WHY ARE PEOPLE WITH INTELLECTUAL AND DEVELOPMENTAL DISABILITIES LEFT OUT OF CLINICAL RESEARCH TRIALS?

BY LORENE REAGAN, MS, RN

"Clinical trials should, to the extent possible, enroll a population that is representative of the diversity of the population that will use the medical product, if approved." 1 That makes sense, right? Unfortunately, people with intellectual and developmental disabilities (IDD) are typically left out of clinical trials. They are not alone. Other historically underrepresented populations include people with physical disabilities and people with mental illness.

WHAT IS A CLINICAL TRIAL?

Clinical trials provide critical evidence regarding whether a medical product, such as a medication or medical device, is safe and effective.

WHAT ARE THE BARRIERS TO PARTICIPATION IN CLINICAL TRIALS FOR PEOPLE WITH IDD?

According to an article published by the American Institutes for Research (AIR®) Center on Knowledge Translation for Disability and Rehabilitation Research,2 clinical trials funded by the National Institutes of Health, directly or indirectly exclude adults with intellectual disabilities. Some 20 February 2024 • EP Magazine | epmagazine.com

study exclusions specifically disallowed participation by those with cognitive challenges, reduced functional capacity, or the inability to read or write. Additionally, researchers may not have considered the need for accessible study materials, the support needed for people with IDD to participate meaningfully, or the importance of ensuring people with IDD, not proxies, provide direct input, as study participants.

WHY HAVE PEOPLE WITH IDD HISTORICALLY BEEN UNDERREPRESENTED IN CLINICAL TRIALS?

Concerns about informed consent and the capacity to understand the benefits and risks of clinical trial participation, and the potential for exploitation are often cited as reasons for excluding people with IDD from clinical studies. While important, these risks can and should be mitigated through careful attention to inclusive study design.

WHY IS THIS SUCH A PROBLEM?

Excluding people with IDD from clinical trials means the treatments used for a variety of conditions have not been evaluated to determine the benefits or the risks of use in people with specific developmental conditions. One example of this is research involving drugs used to treat Alzheimer's disease. Even though a high percentage of people with Down syndrome will eventually develop dementia by age fifty-five, very few clinical trials involving Alzheimer's disease have included people with Down syndrome.3