A new study in the American Journal of Intellectual and Developmental Disabilities by Kiley McLean and Lauren Bishop uses Wisconsin Medicaid claims data to better understand chronic health conditions among adults with intellectual and developmental disabilities (IDD) including autism and Down syndrome. Their study found that adults with IDD had high rates of heart disease, hypertension, diabetes, and asthma. There are no known biological reasons for the increased likelihood of these conditions, so the study suggests that more inclusive prevention practices may be an important step to improve health outcomes for this group.
McLean and Bishop found that adult Medicaid beneficiaries with intellectual and developmental disabilities had high rates of chronic health conditions. In particular, prevalence of heart disease was high across the groups in the study. Around 39 percent of autistic adults without intellectual disability, 64 percent of autistic adults with intellectual disability, 67 percent of adults with Down syndrome, and 75 percent of adults with an intellectual disability only had claims related to heart disease. Although the overall prevalence of heart disease in autistic adults without intellectual disability was 39 percent, it was much higher for older autistic adults. Roughly 72 percent of autistic adults without intellectual disability aged 50 to 64 and 82 percent of those who were 65 and older had claims for heart disease during the 2008 to 2018 study period. This suggests that health disparities among adults with intellectual and developmental disabilities are likely to increase as they age.
Their other findings show that over 50 percent of autistic adults 65 or older with and without intellectual disabilities had claims for hypertension. Approximately 27 percent of adults within the Down syndrome-only group and 40 percent of adults within the intellectual disability-only group had claims for diabetes during the study period. Approximately 11 percent to 13 percent of all adults in the study had claims for asthma during the study period. “We found that the majority adults with intellectual and developmental disabilities within Wisconsin’s Medicaid system have at least one chronic health condition, suggesting a high level of need for chronic condition treatment and management,” says Bishop.
Until recently, most studies have grouped adults with IDD into a single category. However, McLean and Bishop say that doing so misses important differences. “By separating diagnostic groups, we uncover distinct health challenges that may need targeted, diagnosis-specific care,” says McLean. This offers important context about the health conditions and demographics of adults with IDD who are covered by Medicaid in Wisconsin. One key finding was that their sample contains far more young adults with autism than older adults with autism, likely reflecting shifts in diagnostic practices over time. Their study also finds uneven Medicaid coverage and services across counties in Wisconsin, which are likely related to differences in rural and urban health care infrastructure.
McLean and Bishop say that Medicaid claims data is one of the most efficient ways to study health within an entire health system. Medicaid is a major U.S. program that uses a mix of state and federal funding. In 2018, the end of the period of Medicaid claims that McLean and Bishop studied, it provided medical coverage to over 40 million people in the United States. Medicaid policies and implementation vary state to state, however. Notably, Wisconsin is one of 11 states that have not adopted the 2010 Medicaid expansion. That expansion increases levels of funding states receive from the federal government to provide a variety of healthcare services and expands the covered population. The national Medicaid landscape is complex, and McLean and Bishop write that understanding the specifics of a program like Wisconsin’s can help to improve healthcare research and better inform healthcare policy.
McLean and Bishop’s study offers important details about disparities in health conditions for adults with IDD and has implications for research and policy efforts. Bishop says “This research suggests that Wisconsin now has a new opportunity: to become a national leader in reducing health disparities among people with intellectual and developmental disabilities with targeted intervention and prevention strategies. Additionally, the authors advise that prevention efforts for chronic health conditions should be inclusive and evidence based. McLean and Bishop say that these kinds of interventions, built in partnership with IDD communities, can potentially reduce healthcare costs and improve the overall health, quality of life, and longevity of adults with IDD. According to McLean, “Our study reveals a hidden crisis: adults with intellectual and developmental disabilities face alarmingly high rates of chronic conditions like heart disease and diabetes. This work is a call to action to address these health disparities head-on.”