Not everyone experiences the same disease in the same way. Variations in how diseases affect individuals highlight the importance of diversity in clinical trials.

A lack of inclusion can skew the results, leading to conclusions that a potential new treatment is effective for only a specific population while overlooking others.

In this article, we’ll explore the role of diversity and inclusion in clinical trials and how they contribute to producing more accurate and reliable results.

The current landscape of clinical trial diversity

Before delving into the role of diversity and inclusion in clinical trials, it’s essential to understand the current landscape.

Since the 1990s, the number of countries contributing to global clinical trial data has grown significantly. However, more than half of all clinical trial sites are still located in the United States, which limits the diversity of participant populations.

For example, in the 1990s, approximately 92% of clinical trial participants were white. By the 2000s, this figure dropped to 86%, and by 2020, it had further decreased to 75%. Yet, despite these improvements, diversity remains a persistent challenge.

According to recent NIHR data, randomised controlled trials (RCT) participants by ethnicity are as follows:

  • 86% White
  • 5% Asian
  • 4% Black
  • 1% Mixed
  • 3% Other
  • 2% Unknown

Additionally, the overall mean age of RCT participants was 51, with the mean ages of participants ranging from 2 to 86 years old.

Beyond race and age, socioeconomic diversity also remains an overlooked issue in clinical trials. Many studies focus on participants from specific geographic regions, which can result in a lack of variation in economic or educational backgrounds. This homogeneity may simplify recruitment efforts but undermines the ability to understand how treatments perform across different socioeconomic groups.

Barriers to diversity in clinical trials

Despite ongoing efforts, achieving diversity and inclusion in clinical trials remains a challenge. Several factors contribute to this issue, including the following:

Mistrust

Mistrust in the medical system is a significant barrier, particularly within certain communities. This distrust often stems from historical injustices or negative past experiences with healthcare. When one member of a close-knit community feels mistreated in a medical setting, it can create a ripple effect, causing others in that community to become wary of engaging with the healthcare system, including clinical trials. As a result, potential participants from these communities may be reluctant to volunteer.

Access limitations

Access to resources is another major obstacle. Many individuals lack the financial, technological, or logistical means to participate in clinical trials. On the flip side, local clinics often face resource constraints themselves, limiting their ability to recruit a more diverse pool of participants. These limitations might include insufficient funding to market trials effectively or an inability to accommodate larger, more varied groups of participants.

Transportation

Transportation challenges can prevent eligible candidates from participating. Clinical trials often require visits to a specific site, and participants without reliable transportation may find it difficult to meet these requirements. While public transportation may be an option, it doesn’t always reach remote or under-served areas where potential participants live, further exacerbating this barrier.

Language barriers

Language differences present another hurdle. Potential participants who don’t speak English may struggle to understand the requirements or communicate effectively with clinical staff. When trial administrators or researchers lack multilingual support, these language gaps can exclude non-native speakers from participating. These barriers not only limit diversity in clinical trials but also hinder the quality and applicability of research outcomes. Without a diverse participant pool, the results of clinical trials may not accurately reflect the effectiveness or safety of treatments across different populations, ultimately affecting the broader healthcare landscape.

Why diversity and inclusion in clinical trials matter

A variety of factors influence how individuals respond to medicines or treatments. This is why diversity among participants in clinical trials is crucial as it ensures that medical research reflects the needs of all people, not just a select group.

Consider the process of testing a new drug where researchers aim to evaluate its effectiveness and safety profile. However, if the trial primarily includes participants from a single demographic, the findings won’t provide a comprehensive understanding of how the drug affects different populations.

As we’ve seen, the majority of clinical trial participants are white and based in the United States, with limited representation from other racial and ethnic groups. Additionally, older individuals are often underrepresented in these studies, despite their growing population and greater reliance on medical treatments as lifespans increase.

When clinical trials only include young and middle-aged white adults, there is little data on how the drug impacts other racial and ethnic groups. Since individuals respond differently to medications, therapies, and treatments, a lack of diversity in trials results in data that cannot be fully trusted to represent the broader population.

This is why health equity needs to become a major focus point for clinical trials going forward. Health equity involves ensuring that advancements in medicine meet the needs of everyone, regardless of socioeconomic background, gender, ethnicity or race.

To achieve this, clinical trials must place a greater emphasis on diversity and inclusion. Participant demographics should reflect a balance across different racial and ethnic groups, genders, and socioeconomic statuses. Only then can clinical trials produce findings that are accurate, equitable, and applicable to all.

What next?

Diversity in clinical trials is essential for producing accurate and reliable results. Without a representative population, researchers cannot fully understand how a treatment impacts different individuals. This lack of inclusivity limits the applicability of the findings and can leave significant gaps in medical knowledge.

If you’re interested in participating in a clinical trial, visit our Contact Page to learn more.

 

References

https://www.nature.com/articles/d41586-018-05049-5

https://www.nimhd.nih.gov/resources/understanding-health-disparities/diversity-and-inclusion-in-clinical-trials.html