Mild cognitive impairment is underdiagnosed in US Medicare population

Key takeaways:

• Researchers predicted MCI, dementia and any cognitive impairment based on age, sex, race/ethnicity and dual eligibility.
• Dementia is diagnosed at the expected rate, but MCI remains substantially underdiagnosed.

BOSTON — Now that there are disease-modifying treatments for Alzheimer’s disease, the necessity of identifying “contemporary population-level diagnosis rates of mild cognitive impairment and dementia” is crucial, according to a presenter.

Soeren Mattke, MD, PhD, director of the Center for Improving Chronic Illness Care at the University of Southern California, told attendees at the American Academy of Neurology annual meeting that he and colleagues compared the expected rates of mild cognitive impairment (MCI) and dementia based upon a predictive model to the actual diagnosis rates from U.S. Medicare data.

Researchers used 100% samples for Medicare fee-for-service and Medicare Advantage from 2017 to 2019 and the Health and Retirement Study, which is “nationally representative study of older adults ... that has cognitive assessments every 2 years.” With this study data, they identified the population classified as having dementia or MCI and could predict the two as a function of age, sex, ethnicity and dual eligibility status.

According to results, the prediction model performed well, with reported differences between predicted and observed diagnosis rates of 0.2013 for MCI, 0.015 for dementia and 0.1487 for MCI or dementia. More than 7.2 million MCI cases and nearly 500,000 dementia cases were undiagnosed.

These data sets were “sufficient for such a population-level approach,” Mattke said.

“Dementia rates on average are diagnosed at the expected rate in the elderly population with substantial variability between minority and other disadvantaged populations.”

MCI, he noted, is another story.

Approximately 10 million people in the U.S. have MCI but are undiagnosed when one considers populations both older than 65 years and younger than 65 years, Mattke said.

“[There] is a lot of work ahead of us to close this gap and find proper diagnosis and treatment for these people,” he said, emphasizing the importance of closing this gap within primary care practice.

“This is a very big step to change our diagnostic approach to their condition.”