Data sharing: making good on promises

Nothing damages trust in medical research more than the idea that clinical trial data are being hidden or manipulated. Randomised controlled trials are widely considered the best way to evaluate treatment benefits, but trials are time consuming, expensive, and complex. It is thus vital to make full use of all information collected, and it seems evident that the public interest is served by independent scrutiny and replication of trial results. These things can happen only if trial data are shared. In 2013 The BMJ became one of the first journals to require data sharing in clinical trials of drugs or devices (doi:10.1136/bmj.e7888). In 2015 we extended that policy to require data …