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.