A Privacy Nihilist Perspective on Clinical Data Sharing: Open Clinical Data Sharing is Dead, Long Live the Walled Garden.

Clinical data sharing, combined with deep learning, and soon quantum computing, has the potential to radically accelerate research, improve health care, and lower costs. Unfortunately, those tools also make it much easier to use the data in ways that can harm patients. This article will argue that the vast amounts of data collected by data brokers, combined with advances in computing, have made reidentification a serious risk for any clinical data that is shared openly. The new National Institute of Health data sharing policy acknowledges this new reality by directing researchers to consider controlled access for any individual-level data. The clinical data sharing community would be well-advised to follow the lead of the physics and astronomy communities and create a "walled garden" approach to data sharing. While the investment will be significant, this approach provides a more optimal combination of both access and privacy. Some design considerations for walled gardens are discussed. The article concludes with a list of recommended actions that can be taken by individuals and institutions today.