Global clinical trials are becoming more complex and competitive. They want to be patient-centric, but are structured on endpoints, procedures, and regulatory requirements. At the same time, sponsors are expanding into new regions to accelerate enrollment and diversify their study populations.
For truly patient-centric trials, protocol design must extend beyond patient intent to include a scientific understanding of how these protocols translate into real-life participation for patients. And because patient burden is not universal, there must be a structured, evidence-based way to evaluate how demanding a study will feel to patients across regions, healthcare systems, and lived realities.
This is where a science-driven approach to patient burden becomes essential.
Why protocol should be viewed through a burden-based lens
A protocol that looks feasible on paper may fail in practice if it places unrealistic demands on patients. What feels manageable to a patient in one country may be a dealbreaker in another. Travel distance, visit frequency, caregiver involvement, cultural perceptions of healthcare, and financial strain can all become barriers, especially when scaled across multiple countries. All of these factors influence whether patients can realistically participate.
Applying science to your patient protocol means moving beyond assumptions and systematically measuring these realities before recruitment begins.
What a Patient Burden Index adds to protocol science
SubjectWell’s Patient Burden Index (PBI) is a structured, science and data-driven framework designed to quantify the effort of a patient to participate in a clinical trial.
“In an effort to determine what factors lead participants to drop out post-randomization, perhaps not even consent in the first place, we developed—based on peer-reviewed literature—the Patient Burden Index. At a high level, it is the quantification of perceived patient burden based on protocol-specific factors such as the visit schedule and treatment count.”
Rather than relying on intuition, the PBI evaluates measurable drivers of burden, including:
- Visit frequency and duration
- Travel distance and transportation requirements
- Invasive or complex procedures
- Time away from work or caregiving responsibilities
- Financial, logistical, and emotional strain
When applied consistently, the index provides a comparative view of how demanding a protocol is for patients across regions, sites, and populations.
“This is a bottom-up assessment based on peer-reviewed data—and importantly, apples to apples. We’re not comparing oncology trials to healthy volunteer trials. We’re comparing oncology to oncology, rare disease to rare disease, ensuring phase alignment, disease severity, and overall quality-of-life impact are congruent.”
Why patient burden matters more in global trials
In global recruitment, a single protocol may span countries with vastly different healthcare systems, infrastructure, and cultural norms. Without understanding how burden manifests locally, sponsors risk:
- Overestimating enrollment feasibility
- Selecting sites that struggle to recruit and retain patients
- Designing recruitment strategies that fail to resonate regionally
SubjectWell’s Patient Burden Index shifts the focus from protocol intent to patient reality, enabling more accurate planning and execution at a global scale.
See an in-depth analysis of SubjectWell's PBI
Five ways to apply the Patient Burden Index during protocol planning
1. Stress-testing feasibility before recruitment begins
By applying a PBI during early on during feasibility, sponsors can identify where a protocol may be overly demanding for certain sites, regions or populations. Sites with lower relative burden—or stronger infrastructure to offset burden—are more likely to meet enrollment targets.
This leads to:
- Fewer underperforming sites
- Faster enrollment timelines
- Reduced need for mid-study rescue efforts
The result is a protocol that is not only scientifically sound, but operationally realistic.
“We can see what the total burden looks like—whether a study is, for example, 205% as burdensome as a similar trial. Visit burden looks at how the number of visits compares, how long the treatment period is, and how much time patients are expected to be present at each visit. Treatment burden looks at how those elements are perceived.”
2. Designing regionally aware recruitment strategies
Burden data reveals which aspects of participation are most challenging in each region. Whether that’s travel, time commitment, or procedural intensity. This insight allows teams to tailor messaging, outreach channels, and support services accordingly.
For example:
- In regions where travel is the primary constraint, transportation support and proximity messaging matters most.
- In regions where time away from work or childcare is an issue, flexible scheduling or decentralized options become critical.
Applying science at this stage ensures recruitment plans are aligned with patient reality and far more effective than one-size-fits-all global campaigns.
“The index looks at whether procedures are routine, invasive—like biopsies—or noninvasive, such as imaging or device placement. And what this ultimately tells us is whether a patient will be willing to consent once they’re provided with all the trial information.”
3. Reducing dropout through proactive burden management
Patient burden is one of the leading drivers of attrition, particularly in long or complex studies. A burden-informed protocol allows sponsors to:
- Anticipate dropout risk before enrollment occurs
- Proactively deploy targeted support services in advance
- Design patient-centric interventions that reduce friction over time
This shifts retention from a reactive problem to a preventable outcome and protects both patient experience and data integrity.
“If the trial burden is high—frequent visits, high perceived treatment burden—patients may choose not to participate at all. And even if they initially believe they can manage it, higher burden increases the chance they won’t be able to keep up with trial demands. That’s when patients end up lost to follow-up or dropping out of the trial altogether.”
4. Smarter allocation of support services
Global trials often include patient support services, but without burden data, those services may be misallocated or underutilized.
A Patient Burden Index helps sponsors deploy services where they will have the greatest impact—whether that’s travel coordination, caregiver support, financial assistance, or remote visit options to ensure that investments are driven by data and not guesswork.
5. Stronger cross-functional alignment around patient reality
A PBI creates a shared language across clinical operations, feasibility teams, recruitment partners, and vendors. Instead of debating assumptions, teams can align around measurable burden indicators that inform decisions from protocol design through execution.
Applying science beyond the protocol
As clinical trials continue to globalize, success will depend on more than protocol complexity or statistical power. It will depend on how well sponsors understand and address the lived experiences of patients.
Applying science such as the PBI into your patient protocol means turning patient burden from an abstract concept into an actionable strategy. By embedding burden modeling into feasibility, recruitment planning, and support strategy, sponsors can design trials that enroll faster, retain better, and work in the real world—not just on paper.
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