10/21/2009 — The Stepped Wedge Design: Outstanding Issues

Tanya Granston

The stepped wedge design of cluster-randomized trials has been growing in popularity and becomes increasingly relevant due to the need to efficiently evaluate the rollout of interventions that are individually efficacious in a community setting.  The design becomes especially practical for HIV/AIDS prevention and intervention trials, as the areas in most need are in resource limited settings where it is very likely not feasible to introduce interventions all at once and where there are substantial clusters/communities/groups to provide answers regarding intervention effects.  However, there remain limitations and outstanding issues to this design, which could potentially limit its usefulness where it’s most needed, and there are interesting extensions to the design that need to be explored.