Retention strategies are routinely communicated to potential trial participants but often differ from what was planned in the trial protocol; an analysis of patient information leaflets and their corresponding protocols.

Abstract

Abstract Background Retaining participants in randomised controlled trials (RCTs) is challenging and trial teams are often required to use strategies to ensure retention or improve it. Other than monetary incentives, there is no requirement to disclose the use of retention strategies to the participant. Additionally, not all retention strategies are planned at the design stage of a trial, but some protocols include plans to use strategies to promote participant retention. It is yet unknown if these plans are communicated in the corresponding PILs. The purpose of our study was to determine if Patient Information Leaflets (PILs) communicate plans to promote participant retention and if so, are these outlined in the corresponding trial protocol. Methods 157 PILs and their 121 corresponding protocols from Clinical Trial Units (CTUs) in the UK were analysed. Directed (deductive) qualitative content analysis was used to analyse the participant retention text from the PILs. Data were presented using a narrative summary and frequencies where appropriate. Results Plans to promote participant retention were communicated in 81.5% (n = 75) of PILs. Fifty-six percent (n = 42) of PILs communicated plans to use ‘combined strategies’ to promote participant retention. The most common individual retention strategy was telling the participants that data collection for the trial would be scheduled during routine care visits (16%; n = 12 PILs). The importance of retention and the impact that missing, or deleted, data has on the trial were explained in 6.5% (n = 6) and 5.4% (n = 5) of PILs respectively. Out of the 59 PILs and 58 matching protocols that communicated plans to use strategies to promote participant retention, 18.6% (n = 11) communicated the same information, the remaining 81.4% (n = 48) of PILs either only partially communicated the same information or did not communicate the same information. Conclusion Retention strategies are frequently communicated to potential trial participants in PILs however the information provided often differs from the content in the corresponding protocol. Participant retention considerations are best done at the design phase of the trial and we encourage trial teams to be consistent in the communication of these strategies in both the protocol and PIL.