The Importance of Diversity in Alzheimer's Research Participants

Doctors use Alzheimer's research to understand the best way to treat each person. Because differences between people can change the way they respond to a drug, diversity in research is important.

Age, gender, and ethnicity all affect how well a treatment works. Because of this, research studies must include a wide variety of people. This can help us treat everyone with Alzheimer's disease as well as possible.

The US Food and Drug Administration (FDA) and the National Institutes of Health (NIH) enforce policies that increase clinical trial diversity. But non-white people continue to be under-represented in US clinical trials.¹

Why is participant diversity important in Alzheimer's research?

When clinical trials lack diversity, their findings apply to only certain people with Alzheimer's disease. Participant variety helps expand research findings to more people. For example, drug safety and effectiveness may vary between people of different ages. Some people metabolize drugs differently, which means they need different dosages.²

The only way to discover these differences is to make sure clinical trials include more diverse people. This means including people with Alzheimer's of different:¹

• Races and ethnicities
• Genders
• Education levels
• Income levels
• Ages

Why do clinical trials struggle to include diverse people?

People of color are more likely to have Alzheimer's disease than white people. But people of color are under-represented in clinical trials. According to a 2021 study, white participants make up over 90 percent of clinical trial participants. About 5 percent of participants are Latinx. Only 1 percent of participants are Black.^2,3

The lack of diversity is partly due to poor study practices. Problems recruiting people to participate and enrolling them in studies are common. Past racism in medical research has led some people to mistrust the system. Recruitment plans often do not account for this mistrust. But, many people from under-represented populations are willing to join clinical trials.²

Another cause can be the criteria (standards) set for a person to join a clinical trial. To qualify to enroll, a person may need to:²

• Not have other medical conditions
• Have a caregiver who:
• Can attend every visit with them
• Lives in their home
• Meet education and language requirements, such as fluency in English

Clinical trials use these conditions to ensure participants complete the study as designed. But vague or unnecessary criteria can cause recruiters' implicit (unconscious) biases to influence participant selection. This has the effect of reducing the number and types of people who may join the study. And it often excludes people who are:²

1. Older
2. Female
3. Non-white
4. Less educated
5. Less wealthy

How can we improve participant diversity in Alzheimer's research?

One way to improve diversity is to use better recruitment methods. The NIH has a national strategy to increase inclusion in Alzheimer's research. The goal of the strategy is to involve more diverse people by:^4,5

• Increasing potential participants' awareness and health literacy
• Training the people who select participants to reduce implicit bias
• Engaging local communities
• Building a science of recruitment

Improving trust in medical institutions is important. Trust can increase public support and participation in clinical research. Building partnerships with community members well before trying to recruit from that community can help develop this trust. Direct communication with participants can maintain this trust. Community partnerships can also be used to improve public awareness and health literacy.⁵

Increasing the diversity of research staff can also improve participant diversity. People are more likely to join a clinical trial if they are invited by someone of the same race/ethnicity. So a more diverse workforce can lead to a more diverse set of participants.⁶

Changing enrollment criteria can also help improve diversity. The goal should be to avoid excluding anyone who shows an interest in participation. This includes:^2,5

• Better definitions for when medical conditions exclude someone
• Providing test materials in different languages
• Providing interpreters
• Screening for intellectual disabilities rather than a specific level of education
• Being more flexible with caregiver requirements
• Finding ways of getting informed consent from people with low or no literacy without written materials
• Using tests not influenced by education and culture