The “Common Ontology” between ICD 11 and SNOMED CT medical plausibility vs. ontological soundness Stefan Schulz Medical University of Graz stefan.schulz@medunigraz.at http://purl.org/steschu

ICD-11 – SNOMED CT harmonization Background: ICD: Classification maintained by WHO, currently under revision  ICD-11 SNOMED CT: Ontology-based clinical terminology maintained by IHTSDO (International Health Terminology Standards Development Organisation) Large content overlap between ICD and SNOMED CT disorder / findings hierarchy Joint Advisory Group (WHO and IHTSDO), based on institutional agreement: Synergistic and not antagonistic terminology development Jointly develop a common ontological basis for both ICD-11 and SNOMED CT Maximum of interoperability between ICD and SNOMED coded data It is quite natural to avoid competition between the the two artefacts

ICD-11 Foundation ICD-11 Foundation Ontology ICD-11 Content Model External links Common SNOMED – ICD-11 Ontology Subset of SNOMED CT Content Model Contents Model Schema Linearization A Linearization B (un-nested) External sources External Sources ICD-11 Foundation value sets Linearization set A (nested) ICD-11 Foundation Ontology Linearization C ICD-11 Content Model Query Library Common SNOMED – ICD-11 Ontology Subset of ICD-11

formal description of domain entities: clinical situations, Categorization and formal description of domain entities: clinical situations, information entities, taxonomies, partonomies Inventory of clinicians‘ language: words, terms, phrases Purpose-specific reporting units: billing, health statistics

SNOMED CT ICD-11 SNOMED CT ICD-11 Ontology Vocabulary Classification Categorization and formal description of domain entities: clinical situations, information entities, taxonomies, partonomies Inventory of clinicians‘ language: words, terms, phrases Ontology Vocabulary SNOMED CT SNOMED CT ICD-11 Purpose-specific reporting units: billing, health statistics, research,… Classification ICD-11

SNOMED CT ICD-11 SNOMED CT ICD-11 Ontology Vocabulary Classification Categorization and formal description of domain entities: clinical situations, information entities, taxonomies, partonomies Inventory of clinicians‘ language: words, terms, phrases Ontology Vocabulary SNOMED CT SNOMED CT ICD-11 Purpose-specific reporting units: billing, health statistics, research,… Desiderata: context-independent, precise categorizations Classification Desiderata: Ready-to-use terms, one-click encoding of complex statements ICD-11 Desiderata: pragmatic orderings for specific purposes

SNOMED CT Findings/Disorders and WHO – IHTSDO Common Ontology Fracture of Radius Fracture of Ulna Formal taxonomies of clinical situations (life periods in which one or more clinical conditions are present) Fracture of radius and ulna ICD-11 Linearizations Fracture of forearm Fracture of shaft of ulna Hierarchical orderings of reporting units into disjoint “classes” Fracture of shaft of radius Fracture of shafts of both ulna and radius

SNOMED CT Findings/Disorders and WHO – IHTSDO Common Ontology Multiple hierarchies: Mitral valve disease Rheumatic heart disease Formal taxonomies of clinical situations (life periods in which one or more clinical conditions are present) Rheumatic mitral valve stenosis ICD-11 Linearizations Single hierarchies + exclusions Mitral valve disease Rheumatic heart disease Hierarchical orderings of reporting units into disjoint “classes” Excl: Heart valve diseases Rheumatic mitral valve stenosis

SNOMED CT Findings/Disorders and WHO – IHTSDO Common Ontology Strict taxonomic relations Fibrosis of the skin Disorder of skin of lower limb Formal taxonomies of clinical situations (life periods in which one or more clinical conditions are present) Lipodermatosclerosis ICD-11 Linearizations Approximate taxonomies Chronic peripheral venous insufficiency Hierarchical orderings of reporting units into disjoint “classes” Lipodermatosclerosis

SNOMED CT Findings/Disorders and WHO – IHTSDO Common Ontology Separation Ontology/ Epistemology Tuberculosis Confirmed present Formal taxonomies of clinical situations (life periods in which one or more clinical conditions are present) Tuberculosis of respiratory system Fusion Ontology/ Epistemology ICD-11 Linearizations Tuberculosis of the respiratory system Hierarchical orderings of reporting units into disjoint “classes” Respiratory tuberculosis, confirmed Respiratory tuberculosis, suspected

SNOMED CT Findings/Disorders and WHO – IHTSDO Common Ontology B A C Formal taxonomies of clinical situations (life periods in which one or more clinical conditions are present) Mapping as Querying Query mechanism, e.g. X = select A minus select B Y = select A and B Z = select A and (rel C) … ICD-11 Linearizations Hierarchical orderings of reporting units into disjoint “classes” Y X Z

ICD-11 Foundation ICD-11 Foundation Ontology ICD-11 Content Model External links Common SNOMED – ICD-11 Ontology Subset of SNOMED CT Content Model Contents Model Schema Linearization A Linearization B (un-nested) External sources External Sources ICD-11 Foundation value sets Linearization set A (nested) ICD-11 Foundation Ontology Linearization C ICD-11 Content Model Query Library Common SNOMED – ICD-11 Ontology Subset of ICD-11