Study: Where you live may affect dementia diagnosis rates in the US

In the United States, the probability of receiving a dementia Diagnosis and subsequent treatment vary significantly by geographic location. This disparity also extends to people who belong to marginalized groups, as highlighted by a new study published in Alzheimer’s & Dementia. The research found that the odds of a person being correctly diagnosed and treated for dementia could be twice as high in some regions compared to others.

The study analyzed Medicare fee-for-service data for 4,842,034 older beneficiaries from 2018 to 2019, focusing on Alzheimer’s disease and related dementias (ADRD) diagnoses. Researchers found that ADRD diagnosis intensity varied across hospital referral regions, with diagnosis rates ranging from 0.69 to 1.47. These differences persisted regardless of known risk factors, such as education, obesity, smoking, and diabetes. Diagnosis rates were notably lower for Black and Hispanic individuals, as well as for individuals ages 66 to 74, who are typically the youngest group affected by dementia.

Lycia Neumann, PhD, senior director of health services research at the Alzheimer’s Association of America, noted that dementia is frequently underdiagnosed, a trend confirmed by the Alzheimer’s Disease Facts and Figures 2024 report. Neumann also emphasized that this new study highlights significant geographic disparities in dementia diagnoses, exacerbated by age and racial/ethnic disparities.

Julie P. W. Bynum, MD, senior author of the study and professor of geriatric and palliative medicine at the Johns Hopkins School of Medicine, explained that the exact causes of these disparities are not clear from the data alone. However, she suggested that differences in the health care systems that serve different communities likely contribute. Factors such as primary care providers’ confidence and comfort level in diagnosing dementia, the availability of specialists, and patients’ and families’ attitudes and beliefs about dementia could all play a role.

Neumann also pointed to additional factors that complicate access to care, including health insurance coverage, distance to health care facilities, transportation issues and lack of companionship.

Speaking about underdiagnosed groups, Bynum highlighted that for Black and Hispanic communities, there are systemic issues affecting access to health care and a lower tendency to seek care and diagnosis. Social determinants of health, including the stigma associated with dementia, further prevent people from seeking a diagnosis. Additionally, for people between the ages of 66 and 74, doctors may be less likely to suspect dementia because it is less common in younger populations. Symptoms of early-stage dementia can also be subtle and confused with other conditions such as depression, complicating diagnosis.

Despite these challenges, the study provides valuable information that could help address disparities in dementia care. Neumann believes that integrating claims data with spatial analysis can improve our understanding of disparities in access to dementia care, starting with diagnosis. These data are crucial to developing educational programs and systemic changes to equitably improve diagnosis rates.

However, Neumann also cautioned that the study is based on data from 2018-2019. Advances in diagnostic tools, such as less invasive and more cost-effective blood tests, could improve access to diagnosis in the future. She noted that the Alzheimer’s Association is actively funding research to improve diagnostic methods, including advanced imaging and biomarker tests.

The Alzheimer’s Association is also committed to increasing awareness of the signs and symptoms of dementia, as well as improving access and quality of diagnosis, treatment and care. Neumann is involved in organizing a conference on “Exploring Equity in Diagnosis” in November 2024, which will bring together experts from across the country to discuss and address disparities in dementia diagnosis.