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Stepped Wedge Randomized Controlled Trials

Edited by: Prof David Torgerson

A thematic series published in Trials.

There is often a tension between policy makers wishing to implement a novel intervention and researchers wanting time to do a controlled evaluation. One trial design that can address this tension is the stepped wedged randomized trial. In a stepped wedge trial, all groups or clusters of participants eventually receive the intervention, but the implementation is staggered in a random fashion allowing a robust evaluation to take place. Recently there has been an upsurge in interest in the design, which is not yet well understood. This series of papers reviews previous stepped wedge studies and explores key issues of design, forming a comprehensive overview of the current state of knowledge of the design.

The London School of Hygiene & Tropical Medicine held a free symposium to celebrate the launch of this series on 22 September 2015.

  1. Stepped wedge cluster randomised trials introduce interventions to groups of clusters in a random order and have been used to evaluate interventions for health and wellbeing. Standardised guidance for reportin...

    Authors: Calum Davey, James Hargreaves, Jennifer A Thompson, Andrew J Copas, Emma Beard, James J Lewis and Katherine L Fielding
    Citation: Trials 2015 16:358
  2. Stepped wedge trials (SWTs) can be considered as a variant of a clustered randomised trial, although in many ways they embed additional complications from the point of view of statistical design and analysis. ...

    Authors: Gianluca Baio, Andrew Copas, Gareth Ambler, James Hargreaves, Emma Beard and Rumana Z Omar
    Citation: Trials 2015 16:354
  3. In a stepped wedge, cluster randomised trial, clusters receive the intervention at different time points, and the order in which they received it is randomised. Previous systematic reviews of stepped wedge tri...

    Authors: Emma Beard, James J. Lewis, Andrew Copas, Calum Davey, David Osrin, Gianluca Baio, Jennifer A. Thompson, Katherine L. Fielding, Rumana Z. Omar, Sam Ononge, James Hargreaves and Audrey Prost
    Citation: Trials 2015 16:353
  4. There is limited guidance on the design of stepped wedge cluster randomised trials. Current methodological literature focuses mainly on trials with cross-sectional data collection at discrete times, yet many r...

    Authors: Andrew J. Copas, James J. Lewis, Jennifer A. Thompson, Calum Davey, Gianluca Baio and James R. Hargreaves
    Citation: Trials 2015 16:352
  5. Three arguments are usually invoked in favour of stepped wedge cluster randomised controlled trials: the logistic convenience of implementing an intervention in phases, the ethical benefit of providing the int...

    Authors: Audrey Prost, Ariella Binik, Ibrahim Abubakar, Anjana Roy, Manuela De Allegri, Christelle Mouchoux, Tobias Dreischulte, Helen Ayles, James J. Lewis and David Osrin
    Citation: Trials 2015 16:351