What are the most important unanswered research questions in trial retention? A James Lind Alliance Priority Setting Partnership: The PRioRiTy II (Prioritising Retention in Randomised Trials) study

Dan Brunsdon, Linda Biesty, Peter Brocklehurst, Valerie Brueton, Declan Devane, Jim Elliott, Sandra Galvin, Carrol Gamble, Heidi Gardner, Patricia Healy, Kerenza Hood, Joan Jordan, Doris Lanz, Beccy Maeso, Amanda Roberts, Imogen Skene, Irene Soulsby, Derek Stewart, David Torgerson, Shaun TreweekCaroline Whiting, Sharon Wren, Andrew Worrall, Katie Gillies*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)
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Background: One of the top three research priorities for the UK clinical trial community is to address the gap in evidence-based approaches to improving participant retention in randomised trials. Despite this, there is little evidence supporting methods to improve retention. This paper reports the PRioRiTy II project, a Priority Setting Partnership (PSP) that identified and prioritised unanswered questions and uncertainties around trial retention in collaboration with key stakeholders. Methods: This PSP was conducted in collaboration with the James Lind Alliance, a non-profit making initiative, to support key stakeholders (researchers, patients, and the public) in jointly identifying and agreeing on priority research questions. There were three stages. (1) First an initial online survey was conducted consisting of six open-ended questions about retention in randomised trials. Responses were coded into thematic groups to create a longlist of questions. The longlist of questions was checked against existing evidence to ensure that they had not been answered by existing research. (2) An interim stage involved a further online survey where stakeholders were asked to select questions of key importance from the longlist. (3) A face-to-face consensus meeting was held, where key stakeholder representatives agreed on an ordered list of 21 unanswered research questions for methods of improving retention in randomised trials. Results: A total of 456 respondents yielded 2431 answers to six open-ended questions, from which 372 questions specifically about retention were identified. Further analysis included thematically grouping all data items within answers and merging questions in consultation with the Steering Group. This produced 27 questions for further rating during the interim survey. The top 21 questions from the interim online survey were brought to a face-to-face consensus meeting in which key stakeholder representatives prioritised the order. The 'Top 10' of these are reported in this paper. The number one ranked question was 'What motivates a participant's decision to complete a clinical trial?' The entire list will be available at www.priorityresearch.ie. Conclusion: The Top 10 list can inform the direction of future research on trial methods and be used by funders to guide projects aiming to address and improve retention in randomised trials.

Original languageEnglish
Article number593
Publication statusPublished - 15 Oct 2019

Bibliographical note

The authors would like to thank all stakeholders who took part, all respondents to the initial and interim surveys, and the attendees at the consensus meeting. We would also like to thank staff members at the HSRU who screened abstracts, and specifically Jane Brady and Beverly Smith for their insurmountable work. We would also like to thank Katherine Cowan from the JLA for her work as the lead facilitator at the consensus meeting.

The data sets generated and/or analysed during the current study are not publicly available due to privacy protections but are available from the corresponding author on reasonable request.

The full results of this study are available at www.priorityresearch.ie.


  • James Lind Alliance
  • Participant retention
  • Participation in randomised trials
  • Patient and public involvement
  • Priority Setting Partnership
  • Retention challenges
  • Trials methodology


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