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 developed at the planning stage, i.e. post-funding during protocol development, but some protocols include strategies for participant retention as retention is considered and planned for early in the trial planning stage. It is yet unknown if these plans are communicated in the corresponding participant information leaflets (PILs). The purpose of our study was to determine if PILs communicate plans to promote participant retention and, if so, are these outlined in the corresponding trial protocol.
METHODS: Ninety-two adult PILs and their 90 corresponding protocols from Clinical Trial Units (CTUs) in the UK were analysed. Directed (deductive) 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 = 75/92) of PILs. Fifty-seven percent (n = 43/75) 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 = 12/75 PILs). The importance of retention and the impact that missing or deleted data (deleting data collected prior to withdrawal) has on the ability to answer the research question were explained in 6.5% (n = 6/92) and 5.4% (n = 5/92) of PILs respectively. Out of the 59 PILs and 58 matching protocols that both communicated plans to use strategies to promote participant retention, 18.6% (n = 11/59) communicated the same information, the remaining 81.4% (n = 48/59) of PILs either only partially communicated (45.8%; n = 27/59) the same information or did not communicate the same information (35.6%; n = 21/59) as the protocol with regard to the retention strategy(ies).
CONCLUSIONS: 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 planning stage of the trial and we encourage trial teams to be consistent in the communication of these strategies in both the protocol and PIL.

UNASSIGNED: This study aimed to investigate whether placebo control is differently disclosed in drug and non-drug randomised clinical trial (RCT) participant information leaflets (PILs) and how this might affect participant blinding and direction of study outcomes.
UNASSIGNED: PILs were obtained from trials registered in the International Standard Randomised Controlled Trial Number database via email. Placebo descriptions in PILs were categorised as Full Disclosure (FD), Partial Disclosure (PD), or Missing Information (MI). Associations between intervention type (drug or non-drug)/placebo disclosure (FD or PD/MI) and participant blinding success/trial outcome direction (positive or non-positive) were examined using a two-sided Fisher\'s exact test.
UNASSIGNED: Of 116 collected PILs, 56 % were for drug trials and 44 % were for non-drug trials. Among them, 88 PILs had the corresponding publications available and 68 reports specified primary outcomes. Drug trials were more likely to fully disclose placebo information than non-drug trials (92.3 % vs. 74.5 %, p < 0.05). However, the success rate of blinding was only reported in 3 out of 88 trial publications (3.4 %), precluding further analysis. Furthermore, there was no significant association between the direction of trial results and the type of intervention or placebo disclosure.
UNASSIGNED: Our study findings suggest that drug and non-drug RCTs might differ in the way they reveal placebo control information. Further research is warranted to understand what leads to more common PD of placebo information in non-drug trials than drug trials and to determine the optimal placebo control disclosure in specific trial context.

BACKGROUND: The way information about potential harms of trial intervention is shared within participant information leaflets (PILs) varies widely and can cause subjective \'nocebo\' harms. This study aimed to develop principles to improve the composition of information about potential trial intervention benefits and harms within PILs so that variability and avoidable harms are reduced.
METHODS: We conducted a two-round modified online Delphi survey, followed by a consensus meeting. For the first round of the survey, 27 statements were developed based on previous research and relevant guidance from the UK, the USA and the World Health Organization. Participants included members from each of the following stakeholder groups: patient and public representatives, research ethics committee members, industry representatives, medico-legal experts, psychologists and trial managers. Each participant was asked to rate their degree of agreement or disagreement with each statement on a 9-point Likert scale. In the second round, participants were invited to reappraise their ratings after reviewing the results of the first round. Finally, two members from each stakeholder group participated in a meeting to confirm those statements for which there was agreement.
RESULTS: Two hundred and fifty participants completed round 1, and 201 participants completed round 2. In round 1, consensus was reached for 16 statements. In round 2, consensus was reached for an additional three statements. The consensus meeting confirmed the survey results and consolidated the statements. This process resulted in seven principles: (1) all potential harms of a given intervention should be listed, (2) all potential harms should be separated into serious and less serious, (3) it must be made explicit that not all potential harms are known, (4) all potential benefits should be listed, (5) all potential benefits and harms need to be compared with what would happen if the participant did not take part in the trial, (6) suitable visual representations should be added where appropriate and (7) information regarding potential benefits and harms should not be presented apart by one or more pages.
CONCLUSIONS: Our modified Delphi process successfully generated seven principles that can and should be used to guide how information is conveyed to patients in information leaflets regarding potential trial benefits and harms.

Biobanks are repositories of human biological samples and data. They are an important component of clinical research in many disease areas and often represent the first step toward innovative treatments. For biobanks to operate, researchers need human participants to give their samples and associated health data. In Ireland, research participants must provide their freely given informed consent for their samples and data to be taken and used for research purposes. Biobank staff are responsible for communicating the relevant information to participants prior to obtaining their consent, and this communication process is supported by documentation in the form of Participant Information Leaflets and Informed Consent Forms (PILs/ICFs). PILs/ICFs should be concise, intelligible, and contain relevant information. While not a substitute for layperson and research staff discussions, PILs and ICFs ensure that a layperson has enough information to make an informed choice to participate or not. However, PILs/ICFs are often lengthy, contain technical language and can be complicated and onerous for a layperson to read. The introduction of the General Data Protection Regulation (GDPR) and the related Irish Health Research Regulation (HRR) presented additional challenges to the Irish biobank community. In May 2019, the National Biobanking Working Group (NBWG) was established in Ireland. It consists of members from diverse research backgrounds located in universities, hospitals and research centres across Ireland and a public/patient partner. The NBWG aimed to develop a suite of resources for health research biobanks via robust and meaningful patient engagement, which are accessible, GDPR/HRR-compliant and could be used nationally, including a PIL/ICF template. This open letter describes the process whereby this national biobank PIL/ICF template was produced. The development of this template included review by the Patient Voice in Cancer Research, led by Professor Amanda McCann at University College Dublin and the Health Research Data Protection Network.

While full disclosure of information on placebo control in participant information leaflets (PILs) in a clinical trial is ethically required during informed consent, there have been concerning voices such complete disclosures may increase unnecessary nocebo responses, breach double-blind designs, and/or affect direction of trial outcomes. Taking an example of acupuncture studies, we aimed to examine what participants are told about placebo controls in randomized, placebo-controlled trials, and how it may affect blinding and trial outcomes.
Authors of published randomized, placebo-controlled trials of acupuncture were identified from PubMed search and invited to provide PILs for their trials. The collected PILs were subjected to content analysis and categorized based on degree of information disclosure on placebo. Blinding index (BI) as a chance-corrected measurement of blinding was calculated and its association with different information disclosure was examined. The impact of different information disclosure from PILs on primary outcomes was estimated using a random effects model.
In 65 collected PILs, approximately 57% of trials fully informed the participants of placebo control, i.e. full disclosure, while the rest gave deceitful or no information on placebo, i.e. no disclosure. Placebo groups in the studies with no disclosure tended to make more opposite guesses on the type of received intervention than those with disclosure, which may reflect wishful thinking (BI -0.21 vs. -0.16; p = 0.38). In outcome analysis, studies with no disclosure significantly favored acupuncture than those with full disclosure (standardized mean difference - 0.43 vs. -0.12; p = 0.03), probably due to enhanced expectations.
How participants are told about placebos can be another potential factor that may influence participant blinding and study outcomes by possibly modulating patient expectation. As we have few empirical findings on this issue, future studies are needed to determine whether the present findings are relevant to other medical disciplines and at the same time a routine practice of fully disclosing placebo information in PILs calls for reevaluation.