Representing and sharing knowledge using SNOMED
Proceedings of the 3rd international conference on Knowledge Representation in Medicine (KR-MED 2008)
R. Cornet, K.A. Spackman (Eds)




               Post-Coordination in the Mapping of Interface Terms of a Clinical Wound
                                         Documentation System to SNOMED CT
                                         Martin Boekera, Stefan Schulza, Thilo Schulera,b
                                    a
                                        Dept. of Medical Biometry and Medical Informatics,
                                               University Medical Center Freiburg,
                                                  b
                                                    Department of Dermatology,
                                          University Medical Center Freiburg, Germany
                                                 martin.boeker@uniklinik-freiburg.de

              The objective of this work is to provide a                    The manual mapping process proved to be time
              formalization of the semantics of SNOMED CT’s                 consuming and prone to ambiguous solutions where
              refinement rules in Description Logics and to                 post-coordination of SNOMED CT expressions was
              exemplify their usage on a real world wound                   necessary. However, for most user interface terms a
              documentation system.                                         complete semantic representation could be
              The goal of unambiguous documentation and                     generated. A coverage of nearly 100% of clinical
              communication of medical information with                     user interface terms shows the appropriateness of
              explicit semantics can be reached by combining                SNOMED CT as a reference terminology for the
              standards and terminologies. Information Models               domain under scrutiny. The natural language
              (e.g. the HL7 Clinical Document Architecture on               descriptions of refinement types in the SNOMED
              Level 3) together with terminology systems (e.g.              CT documentation were formalized in Description
              LOINC and SNOMED CT) are promising                            Logics and reduced to four basic patterns.
              candidates for building a semantically interoperable          Problems with coding and post-coordination can be
              framework for electronic health records.                      explained by weak documentation and poor tool
              We investigated how LOINC and SNOMED CT                       support. The structure of the documentation forces
              concepts can unambiguously and completely cover               users to collect necessary information from several
              user interface terms of an existing electronic, form-         SNOMED CT reference documents. Although
              based documentation system used in clinical                   mechanisms for post-coordination allowed to
              dermatology. Especially, the feasibility of post-             express a substantial amount of terms we suggest
              coordinating complex expressions according to the             that tool support and formalized documentation for
              SNOMED CT terminology model is target of our                  post-coordination (refinement) is enhanced. Tool
              investigations. Besides analyzing completeness and            support should reduce browsing complexity,
              uniqueness of the mappings and the user-                      support post-coordination and give clear advice
              friendliness of the mapping process, we discuss the           how to use SNOMED CT according to the
              different ways of post-coordination (refinement               SNOMED CT compositional grammar and
              types) presented in SNOMED CT’s technical                     refinement rules. Furthermore, we recommend a
              documentation. Where post-coordination was                    thorough redesign of the post-coordination
              required, we adhered to the SNOMED CT                         guidelines which entails the clarification of
              terminology model refinement types and the                    SNOMED         CT's    logical   and     ontological
              “SNOMED Compositional Grammar” syntax.                        foundations.




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