Data sharing is the practice of making data available to the wider research community. Sharing registry data and clinical study data allows the data to be used to answer different research questions. Sharing study data allows the results of a published study to be confirmed by other researchers and can also be combined with data from other registries or studies to increase its impact.
Data Sharing Elements and Activities from ” Discussion Framework for Clinical Trial Data Sharing: Guiding Principles, Elements, and Activities” 
National Cancer Institute Center for Biomedical Informatics & Information Technology: Data Sharing and Public Access Policies
Rare Diseases Registry Program (RaDaR): Learn about Data Ownership
Data sharing in clinical trials – practical guidance on anonymising trial datasets [2018 published article]