Background
Pilot trials are a type of feasibility study that aim to determine whether a future definitive randomised controlled trial (RCT) should be conducted, and if so, how [Qualitative research conducted by members of our research group highlighted that sometimes researchers are unable to obtain funding for further research despite demonstrating the feasibility of their external pilot trial [It has been suggested that authors of external pilot trials that do not report progression criteria or report unclear progression criteria, may be more optimistic in reporting that a definitive RCT is feasible [We have since conducted an international web-based survey to explore the outcomes in terms of feasibility and progression of a recent cohort of external randomised pilot trials that we identified during our methodological review [