By Melinda Young

A study of clinical trials involving cancer drugs over the past decade shows that the problem of studies enrolling too few racial and ethnic minorities has not improved, although the issue has been raised publicly for years.1

Investigators examined more than 200 trials that included 112,000 patients, and compared study participants’ demographics to the general United States cancer population. They found African Americans were enrolled in cancer drug clinical trials only about one-fifth as much as expected, says Jonathan Loree, MD, assistant professor at the University of British Columbia in Vancouver. Researchers found that black and Hispanic groups were underrepresented consistently in trials when compared with their burden of cancer incidence.1

“We think the underrepresentation is multifactorial,” Loree says. “The reason for a disparity might vary with each system. In the U.S., the problem is a lack of access to healthcare.”

In Canada, some underrepresented minority groups, such as Native Americans, live farther away from clinical trial sites. This longer distance could be a barrier to study participation, he adds.

Investigators examining representation of minorities in studies had hoped enrollment of racial and ethnic minorities had improved over the decades, but there was no improvement, Loree notes.

“Minorities still are underrepresented,” he says. “There have been statements from the FDA and other groups that this is a priority to address, but over the past decade, we didn’t see any improvement, which suggests we haven’t done enough to address the problem.”

Respect and trust can affect recruitment of underrepresented minorities. When these are lacking, recruitment often is lower. (See article on researchers building trust in minority communities in this issue.)

“We spend a lot of time in bioethics thinking about respect for persons, but we don’t have a good way to put that into practice,” says Stephanie Kraft, JD, assistant professor, bioethics and palliative care at Seattle Children’s Hospital and Research Institute.

“A lot of people are paying attention to minority recruitment now,” Kraft says. “It’s important scientifically and from an inclusion perspective, particularly in implementation science and making sure healthcare is getting out to everybody.”

Demonstrate Respect

Researchers need to find ways to demonstrate respect to underrepresented minorities to encourage research participation, according to Kraft’s recent study.2 Another recent study revealed that researchers could increase Hispanic recruitment 15-fold by sending someone into Latino communities to educate people about the study’s topic of Alzheimer’s disease. The recruitment strategy used brief, in-person, culturally tailored educational sessions in senior centers.3

“I was testing a strategy to increase participation of Latinos in our research study,” says Jaime Perales-Puchalt, PhD, MPH, assistant professor, University of Kansas Medical Center and the University of Kansas Alzheimer’s Disease Center. “We wanted to recruit 30 Latinos, and we did this quicker than I expected,” he says.

In the first six years of a longitudinal study, researchers recruited only two Hispanic participants. One challenge was the low Alzheimer’s disease literacy among the population, Perales-Puchalt notes. Conventional recruitment messaging might not work, whereas visual messaging could succeed.

“For example, every message that I create is pictorial,” Perales-Puchalt says. “There is a picture that explains what I’m saying, and the words are short and simple, instead of overly scientific.”

Educational sessions with potential participants were interactive. “When I give this talk about Alzheimer’s disease, I encourage people to ask me questions as much as possible,” he says. “That’s a great way to know if people understand what I’m saying.”

Using Perales-Puchalt’s strategy, researchers recruited 30 Latinos within one year, from November 2017 to August 2018. This great improvement was not easy. Perales-Puchalt created a 45-minute PowerPoint presentation, in Spanish, about aging and dementia. He gave the presentation to Latino communities, educating people about the disease and the clinical trial.

“I want to emphasize that it’s not translation, it’s application,” Perales-Puchalt says. “I’m not just translating this information. I’ve gone into the community, visited community centers in Kansas City to talk with professionals who serve the Latino community,” he explains. “I’ve gone over the information, slide by slide with them, getting their feedback to make it as user-friendly as possible.” This careful process took him five sessions to complete, he adds.

Breaking Structural Barriers

Investigators who recruited African American women at federally qualified health centers (FQHCs) ran into some structural barriers in enrolling this population, says Jeanne M. Ferrante, MD, MPH, professor of family medicine and community health, and director of the New Jersey Primary Care Research Network, Rutgers Robert Wood Johnson Medical School in New Brunswick.

“The centers did not have adequate staff, space, and time to help with recruitment,” she says. “At many clinics, they were busy and didn’t have extra examination rooms. When we wanted to interview a patient, we would have to wait for a room to open.”

In some cases, researchers would find a patient willing to be enrolled and go through the informed consent process, but the person would have to wait 30 minutes for a room where they could speak privately, Ferrante explains.

“Especially when you are at a federally qualified health center that is crowded and busy, you need to speak ahead of time with clinic administrators to identify which office space is available and the optimum time to be in those clinics,” she says.

Trust is another barrier. Ferrante recalls a study in which African American women were reluctant to sign the consent form. “They said, ‘No, I don’t want to sign my name or anything.’”

It also helps to employ a community member on the research team. This would be someone with whom participants are familiar, or who has already enrolled in the study, who could talk about the study with them, Ferrante says.

“In other studies, we’ve found that it helps if we hire African American recruiters,” she says. “In this study, recruitment took longer than we anticipated. We had to recruit more staff, and didn’t have the opportunity to hire just African American women.”

Ferrante lists these additional methods to improve recruitment:

• Include pictures of the minority group on fliers;

• Keep the informed consent text at a sixth-grade reading level;

• Read the informed consent document to participants, as needed;

• Make language in the consent form more patient-friendly;

• Provide small financial incentives, such as a $25 gift card, to compensate participants for their time.

To recruit in some underrepresented minority communities, researchers need to build partnerships with the community prior to recruiting participants for a study. For instance, in recruiting Latinos for the Alzheimer’s disease enrollment study, researchers built a partnership with the centers that serve Latinos, Perales-Puchalt says.

“That’s the first thing that worked,” he says. “Go where the community is, instead of having them come to you. That’s what I’ve done.” Perales-Puchalt met potential participants at their community centers, and this also resolved the transportation barrier.

IRBs and research communities need to learn more about how to increase underrepresented minority enrollment. Studying this issue can help, he says. “We have a focus group to talk about best practices in enrolling Latinos in Alzheimer’s research,” he adds.


  1. Loree JM, Anand S, Dasari A, et al. Disparity of race reporting and representation in clinical trials leading to cancer drug approvals from 2008 to 2018. JAMA Oncol 2019; Aug 15:e191870. doi: 10.1001/jamaoncol.2019.1870. [Epub ahead of print].
  2. Kraft S. Re-conceptualizing respect for persons to improve engagement with diverse populations: What are researchers’ obligations? Presented at the 2019 PRIM&R Advancing Ethical Research Conference, held Nov. 17-20, 2019, in Boston. Poster: 33.
  3. Perales-Puchalt J, Shaw A, McGee JL, et al. Preliminary efficacy of a recruitment educational strategy on Alzheimer’s disease knowledge, research participation, attitudes, and enrollment among Hispanics. Hisp Health Care Int 2019; doi: 10.1177/1540415319893238. [Epub ahead of print].