To the Editor The Viewpoint by Ms Mikk and colleagues1 aimed to improve patient engagement and health care informatics and to recommend technical improvements to electronic health care records. The authors proposed a data use agreement (DUA) that relates to data quality, integrity, privacy, and security. Our principal concern is with the use of such a DUA to grant patients control over all uses of health data, including in secondary research. This measure of control is apparently what the authors referred to as “patient data ownership” in their title, although the term was not used in the body of the article.