Designing Decentralised Clinical Trials for Patient Diversity

Clinical trials still struggle with diversity. Decentralised clinical trial (DCT) approaches are now being proven as one of the most effective ways to strategically build patient diversity into clinical trials.

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The Evidence: What the PACT Consortium Data Shows

In January 2025, Medable and the Tufts Center for the Study of Drug Development (CSDD) released the inaugural data from the PACT Consortium — a multi-sponsor, prospective research initiative specifically designed to measure the demographic impact of decentralised trial elements across a standardised trial dataset.

The analysis covered 69 clinical trials across a range of therapeutic areas, comparing participant demographics in DCT-enabled trials against those in conventional site-based trials.

The findings were consistent across multiple demographics: 

• Asian participants: 20.9% representation in DCT-enabled trials versus 14.2% in conventional trials, a six per centage point increase.
• American Indian or Alaska Native participants: 1.9% versus 0.5% in conventional trials — nearly quadruple the representation.
• Female participants: 55.7% versus 49.0%, a shift that makes DCT trial populations more accurately representative of the general U.S. population.

The PACT Consortium data represents only the first year of a multi-year research programme. The consortium intends to double the number of trials in the dataset and is exploring additional variables including socioeconomic status, geographic distribution, and disability status.

This makes it the most rigorous prospective evidence base for DCT diversity outcomes currently available.

Why Patient Diversity in Clinical Trials Really Matters

Regulatory agencies are increasingly explicit: Clinical trial populations must reflect the patients who will actually receive the drug.

The U.S. Food and Drug Administration's Diversity Action Plan requirement, which underpins the PACT research context, obligates sponsors to set enrolment diversity goals and document strategies for meeting them.

The European Medicine Agency has issued parallel guidance on inclusive trial design.

For sponsors, this is no longer a reputational aspiration. This is a regulatory submission requirement.

Beyond compliance, there is a strong scientific case. A drug approved on the basis of a homogeneous trial population may produce different efficacy and safety profiles in populations that were excluded from the pivotal study.

Post-market safety signals, label restrictions, and health technology assessment challenges are all more likely when trial populations do not reflect real-world patient demographics.

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How DCT Design Drives Patient Diversity

DCT approaches improve diversity through two primary mechanisms.

The first is geographic access. By enabling participation from patients’ homes or local healthcare facilities rather than requiring travel to academic medical centres, DCTs remove a structural barrier that disproportionately affects rural populations, working-age patients, caregivers, and lower-income groups.

The second is reduced participation burden. Fewer clinic visits, flexible scheduling, and remote outcome assessments lower the cost of participation for patients and improve retention across demographic groups.

ICH E6(R3) guidelines support decentralised trial elements explicitly, including digital tools, remote monitoring, and participation from geographically diverse populations, as mechanisms for reducing patient burden and improving representation.

Major regulators including the FDA, EMA, and MHRA have signalled alignment with these principles, though implementation timelines vary by region.

What are the Challenges for DCT and Patient Diversity?

The PACT Consortium data establishes that most DCT approaches have improved patient diversity metrics. But this might not be causative, and the diversity gains are not uniform.

The Consortium's own researchers note that DCT technology alone does not guarantee diversity. It is strategic implementation that matters.

Sponsors who deploy DCT tools without culturally tailored recruitment strategies, multilingual consent materials, or targeted community outreach see smaller diversity gains than those who combine technology with intentional recruitment design.

Data quality in remote settings remains a known operational challenge. Ensuring that the diversity gains of DCT enrolment are not offset by higher dropout rates, missing data, or protocol deviations in remote participants requires investment in digital patient engagement, site staff training, and real-time data monitoring infrastructure.

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What Trial Design Leaders Should Act on Now

Three priorities emerge from the evidence. First, build DCT diversity data into the regulatory submission narrative. Sponsors designing trials with the FDA’s Diversity Action Plan can reference PACT Consortium evidence when justifying DCT elements as a diversity strategy.

Second, invest in recruitment design, not just recruitment technology. The diversity gains in PACT-enrolled trials came from strategic DCT implementation alongside regulatory rigour, not from technology deployment alone.

Third, track demographic data in real time. Sponsors who monitor enrolment diversity against their Diversity Action Plan targets throughout the trial can intervene early when specific demographic groups are underenrolled, rather than discovering the gap at data lock.

At Pharmatica, we track the evidence base on trial design innovation and diversity, giving clinical operation leaders the data they need to make faster, better clinical trial design decisions.

Pharmatica: Insight. Connection. Impact.