Cochrane Collaboration calls for free access to all clinical trials data

11 October 2011

The Cochrane Collaboration, the world's leading independent assessor of medical interventions and medical research, has called for free access to all data from all clinical trials in order to provide the best care for patients globally.

In its statement, The Cochrane Collaboration argues that selective reporting of trial results occurs frequently, leading to exaggerated findings of the beneficial effects of healthcare interventions and to underestimates of their harms. As a consequence, many patients are unknowingly treated with interventions that have little or no effect and may be harmed unnecessarily.

 Jonathan Craig, Co-Chair of The Cochrane Collaboration’s Steering Group said, “The Cochrane Collaboration strives to provide the best health evidence so patients can receive the best treatment. This evidence includes access to all clinical trial data and it should be mandatory that this information is freely available.”

The statement produced by the Collaboration calls for the following:

  • all randomised clinical trials to be registered at their inception, before recruitment of the first participant;
  • all data from all randomised clinical trials, including raw anonymised individual participant data that do not allow identification of individual participants, and the corresponding trial protocols to become publicly available free of charge and in easily accessible electronic formats;
  • governments to consider introducing legislation requiring data from all trials to be made public within 12 months from the end of the randomised phase of the trial, in accordance with most international calls for data sharing; and
  • governments to also consider the following measures: punitive measures for non-compliance; a requirement to continue to hold and make available core data indefinitely, or to pass such data to a central and accessible repository; and recognition that ownership of trial data should be shared between sponsors, investigators and trial participants.

Peter C Gøtzsche, Director of the Nordic Cochrane Centre, awaits publication of his article on this very issue in the journal, Trials (provisionally accepted). His article, “Why we need easy access to all data from all clinical trials and how to accomplish it,” argues that the distinction between publicly-funded and industry-funded research is an artificial and irrelevant one, as the interests of the patients must override commercial interests. Echoing the sentiments of the Collaboration, Gøtzsche feels calls for data sharing should not be restricted to publicly-funded research.

“The over-riding objective of healthcare research is to improve patient care and health policy. It is pretty clear that if commercial concerns lead to the withholding of data that are important for rational decision-making by doctors and patients, there is something fundamentally wrong. Selective reporting also violates the Declaration of Helsinki and the implicit contract with the trial participants,” says Gøtzsche.

Further information

The Collaboration will present this statement to its members at its 19th Cochrane Colloquium, in Madrid, Spain at its Annual General Meeting on Oct. 20, 2011.

The full text of the Collaboration’s statement can be found at


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