The HL7 approach to semantic interoperability

Health Level 7 (HL7) is an international standards development organisation in the domain of healthcare information technology. Initially the mission of HL7 was to enable data exchange via the creation of syntactic standards for point-to-point messaging. For some 10 years, however, HL7 has increasingly conceived its mission as one of creating standards for semantic interoperability in healthcare IT on the basis of its 'version 3' (v3) family of standards. Unfortunately, v3 has been marked since its inception by quality and consistency issues, and it has not been able to keep pace with recent developments either in semantics and ontology or in computer science and engineering. To address these problems, HL7 has developed what it calls the 'Services-Aware Interoperability Framework' (SAIF), which is intended to provide a foundation for work on all aspects of standardization in HL7 henceforth and which includes HLT's Reference Information Model as general purpose upper ontology. We here evaluate the SAIF in terms of design principles that must be satisfied by a semantic interoperability framework, principles relating both to ontology (static semantics) and to computational behaviour. We conclude that the SAIF fails to satisfy these principles.