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ANN ARBOR, Mich. — In the race against time that is Alzheimer’s disease, getting an early diagnosis can make all the difference. But what if your chances of being diagnosed depended not on your symptoms or risk factors but on your mailing address?
A new study from the University of Michigan reveals a startling truth: where you live in the United States could dramatically influence whether you receive a timely diagnosis of Alzheimer’s disease or related dementias (ADRD). This geographic disparity in diagnosis rates persists even after accounting for known risk factors, suggesting that the quirks of local healthcare systems may play a bigger role in who gets diagnosed than we ever imagined.
A formal diagnosis of Alzheimer’s is the key that unlocks access to these cutting-edge therapies, as well as crucial support services for patients and caregivers. However, if diagnosis rates vary widely based on geography, it raises troubling questions about health equity and access to care across the nation.
“These findings go beyond demographic and population-level differences in risk, and indicate that there are health system-level differences that could be targeted and remediated,” says Dr. Julie Bynum, the U-M Health geriatrician and health care researcher who led the study, in a media release. “The message is clear: from place to place the likelihood of getting your dementia diagnosed varies, and that may happen because of everything from practice norms for health care providers to individual patients’ knowledge and care-seeking behavior. But the good news is, these are things we can act on once we know where to look.”
The study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, analyzed Medicare claims data for a staggering 4.8 million older adults across 306 hospital referral regions in the U.S. The researchers developed a novel measure called “ADRD-specific diagnosis intensity” to compare actual diagnosis rates in each region to what would be expected based on population risk factors.
The results paint a picture of stark geographic inequality. In some areas, older adults were twice as likely to receive an ADRD diagnosis compared to regions with the lowest diagnosis rates. This variation was most pronounced for adults between 66 and 74 years of age and for Black and Hispanic individuals – groups that are often underdiagnosed.
Surprisingly, the geographic pattern that emerged didn’t match previously observed trends like the “stroke belt” in the Southeast. Instead, diagnosis intensity varied in a more localized, patchwork fashion across the country. This suggests that factors specific to local healthcare systems – like the availability of memory clinics or physician training – may be driving these disparities more than broad regional trends.
“The goal these days should be to identify people with cognitive issues earlier, yet our data show the younger age group of Medicare participants is the one with the most variation,” Bynum notes. “For communities and health systems, this should be a call to action for spreading knowledge and increasing efforts to make services available to people. And for individuals, the message is that you may need to advocate for yourself to get what you need, including cognitive checks.”
With nearly seven million Americans currently diagnosed with dementia and millions more likely living with undiagnosed symptoms, addressing these geographic disparities in diagnosis could have a massive impact on public health. It could mean the difference between early intervention and years of unnecessary struggle for countless families.
As the population ages and new Alzheimer’s treatments emerge, ensuring equitable access to timely diagnosis becomes increasingly crucial. This study provides a valuable roadmap for targeting interventions and resources to areas where underdiagnosis may be most prevalent.
The next step will be to dig deeper into the specific factors driving these regional variations. Are there best practices from high-performing regions that could be adopted more widely? What systemic barriers in low-performing areas need to be addressed?
By shining a light on these hidden geographic disparities, this research takes an important step toward ensuring that all older adults receive equitable, high-quality care for ADRD – no matter where they call home. In the fight against Alzheimer’s, your zip code shouldn’t determine your fate.
Paper Summary
Methodology
The researchers analyzed Medicare claims data for 4.8 million adults 66 and older across the U.S. They identified new ADRD diagnoses in 2019 and calculated diagnosis rates for 306 hospital referral regions. To account for population differences, they used statistical models to estimate the expected number of ADRD cases in each region based on demographics, education levels, and health risk factors like smoking, obesity, and diabetes. They then compared the actual number of diagnoses to this expected number to create an “ADRD-specific diagnosis intensity” measure for each region.
Key Results
The study found that new ADRD diagnosis rates varied from 1.7 to 5.4 per 100 older adults across regions. Even after accounting for population risk factors, the likelihood of receiving an ADRD diagnosis varied up to 2-fold between the highest and lowest intensity regions. This variation was most pronounced for adults aged 66-74 and for Black and Hispanic individuals. Overall, about 7% of people covered by traditional Medicare have a dementia diagnosis at any given time, and 3% of this population is diagnosed each year, with an average age at diagnosis of about 83 years.
Study Limitations
The study was limited to Medicare fee-for-service beneficiaries and may not represent all older adults. The researchers couldn’t account for all potential risk factors, and their population-level measures may not capture individual-level risk perfectly. The study also couldn’t determine the specific causes of regional variations or whether they led to differences in health outcomes.
Discussion & Takeaways
This study reveals significant geographic disparities in ADRD diagnosis that aren’t explained by population risk factors alone. It suggests that local health care practices and access issues may play a big role in determining who gets diagnosed. The findings highlight potential inequities in care, especially for younger seniors and racial/ethnic minorities. They also point to the need for more standardized diagnostic approaches and targeted interventions in low-performing regions. The researchers suggest that areas with lower-than-expected diagnosis rates could use these findings to identify and address barriers to diagnosis.
Funding & Disclosures
This study was funded by the National Institute on Aging of the National Institutes of Health (P01AG019783). The authors are affiliated with the University of Michigan and Dartmouth College.
