The Relationship Between Participant Diversity and DCT Use in Clinical Trials

Ken Getz, MBA, Executive Director and Research Professor, Tufts Center for the Study of Drug Development, Tufts University School of Medicine

Improved access to clinical trials, particularly among underserved communities, features prominently in the value proposition of decentralized solutions use in clinical trials. A growing body of evidence is characterizing ways that virtual and remote solutions use may not only improve access but also may fall short and/or present new challenges that must be mitigated.

In one study—conducted in 2023 among 11,235 global respondents by the Center for Information and Study on Clinical Research Participation (CISCRP)—prospective and past clinical trial volunteers viewed decentralized clinical trial (DCT) solutions favorably, but with some caveats. Between 90% and 95% of respondents in each of four primary racial or ethnic groups—Asian, Black and of African Descent, Hispanic and Latino, and White— considered it “very” or “somewhat” important to have in-person, remote, and virtual study visit “options.” Specifically, these options included televisits, home visits, local and specialty labs and facilities, and wearable and mobile devices.

Each racial and ethnic group also expressed a high comfort level (70%–85%) using various remote and virtual solutions. However, between 50% and 60% of respondents in each group expressed—particularly those who identify as Black and of African Descent—concern that DCT solutions might compromise their privacy and diminish the quality of their relationship with study staff. And a significantly higher percentage of patients (43%) who identified as Hispanic and Latino expressed concerns that DCT solutions would increase their mobile devices’ data plan costs.

Another recent study conducted by the Tufts Center for the Study of Drug Development (Tufts CSDD) has found an association between DCT use and patient enrollment diversity, but, as hypothesized, only select decentralized solutions showed this relationship.

Study set-up

Tufts CSDD collected data on 950 individual protocols from 16 pharmaceutical companies and contract research organizations (CROs). As part of the data collection process, Tufts CSDD asked participating companies to indicate whether any of the following individual remote and virtual solutions were used to support clinical trial execution:

• Virtual or televisit (defined as a scheduled participant evaluation in which procedures are performed outside of the clinic e.g., telephone/mobile telephone, video conference app, secured electronic mail, social media platforms).
• Home visits (a home healthcare professional visits the participant’s home to perform evaluations or procedures).
• Devices or wearables (where the study participant is provided with a wearable or other device [i.e., iPad or a tablet] to use at home for data collection and recording, or where participants were asked to download an app to a personal device that will be used to complete surveys or collect other data).
• Local labs and facilities (the study volunteer travels to a local lab or clinic instead of the investigative site to have procedures or tests performed).

Sponsors and CRO companies were also asked to provide National Clinical Trial (NCT) numbers. Tufts CSDD researchers next collected and compiled reported racial and ethnic demographic data for protocols that had a corresponding NCT number.

A measurable association

In total, Tufts CSDD researchers evaluated 331 protocols that used one or several DCT solutions and provided participant demographic data, the majority of which were Phase II and III studies.

Protocols in the sample were nearly evenly divided between small-molecule therapies and biologics. Immunology, rheumatology, and oncology were the most common therapeutic areas.

On average, male participants made up slightly more than half (52.9%) of the patients enrolled in the clinical trials evaluated. The majority of enrolled patients were White (73.5%); Asian participants made up the next largest racial demographic (15.9%) group. Patients who identified as Black and of African Descent comprised 9.8% of the total. Approximately one out of eight participants (12.7%) were identified as Hispanic and Latino.

The results showed that when one or more DCT solution was used in a clinical trial, the percentage of White participants was lower—72.7%—compared to 81.3% in clinical trials where no DCT solution was used (t-test, p = .0455). No other significant differences were observed in this comparison.

When virtual or televisits were used in a clinical trial, the percentage of Black participants enrolled was significantly lower, from 11.4% in clinical trials with no virtual or televisits, to 5.5% in clinical trials with virtual or televisits (t-test, p = .0023). Other demographic groups did not show any significant differences.

No significant differences were found in demographic distributions for clinical trials with and without mobile or wearable devices. Significant differences were observed, however, between clinical trials that used local labs and those that did not. For those clinical trials that used local labs, the percentage of White participants was significantly lower (t-test, p = .0354).

Underlying factors

The results of this study demonstrate an association between the use of DCT solutions in clinical trials and the racial and ethnic diversity of patients enrolled in them. In this study, the association was not uniform across all DCT solutions used. Specifically, the use of local labs was associated with a lower percentage of White patients enrolled, and the use of virtual visits and televisits was associated with a lower percentage of enrolled patients who identified as Black or of African descent.

Virtual visits and televisits, in particular, require the use of technology and infrastructure (e.g., desktop or laptop computer or tablet; reliable, high-speed internet connectivity and computing power) that may not be available to a disproportionate number of people within select—and likely underserved—communities. The use of mobile and wearable devices showed no significant differences in the demographic distribution of enrolled participants. This may be due, in part, to varying levels of comfort among study volunteers by demographic subgroup in the use of mobile technologies, especially as a replacement for in-person interactions.

For those clinical trials that used local labs, because no other single racial demographic showed a significant increase, the increase was likely distributed among all of the non-White racial demographics, resulting in a more diverse mix of study volunteers. This finding is partially explained by published research exploring the relationship between participation convenience and patient willingness to enroll. The CISCRP study mentioned earlier in this article also provides some insight here.

The location of the research center has been shown to be one of the most important factors influencing a patient’s decision to participate in a clinical trial and a majority of patients are unwilling to enroll in clinical trials that require them to travel more than 20 miles. The use of local labs and facilities for clinical trial visits adds convenience and reduces travel burden while continuing to offer in-person interaction. The very low prevalence of home visits in our dataset may be explained by the high relative cost and the difficulty scheduling and arranging for home healthcare professionals to visit participants’ homes.

It’s important to note that this Tufts CSDD study is based on a relatively small convenience sample. And the study only looked at general distribution by demographic subgroup without taking disease prevalence into account.

Demographic differences may be due to lower or higher disease-specific prevalence rates among demographic subgroups and not to the use (or lack thereof) of a given virtual or remote solution.

More evidence is coming

But stay tuned. In Q4 2024, the Partnership for the Advancement of Clinical Trials (PACT) consortium will be publishing the results of a detailed and robust study of 69 active protocols that are using DCT solutions. This study is comparing these protocols with benchmarks that did not use any virtual or remote solutions support to understand how specific DCT solutions impact clinical trial performance and quality. Funded in part by the Reagan-Udall Foundation for the FDA, PACT has made significant progress in gathering hard, empirical evidence on the value proposition ofDCT deployments.

This growing body of evidence is helping to inform effective strategies to leverage the benefits, while managing the risks, of targeted and customized virtual and remote solutions use in clinical trials.

Ken Getz, MBA, Executive Director and Research Professor, Tufts Center for the Study of Drug Development, Tufts University School of Medicine