Last month the BMJ announced a new policy on sharing data from clinical trials.1 From January 2013, trials of drugs and medical devices will be considered for publication only if the authors commit to making the relevant anonymised patient level data available on reasonable request.2 This new policy will apply to any paper that reports the main endpoints of a randomised controlled trial of one or more drugs or medical devices in current use, whether or not the trial was funded by industry (box).

Why the new policy? Because it is no longer possible to pretend that a report of a clinical trial in a medical journal is enough to allow full independent scrutiny of the results. Journals are, of course, not the only potential channel for such scrutiny, but as long as publication remains the main currency for academic recognition, journals have a responsibility to use what power they have to push for greater transparency. If research is to help doctors and patients make the best clinical decisions, it must be reliable and reproducible, but these are qualities that current peer review processes cannot assure.

Since announcing the new policy we have been asked why it applies only to trials of drugs and devices, what is meant by “relevant,” and who will judge whether a request is “reasonable.” We have started with drugs and devices as being the area of medicine where most evidence exists for incomplete and misleading trial publication, but we expect that …