5 tips to improving participant engagement

Engagement drives compliance. But engagement is not something you can mandate or automate your way into. It is built through consistent, respectful, and genuinely human interactions throughout the study, sustained across weeks or months rather than concentrated into a single enthusiastic onboarding call.

A rapid review of 19 systematic reviews on digital engagement strategies in large cohort studies offers a useful sanity check on this. Most of the e-engagement strategies it examined, from reminders to personalised content, were found to be genuinely effective, which is reassuring. But the review also found that participants had specific, consistent preferences about how that content should be delivered: new knowledge, reminders, and suggestions presented clearly, briefly, and in a personalised way, not just delivered more often or with more urgency. Here are five approaches that tend to make a real difference, several of which map directly onto that finding.

1. Keep participants informed

People take part in research for a reason. There is already some level of interest or investment. Use that.

• Send occasional summaries of where the study is going and what has been learned so far, even in general terms
• Share relevant news from the field where appropriate: new research on a related topic, upcoming findings from similar work
• Ask at onboarding how they would like to receive updates and through which channel (email, SMS, phone). Some want weekly check-ins; others prefer minimal contact. Letting them choose reduces opt-outs and improves the quality of the connection

The review above found this kind of content preference to be consistent across studies: participants wanted information short, clear, and specific to their own situation, not a generic newsletter sent to everyone regardless of relevance.

2. Make them feel part of the research

Participants contribute something real. Treating them as data sources misses the point.

• Use their name in communications. It is a small thing that makes messages feel individual rather than automated
• Share tangible numbers when appropriate: how many people are involved, what similar research has shown, what the study aims to contribute
• Acknowledge that their time and effort matter. There is no study without participants. Saying so is not just polite; it is accurate

3. Do not burden them

More data collection is not always better, and more communication is definitely not always better.

• Ask yourself regularly whether the amount you are asking of people is reasonable, especially for participants who may be unwell or managing other demands
• If you are seeing elevated drop-off rates, fewer responses, or more opt-outs, treat that as a signal rather than a setback. The data is telling you something
• Always offer easy opt-out routes from any communications. Nobody should feel trapped

4. Make participation as easy as possible

The effort required to participate directly affects retention.

• For site visits, provide practical information: directions, parking, how long the visit will take, where to find facilities nearby
• For data collection tasks, prioritise a clean, clear user experience. If it takes more than two minutes to figure out how to submit a form, it needs redesigning
• Anticipate where people will get stuck and remove the obstacle before they encounter it. Pre-fill where you can, automate reminders, and make support genuinely easy to reach

5. Offer meaningful reward

Reward does not always mean money. And for many participants, it is not the most important thing.

• At study close, consider releasing a plain-language summary of findings and unblinding participants to what they received where appropriate. Many participants are genuinely curious about the outcome of their contribution
• Small non-monetary gestures, like a personalised thank-you message or a relevant resource related to the study topic, can mean more than a voucher
• A sincere, specific thank-you at the end of a long study carries real weight. People notice when it feels genuine rather than automated

The common thread

Look back across all five tips and the same principle keeps reappearing: personalisation and clarity outperform volume and generic reach. The review cited above found this held true across a genuinely wide range of studies, populations, and delivery channels, which is a useful thing to remember whenever the instinct is to solve an engagement problem by simply sending more messages. More often than not, the fix isn't more contact. It's better-targeted contact that a specific participant would actually recognise as being about them.