Published on October 06, 2021

With increased awareness of the need for inclusion, equality, and diversity across many industries, the Castor team is thrilled to see an increasing emphasis on diversity of race, gender, and even geography amongst clinical trial participants. Critically, experts call for not just increased diversity on a statistical basis, but that the studied population is representative of the distribution of the disease. 

Many factors—including age, gender, weight, and a person’s ethnic background—can influence how a person reacts to a therapeutic intervention. It’s essential for clinical trials to include an appropriate spectrum of participants to demonstrate the safety and efficacy of a treatment—and if that holds true for a cross-section of individuals in the population a therapy is intended for. 

Clinical trials rely on volunteers to participate in the study, but the ability and willingness to participate is not equally distributed across demographics. It’s therefore important that volunteers are explicitly recruited from diverse backgrounds, or researchers risk biasing the efficacy data toward the ethnic and socioeconomic groups most likely to participate in research. Diversity within trials doesn’t just happen—it requires intentional study design. To this end, decentralized clinical trials (DCT) can support and accelerate diversity within clinical research. In this article, we’ll explore how DCT can successfully address the challenges of maintaining diversity within clinical research. 

The historical challenges

Patients from certain backgrounds have historically had a fraught relationship with the medical system, resulting in a lingering hesitancy to participate in clinical trials today. Due to past injustices experienced at the hands of a system that should have cared for them, many are left feeling distrustful and uncertain of new therapies—and especially of participating in the clinical research required to bring these innovations to market. 

The effects of traumatic history—and a lack of effective initiatives to recruit a diverse participant population—has deeply affected the state of clinical research. For example, a 2019 JAMA Oncology article highlighted the disparities in race reporting and diversity in clinical trials within the cancer field. In their study, they found that only 63% of the 230 trials leading to FDA oncology drug approvals over the past decade included any information about the race of their participants. Of those who did a report on racial diversity amongst participants, only 7.8% of the trials documented the “four major races in the United States (white, Asian, Black, and Hispanic)”. On average, however, 76.3% of participants were white, 18.3% Asian, 6.1% Hispanic, and 3.1% Black. According to the study, “black and Hispanic patients were consistently underrepresented compared with their expected proportion based on cancer incidence and mortality in the United States.”

Unfortunately, this is only one example of inadequate race reporting and representation within landmark trials. In addition to distrust toward medical research, other factors contributing to the lack of diversity in clinical trials include language barriers; overly rigid inclusion and exclusion criteria; and difficulty finding transportation to research sites, which tend to be disproportionately located within areas of certain demographics. Increased efforts are required to eliminate these disparities and enhance representation within clinical research.

The goal

The goal of diversity in clinical trials is to accurately represent the distribution of disease so that the efficacy of a putative therapy can be assessed in the context of its actual use. At this point, it is well-established that certain diseases and genetic disorders are most likely to occur amongst people whose ancestry traces back to certain geographic areas or historical communities. Individuals in ethnic groups often share genes that may predispose one to a certain disease, or alter the pharmacokinetics of medication.

In other words, the clinical trial should focus on the patients who are most likely to need therapeutic intervention. But how can such patients be most effectively recruited and included in a study?

Possible solutions

In November 2020, the FDA published a guidance document with specific, actionable suggestions on how clinical trials can enhance diversity. The most interesting part? Many of these suggestions can be easily implemented through the use of decentralized trial methods

Here are some of the specific suggestions made by the FDA, and how DCT supports them:


According to the FDA’s recent guidance, researchers need to ensure “that clinical trial sites include geographic locations with a higher concentration of racial and ethnic minority patients and indigenous populations, as well as locations within the neighborhoods where these populations receive their health care, because restricting clinical trial sites to selected geographic locations may limit the ability to enroll a diverse trial population.” 

DCT solution: DCT makes the enrollment process easier and more accessible to a wide range of participants. Marketing for many trials can be done online, therefore reaching a large target audience. By removing the need for participants to travel to the research site, sponsors can recruit participants from diverse geographic locations if these best accurately represent the disease. 

Site staff

The recent FDA guidance asks researchers to consider “diversity when selecting health care providers and study coordinators to assist with clinical trial recruitment.”

DCT solution: Participants may prefer a health care provider of their same cultural background for many reasons—shared language, perspectives, experiences, etc. By leveraging remote technology and removing the need for site staff to actually be on-site, trials can recruit site staff from a larger demographic.

Informed consent process

The FDA asks researchers to consider “using ‘electronic informed consent’ to allow participants to read and sign necessary forms remotely instead of traveling to a clinical trial site while ensuring that all potential participants, including those with literacy issues, understand all necessary information.”

DCT solution: An eConsent solution allows patients to go through the entire enrollment process online, thus eliminating possible travel difficulties. Each patient’s personal needs can easily be met through language translation, audio and video recordings, and additional information to help patients fully understand the details of the trial. As an added bonus, eConsent can be done at a participant’s preferred pace. Patients are also able to discuss their decision with family and friends and meet with a researcher via videoconferencing to have all their questions answered. All of these factors result in confident decision-making.

Reduced site visits

Another piece of advice from the FDA asks sponsors “to think about reducing visit frequency, when appropriate, in addition to considering whether flexibility in visit windows is possible and whether electronic communications, such as phone, email, social media platforms, or other digital health technology tools can replace site visits and provide investigators with real-time data.”

DCT Solution: Throughout the entire duration of a trial, DCT allows site teams to remain in constant contact with trial participants—sometimes without participants ever having to travel on-site at any point during the trial! A range of digital tools can be deployed to stay connected, resolve questions, and monitor participants’ health status. Decentralized clinical trials (DCT) are collecting many kinds of data remotely through everything from wireless vital sign monitoring patches to mobile-connected products. These innovations benefit both site teams and patients—and make it much easier for trials to retain patients from remote areas. 

The responsibility

Decentralized methods may prove to be the lynchpin in making true progress in the urgent pursuit of achieving true diversity within clinical research. At the same time, this group of tactics is not a magic bullet. Most importantly, clinical researchers must commit to greater diversity within their trials and create metrics to measure progress. It may also mean going above and beyond former recruitment efforts. Some approaches have seen success by prioritizing a helpdesk to troubleshoot technical issues with study equipment or online portals along the way—thus increasing participant confidence and accommodating those who may have less experience with certain digital tools. 

The time is now for diversity within clinical trials. Fortunately, decentralized methods support patient-centric trials and can enhance participant trust while also benefiting site teams. Learn more about how you can use Castor DCT in your next clinical trial here.

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