### Summary box Over the past several years, we have seen a movement towards a more open way of conducting science, with recommendations that ought to lead to reproducible methods, analyses and results, as well as reusable data. Data sharing is widely encouraged and its importance has been noted in the context of health data, including clinical trials.1 2 It is now a standard requirement by publishers, research institutions and regulatory agencies to share data. Many types of health data are increasingly viewed as global public goods that should be made available to the wider scientific community without unnecessary delays, ensuring important findings can be extracted as soon as possible.3 4 Major funders such as the European Commission, National Institutes of Health, Wellcome Trust, Bill & Melinda Gates Foundation and The European and Developing Countries Clinical Trials Partnership (EDCTP; www.edctp.org) are imposing contractual obligations on their grantees …