Increased transparency was required when reporting imputation of primary outcome data in clinical trials.

OBJECTIVES: The aim of this study is to explore the transparency of reporting primary outcome data within randomized controlled trials in the presence of missing data. STUDY DESIGN AND SETTING: A cohort examination of randomized controlled trials published in the four major medical journals (NEJM, JAMA, BMJ, Lancet) in 2013 and the first quarter of 2018. Data were extracted on reporting quality, the number of randomized participants, and the number of participants included within the primary outcome analysis with observed or imputed data. RESULTS: Ninety-one of 159 (57%) studies analyzed from 2013 and 19 of 46 (41%) from 2018 included imputed data within the primary outcome analysis. Of these, only 13 of 91 (14%) studies from 2013 and 1 of 19 (5%) studies from 2018 explicitly reported the number of imputed values in the CONSORT diagram. Results' tables included levels of imputed data in 12 of 91 (13%) studies in 2013 and 4 of 19 (21%) in 2018. Consequently, identification of imputed data was a time-consuming task requiring extensive cross-referencing of all manuscript elements. CONCLUSION: Imputed primary outcome data are poorly reported. Participant flow diagrams frequently reported participant status which does not necessarily correlate to availability of data. We recommended that the number of imputed values are explicitly reported within CONSORT flow diagrams to increase transparency.

Developing an online, searchable database to systematically map and organise current literature on retention research (ORRCA2).

BACKGROUND: Addressing recruitment and retention challenges in trials is a key priority for methods research, but navigating the literature is difficult and time-consuming. In 2016, ORRCA (www.orrca.org.uk) launched a free, searchable database of recruitment research that has been widely accessed and used to support the update of systematic reviews and the selection of recruitment strategies for clinical trials. ORRCA2 aims to create a similar database to map the growing volume and importance of retention research. METHODS: Searches of Medline (Ovid), CINAHL, PsycINFO, Scopus, Web of Science Core Collection and the Cochrane Library, restricted to English language and publications up to the end of 2017. Hand searches of key systematic reviews were undertaken and randomised evaluations of recruitment interventions within the ORRCA database on 1 October 2020 were also reviewed for any secondary retention outcomes. Records were screened by title and abstract before obtaining the full text of potentially relevant articles. Studies reporting or evaluating strategies, methods and study designs to improve retention within healthcare research were eligible. Case reports describing retention challenges or successes and studies evaluating participant reported reasons for withdrawal or losses were also included. Studies assessing adherence to treatments, attendance at appointments outside of research and statistical analysis methods for missing data were excluded. Eligible articles were categorised into one of the following evidence types: randomised evaluations, non-randomised evaluations, application of retention strategies without evaluation and observations of factors affecting retention. Articles were also mapped against a retention domain framework. Additional data were extracted on research outcomes, methods and host study context. RESULTS: Of the 72,904 abstracts screened, 4,364 full texts were obtained, and 1,167 articles were eligible. Of these, 165 (14%) were randomised evaluations, 99 (8%) non-randomised evaluations, 319 (27%) strategies without evaluation and 584 (50%) observations of factors affecting retention. Eighty-four percent (n = 979) of studies assessed the numbers of participants retained, 27% (n = 317) assessed demographic differences between retained and lost participants, while only 4% (n = 44) assessed the cost of retention strategies. The most frequently reported domains within the 165 studies categorised as 'randomised evaluations of retention strategies' were participant monetary incentives (32%), participant reminders and prompts (30%), questionnaire design (30%) and data collection location and method (26%). CONCLUSION: ORRCA2 builds on the success of ORRCA extending the database to organise the growing volume of retention research. Less than 15% of articles were randomised evaluations of retention strategies. Mapping of the literature highlights several areas for future research such as the role of research sites, clinical staff and study design in enhancing retention. Future studies should also include cost-benefit analysis of retention strategies.

Using digital tools in the recruitment and retention in randomised controlled trials: survey of UK Clinical Trial Units and a qualitative study.

BACKGROUND: Recruitment and retention of participants in randomised controlled trials (RCTs) is a key determinant of success but is challenging. Trialists and UK Clinical Research Collaboration (UKCRC) Clinical Trials Units (CTUs) are increasingly exploring the use of digital tools to identify, recruit and retain participants. The aim of this UK National Institute for Health Research (NIHR) study was to identify what digital tools are currently used by CTUs and understand the performance characteristics required to be judged useful. METHODS: A scoping of searches (and a survey with NIHR funding staff), a survey with all 52 UKCRC CTUs and 16 qualitative interviews were conducted with five stakeholder groups including trialists within CTUs, funders and research participants. A purposive sampling approach was used to conduct the qualitative interviews during March-June 2018. Qualitative data were analysed using a content analysis and inductive approach. RESULTS: Responses from 24 (46%) CTUs identified that database-screening tools were the most widely used digital tool for recruitment, with the majority being considered effective. The reason (and to whom) these tools were considered effective was in identifying potential participants (for both Site staff and CTU staff) and reaching recruitment target (for CTU staff/CI). Fewer retention tools were used, with short message service (SMS) or email reminders to participants being the most reported. The qualitative interviews revealed five themes across all groups: 'security and transparency'; 'inclusivity and engagement'; 'human interaction'; 'obstacles and risks'; and 'potential benefits'. There was a high level of stakeholder acceptance of the use of digital tools to support trials, despite the lack of evidence to support them over more traditional techniques. Certain differences and similarities between stakeholder groups demonstrated the complexity and challenges of using digital tools for recruiting and retaining research participants. CONCLUSIONS: Our studies identified a range of digital tools in use in recruitment and retention of RCTs, despite the lack of high-quality evidence to support their use. Understanding the type of digital tools in use to support recruitment and retention will help to inform funders and the wider research community about their value and relevance for future RCTs. Consideration of further focused digital tool reviews and primary research will help to reduce gaps in the evidence base.

Investigating the effects of lycopene and green tea on the metabolome of men at risk of prostate cancer: The ProDiet randomised controlled trial.

Lycopene and green tea consumption have been observationally associated with reduced prostate cancer risk, but the underlying mechanisms have not been fully elucidated. We investigated the effect of factorial randomisation to a 6-month lycopene and green tea dietary advice or supplementation intervention on 159 serum metabolite measures in 128 men with raised PSA levels (but prostate cancer-free), analysed by intention-to-treat. The causal effects of metabolites modified by the intervention on prostate cancer risk were then assessed by Mendelian randomisation, using summary statistics from 44,825 prostate cancer cases and 27,904 controls. The systemic effects of lycopene and green tea supplementation on serum metabolic profile were comparable to the effects of the respective dietary advice interventions (R2 = 0.65 and 0.76 for lycopene and green tea respectively). Metabolites which were altered in response to lycopene supplementation were acetate [ß (standard deviation difference vs. placebo): 0.69; 95% CI = 0.24, 1.15; p = 0.003], valine (ß: -0.62; -1.03, -0.02; p = 0.004), pyruvate (ß: -0.56; -0.95, -0.16; p = 0.006) and docosahexaenoic acid (ß: -0.50; -085, -0.14; p = 0.006). Valine and diacylglycerol were lower in the lycopene dietary advice group (ß: -0.65; -1.04, -0.26; p = 0.001 and ß: -0.59; -1.01, -0.18; p = 0.006). A genetically instrumented SD increase in pyruvate increased the odds of prostate cancer by 1.29 (1.03, 1.62; p = 0.027). An intervention to increase lycopene intake altered the serum metabolome of men at risk of prostate cancer. Lycopene lowered levels of pyruvate, which our Mendelian randomisation analysis suggests may be causally related to reduced prostate cancer risk.

Reducing attrition within clinical trials: The communication of retention and withdrawal within patient information leaflets.

BACKGROUND: The recruitment and retention of patients are significant methodological challenges for trials. Whilst research has focussed on recruitment, the failure to retain recruited patients and collect outcome data can lead to additional problems and potentially biased results. Research to identify effective retention strategies has focussed on influencing patient behaviour through incentives, reminders and alleviating patient burden, but has not sought to improve patient understanding of the importance of retention. Our aim is to assess how withdrawal, retention and the value of outcome data collection is described within the Patient Information Leaflets (PIL) used during consent. METHODS: Fifty adult or parent PIL from a cohort of trials starting between 2009-2012 and funded by the NIHR Health Technology Assessment programme were obtained from protocols, websites or by contacting trialists. A checklist of PIL content based on Health Research Authority (HRA) and ICH GCP Guidelines was supplemented with retention specific questions. Corresponding protocols were also evaluated to cross reference trial specific procedures with information communicated to patients. RESULTS: PIL frequently reiterated the patient's right to withdraw at any time (n = 49, 98%), without having to give a reason and without penalty (n = 45, 90%). However, few informed patients they may be asked to give a withdrawal reason where willing (n = 6, 12%). Statements about the value of retention were infrequent (n = 8, 16%). Consent documents failed to include key content that might mitigate withdrawals, such as the need for treatment equipoise (n = 3, 6%). Nearly half the trials in the cohort (n = 23, 46%) wanted to continue to collect outcome data if patients withdraw. However, in 70% of PIL using prospective consent, withdrawal was described in generic terms leaving patients unaware of the difference between stopping treatment and all trial involvement. Nineteen (38%) trials offered withdrawing patients the option to delete existing data. CONCLUSIONS: Withdrawal and retention is poorly described within PIL and addressing this might positively impact levels of patient attrition, reducing missing data. Consent information is unbalanced, focussing on patient's rights to withdraw without accompanying information that promotes robust consent and sustained participation. With many citing altruistic reasons for participation it is essential that PIL include more information on retention and clarify withdrawal terminology so patients are aware of how they can make a valuable contribution to clinical studies. There is a need to determine how retention can be described to patients to avoid concerns of coercion. Future research is needed to explore whether the absence of information about retention at the time of consent is impacting attrition.

Identifying research priorities for effective retention strategies in clinical trials.

BACKGROUND: The failure to retain patients or collect primary-outcome data is a common challenge for trials and reduces the statistical power and potentially introduces bias into the analysis. Identifying strategies to minimise missing data was the second highest methodological research priority in a Delphi survey of the Directors of UK Clinical Trial Units (CTUs) and is important to minimise waste in research. Our aim was to assess the current retention practices within the UK and priorities for future research to evaluate the effectiveness of strategies to reduce attrition. METHODS: Seventy-five chief investigators of NIHR Health Technology Assessment (HTA)-funded trials starting between 2009 and 2012 were surveyed to elicit their awareness about causes of missing data within their trial and recommended practices for improving retention. Forty-seven CTUs registered within the UKCRC network were surveyed separately to identify approaches and strategies being used to mitigate missing data across trials. Responses from the current practice surveys were used to inform a subsequent two-round Delphi survey with registered CTUs. A consensus list of retention research strategies was produced and ranked by priority. RESULTS: Fifty out of seventy-five (67%) chief investigators and 33/47 (70%) registered CTUs completed the current practice surveys. Seventy-eight percent of trialists were aware of retention challenges and implemented strategies at trial design. Patient-initiated withdrawal was the most common cause of missing data. Registered CTUs routinely used newsletters, timeline of participant visits, and telephone reminders to mitigate missing data. Whilst 36 out of 59 strategies presented had been formally or informally evaluated, some frequently used strategies, such as site initiation training, have had no research to inform practice. Thirty-five registered CTUs (74%) participated in the Delphi survey. Research into the effectiveness of site initiation training, frequency of patient contact during a trial, the use of routinely collected data, the frequency and timing of reminders, triggered site training and the time needed to complete questionnaires was deemed critical. Research into the effectiveness of Christmas cards for site staff was not of critical importance. CONCLUSION: The surveys of current practices demonstrates that a variety of strategies are being used to mitigate missing data but with little evidence to support their use. Six retention strategies were deemed critically important within the Delphi survey and should be a primary focus of future retention research.

Setting an Agenda for Assessment of Health-related Quality of Life Among Men with Prostate Cancer on Active Surveillance: A Consensus Paper from a European School of Oncology Task Force.

BACKGROUND: Literature on the health-related quality of life (HRQoL) for men with localized prostate cancer (PCa) on active surveillance (AS) shows a need for methodological guidance regarding HRQoL issues and how to address them. OBJECTIVE: The European School of Oncology Task Force (ESO TF) aimed to identify a core set of research questions and related measures to include in AS HRQoL studies. DESIGN, SETTING, AND PARTICIPANTS: A modified Delphi study was used to reach consensus on AS HRQoL research topics and tools between 2014 and 2015. Data were collected by engaging a multidisciplinary team of 15 experts. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: An open-ended questionnaire was used to collect information from ESO TF members regarding issues in AS HRQoL research. Then a structured questionnaire was used to collect ratings on the usefulness/importance of different AS HRQoL aspects. Items that ≥80% of ESO TF members rated as useful/important were retained. Items with a 50-80% rating were discussed to reach final agreement. RESULTS AND LIMITATIONS: Six main research questions concerning the selection of outcome measures, measurement tools, and comparison groups were identified as relevant. The core set of measures identified were related to individual characteristics, psychological dimensions; decision-making-related issues, and physical functioning. The multidisciplinary expertise of ESO TF members was a significant asset, even if bringing different backgrounds to the discussion table represented a challenge. CONCLUSIONS: HRQoL measures have to be sensitive to the specific needs of men on AS. The definition of HRQoL outcomes will enhance a broader understanding of the HRQoL of men on AS and sustain patient-centered medicine. PATIENT SUMMARY: An international panel agreed on a set of health-related quality-of-life aspects to be assessed among men on active surveillance for prostate cancer. Valid relevant questionnaires were identified. The experts' indications lay a foundation for future research and clinical practice.

Inverse association between gastroesophageal reflux and blood pressure: results of a large community based study.

BACKGROUND: In a cross-sectional community based study, as part of a randomised controlled trial of eradication of Helicobacter pylori infection, the association between blood pressure and symptoms of gastro-oesophageal reflux was examined. METHODS: Linear regression was used to examine the association between systolic and diastolic blood pressure and the frequency of heartburn and acid regurgitation in 4,902 of 10,537 participants aged 20-59 years. RESULTS: In multivariable analyses, adjusted mean systolic blood pressure was 4.2 (95% confidence interval 1.5 to 7.0) mm Hg lower in participants with daily acid regurgitation compared to those with less frequent symptoms. Similarly, for diastolic blood pressure, a reduction of 2.1 (0.0 to 4.3) mm Hg wasobserved. CONCLUSION: People who experience daily symptoms of gastro-oesophageal reflux have lower blood pressure than people with less frequent or no symptoms. It is possible that factors influencing nitric oxide concentrations both at the lower oesophageal sphincter and within the vasculature may be involved. This hypothesis requires confirmation. TRIALS REGISTRATION NUMBER: ISRCTN44816925.

Inverse relationship between alcohol consumption and active Helicobacter pylori infection: the Bristol Helicobacter project.

OBJECTIVE: The aim of this study was to examine whether smoking or consumption of alcohol or coffee is associated with active Helicobacter pylori (H. pylori) infection. METHODS: This was a cross-sectional population study conducted as part of a randomized controlled trial of H. pylori infection eradication in southwest England. A total of 10,537 subjects, recruited from seven general practices, underwent 13C-urea breath testing for active infection with H. pylori and provided data on smoking, usual weekly consumption of alcohol, and daily intake of coffee. RESULTS: Smoking or coffee consumption were not related to active H. pylori infection. Total alcohol consumption was associated with a small, but not statistically significant, decrease in the odds of infection. After adjustment for age, sex, ethnic status, childhood and adult social class, smoking, coffee consumption, and intake of alcoholic beverages other than wine, subjects drinking 3-6 units of wine/wk had an 11% lower risk of H. pylori infection compared with those who took no wine: OR = 0.89, 95% CI = 0.80-0.99. Higher wine consumption was associated with a further 6% reduction in the risk of infection: OR = 0.83, 95% CI = 0.64-1.07. Intake of 3-6 units of beer (but no greater intake) was associated with a similar reduction in the risk of infection when compared to no beer intake (OR = 0.83, 95% CI = 0.75-0.91). CONCLUSIONS: This study indicates that modest consumption of wine and beer (approximately 7 units/wk) protects against H. pylori infection, presumably by facilitating eradication of the organism.