Why Diversity in Diabetes Clinical Trials Is Essential for Better Care

Key takeaways:

Despite having higher rates of diabetes and diabetes-related complications, Black, Hispanic, and Indigenous individuals are significantly underrepresented in clinical trial research.
Diabetes care isn’t one-size-fits-all – if most research is based on one group of people, it can lead to less effective treatments for others. Barriers to clinical trial participation include language differences, racial bias, time and cost, and more.
A more inclusive research approach will result in more effective treatments, better technology, and improved outcomes for everyone living with diabetes.

Clinicians and healthcare policymakers often use the term “evidence-based” to describe their decisions – meaning that the best available data should guide the care patients receive. But where does this “evidence” come from?

Clinical trials are considered the gold standard for evaluating new treatments. They are carefully designed to provide accurate results, ensuring that factors like age and other health conditions don’t influence the findings. However, the populations most affected by diabetes – and who could therefore benefit greatly from new treatments being studied – are often the same groups left out of diabetes trials.

On top of shaping the future of diabetes care, research participants can also personally benefit from clinical trials by receiving additional medical attention through regular study visits, financial incentives, and the chance to try new (and potentially expensive) treatments that aren’t yet available to the public for free.

“Imagine a place where you can, at least for a time, have access to these interventions – at no charge – by participating in clinical trials,” said Janet Brown-Friday, ADA President of Health Care & Education, in a 2023 speech.

Despite all the opportunities clinical trials offer, many of those who could benefit the most from these interventions are not adequately represented in these studies. This is the reality for millions of people of color in the U.S., where the majority of diabetes clinical trial participants are white.

The current state of diabetes clinical trials

According to the Centers for Disease Control (CDC)’s most recent National Diabetes Statistics Report, the prevalence of adults with diabetes in 2019-2021 was lowest in non-Hispanic white adults (7%) and highest in communities of color, as shown in the chart below.

In stark contrast, a recent review of type 2 diabetes clinical trials from the past 20 years found that only 24% of the participants were from non-white ethnic or racial groups.

Another study found that 85% of participants in clinical trials for type 1 diabetes technology identified as non-Hispanic white. Despite FDA recommendations for increasing representation of racial and ethnic minorities in clinical trials, none of the trials in this study reported a specified recruitment target for different racial or ethnic minority groups.

This is not just the case for clinical trials. Studies show that Mexican American and non-Hispanic Black adults with diabetes are more likely to be undertreated, particularly for blood sugar management. The same goes for children and adolescents with type 1 diabetes; research reports non-Hispanic Black or Native American youth had a 1.2% higher A1C than non-Hispanic white youth.

This translates to significantly worse health outcomes for people of color with diabetes. For example, non-Hispanic Black or African American adults have higher rates of diabetes-related kidney disease, lower extremity amputations, visual impairments, hospital admissions, and mortality rates compared to non-Hispanic white adults with diabetes.

These trends are seen globally, and the data has been clear for decades. Clinical trials play a vital role in improving people’s lives as research data is essential to developing safe and efficient new therapies, but more needs to be done to ensure the results apply to everyone. The disparities in clinical trial representation and health outcomes highlight a critical need to address the barriers that prevent underrepresented racial and ethnic groups from enrolling and participating in clinical trials.

Why are clinical trials not reaching everyone?

Alejandra Marquez, who leads the Hispanic Initiative at DiabetesSisters and lives with type 1 diabetes, spoke about her experiences participating in clinical trials after moving to the U.S. from Venezuela.

Marquez first heard about the option to participate in diabetes research through her community at DiabetesSisters. “Before that, I had never heard of these trials and wouldn’t have known about them if it wasn’t for DiabetesSisters,” she said.

Many people aren't signing up for clinical trials simply because they don’t know about them – clinicians have limited time during appointments to discuss ongoing research with their patients, so people often learn about clinical trials through word-of-mouth.

“We’re just not being asked,” said Kyle Banks, founder of Kyler Cares, a nonprofit foundation that provides grants for insulin pumps and continuous glucose monitors (CGM) for kids and young adults living with type 1 diabetes.

“Even if physicians of color are in the room, there's not enough time during these appointments to support patients in those settings the way they need to be supported, to make sure the information that is being shared is actually sinking in,” he said.

That is why outreach programs like DiabetesSisters and Kyler Cares are so important for clinical trial recruitment – they provide a means of connecting to underrepresented populations with diabetes to help them learn about current clinical trials.

Marquez also realized that many of the surveys, focus groups, and trials she signed up for did not have a Spanish language option. She said that language barriers are a major challenge for Hispanic individuals who would be interested in participating in clinical trials, but are afraid to do so because of communication issues.

While “Hispanic” refers to a person with ancestry from a country whose primary language is Spanish, it is important that researchers not treat this population as a single entity. “Each Spanish-speaking country has their own culture, traditions, foods, and even different ways of managing diabetes,” Marquez said.

Enhancing the representation of Hispanic individuals in diabetes clinical trials isn’t just enrolling participants from Spanish-speaking countries. It’s also about hiring and training research staff familiar with cultural norms that could influence a participant’s willingness to participate in research.

“When you have someone on the research team who is from your background and can help you connect with that community, it becomes a lot easier to participate in a meaningful way,” Marquez said.

female patient listening to doctor holding tablet

Cultural competence, which is the ability to understand, appreciate, and interact with people from diverse cultural backgrounds, also plays a major role in the conversations that providers and researchers are having with people of color who have diabetes.

A review of clinical trials that evaluated the effectiveness of culturally tailored lifestyle interventions in Black adults with type 2 diabetes showed that programs designed to address the needs and preferences of specific cultural groups saw significant progress in diabetes knowledge, which was associated with improvements in A1C levels.

Another study that tested a culturally tailored telemonitoring program for Hispanic/Latino individuals with type 2 diabetes found significant improvements in A1C levels and blood pressure after six months. The participants self-monitored their vital signs daily, had weekly telehealth visits with a nurse, and were provided educational videos to view throughout the program (with all components delivered in the participants’ language of choice, English or Spanish).

Increasing awareness of clinical trials, providing information about them in multiple languages, and ensuring research staff demonstrate cultural competency are crucial first steps in improving clinical trial diversity.

Clinical trial access and retention

“Once people are in a trial, keeping them in is another issue,” said Banks. “Researchers and clinicians need to have a better understanding of the life circumstances that get in the way of people caring for themselves, like getting time off work or finding childcare for appointments.”

Time and cost are significant barriers that may prevent a participant from seeing a trial all the way through. Many may be balancing multiple jobs or have family responsibilities such as caring for children or relatives. Even if studies provide financial compensation, there may be hidden costs for participating, such as needing transportation to visit trial sites and missing work.

“As trials are being designed, these barriers need to be considered so that adjustments and modifications can be made to support the people participating,” Banks said.

One clinical trial addressed these barriers by employing retention strategies. For example, researchers created flexibility in data collection (like providing several formats for completing surveys and accepting mail-in A1C test kits), as well as improved communication by providing a helpline for participants to ask study-related questions. They also focused on community building by regularly updating clinics with the study’s progress, offering a newsletter about healthy living with diabetes, and emailing personalized birthday cards to participants. At the end of the study, over 90% of participants stayed in the trial.

Since the COVID-19 pandemic, telehealth has become popular and made communication between providers and patients easier. In addition, virtual care removes some of the challenges (for example, transportation) with in-person appointments. Clinical trials have also successfully adopted virtual visits to gather data remotely. A review of trials in Black and Hispanic people with diabetes found that telehealth interventions were associated with a significant reduction in A1C levels compared to other forms of routine care.

The role of trust and implicit bias

While the practical barriers mentioned above can be addressed by making trials more accessible and flexible, there are also complex, systemic factors that play a large role in preventing racial and ethnic minority groups from participating in clinical trials. These factors include a historical mistrust of the medical system, socioeconomic disparities, implicit bias, and a lack of culturally competent care, all of which contribute to ongoing health inequities.

One of the principles of the American Diabetes Association (ADA)’s Health Equity Bill of Rights is “the right to participate in clinical trials without fear.” While it may seem like the disturbing history of clinical research on minority groups is a shameful remnant of the past, its impact continues to fuel a distrust of the medical system today.

Image of Dr Ananta Addala — Dr. Ananta Addala

Dr. Ananta Addala, a Stanford University pediatric endocrinologist who works towards addressing disparities in pediatric type 1 diabetes outcomes, reminds us how this history impacts health outcomes for racial and ethnic minority groups today.

“We’ve designed a lot of our structures without accounting for folks who have historically been marginalized, or frankly, hurt by medicine,” Addala said. “Acknowledgement is the very first step and lays the groundwork for the fact that we should do better.”

Banks added that generational differences also play a role in the varying levels of distrust towards clinical research. Older individuals are more closely connected to a history that has spurred skepticism of trial research, but this doesn’t mean that young people of color are unaffected.

Studies have consistently shown poorer health outcomes and lower use of life-changing diabetes technology in youth with lower socioeconomic status, even though automated insulin delivery (AID) systems have proven more effective than conventional insulin therapy for youth with type 1 diabetes. A meta-analysis of clinical trials showed that AID use was associated with improved time in range, better sleep, and improved psychosocial states in children and adolescents with type 1 diabetes. However, the majority of participants in these trials were non-Hispanic white, college or graduate degree holders, and privately insured.

Addala’s research has shown that implicit bias, or the unconscious attitudes, stigma, and stereotypes people have that affect decision-making, could play a role in providers' recommendations for diabetes technology. While implicit bias against race and ethnicity is prevalent, the study showed that implicit bias against public insurance is also common.

“We really mean, as a society, to do well and hold ourselves to a higher standard. On paper, it seems like it matters to everybody – yet we keep not doing it,” said Addala.

Time for action

For this reason, Addala is taking action and spearheading research that focuses on building the evidence needed to address such disparities. The BEAD-T1D trial, for example, is currently recruiting people aged 12 to 21 years with type 1 diabetes to improve representation of youth in scientific research and better understand the barriers and facilitators for technology use in this population. The study will focus on both the family and providers to identify drivers of disparities, and assess how a brief intervention could increase technology uptake among youth with type 1 diabetes.

“The goal of including both the family and clinician arms is to build an intervention that can start replacing some of the structures we rely on,” Addala explained. “We can’t change the structure of things like how a state runs its health insurance, but we can build parallel systems and operationalize the actions we can take as physicians, caregivers, and people living with type 1 diabetes to make sure some of those gaps can be bridged.”

Addala’s team will also be assessing these intervention strategies in a trial for youth with type 1 diabetes under the age of 12.

Although there is still much work to be done, several studies have demonstrated that ensuring equitable participation in clinical trials can improve outcomes for medically underserved individuals or populations who lack adequate access to healthcare services.

Project ECHO, for example, is a model that connects primary care providers with specialists via video conferencing so that they can be trained on how to handle complex cases. This may empower primary care doctors to reach patients in underserved communities who may not be able to follow up with specialists regularly.

A trial that assessed Project ECHO in a highly diverse and historically underrepresented group of people with diabetes saw significant increases in CGM and insulin pump use, as well as a decrease in the amount of participants with A1C levels greater than 9%.

Another study that assessed what would happen if non-white youth with type 1 diabetes received and adhered to the same diabetes treatment regimens as non-Hispanic white youth found that everyone’s A1C improved by 0.33%.

“Supporting our vulnerable populations means we’re actually supporting everybody,” Addala added.

Moving forward

ADA President of Health Care & Education Brown-Friday’s call-to-action starts with acknowledging past unethical practices to prevent their repetition, but it doesn’t end there. After this acknowledgement comes a need to address unconscious and implicit biases in recruitment.

She also explained that medical researchers should use knowledge about which groups are more likely to be affected by a given disease, and go into these communities so they have the opportunity to contribute and benefit from the research. Finally, research teams must reflect the diversity of clinical trial populations to rebuild trust and improve outcomes.

The path forward requires a collective commitment to change, not just within clinical research, but across the entire healthcare system. By actively engaging underserved populations, addressing barriers to trial participation, and fostering trust through culturally competent care, we can ensure that advancements in diabetes treatment are truly inclusive.

The progress we make in improving diversity in diabetes clinical trials will ultimately benefit everyone, because when we support those most at risk, we raise the standard of care for all.

Interested in learning more about ongoing clinical trials and helping shape the future of diabetes care? Below is a list of trials that are currently recruiting underserved populations:

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