Long-term clinical trial engagement is a behavioural challenge – not just an informational one

We know that for a clinical study to be successful, it needs to be able to keep participants engaged from beginning to end. But we also know that long-term retention is a persistent challenge.

We have spent years trying to solve the retention challenge using better communication strategies. Clearer participant-facing communications, supportive informed consent processes, more educational content, and newer engagement technology are all extremely valuable approaches. But are we falling into the trap of assuming that better (and more) information naturally leads to better long-term participation?

As experienced providers of recruitment and retention strategies and solutions, we’ve found that long-term engagement is not just a communications challenge. It’s also a behavioural one.

A participant’s decision about whether to stay in a clinical study doesn’t only depend on the amount of information they have. Throughout their time on the study, they are continually reassessing whether they can, want to, and need to keep taking part. These decisions are shaped by the way the study fits into their lives and how their experience evolves over time.

If we want to improve retention, we need to understand and influence the experiences and behaviours that sway it, not just find new ways to communicate.

Engagement is behavioural, and it’s shaped by trial experience

Participants join a study at their most motivated and committed. But from the first visit onwards, the reality of being in a study can change. Finding a new routine can be overwhelming, persistent side effects can begin to take their toll, diet and lifestyle changes can become harder to stick to, and interacting with apps and ePROs can become burdensome. All of this alongside family, work and other everyday responsibilities.

As the demands of the study change, so too can people’s willingness and ability to stay.

This means we need to think about engagement as something that is fluid rather than fixed. It’s a behavioural outcome shaped by participants’ experiences and the conditions around them, including:

• Perceived support: Do they feel supported when things get hard?
• Concerns and barriers: What emotional concerns and practical barriers are making it more difficult to take part?
• Burden versus value: Does the value or ‘reward’ for taking part still outweigh the effort and time required?

These are behavioural questions, and the answers can change over time.

Disengagement rarely happens all at once

Withdrawal rarely happens because of a single event. More often it’s the result of a build-up of negative experiences:

• Unanswered questions
• Uncertainty about what happens next
• Increasing burden of study tasks
• Losing sight of the reasons they joined in the first place
• Feeling overwhelmed by what’s being asked of them

It’s the niggles, barriers, and uncertainties that initially seem ‘small’ that can, over time, become reasons to leave.

Early unaddressed concern > persistent barrier > reduced confidence or necessity > disengagement > increased risk of drop-out

The challenge is that these early signs can be difficult to spot. Participants may not always tell site teams that their motivation is dropping. By the time their disengagement becomes visible (missed study visits, unanswered calls, or falling behind on study tasks or treatment schedules), the opportunity to intervene may already have passed.

Retention is not just about responding to these signs. It’s about recognising the subtle behaviours and experiences that often come before them.

Site teams are positioned to influence behaviour

As the most consistent human connection participants have during a trial, site teams play a powerful role in shaping the study experience.

Every interaction has the potential to either support engagement by reinforcing commitment, reducing uncertainty, and building confidence, or make participation feel harder by increasing burden and creating friction.

Our conversations with study participants have shown us that when they have a positive relationship with their site team, feel appreciated, and understand the purpose behind what’s being asked of them, their experience is better, the burden feels more manageable, and they are more likely to stay invested.

But our research with site teams highlights an important gap. While site teams often feel confident managing the operational demands of their role, they report feeling less confident when it comes to the behavioural aspects of engagement.

They want (and need) better support. Not just to communicate with participants, but to recognise what is changing in the participant experience and to know what to do about it. Equipping site teams with the skills to identify discrete barriers and changes in behaviour before they lead to drop-out could be exactly the answer we’ve been looking for.

The shift we need is from reactive retention to proactive behavioural support

This flips our question from:

“How can we provide better information to someone who is disengaging?”

to:

“What experiences and behaviours influence engagement in the first place?”

This switch matters because behavioural support isn’t about providing more information in the hope that it convinces someone that they should stay in a study. It’s about recognising and understanding what is making staying in the study harder, and working with the participant to reduce those barriers where possible.

For example, if an older participant arrives at every clinic visit with high blood pressure after struggling to find parking, the problem isn’t motivational – it’s practical. Over time, this practical barrier could impact whether they continue to attend. Offering transport support could acknowledge and reduce that barrier before it becomes another reason why taking part feels difficult.

Supporting site teams means giving them the confidence to act earlier

If we recognise that site teams are a key driver of trial-related behaviour and long-term engagement, supporting them needs to mean more than providing them with better communication materials.

This means helping site teams:

• Spot early signals: Recognise ‘red flags’, or subtle changes in behaviour that might indicate early disengagement
• Explore what’s driving them: Use prompts and conversation frameworks to understand the emotional, practical, or motivational factors behind the changes
• Respond appropriately, every time: Give teams practical tools, like decision pathways and conversation guides, that help turn behavioural insight into action
• Have better difficult conversations: Create space to discuss concerns, motivation, and even potential withdrawal openly, rather than treating these conversations as signs of failure
• Encourage person-centred flexibility where possible: Consider each individual and offer solutions to their personal barriers or concerns

Good information still matters. But it can’t fix retention alone

We’re not suggesting that participant communications are any less important. Information is still a big part of a positive study experience. But it can’t do all the work on its own.

Good information helps people understand the study. Education can help build confidence, and technology can make some aspects of participation easier. But none of these things, on their own, will keep someone committed for months or years.

Ultimately, long-term engagement comes down to the human experience: what it’s actually like to take part in the study, and how that experience changes over time.

That means we should be giving site teams the confidence and practical tools to pay attention to the small signs that someone might be struggling, understand what’s behind them, and do something about it before those challenges become a reason to leave.

Yes, the right kind of information can support engagement. But if the experience of taking part in a study is becoming too difficult, no amount of information will fix it.

If your retention strategy stops at better information and you’re ready to support the behaviours that keep people engaged, let’s talk.

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