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.

Background

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

It will also include technical notes detailing 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 not yet been implemented.

This Sweden Extension package is dependent upon, and should therefore be consumed in conjunction with the SNOMED CT® February 2024 International Edition release.

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.

Content Development Activity 

Summary

Content from the SNOMED CT® February 2024 International Edition release has been translated and additional concepts and synonyms have been added for use in Sweden. Some areas for which new concepts and synonyms have been added are:

• Collaboration and Harmonization
  • Work with National Collaboration Groups (NAG för användning av Snomed CT and Nationella kvalitetsregister) has been ongoing to develop Swedish content and improve the quality of Swedish translations 
    • Work with the healthcare regions to develop content in the Swedish extension has been ongoing to develop new content and improved translations. For more information about "NAG för användning av Snomed CT", see https://kunskapsstyrningvard.se/kunskapsstyrningvard/programomradenochsamverkansgrupper/nationellasamverkansgrupper/nsgstruktureradvardinformation/snomedct.56158.html
    • Work with housing content and occupational content
  • Work with pathology and microbiology content.
  • Work with professional societies (Dietisternas Riksförbund, Svensk sjuksköterskeförening) has been done to improve the quality of the Swedish translations in these areas.
  • Work with national and local stakeholders to update content in various reference sets. 

• Quality Assurance

  • Work has been done to reduce duplicate terms including the  correction of 200 duplications with 83 changes to improve disorder content. 

  • Work has also been done to update modeling of content, and address other quality issues in the Swedish translation. 

  • A few areas work has been done to improve Swedish content are listed below. For more detailed information about these areas below visit https://www.socialstyrelsen.se/kunskapsstod-och-regler/omraden/e-halsa/snomed-ct/ and see our "Principbeslut" attached to "Språkliga riktlinjer för översättningen av SNOMED CT till svenska".

    • Cervical cord content has uppdated translations
    • Topical content has uppdated translations

Concept statistics

New and Updated Content

New concepts: 51

Table 1 New concepts by hierarchy

Descriptions statistics

New descriptions: 5431
Inactivated descriptions: 283
Re-activated descriptions: 0
New translations: 4444

Some concepts have not been translated into Swedish. The reasons for non-translation varies and can include; concepts that are not relevant in a Swedish context or concepts where the name in Swedish and English are equivalent (e.g. the Latin names of organisms).

Reference sets

No new reference sets.

Updated simple reference sets:

• 62151000052104 |Route of administration reference set, Swedish national medication list (foundation metadata concept)|
• 68591000052102 |Non-licensed occupations reference set (foundation metadata concept)|
• 113471000052100 |Presence of transplant, alert information reference set (foundation metadata concept)|
• 500061000057107 |Microorganism result reference set (foundation metadata concept)|
• 56431000052106 |Observation status reference set (foundation metadata concept)|
• 67081000052106 |Medical specializations simple type reference set (foundation metadata concept)|
• 68581000052104 |Occupation reference set (foundation metadata concept)|

Updated language reference sets:

• 83461000052100 |ICNP Swedish language type reference set (foundation metadata concept)|
• 63461000052102 |Context-specific terms language type reference set, Swedish national medication list (foundation metadata concept)|
• 63451000052100 |Common-language expression language type reference set, Swedish national medication list (foundation metadata concept)|
• 500191000057100 |Laboratory medicine context language type reference set (foundation metadata concept)|

Technical notes

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.  

For this cycle of the SNOMED CT Managed Service - Sweden Extension, the following Known Issues were identified, and agreed to be resolved in the next editing cycle:

Technical notes

Deprecated Refsets

The following refsets are being deprecated from the Sweden Extension Release package from May 2024 onwards.

• 53391000052105 |Reasons for prescription reference set (foundation metadata concept)|

For this May 2024 release, the Refset files have been completely removed from the Sweden Extension Release package.

Note:  However, the RefsetDescriptor record(s) for these deprecated Refsets remain in the package (and remain active), as the Descriptor patterns themselves are still valid, and therefore standard practice dictates that they remain in place.

Please contact the Swedish National Release Center via ehalsa@socialstyrelsen.se for any further details, or if you need assistance with these deprecations.

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 will necessarily involve a few changes to process/packages:

• Delta files have been removed from both International and Managed Service release packages, including the Sweden 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 release dates - you can find it here:
  • https://github.com/IHTSDO/delta-generator-tool/releases

• The ICD-O/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 will be removed from the Sweden Extension from the May 2022 Release onwards.

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

Notice of changes to the SE Extension Release package

Annotations format changes

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

Refset File Naming conventions

The new naming conventions for additional reference sets files have now been applied to the SE Extension release package, from the November 2024 SE Managed Service Release onwards.  The new convention updates the file names to use RefsetID prefixes instead of the old human readable format, in order to improve maintainability and allow for machine reading of the file names.  However, this convention will ONLY be applied to additional refsets, and not core refsets such as Language refset, Association refset, MRCM refset files, etc. (as these were considered to incur too high an impact on end users if the naming conventions were to be changed)

So, for example, in the November 2024 SE Managed Service Release the additional refset file names have changed from:

• der2_Refset_urvalPreciseringAvAdministreringsställeNationellaLäkemedelslistanSimpleRefsetDelta_SE1000052_20241130.txt   →    der2_Refset_62191000052109SimpleRefsetDelta_SE1000052_20241130.txt
• der2_Refset_urvalFörekomstAvTransplantatUppmärksamhetsinformationSimpleRefsetDelta_SE1000052_20241130.txt                →    der2_Refset_113471000052100SimpleRefsetDelta_SE1000052_20241130.txt
• ...etc.

Please contact the Swedish National Release Center via ehalsa@socialstyrelsen.se for any further details, or if you need assistance with these improvements.