Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 1 Medical Informatics Lessons Learned Experiences MHS AHLTA interoperability Private sector SNOMED CT implementation and legacy migration CPOE implementation

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 2 Medical Informatics Lessons Learned Lack of definitions Divergent information models Ontologic weakness of reference terminology Quality assurance Communication across team

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 3 Medical Informatics Lesson Learned Importance of definitions SNOMED CT and most terminologies in use lack explicit definitions of concepts and relationships Meaning may be implied by common usage or position in hierarchy Domain experts often disagree on meaning

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 4 Medical Informatics Lesson Learned Description Logic in SNOMED CT Appendicitis (Fully defined by) Associated morphology Inflammation Finding site Appendix structure Fully defined concepts may reduce need for text definition Up to half of disorders in SNOMED CT lack full Description Logic definition

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 5 Medical Informatics Lesson Learned Divergent information models SNOMED CT disorder context model Subject Temporality Assertion/negation Modal status Laterality Severity Acuity Course/stages

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 6 Medical Informatics Lesson Learned Divergent information models Precoordinated Postcoordinated SNOMED CT implements context model inconsistently Similar inconsistencies in other terminologies

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 7 Medical Informatics Lesson Learned Ontologic weakness of SNOMED CT Confusion in Hierarchy Semantic type confusion IS-A overload SNOMED CT SEP anatomy model

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 8 Medical Informatics Lesson Learned Confusion in Hierarchy Many use cases rely on subsumption of clinical disorders Medications are more complicated Ontologic hierarchy may not reflect clinical view Numerous exceptions to hierarchy complicate implementation and maintenance

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 9 Medical Informatics Lesson Learned SNOMED CT Semantic type confusion Disorder vs. morphology Finding vs. observable Confusion in understanding of intent by implementers

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 10 Medical Informatics Lesson Learned Is-a Overload Confusion of Is a subclass of Is a part of Is contained in

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 11 Medical Informatics Lesson Learned SNOMED CT SEP anatomy model Entire hand Hand structure Hand part Structure of left hand Structure of right hand Anatomic region vs. anatomic surface area

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 12 Medical Informatics Lesson Learned Limitations of 1:1 map Equivalent Narrower than Broader than Other relationship

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 13 Medical Informatics Lesson Learned Quality Assurance burden Difficult without automated tools Full definition in Description Logic enables automated error checking

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 14 Medical Informatics Lesson Learned Communication issues Medical informaticist Ontologist Domain expert Software developer Use and design of tools

Semantic Interoperability in Health Informatics: Lessons Learned 10 January 2008Semantic Interoperability in Health Informatics: Lessons Learned 15 Solutions Improve the ontological basis of standard terminologies Educate informaticists and domain experts about ontology practices Address information model issues Create mapping tools to support interoperability Semantic type subsets Medical specialty subsets