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 May 2021 release of the SNOMED Clinical Terms^® Managed Service Sweden 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 Sweden Extension package is dependent upon, and should therefore be consumed in conjunction with the SNOMED CT® January July 2021 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

Content from the SNOMED CT® May 2021 International Edition release has been translated and additional concepts and synonyms for use in Sweden have been added. The main areas for which new concepts and synonyms have been added are:

• Highly specialized medical care is quaternary care only provided by a few selected centers on a national level, at most five centers in the Swedish context. About 30 concepts have been produced and the use could be in national electronic referrals or by healthcare advice services like "Hitta och jämför vård" on 1177.se.

• Six new Body structure concepts were created for to the prostate organ (for use in the synoptic reports for anatomical pathology and/or radiology.)

• The Swedish national release center has worked with the Swedish association of clinical dietitians (DRF) to update terms in the area of nutrition.
• In cooperation with Region Västra Götaland approximately 200 procedure concepts have been developed to support ordering and documentation of surgical procedures.

Concept statistics3.2 New and Updated Content

New concepts: 

Table 1 New concepts by hierarchy

Twelve concepts from the Swedish extension were inactivated for this release.

Fifteen concepts in the the Swedish extension were changed.

Descriptions statistics

New synonyms added: 2 602
Inactivated descriptions: 859
New translations: 5 746

Some concepts have not been translated into Swedish. The reasons for non-translation can vary and include concepts not relevant in a Swedish context and concepts were the name in Swedish and English is equivalent (e.g. the Latin names of organisms).

Table 2 Non-translated concepts by hierarchy

Reference sets

Two new simple type reference sets has been added to the Swedish SNOMED CT extension: 

• 73171000052105 | Edema as sign of heart failure reference set (foundation metadata concept) |
• 59901000052102 | Food hypersensitivities, alert information reference set (foundation metadata concept) |

Language type reference sets is a mechanism for contextualizing terms used in SNOMED CT. For this release, and for the first time, six context-specific language type reference sets were added to distinguish preferred terms in the domains of laboratory medicine, chief complaints, and medications. Supporting the National Medication List, four language type reference sets were added for professional terms, common-language expressions, plural terms and abbreviations.

• 500191000057100 | Laboratory medicine context language type reference set (foundation metadata concept) |
• 64311000052107 | Chief complaints context language type reference set (foundation metadata concept) |
• 63491000052105 | Dose unit abbreviation language type reference set, Swedish national medication list (foundation metadata concept) |
• 63481000052108 | Dose unit plural language type reference set, Swedish national medication list (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) |

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.  

For the SNOMED CT Managed Service - Sweden Extension May November 2021, the following Known Issues were identified, and agreed to be resolved in the next editing cycle:

4.2 Technical notes

Promoted concepts

Some concepts from the Swedish extension have been promoted to the international release (900000000000207008 | SNOMED CT core module (core metadata concept) |). The concepts have been added to the international release files with an effectiveTime which supersedes the latest effectiveTime in the Swedish extension release files. The concepts will be retained in the Swedish extension snapshot files in perpetuity as per SNOMED International recommendations and anyone using these files will have to manage the possibility of duplicated ids (with different effectiveTime) across release files. The risk of issues can be mitigated by filtering to only use Swedish extension records with effectiveTime:s greater than their International counterparts. Links to relevant documentation will be added to these release notes once that documentation has been updated.

The promoted concept in the May November 2021 release is: 66621000052103 | Sublabial route (qualifier value) |