1 Introduction

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.

The International Health Terminology Standards Development organisation (IHTSDO^®), trading as 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.

2 Background

This document provides a summarized description of the content changes included in the March September 2024 release of the SNOMED Clinical Terms^® Managed Service Denmark Extension package.

It will also includes technical notes detailing the known issues which have been identified (should any of these exist). 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 Denmark Extension package is dependent upon, and should therefore be consumed in conjunction with the SNOMED CT® February August 2024 International Edition release.

2.1 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.

3 Content Development Activity

3.1 Summary

This release contains translation corrections and improvements to existing content as well as minor technical corrections made as a result of upgrading the extension to use the SNOMED CT® February August 2024 International Edition release.

4 Technical notes

4.1 Known Issues

Known Issues are content or technical issues where the root cause is understood, and the resolution has been discussed and agreed, but has yet to be implemented.  This can be due to a number of reasons, from lack of capacity within the current editing cycle, to the risk of impact to the stability of SNOMED CT if the fix were to be deployed at that stage in the Product lifecycle.  

4.2 Resolved Issues

4.3  Notice of changes to the International Edition Release Schedule

As you may already know SNOMED International have transitioned to a monthly delivery schedule for the International Edition of SNOMED CT. The move towards more frequent releases of SNOMED CT realizes several benefits, including:

• The potential to be able to get content changes into the terminology in a shorter time frame.
• The fostering of better interoperability, as a result of entities being able to consume release content that is more aligned with other organizations.
• The prevention of circular dependencies that occur in longer projects, due to the move towards smaller, more manageable authoring projects.
• More automated validation services, as a result of the inherent removal of the Alpha/Beta stages in the Release cycle.

Whilst most users will continue unaffected (as they can simply continue to download the releases every 6 months as always), this transition necessarily involves a few changes to process/packages:

• Delta files have been removed from both International and Managed Service release packages, including the Denmark Extension.  A Delta Generation service will be provided for those who need it. The Delta Generation Tool allows users to create their own Delta between two fixed International release dates - you can find it here:
  • https://github.com/IHTSDO/delta-generator-tool/releases

• The ICD-0/ICD-10 Maps will continue to be published in each Monthly International Edition release package (in line with that month's content) for the foreseeable future, unless we experience issues with the new process in Production, and they need to be removed at a later date.

The first monthly Release of the SNOMED CT International Edition was published on the 28th February 2022 with the Delta files having been removed, and therefore they were removed from the Denmark Extension from the March 2022 Release onwards.

Please note - While the SNOMED CT International Edition is moving to monthly releases, the Denmark Extension of SNOMED CT will remain on the current bi-annual release schedule of March and September.

For any further questions, please ask the Denmark NRC for details.

4.4  Changes to the Identifier file format

In line with the proposals documented here:  https://confluence.ihtsdotools.org/mag/snomed-international-proposal-to-change-the-rf2-identifier-file-specification - the Denmark Extension Release will from now on include the following changes to the format of the Identifier files:

• < identifierSchemeId    alternateIdentifier    effectiveTime    active    moduleId    referencedComponentId           ...to
• > alternateIdentifier    effectiveTime    active    moduleId    identifierSchemeId    referencedComponentId

These improvements are introduced in the September 2023 Denmark Extension release, and will be used in all future Denmark Extension releases until further notice.

4.5  Notice of changes to the DK Extension Identifier files

As from the March 2024 DK Extension release onwards, the Danish NRC will no longer release the DK Extension Identifier content as part of the Danish extension release packages.

This is in line with the previous communications sent by the Danish NRC in September 2023, providing advanced notification of the removal of this unwanted historical content from the DK Extension.

The following files will, therefore, no longer contain any content (other than the file headers) until further notice:

• sct2_Identifier_Full_DK1000005_20240331.txt
• sct2_Identifier_Snapshot_DK1000005_20240331.txt

Please contact the Denmark NRC if you have any questions regarding these changes.

4.6  Notice of changes to the DK Extension Release package

In line with the refined implementation of Annotations, we are updating all Extensions in order to align them with the updated version of the refsets in the International Edition Release package (which were first published in June 2024).

The languageCode field was specified as the two characters of ISO-639-1 code for the language of the annotation text. The change includes support for specifying dialect when it is applicable by adhering to RFC 5646, which allows the combination of two characters of ISO 639-1 code and two uppercase letters of country code (ISO 3166) separated by a hyphen.  The changes apply to both the Member Annotations String Value Reference Set + Component Annotation String Value reference set:

• • The column "languageCode" has therefore been changed to "languageDialectCode".
    • Component Annotations (1292992004)
      • OLD:    id    effectiveTime    active    moduleId    refsetId    referencedComponentId    languageCode    typeId    value
      • NEW:   id    effectiveTime    active    moduleId    refsetId    referencedComponentId    languageDialectCode    typeId    value
    • Member Annotations (1292995002)
      • OLD:   id    effectiveTime    active    moduleId    refsetId    referencedComponentId    referencedMemberId    languageCode    typeId    value
      • NEW:  id    effectiveTime    active    moduleId    refsetId    referencedComponentId    referencedMemberId    languageDialectCode    typeId    value