Secondary use of health data has a vital role in improving and advancing medical knowledge. While digital health records offer scope for facilitating the flow of data to secondary uses, it remains essential that steps are taken to respect wishes of the patient regarding secondary usage, and to ensure the privacy of the patient during secondary use scenarios. Consent, together with depersonalisation and its related concepts of anonymisation, pseudonymisation, and data minimisation are key methods used to provide this protection. This paper gives an overview of technical, practical, legal, and ethical aspects of secondary data use and discusses their implementation in the multi-institutional @neurIST research project.