Developing a core outcome set for acetabular fractures: a systematic review protocol.

BACKGROUND: Clinical trials investigating acetabular fractures are heterogeneous in their investigated outcomes and their corresponding measurements. Standardization may facilitate comparability and pooling of research results, which would lead to an increase in knowledge about the optimal treatment of acetabular fractures, resulting in long-term evidence-based treatment decisions and improvements in patient care. The aim of this systematic review is to identify the reported outcomes and their measurements from studies on treatments for acetabular fractures to develop a core outcome set which contains the most relevant outcome measures to be included in future studies. METHODS: Studies published in English and German including patients aged 16 years and older, with a surgically treated acetabular fracture, will be included. Studies with nonsurgical treatment, pathologic fractures, polytraumatized patients, and patients younger than 16 years of age will be excluded because other outcomes may be of interest in these cases. Any prospective and retrospective study will be included. Systematic reviews will be excluded, but their included studies will be screened for eligibility. The literature will be searched on MEDLINE, CENTRAL, Web of Science, ClinicalTrials.gov, and WHO ICTRP. Risk of selective reporting of outcomes will be assessed using the Outcome Reporting Bias in Trials classification system. Heterogeneously defined outcomes that measure the same outcome will be grouped and subsequently categorized into outcome domains using the taxonomy of the Core Outcome Measures in Effectiveness Trials Initiative. DISCUSSION: It is expected that a high number of studies will be included, and many outcomes will be identified using different definitions and measurement instruments. A limitation of this systematic review is that only previously investigated outcomes will be detected, thus disregarding potentially relevant outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022357644.

Defining and Risk-Stratifying Immunosuppression (the DESTINIES Study): Protocol for an Electronic Delphi Study.

BACKGROUND: Globally, there are marked inconsistencies in how immunosuppression is characterized and subdivided into clinical risk groups. This is detrimental to the precision and comparability of disease surveillance efforts-which has negative implications for the care of those who are immunosuppressed and their health outcomes. This was particularly apparent during the COVID-19 pandemic; despite collective motivation to protect these patients, conflicting clinical definitions created international rifts in how those who were immunosuppressed were monitored and managed during this period. We propose that international clinical consensus be built around the conditions that lead to immunosuppression and their gradations of severity concerning COVID-19. Such information can then be formalized into a digital phenotype to enhance disease surveillance and provide much-needed intelligence on risk-prioritizing these patients. OBJECTIVE: We aim to demonstrate how electronic Delphi objectives, methodology, and statistical approaches will help address this lack of consensus internationally and deliver a COVID-19 risk-stratified phenotype for "adult immunosuppression." METHODS: Leveraging existing evidence for heterogeneous COVID-19 outcomes in adults who are immunosuppressed, this work will recruit over 50 world-leading clinical, research, or policy experts in the area of immunology or clinical risk prioritization. After 2 rounds of clinical consensus building and 1 round of concluding debate, these panelists will confirm the medical conditions that should be classed as immunosuppressed and their differential vulnerability to COVID-19. Consensus statements on the time and dose dependencies of these risks will also be presented. This work will be conducted iteratively, with opportunities for panelists to ask clarifying questions between rounds and provide ongoing feedback to improve questionnaire items. Statistical analysis will focus on levels of agreement between responses. RESULTS: This protocol outlines a robust method for improving consensus on the definition and meaningful subdivision of adult immunosuppression concerning COVID-19. Panelist recruitment took place between April and May of 2024; the target set for over 50 panelists was achieved. The study launched at the end of May and data collection is projected to end in July 2024. CONCLUSIONS: This protocol, if fully implemented, will deliver a universally acceptable, clinically relevant, and electronic health record-compatible phenotype for adult immunosuppression. As well as having immediate value for COVID-19 resource prioritization, this exercise and its output hold prospective value for clinical decision-making across all diseases that disproportionately affect those who are immunosuppressed. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/56271.

European Autism GEnomics Registry (EAGER): protocol for a multicentre cohort study and registry.

INTRODUCTION: Autism is a common neurodevelopmental condition with a complex genetic aetiology that includes contributions from monogenic and polygenic factors. Many autistic people have unmet healthcare needs that could be served by genomics-informed research and clinical trials. The primary aim of the European Autism GEnomics Registry (EAGER) is to establish a registry of participants with a diagnosis of autism or an associated rare genetic condition who have undergone whole-genome sequencing. The registry can facilitate recruitment for future clinical trials and research studies, based on genetic, clinical and phenotypic profiles, as well as participant preferences. The secondary aim of EAGER is to investigate the association between mental and physical health characteristics and participants' genetic profiles. METHODS AND ANALYSIS: EAGER is a European multisite cohort study and registry and is part of the AIMS-2-TRIALS consortium. EAGER was developed with input from the AIMS-2-TRIALS Autism Representatives and representatives from the rare genetic conditions community. 1500 participants with a diagnosis of autism or an associated rare genetic condition will be recruited at 13 sites across 8 countries. Participants will be given a blood or saliva sample for whole-genome sequencing and answer a series of online questionnaires. Participants may also consent to the study to access pre-existing clinical data. Participants will be added to the EAGER registry and data will be shared externally through established AIMS-2-TRIALS mechanisms. ETHICS AND DISSEMINATION: To date, EAGER has received full ethical approval for 11 out of the 13 sites in the UK (REC 23/SC/0022), Germany (S-375/2023), Portugal (CE-085/2023), Spain (HCB/2023/0038, PIC-164-22), Sweden (Dnr 2023-06737-01), Ireland (230907) and Italy (CET_62/2023, CEL-IRCCS OASI/24-01-2024/EM01, EM 2024-13/1032 EAGER). Findings will be disseminated via scientific publications and conferences but also beyond to participants and the wider community (eg, the AIMS-2-TRIALS website, stakeholder meetings, newsletters).

Survival analysis for AdVerse events with VarYing follow-up times (SAVVY): summary of findings and assessment of existing guidelines.

BACKGROUND: The SAVVY project aims to improve the analyses of adverse events (AEs) in clinical trials through the use of survival techniques appropriately dealing with varying follow-up times and competing events (CEs). This paper summarizes key features and conclusions from the various SAVVY papers. METHODS: Summarizing several papers reporting theoretical investigations using simulations and an empirical study including randomized clinical trials from several sponsor organizations, biases from ignoring varying follow-up times or CEs are investigated. The bias of commonly used estimators of the absolute (incidence proportion and one minus Kaplan-Meier) and relative (risk and hazard ratio) AE risk is quantified. Furthermore, we provide a cursory assessment of how pertinent guidelines for the analysis of safety data deal with the features of varying follow-up time and CEs. RESULTS: SAVVY finds that for both, avoiding bias and categorization of evidence with respect to treatment effect on AE risk into categories, the choice of the estimator is key and more important than features of the underlying data such as percentage of censoring, CEs, amount of follow-up, or value of the gold-standard. CONCLUSIONS: The choice of the estimator of the cumulative AE probability and the definition of CEs are crucial. Whenever varying follow-up times and/or CEs are present in the assessment of AEs, SAVVY recommends using the Aalen-Johansen estimator (AJE) with an appropriate definition of CEs to quantify AE risk. There is an urgent need to improve pertinent clinical trial reporting guidelines for reporting AEs so that incidence proportions or one minus Kaplan-Meier estimators are finally replaced by the AJE with appropriate definition of CEs.

Investigation of normalization procedures for transcriptome profiles of compounds oriented toward practical study design.

The transcriptome profile is a representative phenotype-based descriptor of compounds, widely acknowledged for its ability to effectively capture compound effects. However, the presence of batch differences is inevitable. Despite the existence of sophisticated statistical methods, many of them presume a substantial sample size. How should we design a transcriptome analysis to obtain robust compound profiles, particularly in the context of small datasets frequently encountered in practical scenarios? This study addresses this question by investigating the normalization procedures for transcriptome profiles, focusing on the baseline distribution employed in deriving biological responses as profiles. Firstly, we investigated two large GeneChip datasets, comparing the impact of different normalization procedures. Through an evaluation of the similarity between response profiles of biological replicates within each dataset and the similarity between response profiles of the same compound across datasets, we revealed that the baseline distribution defined by all samples within each batch under batch-corrected condition is a good choice for large datasets. Subsequently, we conducted a simulation to explore the influence of the number of control samples on the robustness of response profiles across datasets. The results offer insights into determining the suitable quantity of control samples for diminutive datasets. It is crucial to acknowledge that these conclusions stem from constrained datasets. Nevertheless, we believe that this study enhances our understanding of how to effectively leverage transcriptome profiles of compounds and promotes the accumulation of essential knowledge for the practical application of such profiles.

[Interpretation of the reporting specifications for mixed methods systematic reviews].

The number of mixed methods systematic reviews (MMSRs) published internationally is increasing day by day, thanks to the continuous development and improvement of MMSRs methodological guidelines and reporting specification, which effectively promote the depth and breadth of evidence synthesis and integration results. However, the application of this method has yet to be popularized in China. With the continuous development of mixed methods research and evidence-based medicine in our country, the number of MMSRs will gradually increase. This paper aims to analyze the reporting specifications for MMSRs with cases to improve the quality of evidence integration and reporting standardization of domestic relevant researchers in MMSRs.

Heuristic Research in Nursing Science.

The purpose of this article is to reintroduce and describe the processes and phases of heuristic inquiry and to illustrate how the method can advance nursing science. Heuristic inquiry is a rigorous, systematic, phenomenologically orientated research method developed by Clark Moustakas for investigating, discovering, and understanding the nature and meaning of living experiences. Heuristic inquiry invites the inclusion of the researcher's autobiographical living of experience being investigated honoring the personal experiences of the phenomenon from self and each participant in the research study. The author proposes that heuristic inquiry be used in nursing science by including a theoretical interpretive process connecting the thematic essences of the nursing conceptual framework guiding the study. Nursing theory-guided heuristic research advances the study of caring for persons experiencing human-environmental-health transitions to enhance human betterment and wellbecoming.

Multi-arm multi-stage (MAMS) randomised selection designs: impact of treatment selection rules on the operating characteristics.

BACKGROUND: Multi-arm multi-stage (MAMS) randomised trial designs have been proposed to evaluate multiple research questions in the confirmatory setting. In designs with several interventions, such as the 8-arm 3-stage ROSSINI-2 trial for preventing surgical wound infection, there are likely to be strict limits on the number of individuals that can be recruited or the funds available to support the protocol. These limitations may mean that not all research treatments can continue to accrue the required sample size for the definitive analysis of the primary outcome measure at the final stage. In these cases, an additional treatment selection rule can be applied at the early stages of the trial to restrict the maximum number of research arms that can progress to the subsequent stage(s). This article provides guidelines on how to implement treatment selection within the MAMS framework. It explores the impact of treatment selection rules, interim lack-of-benefit stopping boundaries and the timing of treatment selection on the operating characteristics of the MAMS selection design. METHODS: We outline the steps to design a MAMS selection trial. Extensive simulation studies are used to explore the maximum/expected sample sizes, familywise type I error rate (FWER), and overall power of the design under both binding and non-binding interim stopping boundaries for lack-of-benefit. RESULTS: Pre-specification of a treatment selection rule reduces the maximum sample size by approximately 25% in our simulations. The familywise type I error rate of a MAMS selection design is smaller than that of the standard MAMS design with similar design specifications without the additional treatment selection rule. In designs with strict selection rules - for example, when only one research arm is selected from 7 arms - the final stage significance levels can be relaxed for the primary analyses to ensure that the overall type I error for the trial is not underspent. When conducting treatment selection from several treatment arms, it is important to select a large enough subset of research arms (that is, more than one research arm) at early stages to maintain the overall power at the pre-specified level. CONCLUSIONS: Multi-arm multi-stage selection designs gain efficiency over the standard MAMS design by reducing the overall sample size. Diligent pre-specification of the treatment selection rule, final stage significance level and interim stopping boundaries for lack-of-benefit are key to controlling the operating characteristics of a MAMS selection design. We provide guidance on these design features to ensure control of the operating characteristics.

An Assessment of the Quality of Competence Restoration Research.

A systematic review of the literature on restoration of competence to stand trial identified a predominance of retrospective case studies using descriptive and correlational statistics. Guided by National Institutes of Health (NIH) quality metrics and emphasizing study design, sample size, and statistical methods, the authors categorized a large majority of studies as fair in quality, underscoring the need for controlled designs, larger representative samples, and more sophisticated statistical analyses. Implications for the state of forensic research include the need to use large databases within jurisdictions and the importance of reliable methods that can be applied across jurisdictions and aggregated for meta-analysis. More sophisticated research methods can be advanced in forensic fellowship training where coordinated projects and curricula can encourage systematic approaches to forensic research.

Promising advances in treatments for the management of idiopathic pulmonary fibrosis.

INTRODUCTION: Following the INPULSIS and ASCEND studies, leading to the first two approved antifibrotic therapies for patients with IPF, ongoing investigations are firmly exploring novel agents for a targeted effective and better tolerated therapy able to improve the natural history of the disease. AREAS COVERED: This review aims to analyze recent advances in pharmacological research of IPF, discussing the currently available treatments and the novel drugs under investigation in phase 3 trials, with particular emphasis on BI 1015550 and inhaled treprostinil. The literature search utilized Medline and Clinicaltrials.org databases. Critical aspects of clinical trial design in IPF are discussed in light of recently completed phase III studies. EXPERT OPINION: While randomized clinical trials in IPF are currently underway, future objectives should explore potential synergistic benefits when combining novel molecules with the existing therapies and identify more specific molecular targets. Moreover, refining the study design represent another crucial goal. The aim of the pharmacological research will be not only stabilizing but also potentially reversing the fibrotic changes in IPF.

Alternatives to the P value: connotations of significance.

The statistical significance of a clinical trial analysis result is determined by a mathematical calculation and probability based on null hypothesis significance testing. However, statistical significance does not always align with meaningful clinical effects; thus, assigning clinical relevance to statistical significance is unreasonable. A statistical result incorporating a clinically meaningful difference is a better approach to present statistical significance. Thus, the minimal clinically important difference (MCID), which requires integrating minimum clinically relevant changes from the early stages of research design, has been introduced. As a follow-up to the previous statistical round article on P values, confidence intervals, and effect sizes, in this article, we present hands-on examples of MCID and various effect sizes and discuss the terms statistical significance and clinical relevance, including cautions regarding their use.

A practical guide for writing a PhD thesis.

There is an increasing number of PhD students in health sciences, but no formal reporting guideline for writing a thesis exists. This review provides a practical guide with an overview of the article-based/synopsis PhD thesis that consists of eight parts: 1) initial formalities, 2) introduction, 3) methodological considerations, 4) study presentations, 5) discussion, 6) conclusion, 7) perspectives, and 8) concluding formalities. It is elaborated with detailed information, practical advice, and a template, so the thesis complies with the demands of the Danish Graduate Schools of Health Sciences.

Amplifying the Patient's Voice in Oncology Early-Phase Clinical Trials: Solutions to Burdens and Barriers.

Dose-finding oncology trials (DFOTs) provide early access to novel compounds of potential therapeutic benefit in addition to providing critical safety and dosing information. While access to trials for which a patient is eligible remains the largest barrier to enrollment on clinical trials, additional direct and indirect barriers unique to enrollment on DFOTs are often overlooked but worthy of consideration. Direct barriers including financial costs of care, travel and time investments, and logical challenges including correlative study designs are important to bear in mind when developing strategies to facilitate the patient experience on DFOTs. Indirect barriers such as strict eligibility criteria, washout periods, and concomitant medication restrictions should be accounted for during DFOT design to maintain the fidelity of the trial without being overly exclusionary. Involving patients and advocates and incorporating patient-reported outcomes (PROs) throughout the process, from initial DFOT design, through patient recruitment and participation, is critical to informing strategies to minimize identified barriers to offer the benefit of DFOTs to all patients.

Evaluation of a unique and innovative diabetes care model in primary care in Ontario, Canada: protocol for a multiple-methods study with a convergent parallel design.

INTRODUCTION: The growth and complexity of diabetes are exceeding the capacity of family physicians, resulting in the demand for community-based, interprofessional, primary care-led transition clinics. The Primary Care Diabetes Support Programme (PCDSP) in London, Ontario, is an innovative approach to diabetes care for high-risk populations, such as medically or socially complex and unattached patients. In this study, we will employ a quadruple-aim approach to evaluate the health system impacts of the PCDSP. METHODS AND ANALYSIS: We will use multiple methods through a convergent parallel design in this project across five unique studies: a case study, a patient study, a provider study, a complications study and a cost-effectiveness study. The project will be conducted in a dedicated stand-alone clinic specialising in chronic disease management, specifically focusing on diabetes care. Participants will include clinic staff, administrators, family physicians, specialists and patients with type 1 or type 2 diabetes who received care at the clinic between 2011 and 2023. The project design will define the intervention, support replication at other sites or for other chronic diseases and address each of the quadruple aims and equity. Following the execution of the five individual studies, we will build a business case by integrating the results. Data will be analysed using both qualitative (content analysis and thematic analysis) and quantitative techniques (descriptive statistics and multiple logistic regression). ETHICS AND DISSEMINATION: We received approval from the research ethics boards at Western University (reference ID: 2023-1 21 766; 2023-1 22 326) and Lawson Health Research Institute (reference ID: R-23-202). A privacy review was completed by St. Joseph's Healthcare Corporation. The findings will be shared among PCDSP staff and patients, stakeholders, academic researchers and the public through stakeholder sessions, conferences, peer-reviewed publications, infographics, posters, media interviews, social media and online discussions. For the patient and provider study, all participants will be asked to provide consent and are free to withdraw from the study, without penalty, until the data are combined. Participants will not be identified in any report or presentation except in the case study, for which, given the number of PCDSP providers, we will seek explicit consent to identify them.

Global prevalence of Borrelia burgdorferi and Anaplasma phagocytophilum coinfection in Ixodes tick populations: protocol for a systematic review and meta-analysis.

INTRODUCTION: Ixodes ticks are pivotal in transmitting diseases like Lyme disease and human granulocytic anaplasmosis, caused by Borrelia burgdorferi and Anaplasma phagocytophilum, respectively. These pathogens not only affect humans through single or multiple tick bites but also pose risks to animal hosts, leading to potential coinfections. Despite regional studies indicating significant prevalence, their global coinfection data remain sparse. This study aims to bridge this gap through a systematic review and meta-analysis of B. burgdorferi and A. phagocytophilum coinfections in Ixodes ticks worldwide. Addressing data limitations and study variability, it seeks to provide a nuanced understanding of coinfection patterns, their epidemiological implications and inform targeted prevention strategies. METHODS AND ANALYSIS: Following Preferred Reporting Items for Systematic Review and Meta-analysis Protocols 2015 guidelines and PROSPERO registration, this study will undertake a thorough database search without constraints on language or publication date, using standardised screening and data extraction protocols. The quality and bias of studies will be evaluated using Joanna Briggs Institute tools. In the statistical analysis phase, conducted in R, we will initially determine the use of fixed or random-effects models based on the assessment of data heterogeneity. This choice will guide the framework for subsequent analyses. Within the selected model's framework, we will perform subgroup analyses and meta-regression to investigate the effects of various factors, ensuring that each step is tailored to the initial model selection to maintain analytical consistency. ETHICS AND DISSEMINATION: As this study does not involve clinical research or data collection from subjects, ethical approval is not required. We will uphold ethical standards in synthesising and reporting data. Study outcomes will be published in peer-reviewed journals, communicating findings to the scientific community and contributing to the understanding of Ixodes tickborne diseases. PROSPERO REGISTRATION NUMBER: CRD42023449735.

Neonatal Resuscitation Online Registry in Shenzhen: protocol for a prospective, multicentre, open, observational cohort study.

INTRODUCTION: Preterm birth complications and neonatal asphyxia are the leading causes of neonatal mortality worldwide. Surviving preterm and asphyxiated newborns can develop neurological sequelae; therefore, timely and appropriate neonatal resuscitation is important to decrease neonatal mortality and disability rates. There are very few systematic studies on neonatal resuscitation in China, and its prognosis remains unclear. We established an online registry for neonatal resuscitation in Shenzhen based on Utstein's model and designed a prospective, multicentre, open, observational cohort study to address many of the limitations of existing studies. The aim of this study is to explore the implementation and management, risk factors and outcomes of neonatal resuscitation in Shenzhen. METHODS AND ANALYSIS: This prospective, multicentre, open, observational cohort study will be conducted between January 2024 and December 2026 and will include >1500 newborns resuscitated at birth by positive pressure ventilation at five hospitals in Shenzhen, located in the south-central coastal area of Guangdong province, China. Maternal and infant information, resuscitation information, hospitalisation information and follow-up information will be collected. Maternal and infant information, resuscitation information and hospitalisation information will be collected from the clinical records of the patients. Follow-up information will include the results of follow-up examinations and outcomes, which will be recorded using the WeChat applet 'Resuscitation Follow-up'. These data will be provided by the neonatal guardians through the applet on their mobile phones. This study will provide a more comprehensive understanding of the implementation and management, risk factors and outcomes of neonatal resuscitation in Shenzhen; the findings will ultimately contribute to the reduction of neonatal mortality and disability rates in Shenzhen. ETHICS AND DISSEMINATION: Our protocol has been approved by the Medical Ethics Committee of Shenzhen Luohu People's Hospital (2023-LHQRMYY-KYLL-048). We will present the study results at academic conferences and peer-reviewed paediatrics journals. TRIAL REGISTRATION NUMBER: ChiCTR2300077368.

Expert consensus on a protocol for conducting bibliometric analysis of scientific articles on global migration health (GMH).

BACKGROUND: Migration and health are key priorities in global health and essential for protecting and promoting the health of migrants. To better understand the existing evidence on migration health, it is critical to map the research publication activity and evidence on the health of migrants and mobile populations. This paper presents a search strategy protocol for a bibliometric analysis of scientific articles on global migration health (GMH), leveraging the expertise of a global network of researchers and academics. The protocol aims to facilitate the mapping of research and evidence on the health of international migrants and their families, including studies on human mobility across international borders. METHODS: A systematic search strategy using Scopus will be developed to map scientific articles on GMH. The search strategy will build upon a previous bibliometric study and will have two main search components: (1) 'international migrant population', covering specific movements across international borders, and (2) 'health'. The final search strategy will be implemented to determine the final set of articles to be screened for the bibliometric analysis. Title and abstract screening will exclude irrelevant articles and classify the relevant articles according to predefined themes and subthemes. A combination of the following approaches will be used in screening: applying full automation (ie, DistillerSR's machine learning tool) and/or semiautomation (ie, EndNote, MS Excel) tools, and manual screening. The relevant articles will be analysed using MS Excel, Biblioshiny and VOSviewer, which creates a visual mapping of the research publication activity around GMH. This protocol is developed in collaboration with academic researchers and policymakers from the Global South, and a network of migration health and research experts, with guidance from a bibliometrics expert. ETHICS AND DISSEMINATION: The protocol will use publicly available data and will not directly involve human participants; an ethics review will not be required. The findings from the bibliometric analysis (and other research that can potentially arise from the protocol) will be disseminated through academic publications, conferences and collaboration with relevant stakeholders to inform policies and interventions aimed at improving the health of international migrants and their families.

Development of a core outcome set for cardiac rehabilitation in patients with myocardial infarction: a study protocol.

INTRODUCTION: Heterogeneous outcome reporting is common in clinical trials focused on cardiac rehabilitation for myocardial infarction (MI); this practice often results in the exclusion of data from clinical trials in systematic reviews. Developing a core outcome set (COS) may solve this problem. METHODS AND ANALYSIS: We will first identify a preliminary list of outcomes through a systematic review. Next, we will conduct semistructured interviews with patients to explore additional potential outcomes deemed important by patients. Then, we will engage various stakeholders such as clinicians, researchers and methodologists in two Delphi survey tends to refine and prioritise the identified outcomes. Subsequently, we will gather insights directly from patients with MI by administering plain language patient surveys; patients will be involved in questionnaire development. Finally, we will hold two face-to-face consensus meetings for patients and other stakeholders to develop the final COS for cardiac rehabilitation in MI. ETHICS AND DISSEMINATION: The Ethics Committee of Dongzhimen Hospital, Beijing University of Chinese Medicine approved this study (2022DZMEC-349). The final COS will be published in a peer-reviewed journal and disseminated in conferences. TRIAL REGISTRATION: We registered this study in the Core Outcome Measures in Effectiveness Trials Initiative (COMET) platform. REGISTRATION NUMBER: 1725 (http://www.comet-initiative.org/studies/details/1725).

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

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). 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 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.