The secondary use of quality assured study-data originating from clinical trials is an important step for research networks to generate new hypotheses and conduct feasibility studies. The i2b2 software project, which is based on an open source software license, provides graphical query and analysis tools for medical data records. These tools are based on a relational database whose underlying scheme is optimized to handle large amounts of data. Using pseudonymization within the i2b2 framework acting as a research database is an important goal to satisfy privacy protection rules and to enable...