Skip to content


  • Oral presentation
  • Open Access

Assessing the effectiveness of a ‘site visit’ on recruitment rates in a multicentre randomised trial: SWAT-1

  • 1, 3,
  • 2,
  • 1 and
  • 3
Trials201516 (Suppl 2) :O10

  • Published:


  • Public Health
  • Primary Outcome
  • Research Council
  • Medical Research
  • Randomise Trial


The SWAT (Studies within a Trial) programme, established by the All-Ireland Hub for Trials Methodology Research in collaboration with the Medical Research Council Network of Hubs in the UK and others, is developing methods to resolve uncertainties about trial conduct through embedded research. SWAT-1 provides an initial example.


To evaluate the effects of a site visit on recruitment rates in a multi-centre randomised trial.


Using the SWAT-1 design, a before-and-after comparison used the date of the site visit as the time point for the intervention. Site A received the site visit. Sites B and C did not receive it and acted as the controls. The primary outcomes were the difference in recruitment in each site from 1 and 3 months pre-intervention to 1 and 3 months post-intervention.


Recruitment rates increased in Site A post-intervention (17% and 14% percentage point increases at 1 and 3 months, respectively). No differences in recruitment occurred in Site B or in Site C. At 3 months post-intervention, a significant difference was detected in favour of higher recruitment in A compared to B+C (34% versus 25%; odds ratio 1.57, 95% confidence interval 1.09-2.26). These findings suggest that recruitment might increase from 2 participants per week before the site visit to 4-5 per week after it.


This initial example of a SWAT provides evidence that a site visit increases recruitment rates in a trial. Further SWAT-1s are required to substantiate these findings and to examine the effects in different trials in different settings.

Authors’ Affiliations

Trinity College Dublin, Dublin, Ireland
Queen's University, Belfast, UK
National University of Ireland, Galway, Ireland


© Smith et al. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. Please note that comments may be removed without notice if they are flagged by another user or do not comply with our community guidelines.