Guidance front pageRandomised trials are a central component of all evidence-informed health care systems and the evidence coming from them helps to support health care users, health professionals and others to make more informed decisions about treatment. The evidence available to trialists to support decisions on design, conduct and reporting of randomised trials is, however, sparse.

One way to fill gaps in evidence is to run Studies Within A Trial, or SWATs. This first piece of Trial Forge guidance provides a brief definition of SWATs, an explanation of why they are important and some practical ‘top tips’ that come from existing experience of doing SWATs.  By coordinating evaluation of the same SWAT in several trials, we can reduce uncertainty about intervention effects much faster.

We hope the guidance will be useful to trialists, methodologists, funders, approvals agencies and others in making clear what a SWAT is, as well as what is involved in doing one.

The guidance is published in Trials at https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-018-2535-5