are important demographic risk factors to consider. But because of the lack of that data, researchers estimated ADRD in people aged 65 years and older by age, sex, race and ethnicity from 2015 to 2060 using Medicare numbers from 2014. At that time, some 11.5% of 3.2 million Medicare fee-for-service beneficiaries had received a diagnosis of ADRD in 2014.
The study, published in Alzheimer’s & Dementia this month, concluded that while the burden of ADRD in 2014 was an estimated 5 million adults aged 65 years and older, there are significant imbalances in the number of sufferers defined by race and ethnicity. They predict that the ADRD burden will double from 1.6% of the population in 2014 to 3.3% by 2060, when some 13.9 million Americans are projected to have the disease. But the highest numbers will be among Hispanics and African Americans.
And because numbers were higher in U.S. minority group projections, the researchers are calling for a higher index of suspicion for early signs of ADRD, more screening and increased culturally competent care among these populations. They hope their estimates will be used to guide policy, planning and interventions related to caring for the ADRD population and supporting caregivers.
“Given the differences in the growth rates of different population subgroups in the United States, it is critical that culturally sensitive information be provided to obtain a diagnosis as early as possible and to improve the uptake of preventive health behaviors in all racial and ethnic subgroups in the United States,” wrote lead study author Kevin A. Matthews, of the Division of Population Health at the CDC’s National Center for Chronic Disease Prevention and Health Promotion, in Atlanta, Georgia, along with colleagues at the University of Wisconsin-Milwaukee and Morehouse School of Medicine.
The findings also support surveillance activities outlined in The Healthy Brain Initiative: A National Public Health Road Map to Maintaining Cognitive Health to assess cognitive decline in the population at risk for ADRD. The Initiative describes how public health agencies can promote cognitive functioning and early diagnosis in older adults, help local communities provide resources to people as they cope with cognitive impairment and provide assistance to formal and informal caregivers.
Researchers say they hope their findings will also help the public, health-care community, public health professionals and policy-makers anticipate disease burden among population subgroups.
According to the Alzheimer’s Association, Alzheimer’s disease (AD) is the sixth leading cause of death in the U.S. and the fifth leading cause of death among adults aged 65 years and older.
“Our estimates complement other estimates of the future burden of dementia,” the authors wrote. “The most commonly cited estimates for AD show that 4.7 million Americans had AD in 2010, and 13.8 million will have the disease by 2050. The most recent estimates in the US show that 6.1 million people had clinical AD or mild cognitive impairment in 2017, which is expected to grow to 15.0 million by 2060.”
Data from Medicare claims are useful for studying the prevalence of dementia because beneficiaries represent most people aged 65 years and older in the U.S., and billing records document their conditions. As soon as someone is diagnosed with any type of dementia, the information is entered into the clinical record and used for billing. Researchers wrote that, although the gold standard for obtaining reliable estimates of the prevalence of dementia would be to clinically evaluate a nationally representative sample of older Americans, such studies can be quite expensive, and the group studied may not be representative of the U.S. population anyway.
Researchers noted that the prevalence of ADRD is highest among minority groups because it is these groups that will experience the highest rates of population growth in the coming years. The number of people aged 65 and older is expected to double from 46.5 million in 2014 to 83.7 million by 2060, but some groups will increase much faster than others.
“Minority populations, those classified by the U.S. Census Bureau as racial and ethnic groups other than non-Hispanic white, are expected to outpace the growth of the nonminority population in the next few decades,” the authors wrote. “By 2060, minority populations aged ≥65 years will represent 45% of the US population for that subgroup, which is up from 22% in 2014. The percentage increase in total population by race and ethnicity by 2060 is estimated to be 75% for non-Hispanic whites, 172% for African Americans, 270% for Asian and Pacific Islanders, 274% for American Indian and Alaska Natives, and 391% for Hispanics.”
Researchers at the CDC examined a nationally representative sample of more than 28 million Medicare fee-for-service beneficiaries in 2014. The results showed that the prevalence of ADRD was 13.3% among women and 9.2% among men. As expected, the rates increased with age, from 3.6% among those aged 65 to 74 years, to 34.6% among those aged 85 and older.
The new data showed that the estimated ADRD prevalence was highest among blacks, at 14.7%, followed by Hispanics, at 12.9%, non-Hispanic whites, at 11.3%, American Indian and Alaska Natives, at 10.5%, and Asian and Pacific Islanders, at 10.1%.
Hispanics will see the largest projected increase in ADRD cases through 2060, according to the study. Still, given its population size relative to other groups, the non-Hispanic white population will have the largest total number of cases in all years.
Prevalence of ADRD in African Americans is 64% higher than for caucasions, the authors note. And Hispanics are one and half times as likely to have ADRD than non-Hispanic whites. African Americans have the highest prevalence of ADRD.
“As the United States becomes a majority-minority nation by 2050, increases in the number of non-Hispanic whites with ADRD will begin to plateau around 2030 while the number in minority populations will continue to grow, particularly among Hispanics,” the authors write. “These findings support efforts to develop a culturally competent workforce of health-care providers of all types. Such training would help to improve the recognition of early signs of dementia despite cultural differences and to identify ways health-care workers can assist people with dementia in navigating the health-care system.”
Authors admit there are limitations to their study. They are assuming the prevalence of ADRD is the same between Medicare beneficiaries and the general population. There are problems with claims data, which rely on the accurate capture of the proper information and diagnosis. Educational attainment is not noted in medical records. And researchers are assuming the prevalence estimates in 2014 will be constant over time.
“Despite these limitations, the estimates of future burden of ADRD are driven more by the rapid growth in the population of those aged 65 years than by the ADRD prevalence estimates in 2014,” the authors wrote. “The public health message remains the same that, given the differences in the growth rates of different population subgroups in the United States, it is critical that culturally sensitive information be provided to obtain a diagnosis as early as possible and to improve the uptake of preventive health behaviors in all racial and ethnic subgroups in the United States.”
The researchers say their estimates can be used for public health planning related to providing culturally competent care for the ADRD population and supporting caregivers from diverse backgrounds, especially for regions that will face a disproportionately high increase of dementia.
Study authors point out that age, family history and heredity are unchangeable risk factors related to ADRD, “but there is growing evidence proving the importance of preventive interventions to decrease prevalence. Proper management of health, lifestyle and wellness choices can reduce the risk of ADRD. Increasing healthy behaviors can decrease the chance of developing chronic diseases that are risk factors for developing ADRD. Risk of developing ADRD can also be reduced through maintaining strong social connections, physical exercise, healthy eating and keeping oneself mentally active. Genetic testing and counseling for genetically linked dementias can also heighten awareness and be informative to the patient and provider for precautionary and preventive action.”
Researchers hold that given the expected growth in the burden of disease, particularly among minority populations, culturally competent care for these groups will be of paramount importance. They call for better monitoring and evaluation of minority populations, more education and awareness about dementia and—given that some states have higher proportions of minority populations—support for policy development to deal with the explosion of new cases of ADRD.
Caregiver support is also a target of researchers. They write that while the proportion of younger adults is declining in the U.S., they are the very ones who are likely to become caregivers as the “population of adults aged 65 years will double to 72 million and account for 20% of the population by 2030. Currently, there are seven potential caregivers to one adult in the high-risk age group, but this caregiver support ratio is expected to decline to four to one by 2030.”
And they call for more research. They suggest studying minority populations including where they live to determine whether ADRD is driven by specific health conditions that may differ from those driving a similar prevalence in a different area. “The disproportionate prevalence of ADRD in minority populations could further magnify existing neighborhood socioecologic disparities and potentially lead to worsening of health outcomes in these groups,” they write. “Furthermore, understanding the reasons why ADRD varies by place may lead to the development of services and resources for formal and informal caregivers that are consistent with the local needs and circumstances.”