Problems encountered during stepped-wedge cluster randomised trials and potential solutions: Systematic review and survey

What are the problems and possible solutions when undertaking stepped wedge cluster randomised trials? This research will aim to summarise published problems and solutions and then by contacting researchers, who are involved in these trials, explore these issues further. Finally, the target is to produce a publication that forms a single point of reference, offering practical advice for those carrying out stepped wedge cluster randomised trials.

Part of our Novel Methods to Aid and Evaluate Implementation research theme

Stepped-wedge cluster trials use groups of people (“clusters”) to test the effects of service or policy changes. Initially, none of the groups has the intervention. Then, at regular intervals (“steps”), the intervention is rolled-out, to one or more groups, typically picked at random, until they all have the intervention.

The advantage of such trials is that all participants receive the intervention, which is expected to be effective, but at different times. The staged roll-out of the intervention overcomes any logistical problems preventing it being implemented immediately.

However, there are substantial issues regarding implementing the design in terms of delivery of the intervention, recruitment, follow-up and analysis. This project aims to identify problems and provide practical solutions for researchers undertaking this type of study.

This research is split into two stages:

Stage 1:
Systematic review to identify and summarise reported problems and solutions when conducting a stepped wedge cluster randomised trial. We are currently in the process of sorting through the abstracts (summaries of academic papers) which have been identified from our search of the literature for possible inclusion in our systematic review. This selection process is being carried out by two people independently. This approach is recommended to avoid the possibly overlooking a relevant study.

Stage 2:
Survey and/or Interviews with leading researchers involved in published and ongoing stepped wedge studies identified in our systematic review. These will aim to identify unpublished problems and solutions and explore further those that were reported.

Click here for the full study protocol

How we are involving patients and the public

Not currently involved. We will aim to involve PPI representatives at a later stage to help raise the profile of this type of study.

How we are planning to implement the research outputs

We plan to produce a comprehensive guide for researchers who are interested in investigating changes in the delivery of health services by offering practical advice on conducting stepped wedge cluster randomised trials. This advice will be published in a medical journal.

We will also disseminate our research findings more broadly so that providers and patients can be become familiar with this type of research study, as it differs from the more familiar clinical trial where some patients (or groups of patients) receive the treatment under study and some patients receive a different treatment or no treatment.