COVID-19 Highlights Need to Overcome Inclusion Barriers in Research Studies

Black woman speaks into a microphone at a conference as other conference attendees look on

A meeting to discuss the underrepresentation of people in biomedical research evolved, due to the COVID-19 pandemic, into a more detailed study of how inclusion is essential to reducing health inequities.

As detailed in a paper published in the Journal of Clinical and Translational Science, 118 individuals from 75 Clinical and Transformational Science Award (CTSA) Program hubs assembled in March 2020 at a CTSA Program Un-Meeting to discuss barriers and solutions to the underrepresentation of “special populations”—such as underrepresented racial, ethnic, sexual or gender identity groups; older adults; and pregnant women—in research. These populations often are impacted by adverse social determinants of health and by bias in access to and treatment in healthcare settings that reduce access to participate in research.

While the group planned to summarize their findings on underrepresentation in a manuscript, the pandemic forced researchers to broaden their scope to look at how the inclusion of representative populations in research is vital for reducing health inequities.

“The exclusion of special populations in research studies is a pervasive issue,” said lead author Susanna A. McColley, M.D., associate clinical director for child health at the Northwestern University Clinical and Translational Sciences Institute and professor of pediatrics, Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago. “COVID-19 continues to have a devastating impact on special populations, with increased morbidity and mortality, and it is greatly amplifying how exclusion can increase health inequities.”  

Structural competency framework

While previous reviews of underrepresentation examined factors influencing research participation and retention, few focused on the barriers to participation in biomedical research. Using a lens of “structural competency,” the group emphasized the importance of social conditions and institutional practices as drivers of health inequity and research participation.

Following a comprehensive review of existing literature, researchers identified several barriers and solutions to the recruitment and retention of underrepresented populations in research, including:

  • People from racial and ethnic minority groups may hesitate to participate in research due to distrust and concern that research staff would treat them as “guinea pigs” due to long-term mistreatment in medical and research settings. Engaging in community-based participatory research and building community partnerships can improve recruitment and retention.
  • Factors affecting older adult participation include the need for transportation to study sites, misunderstanding of study procedures and side-effect concerns. Recruitment focused on utilizing methods of contact appropriate for older adults, such as TV and radio announcements, may improve recruitment.
  • Lower socioeconomic status and lack of childcare or transportation may impede research recruitment among pregnant women, children and adolescents. Flexible approaches to recruitment and retention are beneficial, including targeted and tailored interventions.

COVID-19’s impact

A review of studies published during the COVID-19 pandemic revealed specific challenges to COVID-19 research impacting representation.

Many special populations face a greater risk of death or hospitalization from COVID-19 while also being underserved by the healthcare system or being excluded from research. For example, while older adults and pregnant women are often excluded from clinical trials of new therapies due to safety reasons, these groups have high morbidity and mortality from COVID-19.

Researchers assert that the ongoing exclusion of the most adversely affected populations from COVID-19 research studies may have serious repercussions and result in a lack of understanding of treatment effects, dosing, side effects and potential benefits of treatment.

As COVID-19 research has highlighted longstanding issues in the recruitment and retention of special populations, they suggest that further research be done to address structural barriers to participation derived from adverse social determinants.


This work was funded in part by the University of Rochester Center for Leading Innovation and Collaboration (CLIC), under Grant U24TR002260 and supported by CLIC’s Synergy Paper program.