A study of Wisconsin Medicaid enrollees with Down syndrome has found that more than half of those ages 55 and older have filed at least three claims for dementia and nearly a third have filed at least three claims for Alzheimer disease. The analysis was funded by the National Institutes of Health and the Agency for Health Care Research and Quality. It appears in JAMA Neurology.

People with Down syndrome are at higher risk for dementia as they age. The study authors noted that nearly all adults with Down syndrome develop neurological changes by age 40, but symptoms may not appear for decades. The authors added that population studies are needed to identify when symptoms begin so that families and health care systems can plan care for people with Down syndrome as they age.

In the current study, researchers led by Eric Rubenstein, PhD, and colleagues at the University of Wisconsin-Madison analyzed claims records by 2,968 Wisconsin Medicaid enrollees with Down syndrome from 2008 to 2018. Among those ages 40 to 54, 18.8% (190 of 1013) had filed dementia claims. There was a 40% chance that a person with Down syndrome age 40 to 54 years old would file a dementia claim over the next 11 years; there was a 67% chance that a person with Down syndrome age 55 or older would file such a claim. Among men and women with Down syndrome younger than 40, the likelihood of dementia was roughly equal, but from ages 40 to 54, dementia was 23% more likely in women.

Because eligibility requirements for people with Down syndrome are similar among Medicaid programs, other states may likely have a comparable proportion of claims for dementia and Alzheimer disease in this population.