1 Introduction

1.1 Background

SNOMED CT terminology provides a common language that enables a consistent way of indexing, storing, retrieving, and aggregating clinical data across specialties and sites of care.

SNOMED International maintains the SNOMED CT technical design, the content architecture, the SNOMED CT content (includes the concepts table, the descriptions table, the relationships table, a history table, and ICD mappings), and related technical documentation.

1.2 Purpose

This document provides a summarized description of the content changes included in the January 2018 release of SNOMED Clinical Terms^® (SCT) International Release.

It also includes technical notes detailing the known issues which have been identified. These are content or technical issues where the root cause is understood, and the fix has been discussed and agreed, but has yet to be implemented.

This document is available alongside the January 2018 International Edition release.

1.3 Scope

This document is written for the purpose described above and is not intended to provide details of the technical specifications for SNOMED CT or encompass every change made during the release.

1.4 Audience

The audience includes National Release Centers, WHO-FIC release centers, vendors of electronic health records, terminology developers and managers who wish to have an understanding of changes that have been incorporated into the January 2018 International Edition release.

2 Content Development Activity

2.1 Summary

Continuous quality improvement and enhancement of existing content is ongoing based on requests received via the Content Request System (CRS). A review of the pre-coordination patterns that are blocking CRS tickets from progressing has commenced and will continue into 2018.

A review of requests currently in the 'In Inception' status in the CRS tool is underway and where it is feasible to progress a request prior to resolving the tracker issue, the request is being identified for progression. Given this work (and the pre-coordination patterns review) the number of requests in 'In Inception' status has decreased by over 1000. This work will continue into 2018.

The January 2018 International Release has seen a continuation of the work driven by contributions from: Kaiser Permanente Convergent Medical Terminology (CMT), Global Medical Device Nomenclature Agency (GMDNA), World Health Organization (WHO) ICD-11 Beta and International Classification for Nursing Practice ( ICNP®) to add new content to SNOMED CT.  

Additionally, member-identified priority projects, have driven enhancements in the anatomy hierarchy, while other project-driven changes have resulted in new content additions and enhancements to existing content detailed below.

2.2 Content Quality Improvement

4979 new concepts were added

21080 changes were made to existing content

2.2.1 Anatomy 

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        • 462 new lateralized body structure concepts and nearly 1000 new lateralized findings, disorders and procedures. There are over 5,000 lateralized concepts in SNOMED CT.

        • 30 new concepts for 736503009 | Structure of mucous membrane of nasal cavity and/or nasal sinus (body structure)| and descendants and refined the existing hierarchical relationships.

        • New concepts for transplanted cardiac values and structure of vertebral column and/or spinal cord to support concept modeling from ICD-11 content.

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        • Identified and added 329 new IS A relationships. 

        • Inactivated 136 redundant or incorrect IS A relationships.

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      • 42 changes to the SE refset.

      • 4 changes to the SP refset.

      • 42 new members for lateralizable body structure refset and 10 inactivations.

2.2.2 Clinical finding

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      • IHTSDO-418 - 84017003 | Bursitis (disorder).

      • IHTSDO-772 - Suspected - findings / disorders, should be situations.

      • IHTSDO-412 - Intra-operative complication.

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      • IHTSDO-451 - Has definitional manifestation.

      • IHTSDO-703 - Inactivation of 'unilateral' concepts.

      • IHTSDO-614 - Rework hierarchy 441457006|Cyst (disorder)|.

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      • Remodel and fully define 63491006|Intermittent claudication (finding) and subtypes.

      • Review and remodel of 128200000|Complex regional pain syndrome (disorder)| and subtypes.
        

      • 7 new laboratory finding concepts added along with 30 changes made to existing laboratory concepts.

      • Revision of spinal injury content - many concepts were primitives and represented as flat list under 26738009|Spinal cord injury without spinal bone injury (disorder)|. This sub-hierarchy has been reviewed and 85 concepts have been remodeled. Most concepts have been defined based on complete, incomplete injuries and levels. These changes have also addressed the reported duplication issues.

      • Remodel 3238004|Pericarditis (disorder)| and subtypes with primitive parent and changes to relationship groups where required to achieve consistency, approximately 100 concepts were remodeled.

2.2.3 Convergent Medical Terminologies (CMT)

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      • CMT Neurology

      • CMT Musculoskeletal

      • CMT Radiology

2.2.4 Procedure Hierarchy

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     • MRI 53

     • CT 38

     • Plain X-ray 15

     • Fluoroscopy 73

     • Imaging guided procedure (various modalities) 102

     • Ultrasonography 82

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      • IHTSDO-111 - Review of hierarchy 23968004|Colectomy (procedure) with inactivation of duplicate content, concepts remodeled with primitive parent and changes to relationship groups where required.

      • IHTSDO-691 - Remodel content 243185007 | Advanced life support (procedure) and subtypes.

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       • Remodel and fully define 180081001|Correction of congenital deformity of hand (procedure)| and its descendants.

       • Fixed MRCM rule violation for 156 Evaluation procedures and removed Observable entities as values for Component Attribute.

       • Care program approach - realm specific concepts inactivated from International release.

2.2.5 Collaboration/Harmonization Projects

2.2.6 Morphologic Abnormality

2.2.7 Observable Entity

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      • Inactivated 704318007 |Property type (attribute)| and replaced it with 370130000 |Property (attribute) for 162 modeled Observable entity concepts which had previously used 704318007 |Property type (attribute)|. Updated related MRCM rules and Editorial Guide.
        

2.2.8 Organism

2.2.9 Pharmaceutical / biologic product

Summary of changes

2.2.10 Veterinary Extension

2.2.11 Situation with Explicit Context

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      • artf222723 - 19 new concepts for situation hierarchy to replace inactivated concepts in the event hierarchy 398033008|Death of relative (event)|.

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       • IHTSDO-703 - The inactivation of 'unilateral' concepts with creation of lateralised replacement concepts where not already present in the terminology has commenced. This work will continue into 2018.

2.2.12 Record Artifact

2.2.13 Specimen

2.2.14 Substances