Clinical trials have become more complex, more distributed and more inclusive in ambition. Yet one of the most influential elements, how studies are explained and supported across the patient journey, remains largely unstructured. As expectations around retention and diversity increase, this gap is becoming harder to ignore.
Clinical development has changed significantly over the past decade. Protocols have become more complex, digital tools now sit across much of the trial lifecycle, and decentralised models have expanded both how and where studies are delivered.
At the same time, expectations around inclusion and participant experience have increased. Organisations such as the FDA, the MHRA and the European Medicines Agency continue to place growing emphasis on diversity, accessibility and more patient-centred approaches to clinical research. Despite these advances, two challenges remain difficult to resolve - participant retention and population diversity.
Much of the industry’s focus has centred on recruitment strategy, site models and improving access. What tends to receive less attention is something more fundamental: how consistently clinical trials are explained and supported throughout the patient journey.
Not a New Problem - But Easier to See Now
Variability in patient communication has always existed. What has changed is how visible it has become, and how much it seems to matter in practice.
Decentralised and hybrid trials, accelerated during the COVID-19 pandemic, are now part of routine delivery, with regulatory guidance formalising their role across both US and European settings. As trials extend across more sites, settings and patient populations, differences in communication no longer remain local. They begin to accumulate.
In traditional site-based settings, patients could revisit information and ask questions more easily. In more distributed models, interactions are often shorter or more spaced out. When that happens, each interaction tends to carry more weight than it once did.
Inclusion and the Limits of Access
Efforts to improve diversity in clinical trials are increasingly shaped by regulatory expectations, with recent FDA guidance on Diversity Action Plans, alongside UK and European initiatives, reflecting a broader push towards more inclusive research. Access alone, however, does not necessarily translate into participation.
Reaching more diverse populations means engaging with individuals who may have varying levels of health literacy, different expectations of healthcare, and limited familiarity with clinical research. In practice, this places greater pressure on how clearly and consistently information is communicated.
Without some consistency in how trials are explained, not only at entry but throughout participation, those efforts can begin to stall. Patients may be recruited successfully, but not always supported in a way that helps them remain engaged. Even relatively small numbers of drop-outs can then have a disproportionate effect on timelines and on whether diversity targets are ultimately met.
Complexity Without Much Support
Trial design has continued to evolve, and increasing protocol complexity, alongside adaptive designs and biomarker-driven approaches, has been widely documented. These designs are necessary, but they are not always straightforward to explain in practice.
Healthcare professionals are expected to translate these concepts into something patients can follow, often within a limited time and without much structured support. The gap is not one of knowledge, but of communication.
A Controlled System with One Uncontrolled Element
Clinical trials are designed to minimise variability, with tightly controlled protocols, standardised processes and clearly defined data collection. Patient communication tends to sit outside that structure.
In practice, explanations vary between sites and individuals, communication quality is rarely measured in a consistent way, and training is more often focused on compliance than on how conversations are actually delivered. The result is a system that is highly controlled in most respects, but still depends on interactions that are not controlled in the same way.
This is not simply a variation in individual approach. It is a structural gap in how trials are designed and delivered. This is most visible during onboarding, although it continues across the full patient journey.
Communication Beyond Onboarding
Onboarding is a critical moment, but it is only the starting point.
As trials progress, patients encounter new information, uncertainty and, at times, discomfort. Side effects, logistical challenges or simple fatigue can all contribute to a gradual loss of engagement.
Protocols define how to respond clinically, but they offer far less guidance on how to communicate in these situations. The ability to explain clearly, provide reassurance and respond to concerns becomes more important as motivation begins to decline.
At that stage, communication is no longer just about conveying information. It starts to influence trust, confidence and the decision to remain in the study, something reflected in evidence showing that lower comprehension is associated with higher drop-out rates.
Predicting Drop-Out vs Influencing It
The industry has invested heavily in predicting patient drop-out risk, using advanced analytics, patient profiling and AI models to identify participants who may be more likely to disengage.
That insight is useful, but it does not fully capture the point at which many of these decisions are made. In practice, those decisions often happen within the interaction between the patient and the healthcare professional.
These conversations, particularly when there is uncertainty, tend to shape whether a patient continues or withdraws. Without strengthening what happens in those moments, prediction alone will always have a limited impact.
Training Covers the Content, Not the Conversation
Healthcare professionals receive extensive training in protocols, safety and compliance, which helps ensure that the correct information is delivered.
What is less consistently developed is how that information is communicated, either during formal education or in practice. Opportunities to practise patient interactions, receive feedback or build confidence in handling more complex situations remain limited.
Many investigators and coordinators are strong communicators, but maintaining that level of consistency across different sites and studies remains a challenge.
Simulation and Practice
Simulation-based training is widely used across healthcare to prepare for complex interactions, and more recent evidence continues to show its effectiveness in improving communication and decision-making. Its use in clinical research remains uneven.
Similar approaches are already applied elsewhere in the pharmaceutical value chain, where structured practice and feedback help improve the consistency of conversations. Applying this more systematically to clinical trials is not a significant leap, particularly as established frameworks such as the Cambridge-Calgary model could be used as a foundation, given its widespread use in medical education and communication training, including within NHS settings.
This becomes particularly relevant at key moments throughout the study, when patients experience side effects, express uncertainty or begin to question whether to continue. These situations require judgement, clarity and emotional awareness, which are not always explicitly supported.
Where It Shows Up
The effects of communication variability are not always immediately visible.
Patients may enter trials with slightly different understandings of what participation involves. Over time, those differences can influence adherence, engagement and confidence.
Some participants disengage earlier than expected, others follow the protocol less closely, and in some cases, confidence in the study begins to decline. These patterns are often attributed to burden, logistics or site variation, even though communication is frequently one of the earliest points where divergence begins.
Across multiple sites and studies, those differences accumulate.
Toward More Consistent Communication
Improving communication does not require removing individual judgment or attempting to standardise every interaction.
It does require recognising communication as part of the system rather than leaving it entirely to individual variation. In practice, this means being clearer about which moments matter most, offering more structured support for explaining complex information, creating opportunities for practice and feedback, and developing better visibility into how communication is delivered across sites.
This will not eliminate variability, but it can make its effects more manageable.
Conclusion
Clinical trials are more distributed and more complex than they were previously, and expectations around inclusion continue to increase.
At the same time, the system still relies on human interactions that are not managed with the same level of structure as other aspects of trial delivery.
Onboarding is one important point, but it sits within a broader pattern that runs across the full patient journey, where communication remains one of the least standardised, yet most influential, elements of clinical research.
As expectations around retention and diversity increase, this gap becomes harder to absorb - and more important to address.
References
1. European Medicines Agency: https://www.ema.europa.eu/en/documents/regulatory-procedural-guideline/guideline-computerised-systems-and-electronic-data-clinical-trials_en.pdf
2. U.S. Food and Drug Administration: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/diversity-action-plans-improve-enrollment-participants-underrepresented-populations-clinical-studies
3. European Medicines Agency: https://www.ema.europa.eu/en/about-us/how-we-work/regulatory-science-strategy
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