We have now published two articles with supplementary data accompanying the article deposited with the Dryad repository: Heneghan et al. on medical device recalls with data here, and Dmello et al. on cystic fibrosis with data here.

Authors can share supplementary data or underlying datasets through Dryad. BMJ Open is the first medical journal to partner with Dryad, an online repository which provides a permanent, citable, and open access online home for datasets related to peer reviewed published articles in biosciences. Data depositiop is integrated with the manuscript submission system.

BMJ Open provides plenty of practical, ethical, and technical guidance on how to share data responsibly here.

Why share data?
Data sharing is increasingly being strongly encouraged by major academic research funders in the UK and the US, such as the Medical Research Council and the National Institutes of Health, for the benefit of both medical science and patients.

Data sharing aims to help scientists and doctors validate and scrutinise researchers’ findings in a bid to prevent fraud and eradicate the kind of selective reporting that has enabled some treatments to acquire regulatory approval, based on incomplete and biased data.

In some cases this lack of transparency has prompted the subsequent restriction or withdrawal of certain treatments because of patient safety or effectiveness concerns, which were already evident in the unpublished data.

Data repositories also allow researchers to develop new methods of analysis and use the data to answer questions that the original researchers have not thought of. They also facilitate the acquisition of data for meta analysis (more in-depth comparative reviews).

Data sharing is widespread in laboratory science, but is a new and more complex issue in medical research, because of the need to protect the privacy of research participants and/or seek their consent before sharing data.