Developing the ontological foundations of a terminological system for end-stage diseases, organ failure, dialysis and transplantation.

The Etablissement français des Greffes (EfG) is a state agency dealing with Public Health issues related to organ, tissue and cell transplantation in France. The evaluation of organ retrieval and transplantation activities, one of its missions, is supported by a national information system (EfG-IS). The EfG-IS is moving towards a new n-tier architecture comprising a terminology server for end-stage diseases, organ failure, dialysis and transplantation (EfG-TS). Following a preliminary audit of the existing coding system and in order to facilitate data recording, to improve the quality of information, to assume compatibility with terminological existing standards and to allow semantic interoperability with other local, national or international registries, a specific work has been conducted on the thesauri to integrate within the EfG-TS. In this paper focusing on the server's content rather than the container, we report first the functional and cognitive requirements that resulted from the preliminary audit. We then describe the methodological approach used to build the terminological server on "sound ontological foundations". We performed the semantic analysis of existing medical terms to set up disease description frame-like structures. These diseases description frames consist of a limited set of nosological discriminating slots such as etiology, semiology, pathology, evolution and associated diseases. Each relevant medical term is thus associated to a concept defined and inserted within a hierarchy according to disease description frame resulting from the semantic analysis. Last, because this terminological server is shared by various transplant and dialysis centers to record patient data at different time point, contextualization of terms appeared as one of the functional requirements. We will also point out various contexts for medical terms and how they have been taken into account.

How should therapeutic information be transferred to users?

Without an efficient solution to the problems that prevent prescribers and consumers having easy access to published and unpublished evidence, Evidence-Based Medicine will never become a reality. Among the problems, dissemination of the summarized evidence is a major one. It involves representing the summarized evidence in a format that corresponds to the users' needs and knowledge, interpreting it within the context of other related evidence, putting it in perspective, and then delivering it physically to the users at the appropriate time. The current formats, vehicles and representation models, e.g. those for guidelines or textbooks, do not seem efficient enough to fill in the gap of knowledge. We suggest that a new approach is possible by reducing the transferred information to its core and integrating it through appropriate representation models into the doctor's decision-making process.

Which coding system for therapeutic information in evidence-based medicine.

The coding of information in the computer representation of clinical trials is essential both for the rationalisation of the activities involved in the production of therapeutic information for evidence-based decision support and for the integration of the messages produced by these activities with clinical information and electronic patient record systems. There is no standard coding system available, however, so building on existing evaluations, we performed a simple semi-quantitative evaluation of ICD-10, CDAM, MEDDRA, MESH, READ, SNOMED and UMLS to provide objective criteria for the choice of a coding system. Inclusion and exclusion criteria for four clinical trials recorded in TriSum constituted the corpus of evaluation texts. Criteria included coding coverage, size, integration and language coverage. The results of the comparison lead us to choose SNOMED as the most appropriate coding system for our needs. The absence of a European Medical Language System project is observed, as is the need for combinatorial as opposed to enumerative systems.

Design considerations for an ontology in the domain of organ failure and transplantation.

The Etablissement français des Greffes (EfG) is a national agency dealing with Public Health issues related to organ, tissue and cell transplantation in France. The evaluation of organ retrieval and transplantation activities, one of its missions, is supported by a national information system (IS). In order to facilitate data recording, to improve the quality of information and to prepare semantic interoperability with other information systems, the existing thesaurus of the EfG was audited, leading to the design a new terminological module devoted to the support of the domain ontology.