A systematic review of non-randomised evaluations of strategies to improve participant recruitment to randomised controlled trials.

Background: Recruitment to trials can be challenging. Currently, non-randomised evaluations of trial recruitment interventions are rejected due to poor methodological quality, but systematic assessment of this substantial body of work may inform trialists' decision-making about recruitment methods. Our objective was to quantify the effects of strategies to improve participant recruitment to randomised trials evaluated using non-randomised study designs. Methods: We searched relevant databases for non-randomised studies that included two or more interventions evaluating recruitment to trials. Two reviewers screened abstracts and full texts for eligible studies, then extracted data on: recruitment intervention, setting, participant characteristics, number of participants in intervention and comparator groups. The ROBINS-I tool was used to assess risk of bias. The primary outcome was the number of recruits to a trial. Results: We identified 92 studies for inclusion; 90 studies aimed to improve the recruitment of participants, one aimed to improve the recruitment of GP practices, and one aimed to improve recruitment of GPs. Of the 92 included studies, 20 were at high risk of bias due to confounding; the remaining 72 were at high risk of bias due to confounding and at least one other category of the ROBINS-I tool. The 20 studies at least risk of bias were synthesised narratively based on seven broad categories; Face to face recruitment initiatives, postal invitations and responses, language adaptations, randomisation methods, trial awareness strategies aimed at the recruitee, trial awareness strategies aimed at the recruiter, and use of networks and databases. The utility of included studies is substantially limited due to small sample sizes, inadequate reporting, and a lack of coordination around deciding what to evaluate and how. Conclusions: Careful thought around planning, conduct, and reporting of non-randomised evaluations of recruitment interventions is required to prevent future non-randomised studies contributing to research waste. Registration: PROSPERO CRD42016037718.

Using systematic data categorisation to quantify the types of data collected in clinical trials: the DataCat project.

BACKGROUND: Data collection consumes a large proportion of clinical trial resources. Each data item requires time and effort for collection, processing and quality control procedures. In general, more data equals a heavier burden for trial staff and participants. It is also likely to increase costs. Knowing the types of data being collected, and in what proportion, will be helpful to ensure that limited trial resources and participant goodwill are used wisely. AIM: The aim of this study is to categorise the types of data collected across a broad range of trials and assess what proportion of collected data each category represents. METHODS: We developed a standard operating procedure to categorise data into primary outcome, secondary outcome and 15 other categories. We categorised all variables collected on trial data collection forms from 18, mainly publicly funded, randomised superiority trials, including trials of an investigational medicinal product and complex interventions. Categorisation was done independently in pairs: one person having in-depth knowledge of the trial, the other independent of the trial. Disagreement was resolved through reference to the trial protocol and discussion, with the project team being consulted if necessary. KEY RESULTS: Primary outcome data accounted for 5.0% (median)/11.2% (mean) of all data items collected. Secondary outcomes accounted for 39.9% (median)/42.5% (mean) of all data items. Non-outcome data such as participant identifiers and demographic data represented 32.4% (median)/36.5% (mean) of all data items collected. CONCLUSION: A small proportion of the data collected in our sample of 18 trials was related to the primary outcome. Secondary outcomes accounted for eight times the volume of data as the primary outcome. A substantial amount of data collection is not related to trial outcomes. Trialists should work to make sure that the data they collect are only those essential to support the health and treatment decisions of those whom the trial is designed to inform.

Trial Forge Guidance 2: how to decide if a further Study Within A Trial (SWAT) is needed.

The evidence base available to trialists to support trial process decisions-e.g. how best to recruit and retain participants, how to collect data or how to share the results with participants-is thin. One way to fill gaps in evidence is to run Studies Within A Trial, or SWATs. These are self-contained research studies embedded within a host trial that aim to evaluate or explore alternative ways of delivering or organising a particular trial process.SWATs are increasingly being supported by funders and considered by trialists, especially in the UK and Ireland. At some point, increasing SWAT evidence will lead funders and trialists to ask: given the current body of evidence for a SWAT, do we need a further evaluation in another host trial? A framework for answering such a question is needed to avoid SWATs themselves contributing to research waste.This paper presents criteria on when enough evidence is available for SWATs that use randomised allocation to compare different interventions.

A protocol for a systematic review of non-randomised evaluations of strategies to increase participant retention to randomised controlled trials.

BACKGROUND: Randomised control trials are regarded as the gold standard for evaluating the effectiveness and efficacy of healthcare interventions with thousands of trials published every year. Despite significant investment in infrastructure, a staggering number of clinical trials continue to face challenges with retention. Dropouts could lead to negative consequences-from lengthy delays to missing data that can undermine the results and integrity of the trial. Summarising evidence from non-randomised evaluations of retention strategies could provide complementary information to randomised evaluations that could guide trialists to the most effective ways of increasing retention of participants in clinical trials. METHODS: The following electronic databases will be searched for relevant studies: EMBASE, MEDLINE, the Cochrane Controlled Trials Register, and Cochrane Methodology Register and the search will be limited to English-published studies during the last 10 years to increase relevance to current trials. Non-randomised studies (observational studies) including a comparison of two or more strategies to increase participant retention in randomised trials or comparing one or more strategies with no strategy will be included. The primary outcome will be the proportion of participants remained at the primary analysis as determined in each retention study. DISCUSSION: This review aims to gather and evaluate evidence on the effect of retention strategies examined in non-randomised studies. It is imperative to collect evidence from obseravational studies to infer whether or not these studies could be considered a practical way to complement or even replace a broadly favourable randomised design. If we find that non-randomised studies to be included in this review are of high quality with adequate control of biases, we will recommend to trialists and others not to rely exclusively on randomised studies and to give meticulous attention to the plentiful evidence that can be obtained from non-randomised studies. Should the results of this review suggest that evaluating retention strategies in observational studies provides insufficient evidence to trialists planning their retention strategies, we will be able to say that there is little point in conducting non-randomised studies and that they would do better to invest their time and resources in a randomised evaluation if possible. Where a non-randomised study design is chosen, the review authors will offer recommendations to trialists and others regarding how to ensure that these studies are conducted in a way that can minimise the risk of bias and increase confidence in the findings. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2017: CRD42017072775 .

Trial Forge Guidance 1: what is a Study Within A Trial (SWAT)?

Randomised trials are a central component of all evidence-informed health care systems and the evidence coming from them helps to support health care users, health professionals and others to make more informed decisions about treatment. The evidence available to trialists to support decisions on design, conduct and reporting of randomised trials is, however, sparse. Trial Forge is an initiative that aims to increase the evidence base for trial decision-making and in doing so, to improve trial efficiency.One way to fill gaps in evidence is to run Studies Within A Trial, or SWATs. This guidance document provides a brief definition of SWATs, an explanation of why they are important and some practical 'top tips' that come from existing experience of doing SWATs. We hope the guidance will be useful to trialists, methodologists, funders, approvals agencies and others in making clear what a SWAT is, as well as what is involved in doing one.