The Importance of Diversity in Clinical Trials

SCTR’s experts from the Integrating Special Populations (ISP) Program participated in a Q&A addressing diversity in clinical trials. Why do we think this is an important conversation to share? We know that people are diverse and may react differently to the same treatment based on individual factors related to their gender, age, race, and ethnicity. More diversity is needed in clinical trials so that we can be more confident that results are generalizable to the populations most impacted.

The aims of ISP are to (1) develop, demonstrate, and disseminate innovative strategies to overcome barriers to clinical and translational research (CTR) awareness and participation for underrepresented communities, and (2) provide consultation, training, and innovative resources to investigative teams to enhance recruitment and inclusion of special populations in CTR.

The ISP program is managed by SCTR, one of more than 60 CTSA (Clinical and Translational Science Awards) program hubs across the nation. The ISP program helps study teams integrate special populations into a research study. This is a consideration that should not be limited to health disparities research, but rather is a strategy every research study should embrace.

What follows is the first of a 2-part series featuring highlights from the group discussion among our experts. In part 1, we learn how Special Populations are defined, why the inclusion of these populations is so important in clinical and translational research and hear about some lessons learned by our experts.

Part 2 features a review of the services and resources available to assist in recruiting special populations, offers an introduction to some common pitfalls, and provides some expert strategies to increase the likelihood of success in integrating special populations.

What are special populations?

Cristina López
When we talk about special populations, we’re really looking at the populations that are particularly vulnerable or have been underrepresented in research. Typically, think of racial and ethnic minorities, rural populations, non-English speaking populations, and people living with HIV. We’re looking at military populations, women who are pregnant, people who are imprisoned… there are several layers of special populations.

It's really just making sure that you're being representative of all segments of the US population, considering sexual and gender minorities, knowing who has not been represented in research previously, and making sure that they are involved now.

Why is the participation of special populations in clinical and translational research important?

Marvella Ford
Back in the 1920s and 1930s, a lot of the large research studies included primarily white men. They were not representative of the US population. We want to make sure that we have a goal of inclusivity, specifically including populations that have historically been underrepresented in clinical trials (those groups that Dr. Lopez just described).

That kind of speaks to the point of why it's important. Why do we need inclusivity? And that's related to the distribution of the risks and benefits of the research. We want to make sure that the risks and benefits of the research are equitably distributed across the population, particularly among the groups that experience whichever condition is being researched.

It's a little unnerving to be in 2022 and realize that nationally minoritized populations typically comprise about 10% of genetic genomic studies. We know that healthcare is moving toward personalized medicine and that if these groups are not included in the research, we won't know how applicable the results are to members of this group. A patient may be sitting in their doctor's office, and their doctor is thinking about the paper they just read of a large study that only included a 1% minoritized population, wondering “should I give this treatment to this patient? Is it going to work for them?”

We want to make sure that we have representation of the population in clinical trials so that at the end of the day we'll have a better sense of how well the therapies, treatments, or interventions will work in these different population groups.

“We want to make sure that the risks and benefits of the research are equitably distributed across the population, particularly among the groups that experience whichever condition is being researched.” -- ISP director Marvella Ford, Ph.D.

Cristina López
The only thing I would add to that is pushing back on folks who say “well, I'm not a health disparities researcher.” We're not talking about health disparities researchers. We're talking about how every research study should have a representative population. It's not about health disparities. Researchers, whatever you are studying, you should have a representative population. If you’re in Charleston and the Charleston population is 30% African American, you should have a representative population so that, as Dr. Ford said, the risks and benefits are equitably distributed across groups and there’s generalizability. Even if you have a treatment that works, if it's not going to be accepted, then we're not getting the treatment outcomes that we want.

Stephanie Gentilin
At its foundation, what we're trying to do is address the key concept of justice as it was described in the Belmont report. It's trying to take that fairness and that representation and recognize that no one group should disproportionately reap the benefit or carry the burden of clinical research. We need to make sure it's equitable. It goes back to that fundamental principle. We've been making incremental steps toward that.

Marvella Ford
Justice is something that applies to all investigators. We should all be striving for justice in our research. It's not limited to cancer or health disparities. All investigators should be striving for justice.

Kimberly Brown
There are five broad categories that we talk about when we talk about the inclusivity of special populations: 1) ethics (the Belmont principles of respect for persons, beneficence, and justice), 2) generalizability, 3) relevance to these populations, 4) funding, and 5) impact. We know that it is important to include these populations so that you can be funded and that including these populations will lead to a greater impact and health outcomes.

What has been your experience recruiting special populations?

Cristina López
I think one of the most memorable moments for me is when I was working clinically with migrant workers, who were predominantly undocumented. They didn't necessarily speak English, but their kids were born here and would be eligible for a lot of the research studies that were being done in pediatrics and behavioral health. There was the impression that they wouldn't want to participate so nobody asked them. To be inclusive, it’s better to ask than assume. This was a while ago now, and I hope provider and research team bias is more well-known and that this doesn't continue to happen.

“We're not talking about health disparities researchers. We're talking about how every research study should have a representative population.” -- ISP co-director Cristina López, Ph.D.

Working with non-English speaking populations as participants became a very salient moment in my training. When I came to MUSC, I wanted to make sure, if possible, to include special populations in research, especially if I provided translated informed consent.

Currently, I work with people living with HIV and also experiencing traumatic events. Sadly, you need to be very sensitive to the historical stigma, not just of research, but of living with HIV. When someone says they no longer want to participate in a study, we appreciate the feedback but should consider what behavioral health support they may need, or maybe just consider their comfort level with the study team. While we may have just written them off as a withdrawal, it may be an issue of connecting them with resources or providing them with the help they need to be a successful participant.

Marvella Ford
Picking up on what Dr. Lopez said, I think one of the most important points for me in recruiting special populations is paying attention to those social determinants of health and understanding that participating in our study may not be the most important component of that person's life at that time. They may have other things going on. What's been beneficial for me is trying to build some type of service into a research study. Patient navigation has become that service. When we talk about recruiting special populations, navigators can help.

The navigators function like global positioning systems. Like when we have GPS systems in our cars we can plug in an address and get turn-by-turn instructions on how to get there. They help when we identify people in the community or our patient population who are potentially eligible for studies and who are members of special population groups. They reach out to them and find out whether they have any competing needs that might prevent them from enrolling in the study. Do they have childcare issues? Do they have transportation issues? Patient navigators are exceptional resources in helping to meet the social determinants of health-related barriers.

What could keep people from participating in a trial? I always remember the first large clinical trial that I led focused on recruiting black men for prostate, lung, and colorectal cancer screening trials. We learned pretty quickly in that initial study that the partners of the men played a very important role in their participation. Moving forward, our focus included patient navigation. We also navigated the wives or the partners or the spouses of the black men that we were screening.

Because people don't exist in isolation, they often exist in the context of families or close friends.

And so particularly in special populations, it's important to ask the person sitting in front of you as you consent if there is anyone else in their life who will help them to decide whether to consent to the study.

Sometimes people will say yes to us, they'll sign the consent form and then we'll get a call a few hours later, or a day or two later, from someone, particularly with older adults saying, “you know, I talked to my son or daughter, and they said, I don't need to be in that study.” 

“And so particularly in special populations, it's important to ask the person sitting in front of you as you consent them if there is anyone else in their life who will help them to decide whether to consent to the study?” -- ISP director Marvella Ford, Ph.D.

That could have been avoided if we had asked the person, “is there anyone else who's going to help you decide to consent to the study?” Let's get them on the phone. Let's bring them in. Let's get them on a virtual meeting. Let's talk through this together.

At what point during the study life cycle should a consultation be requested?

Cristina López
Ideally, in the beginning, you've already thought about recruiting special populations based on prior work or based on a consultation with ISP. But we can also help put out fires. If you're toward the end of recruitment and wondering why your sample is 85% white, some strategies can be applied there, but really, the stronger approaches are built in, like Dr. Ford said, at the time of consent. You’re talking about who else would be able to make this decision with a participant, looking at different budgeting options for recruitment, and considering your inclusion/exclusion criteria to make sure that you are not inadvertently excluding a population because your criteria are too tight.

Meet our Experts

Marvella Ford, Ph.D., has 17 years of research experience at MUSC, where she is a Professor in the Department of Public Health Sciences as well as the Associate Director of Population Sciences and Cancer Disparities, and Director of Community Outreach and Engagement, in the Hollings Cancer Center. She is a behavioral scientist with a strong track record in cancer disparities research, particularly recruiting and retaining diverse populations for cancer research studies and intervention design and conduct, with expertise in collaborating with local and national stakeholders to inform her research.

Cristina López, Ph.D., is an Associate Professor and has 21 years of research experience, including working on externally funded research projects recruiting under-represented populations (e.g., Spanish-speaking populations, rural Black youth, people living with HIV, and other trauma-exposed populations) as primary investigator in the past 10 years. In her current role as SCTR’s ISP Co-director, she helps in the delivery of consultative services, lectures, and focus groups to support research teams in their enhancement of representative samples in research activities across the institution.

Stephanie Gentilin, MA, CCRA, directs the SUCCESS research support services center and has over 28 years of clinical research experience. She oversees the delivery of SCTR’s high-quality, expert consultative services to investigators and research staff, and works to develop institutional research policies aimed at streamlining processes and breaking down barriers in conducting translational research.

Tara Pittman, MA, CCRP, has 14 years of research experience at MUSC. Before her role with SCTR, she worked as a program coordinator for research studies related to drug/alcohol addiction and trauma. She has also worked with the veteran population, coordinating trials at the Ralph H. Johnson VA Medical Center. In her current role as SCTR’s recruitment manager, Tara works in partnership with the Integrating Special Populations team to help identify novel and impactful ways to recruit particular groups, especially through local partnerships, community champions, and focus groups with populations of interest.

Kimberly Brown, MPA, joined MUSC 2 years ago, bringing with her an extensive background working in community-based advocacy organizations with various populations including refugees and LGBTQ+ individuals. In her current role as SCTR’s Special Populations (ISP) and Community Engagement (CE) coordinator, she supports team efforts to ensure that all MUSC studies are recruiting participants who are representative of our community through education, programming, consultation, and community connections.

Related Links 

SCTR’s Integrating Special Populations Program

SCTR’s Recruitment Program