Ubiquitous information is currently one of the most challenging slogans in medical informatics research. An adequate architecture for shared electronic patient records is needed which can use data for multiple purposes and which is extensible for new research questions. We introduce eardap as architecture for using routine data for nationwide clinical research in a multihospital environment. Eardap can be characterized as terminology-based. Main advantage of our approach is the extensibility by new items and new research questions. Once the definition of items for a research question is finished, a consistent, corresponding database can be created without any informatics skills.Our experiences in pediatric oncology in Germany have shown the applicability of eardap. The functions of our core system were in routine clinical use in several hospitals. We validated the terminology management system (TMS) and the module generation tool with the basic data set of pediatric oncology. The multiple usability depends mainly on the quality of item planning in the TMS. High quality harmonization will lead to a higher amount of multiply used data. When using eardap, special emphasis is to be placed on interfaces to local hospital information systems and data security issues.