Retention to clinical trials: how can we keep participants involved?

In this blog for all those involved in clinical trials, Katie Gillies and Derek Stewart, from the PRioRiTy II group, highlight the need for the identification of a national research agenda on retention to clinical trials developed and prioritised by all relevant stakeholders.

This page was updated on 1 April 2021

What do we know about the best ways to keep people involved in clinical trials? Frankly, not a lot.

Clinical trials can provide evidence about which treatments work. Clinical trials are research studies that involve people and compare different groups of people receiving different treatments and look at which treatments improve outcomes (like pain) the most. During the design of a trial, calculations are made about how many people need to join the trial and complete all of the data collection requirements (which might be, for example, a questionnaire or a clinic appointment). These calculations allow the researchers to be confident in the results at the end of the trial.

If there are problems with keeping people involved in a clinical trial this can often result in a delay in completing the trial or problems in using the results to make informed decisions about clinical care. Identifying ways to keep people involved in trials, i.e. they provide all of the data or measurements that the trial needs, has been identified as one of the top priorities for research into the design and delivery of clinical trials.

What is already known about retention to clinical trials?

So, we don’t know a lot about how to keep people in trials but we do know a little.  What we do know focuses on how to get trial participants to return postal questionnaires. It seems money helps! Evidence from a Cochrane Review Strategies to improve retention in randomised trials* suggests that including a monetary incentive can improve return rates of postal questionnaires. However, we do not know what the optimal value of the incentive should be, nor do we know whether the incentives should be provided to everyone or just focussed on those who don’t respond. We also don’t know whether trial participants deem this type of ‘reimbursement’ of their time to be acceptable. Anecdotal evidence from trial teams suggests that some participants would rather not receive gift vouchers as recognition of their contribution to the trial. Indeed some vouchers have been returned unused with requests for public monies to be spent on more research not on thank you notes.  This tells us that monetary incentives may not work for everyone but more importantly that we should be involving trial participants in decisions about how best to improve retention.  Of the studies included in the Cochrane Review on strategies to improve retention to RCTs only a handful included patients as partners in their design – this needs to change.

Prioritising Recruitment in Randomised Trials (PRioRiTy)

Methodological research into trials (in other words researching the best ways to design and deliver clinical trials) has been slightly behind the curve with regard to patient and public involvement (PPI).

There are some exemplar studies out there, not least the Prioritising Recruitment in Randomised Trials study (PRioRiTy).  PRioRiTy identified research questions that focussed on the process of recruiting people to clinical trials. The study was a priority setting partnership (PSP) that was designed and delivered in association with the James Lind Alliance (JLA). The JLA aims to bring patients, clinicians, carers and other relevant stakeholders together to discuss and identify research priorities. This process allows for identification of a research agenda that is fit for purpose and endorsed by all of those who have a stake in it. These prioritisation exercises help researchers and funders to focus on what matters most to all of those involved and ultimately contributes to global efforts to minimise waste in research by focussing activities.

From recruitment to retention: PRioRiTy II

The obvious step for improving what we know about retention to clinical trials was to duplicate the work of the PRioRiTy study but to focus on retention – and so (like all good sequels) PRioRiTY II was born. PRioRiTY II has brought together a large group of individuals ranging from patients, trial methodologists, trial managers, data coordinators, research nurses, and representatives from the JLA.

@DerekCStewart is a patient advocate actively involved in many aspects of research practice, policy and public involvement including being a member of PRioRiTY study steering group. Derek is an Associate Director with the NIHR Clinical Research Network and interim Director for Patient Involvement at Nottingham Biomedical Research Centre.

The work of PRioRiTY II is being informed by a committed group of patient and public involvement members with a range of personal experience of health research. Some people are entirely new to methodological research and a few were involved in the earlier PRioRiTY study. This involvement is influencing each other’s thinking and practice. The whole team are working together looking at language and the way we explain trial methodology as well as finding new ways to reach out to be an inclusive as possible. We are recording our expectations and experiences as we go along and this will form a separate report.

This group advises on all aspects of the project and ensure that, as much as possible, all relevant voices are heard and listened to throughout the project.

PRioRiTY II is composed of three stages: a very broad survey to identify any aspect of trial retention that people think is important; a second survey that aims to prioritise those items identified in the first survey; and then a final meeting where up to 30 stakeholders (including patients and researchers) will meet to agree on the top 10 priorities for research into trial retention.  The video below explains further.

The first survey is currently open and will be accepting responses until the 25th May. We want to hear from as many people as possible including patients who have taken part in a trial, parents or carers of someone who has taken part in a trial, anyone (patients and researchers) who has contributed to the design or running of clinical trials, health professionals, ethics committee members, and trial methods experts. Without the input from all relevant stakeholders we risk conducting sub-optimal research.  So if you haven’t already responded please do complete the survey and help us set the agenda for research into how to improve trial retention and ultimately improve the evidence on which decisions about healthcare are made. Join the retention revolution! #TrialRetention. (Please note the survey has now closed).

*Editor’s note: The Cochrane Review Strategies to improve retention in randomised trials was updated in March 2021. The authors of this blog will be updating the blog soon.

Join in the conversation on Twitter with @GilliesKatie @DerekCStewart @CochraneUK or leave a comment on the blog.

Katie Gillies and Derek Stewart having nothing to disclose.

References [PDF]

Retention to clinical trials: how can we keep participants involved? by Katie Gillies

is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International

2 Comments on this post

  1. […] eschewing financial gain from trial participation, of course, but the broader population, too. Kate Gillies and Derek Stewart, at Cochrane UK, say that some participants who have been sent gift vouchers as recognition for […]

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    I am student of clinical research. I found your article very helpful for my project research. It has cleared my doubts about this topic and I am obliged for this informative post. Keep sharing.

    Clinical Research / Reply

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