With new drugs on the market or in development for Alzheimer’s disease and other types of dementia, a new study suggests that getting the diagnosis needed to access these new treatments may depend on where you live.
The study finds that the percentage of people receiving a new diagnosis of dementia each year varies widely across U.S. regions.
And the differences across regions of the country are even greater for people at the younger end of the dementia risk age range, ages 66 to 74, and for those who are black or Hispanic.
In fact, the study shows that the same person may be twice as likely to receive a diagnosis of dementia in some areas of the United States than in others. The results suggest that the likelihood of receiving a diagnosis may depend more on the health care system than on individual factors that affect the risk of developing dementia.
Access to new advanced tests and treatments for dementia requires a formal diagnosis. Many of these are aimed at slowing the progression of dementia in its early stages, called mild cognitive impairment or mild Alzheimer’s disease.
The new study focuses on regional differences in the “diagnostic intensity” of dementia — the kind of difference that exists even after accounting for all types of dementia risk factors and regional differences in population and health care.
Conducted by a team based at the University of Michigan, it is published in Alzheimer’s and dementia:The journal of the Alzheimer’s Association.
“These findings go beyond demographic and population-level differences in risk and indicate that there are health system-level differences that could be addressed and remedied,” said Julie Bynum, MD, MPH, a geriatrician and healthcare researcher at UM Health who led the study.
“The message is clear: From place to place, the likelihood of being diagnosed with dementia varies, and that can be due to a variety of factors, from health care providers’ practice standards to each patient’s knowledge and care-seeking behavior,” said Bynum, a professor of internal medicine at the U-M School of Medicine. “But the good news is that we can act on these issues once we know where to look.”
Bynum and colleagues at U-M and the Geisel School of Medicine at Dartmouth College conducted the study using data from the records of 4.8 million people who were covered by traditional Medicare and were over age 66 in 2019.
They note that while nearly 7 million Americans currently have a diagnosis of dementia, millions more likely have symptoms but no formal diagnosis.
Insurance coverage for new biomarker tests, brain imaging scans and medications to delay dementia depends on the diagnosis. But even for those who don’t qualify for them, a confirmed diagnosis can be important for accessing specialized care and support for patients and their family members or friends who act as caregivers.
Beyond risk factors: more about the study
Researchers have already discovered many factors that are linked to an increased risk of developing Alzheimer’s disease and other forms of dementia. These include years of high blood pressure, high cholesterol, and tobacco or alcohol use, as well as lower levels of formal education, sleep, and social interaction.
But the new study shows for the first time that differences in diagnosis by region are not explained by differences in the level of risk of dementia between different populations.
Diagnoses within each of the 306 hospital referral regions developed for the Dartmouth Health Care Atlas and used in many studies were analyzed. Each HRR includes at least one hospital capable of performing advanced heart and brain surgery; the researchers chose to use these regions because dementia diagnosis and advanced treatment also require specialized services.
In total, 143,029 of the people in the total population used in the study were newly diagnosed with Alzheimer’s or another form of dementia in 2019. The remaining 356,656 people who had that diagnosis in this population had been diagnosed before 2019.
This means that 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.
The researchers calculated regional rates of new diagnoses and total people diagnosed in 2019 for each HRR. The prevalence of diagnosed dementia ranged from a low of 4% to a high of 14% depending on the HRR, and the rate of new dementia diagnoses in 2019 ranged from 1.7% to 5.4%.
They then looked at rates for three age groups (66 to 74, 75 to 84, and 85 years or older) and for people identified as white, black, or Hispanic. They also included data on the percentage of the population in each dementia risk group who had less than a high school education, who smoked, and who had obesity or diabetes.
They also incorporated information on the overall intensity of all types of chronic disease diagnoses in each HRR.
Taking all these factors into account, the researchers were able to calculate a predicted rate of new and total Alzheimer’s and dementia diagnoses for each HRR and for the individuals in each HRR. This is what they called diagnostic intensity.
Compared to the national average, people living in the lowest intensity areas are 28% less chances of being diagnosed, while those residing in areas of higher intensity are 36%. further You are likely to be diagnosed.
The overall concentration of diagnosed dementia cases was highest in the southern US, similar to the high-risk “stroke belt” for stroke and cardiovascular disease.
But the South was no longer a uniform hotbed of dementia diagnoses once researchers adjusted for other factors.
Implications for regional change
Bynum explains that the findings could reflect variations in clinical practices, for example, how often primary care physicians screen people for early signs of dementia, or the availability of specialists to make a confirmed diagnosis.
Variation could also be due to cultural or personal differences in the likelihood that a person would seek care of any kind, schedule an appointment specifically for memory problems, or mention memory or proactive thinking problems to a health care provider without being prompted during an existing appointment.
While the researchers can’t say for sure whether the variation reflects underdiagnosis or overdiagnosis, they do say that areas with lower-than-expected rates of dementia diagnosis could use the new findings to look at what barriers might stand in the way of someone being diagnosed.
“The current goal should be to identify people with cognitive problems earlier, but our data show that the youngest age group of Medicare participants has the greatest variation,” Bynum said. “For communities and health systems, this should be a call to action to spread awareness and increase efforts to make services available to people. And for individuals, the message is that they may need to advocate for themselves to get what they need, including cognitive screening.”
He adds that Medicare covers a cognitive assessment during each member’s annual wellness visit.
She also notes that Medicare’s recent launch of the GUIDE model for dementia care may offer a path to improving care. The model incentivizes clinical practices to better coordinate dementia care and offer 24-hour access to a trained provider.
In addition to Bynum, the study’s authors are Slim Benloucif and Jonathan Martindale of the U-M Department of Internal Medicine, A. James O’Malley of Dartmouth College and Matthew A. Davis, Ph.D., of the U-M School of Nursing and the Department of Health Sciences Learning at the U-M Medical School.
Bynum and Davis are members of the UM Institute for Health Care Policy and Innovation and leaders of the Center for Accelerating Population-Based Alzheimer’s Research, or CAPRA.
The study was funded by the National Institute on Aging of the National Institutes of Health (P01AG019783).
Full details on the diagnostic intensity rate and other data for each HRR will be available on the CAPRA website and at https://michmed.org/38XeZ .