MEDINFO 2001 V. Patel et al. (Eds) Amsterdam: IOS Press © 2001 IMIA. All rights reserved 735 Experience with an XML/HTTP-based Federative Approach to Develop a Hospital- Wide Clinical Information System Antoine Geissbuhler, Christian Lovis, Alexander Lamb, Stéphane Spahni Division of Medical Informatics, Geneva University Hospital, Geneva, Switzerland Abstract The authors present a two-year experience with an approach aimed at federating applications into a component-based hospital-wide clinical information system. Recognizing the need for better integration, clearer separation of knowledge from applications, as well as the necessity to respect and integrate the diversity of roles in a healthcare network, a strategy was implemented that included the development of a shared vision, organizational changes to promote appropriation at all levels, and the elaboration and maintenance of a common architecture and terminology by an instrumental technical group. Choices for federative technologies were in part based on their level of acceptance and potential to evolve. XML was used as the syntactic framework and HTTP as the transfer protocol. Within twelve months, the shared vision was developed, the architecture was specified, the key central components implemented, incorporated into the applications, and applications teams started producing shareable services using XML and HTTP. Keywords: Clinical Information System; Architecture; Organizational Issues; Change Management Introduction A large hospital is often described as a "city in the city". Thousands of collaborators, dozens of professions coexist, interact and cooperate to provide healthcare to patients. Professional groups each have their own specific culture, their view of the world and their information needs. Historically, computer-based systems have been built to help each professional group deal with their information needs, thus respecting or reinforcing the functional boundaries of the groups. These systems have then been interfaced to others in order to form hospital-wide information systems, generally in a way that mimicked existing paper-based transactions. The need for tighter integration and for the development of synergies between various professional groups has led to the IAIMS initiative [1] and to a more patient-centric design of information systems, based upon reusable infrastructure and bridges across professional boundaries. The development of healthcare delivery networks is increasing the diversity of different stakeholders, thus complicating the task of integration. A good example of this progression is the evolution of the IAIMS acronym: originally standing for Integrated Academic Information Management System, the meaning of the letter "A" changed to Advanced, then, as Stead [2] suggested, to Area, illustrating the importance of integrating healthcare information at a regional level. Beyond hardware and software architectures, it is crucial to build such complex and evolving systems upon people, their knowledge and the processes they use [3,4]. The diversity of stakeholders is a characteristic of a large health care organization. Each professional group deals with its own, and often partial view of the global system, with its knowledge, culture and terminologies. Moreover, the same specialized physicians patient payers administration other care providers students general practitioner home care coders case managers regulatory agencies family patient record(s) local knowledge global knowledge researchers pharmacies laboratories Figure 1 - healthcare stakeholders and information types: diversity, blurred boundaries, interdependency