Sharing raw data from clinical trials: what progress since we first asked "Whose data set is it anyway?".

Ten years ago, one of the first papers published in Trials was a commentary entitled "Whose data set is it anyway?" The commentary pointed out that trialists routinely refused requests for data sharing and argued that this attitude was a community standard that had no rational basis. At the time, there had been few calls for clinical trial data sharing and certainly no institutional support. Today the situation could not be more different. Numerous organizations now recommend or require raw data to be made available, including the International Committee of Medical Journal Editors, which recently proposed that clinical trial data sharing be a "condition of … publication." Furthermore, the literature is replete with papers covering an enormously wide variety of topics on data sharing. But despite a tectonic shift in attitudes, we are yet to see clinical trial data sharing become an unquestioned norm, where a researcher can readily download a data set from a trial almost as easily as they can now download a copy of the published paper. The battle over the next few years is to go beyond changing minds to ensuring that real data sets are routinely made available.