b Hospital S. João, Porto Contact address:

Data retrieval and its integration is one of the major problems that face large and complex health organizations. This is especially relevant when patient information is produced in heterogeneous environments. Implementing a Virtual Electronic Patient Record (VEPR) system may provide an adequate and cost-effective solution for most clinical information needs. In this paper, we describe and discuss the use of agent technologies for the retrieval and integration of clinical records in a VEPR, thus making patient information available at any point of care. Between May 2003 and May 2004, a VEPR was designed and implemented at Hospital S. João, a university hospital with over 1.350 beds. An agent-based platform Multi-Agent System for Integration of Data (MAID) ensures the communication among various hospital information systems. Clinical reports are retrieved from clinical department information systems (DIS) and stored into a central repository in a browser friendly format. Documents are retrieved in HTML and PDF format and are digitally signed at storage. MAID is now running for the last 10 months, regularly scanning 7 DIS and collecting a mean of 2.000 new reports each day. A visualization module for the VEPR was made available in October 2004 and the number of users and user sessions has been growing since. Currently, over 200 doctors are using the system on a daily basis. The total budget of the project was less than 400.000 euros. Around 30 % of the costs were spent in software development and MAID accounted for only 13 % of the total project budget. The use of agent technologies in the implementation of a VEPR enabled the successful integratio