Patient and public involvement in randomised clinical trials: a mixed-methods study of a clinical trials unit to identify good practice, barriers and facilitators

BACKGROUND: While patient and public involvement (PPI) in clinical trials is beneficial and mandated by some funders, formal guidance on how to implement PPI is limited and challenges have been reported. We aimed to investigate how PPI is approached within a UK Clinical Trials Unit (CTU)’s portfolio of randomised controlled trials, perceived barriers to/facilitators of its successful implementation, and perspectives on the CTU’s role in PPI. METHODS: A mixed-methods study design, involving (1) an online survey of 26 trial managers (TMs) and (2) Interviews with Trial Management Group members and public contributors from 8 case-study trials. Quantitative survey data were summarised using descriptive statistics and interview transcripts analysed thematically. Two public contributors advised throughout and are co-authors. RESULTS: (1) 21 TMs completed the survey; (2) 19 in-depth interviews were conducted with public contributors (n=8), TMs (n=5), chief investigators (n=3), PPI coordinators (n=2) and a researcher. 15/21 TMs surveyed reported that a public contributor was on the trial team, and 5 used another PPI method. 12/21 TMs reported that public contributors were paid (range £10–50/h). 5 TMs reported that training was provided for public contributors and few staff members had received any formal PPI training. The most commonly reported tasks undertaken by public contributors were the review of participant-facing materials/study documents and advising on recruitment/retention strategies. Public contributors wanted and valued feedback on changes made due to their input, but it was not always provided. Barriers to successful PPI included recruitment challenges, group dynamics, maintaining professional boundaries, negative attitudes to PPI amongst some researchers, a lack of continuity of trial staff, and the academic environment. Successful PPI required early and explicit planning, sharing of power and ownership of the trial with public contributors, building and maintaining relationships, and joint understanding and clarity about expectations/roles. CTUs have an important role to play in supporting recruitment, signposting and coordinating PPI. CONCLUSIONS: While highly valuable, PPI in trials is currently variable. PPI representatives are recruited informally, may not be provided with any training and are paid inconsistently across trials. Study findings can help optimise PPI in trials and ensure researchers and public contributors are adequately supported. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05701-y.