Abstract: To store patients' medical histories and to exchange them between physicians, patient registries are used. Registries contain detailed data on patients and their treatments, and may comprise additional documents. This makes them very valuable for epidemiological research due to the amount of information contained. Providing data for research requires anonymization and pseudonymization to address privacy laws and security concerns. To be able to give feedback to physicians e.g. about discovered treatment possibilities, advanced pseudonymization has to be used. We present progress in the development of patient registries and the required functionality to support research. Usability, explicability, and performance requirements are addressed by incorporating Web technology. Our findings include ways to develop patient registries as well as the description of mechanisms built into them. In particular, we show applications to and implications for crisis management. Â© 2012 ISCRAM.