Do principal investigator site visits boost recruitment in multicentre trials? The first SWAT design

What is it about?

The SWAT (Study Within A Trial) programme embeds research studies inside ongoing clinical trials to generate evidence about how trials themselves should be designed and conducted. This paper presents the first published SWAT design summary using the programme's standardised template, describing a study that tests whether site visits by the principal investigator improve participant recruitment rates in a multicentre randomised controlled trial. The design summary specifies the research question, the proposed methods for embedding the SWAT within a host trial, the outcomes to be measured and the analytic approach. The authors prepared this as a proof-of-concept template that could be replicated and adapted for subsequent SWATs investigating other uncertainties about trial conduct.

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Why is it important?

Recruitment failure is one of the most common reasons clinical trials are delayed, underpowered or abandoned, yet at the time of publication the evidence base for which recruitment strategies actually work was thin and largely anecdotal. The SWAT programme addressed this by turning the methods of clinical trials on trial conduct itself, using rigorous embedded designs to test specific strategies under real trial conditions. This paper established the template for all subsequent SWAT design summaries, creating a standardised, reproducible format for the growing SWAT library. The work sits within the broader MRC-funded trials methodology research agenda and it remains relevant to funders, trialists and research governance bodies seeking to reduce recruitment waste and improve the efficiency of clinical trials.