Accessibility statement


The PROMETHEUS programme (funded by the Medical Research Council (MRC) aimed to facilitate the development of strategies to increase the evidence base around recruitment and retention strategies rapidly.

This programme funded 42 SWATs, embedded within 31 host trials, across 12 CTUs in the UK between 2018 and 2021. This was done by offering trial teams up to £5000 to embed a SWAT within their host trial, alongside methodological support.

This is the biggest single effort to generate SWAT evidence worldwide to date. Below we summarise our work with the PROMETHEUS programme.

What was found?

Initially, the programme aimed to fund 25 SWATs, however, as the average cost was lower than anticipated (£4007), further SWATs were able to be funded. Additionally, the centralised coordination of the programme proved to be efficient. See (Doherty et al., 2022) for more information.

Research areas included in PROMETHEUS

  • Surgical - 11 SWATs
  • Respiratory, smoking cessation, Oncology, Fall reduction, Orthopaedic, Wound care - 3 SWATs in each area.
  • Community Pharmacy, Physiotherapy, Primary care (Signs and symptoms), Rheumatology, Urology - 2 SWATs in each area
  • Oral health, Gastrointestinal, and Gynaecology - 1 SWAT in each area.

The programme’s impact

  • 42 SWATs were funded.
  • Outputs include SWAT result publications, papers on learnings from the program, and a comprehensive HTA report.
  • A database of reviewers for SWAT publications was developed to increase the pool of reviewers and speed up the reviewing process.
  • This programme collaborated with Trial Forge to create the ‘Trial Forge SWAT Network’ as a network that would aid in linking research groups globally that are undertaking methodological (SWAT) research.

Publications (as of May 2023)

SWAT Publications

SWATs (Two-arm & Factorial)

Host trial


Sending pre-notification cards to trial participants before a face-to-face primary outcome measurement to increase attendance (SWAT 76)


Personalised versus standard text message prompts


Using pens as an incentive for questionnaire return in an orthopaedic trial


Personalised text messages compared to non-personalised text messages in an orthopaedic setting


Pre-notification and personalisation of text messages to increase questionnaire completion in a smoking cessation pregnancy RCT


Including a pen and/or cover letter, containing social incentive text, had no effect on questionnaire response rate


Enclosing a pen to improve the response rate to postal questionnaire


Timing of electronic reminders did not improve trial participant questionnaire response


Including a wet-ink signature and photograph in the patient invitation letter for a clinical trial


Christmas Card SWAT (eight trials)


Staff training SWAT (four trials)


Other Publications

Three papers have been published in the Research Methods in Medicine & Health Sciences Journal describing the learning derived from this programme:

  • (Arundel et al., 2023) - Challenges and solutions to the implementation of studies within a trial: The experiences of the PROMETHEUS programme
  • (Clark et al., 2022) - The PROMoting the USE of SWATs (PROMETHEUS) programme: Lessons learnt and future developments for SWATs.
  • (Doherty et al., 2022) - PROMoting the use of studies within a trial (PROMETHEUS): Results and experiences from a large programme to evaluate the routine embedding of recruitment and retention strategies within randomised controlled trials routinely.
  • With a comprehensive HTA report in the process of being disseminated.

Useful links:

Press release

For further details about PROMETHEUS please see the following press release.

PROMETHEUS Hosted Webinars

PROMETHEUS Collaborate Webinar

This webinar gives an overview of both the PROMETHEUS programme and the Trial Forge and describes their collaboration and efforts to promote SWATs and SWAT knowledge.

The implementation and management of Studies Within A Trial (SWATs)

This webinar gives an overview of how SWATs have been implemented and managed in various Trials units in the UK and Ireland with experiences from the teams at:

  • Nottingham Clinical Trials Unit
  • York Trials Unit
  • Oxford Clinical Trials Research Unit
  • Centre for Healthcare Randomised Trials
  • Derby Clinical Trials Support Unit (CTSU)
  • Pragmatic Clinical Trials Unit - Queen Mary University of London


Implementation guidance for SWATs assessing personalised SMS for retention and pens for recruitment

This webinar gives an overview on guidance on how to go about answering questions such as “Where do we need to replicate SWATs?” and “Where do we need to innovate SWATs?”. It also discusses guidance on implementing two SWATs (assessing personalised SMS for retention and pens for recruitment) and who to turn to if support is required to undertake a SWAT.


    Researcher experiences of conducting recruitment and retention research and an introduction to the new Trial Forge Studies Within a Trial (SWAT) network

    This webinar was presented by PROMETHEUS programme collaborators and included the experiences of undertaking SWATs in low and middle-income countries and the use of digital tools for recruitment and retention. The newly established Trial Forge SWAT Network was also outlined.

    PROMETHEUS Christmas webinar

    This webinar presented the results of a simultaneous SWAT evaluating Christmas Cards as a retention strategy. The logistics of setting up this simultaneous SWAT and the processes involved were also detailed. The results of this SWAT are available at:

    Economic evaluations alongside SWATs: an introduction and practical examples

    This webinar introduced cost-effectiveness analyses in SWATs. The current evidence base was summarised, with findings presented from a recent systematic review of economic evaluations alongside SWATs for improving recruitment and retention in RCTs.

    Project details


    Medical Research Council

    Grant number MR/R013748/1

    Sponsor: University of York
    Start date: 1st April 2018
    End date: 30th September 2020


    Contact us

    To contact the York Trial Forge SWAT centre, please email:

    YTU Team

    External Collaborators


    Medium size YTU logo (fits in right hand column)

    Medical Research Council Logo SWATs