New Alzheimer's study finds where you live may affect your chances of diagnosis : NPR

Medical equipment photographed at the Actors Fund's Al Hirschfeld Free Health Clinic in New York City on March 23, 2011. Researchers found that the likelihood of a formal dementia diagnosis in the United States varies depending on the location.

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Spencer Pratt/Getty Images

It's estimated that about 7 million people in the United States have Alzheimer's disease or related dementias. But the number of people who have been formally diagnosed is much smaller. Now, new research suggests that your chances of receiving an official diagnosis may vary depending on where you live.

Researchers from the University of Michigan and Dartmouth College found that dementia diagnosis rates vary widely across countries, and that the different rates cannot be explained simply by dementia risk factors, such as whether certain areas have more cases of high blood pressure, obesity, or diabetes.

The reasons for this disparity are unclear, but the researchers speculate that stigma and access to primary care and behavioral neurology specialists may influence the likelihood of receiving a formal diagnosis.

“We tell anecdotes about how difficult it is to get a diagnosis, but it may be harder in some places. And that's not just imagination; it really does vary from place to place,” said Julie Bynum, lead author of the study and a geriatrician at the University of Michigan Medicine.

These differences could have potential implications: an official Alzheimer's diagnosis could provide access to treatments that could slow the brain changes associated with the disease. Without an official diagnosis, patients can't take part in clinical trials or get insurance coverage for certain drugs. Even in cases of dementia where treatment isn't an option, a diagnosis can help plan a patient's treatment.

of Survey resultsPublished in the journal last week Alzheimer's and Dementiawas born out of two main questions: What percentage of older adults across U.S. communities are diagnosed with dementia, and are the rates we see different than expected?

To answer these questions, the researchers used Medicare and demographic data to create two maps. The first showed the share of people with a formal diagnosis in each Hospital Referral Region (HRR), which divides the country into 306 regions based on where people are likely to seek care. The second estimated what proportions in each HRR would be based on health risk factors and race.

What they found was that the two maps differed significantly, with parts of the Great Plains and Southwest showing fewer diagnoses than expected: Someone living in Wichita Falls, Texas, for example, may be twice as likely to be diagnosed as someone living in Minot, North Dakota.

“Even if you're all within the 80-year-old group, depending on where you live, you could actually be twice as likely to get a diagnosis,” Bynum said.

Because the researchers compared each HRR to the national diagnosis average, rather than the actual number of cases in each community, it's difficult to say with certainty whether an area is underdiagnosed, she added.

But the findings shed new light on why dementia diagnoses are more prevalent in some areas than others, and how this isn't just related to individual risk factors, but also to access to health care resources and education about dementia.

Erin Abner, an epidemiologist at the University of Kentucky who was not involved in the study, said the results were not surprising and that there are many barriers to diagnosis.

“Where we live has a big impact on our brain health,” she says. “In many parts of the country, it's very difficult for adults to access behavioral neurology care, and they often wait months or even years to be seen.”

Due to differences in language and culture, Affecting access to healthcare.

Diagnosing Alzheimer's can be a long process that includes cognitive and neuropsychological evaluations, as well as tests that show the presence of amyloid plaques in the brain. Bynum hopes the findings will help draw attention to diagnosis rates and the role the health care system plays in finding people who may be suffering from dementia without realizing it.

“The other element of the role of the health care system and the public health system in informing and educating the public is also relevant and important,” Bynum said, “and in some ways solving that.”