The BMJ has announced that starting 1st July, researchers submitting any clinical trial to the journal will have to commit to making anonymised patient-level data available to independent researchers on reasonable request. Since January 2013, The BMJ has said that it would only publish clinical trials on drugs and medical devices from researchers who agreed to share data from the trial. [1] Its announcement today extends that requirement to all clinical trials, including trials of surgical operations, diagnostic tools or other health interventions.

Elizabeth Loder, acting head of research, BMJ and Trish Groves, deputy editor and editor-in-chief, BMJ Open set out the reasons for the policy:

“Making anonymised patient level data from clinical trials available for independent scrutiny allows other researchers to replicate key analyses, reduces the possibility that studies will be unnecessarily duplicated, and maximises use of the information from trials, an important moral obligation to trial participants.”

Professor Carl Heneghan, Director, Centre for Evidence-based Medicine, Oxford, co-founding organisation of the AllTrials campaign:

The BMJ is to extend its data sharing policy beyond just drug and devices to all trials that it publishes. This is a useful step as many non-drug intervention trials do affect clinical care. As an example, individual patient data meta-analysis in depressive patients showed low intensity interventions such as guided self-help, limited professional support, and internet-based interventions had similar effects in patients irrespective of the severity of the depression at baseline. [2]

Given the sea-change over trial transparency that has occurred in the last 2 years, other countries might now want to adopt a similar approach to the “Nordic transparency council” (proposed by the Nordic Trial Alliance) to oversee data sharing policies.

We also need other journals to follow suit: to adopt data sharing agreements at the time of publication, to facilitate the important individual patient data analyses that contribute to improved patient care.

The extended policy follows the US Institute of Medicine’s report calling for clinical trial data sharing to “become the norm” and the WHO calling for results from all trials to be made available.


[1] Loder E, Groves T. The BMJ requires data sharing on request for all trials. BMJ 2015; 350 :h23733.

[2] Bower P, Kontopantelis E, Sutton A, et al. Influence of initial severity of depression on effectiveness of low intensity interventions: meta-analysis of individual patient data. BMJ. 2013 Feb 26;346:f540. doi: 10.1136/bmj.f540.