Millions of people over the age of 65 likely suffer from mild cognitive impairment, or MCI, that is, minor problems with memory or decision-making that can, over time, develop into dementia. But two recent studies both concluded that 92% of people with MCI in the United States are not diagnosed early, preventing them from accessing new Alzheimer’s treatments that could slow the cognitive decline if detected early enough.
“We knew it was bad. But we didn’t know that was the case that bad,” says Ying Liu, a statistician at the University of Southern California Dornsife Center for Economic and Social Research and a researcher on both studies.
In the first, published this summer in Alzheimer’s disease research and therapy, Liu’s team aimed to determine how often MCI is diagnosed and how often it is overlooked. Using data from Health and Retirement Study, a longitudinal survey of some 20,000 people in the United States on a wide range of age-related factors, Liu built a model predicting the number of MCI diagnoses expected for the overall population over 65: approximately 8000000. Next, Liu’s team pulled data from all Medicare beneficiaries aged 65 and older enrolled between 2015 and 2019, to see how many of them were actually diagnosed with the disease. They found that only 8 percent of people who their model predicted would be candidates for MCI, based on their health demographics, actually received a diagnosis. That number was even lower for Black and Hispanic beneficiaries and among low-income people. (The team used eligibility for Medicaid, health coverage that supplements Medicare, as a marker of income status.)
A second study, published in October by Liu’s team, examined Medicare claims submitted by 226,756 primary care physicians and compared their MCI detection rates with those predicted by their model. Again, they found that only about 8 percent of predicted cases were actually diagnosed, and that only 0.1 percent of clinicians diagnosed the disease as often as the team estimated they should.
Autopsies reveal that most people who die at an advanced age suffer from some sort of brain pathology that impairs cognition, due to traces of stroke At amyloid plaques which characterize Alzheimer’s disease. Not everyone with these anatomical markers of neurodegeneration has memory problems, but “the more of these things you have in your brain, the more likely you are to develop dementia,” says Bryan James, an epidemiologist at the Rush Alzheimer’s Disease Center. , who did not participate in this research. If someone is experiencing problems like forgetting who their family members are or getting lost while walking familiar paths, a combination of cognitive tests, brain scans, blood tests, or a spinal tap can identify the cause. of his dementia.
The diagnosis of mild cognitive impairment is much more difficult. People may notice something is wrong, but they are still able to function independently. Most are seen by primary care physicians and not by researchers in specialty memory care clinics. Because these doctors don’t see many dementia patients, their confidence in giving someone a potentially life-changing diagnosis may be low. “They don’t want to make a mistake,” says Sarah Kremen, a neurologist at the Jona Goldrich Center for Alzheimer’s Disease and Memory Disorders, who was not involved in this research.
“We’re still struggling as a health profession to figure out the best way to identify mild cognitive impairment,” adds primary care physician Barak Gaster, also a professor of medicine at the University of Washington. Many doctors in Gaster’s field know they lack the training to manage cognitive issues and are eager to learn. However, annual Medicare wellness visits are time limited (often only 60 minutes) and cover a lot of ground. Cognitive assessments are too superficial to detect the subtleties of MCI. “It’s really hard to ask a community health provider to do anything else because they’re already doing it. All“says Nancy Berlinger, a senior fellow at the Hastings Center, an independent bioethics research institute in New York. Additionally, people generally don’t want to be told they have memory problems. “Because of stigma surrounding dementia, primary care providers may simply avoid the topic,” says Berlinger.