HDAB stands for Health Data Access Body, the national authority that decides whether sensitive health data can be reused for secondary purposes such as research, policy, or innovation. In security terms, it acts as a governance layer on top of the data platform: it defines who may request access, what evidence they must provide, and which controls must be in place before data is released.
HDABs matter because health data is highly sensitive and often valuable to attackers, insiders, and careless users alike. Weak approval workflows, inconsistent criteria, or poor coordination can create privacy exposure even when the database itself is technically secure. In a well-designed defense model, the HDAB enforces least privilege, checks metadata and purpose limitations, keeps audit trails, and coordinates decisions across institutions so access remains consistent and defensible.