Introduction

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.

Purpose

This document provides a summarized description of the content changes included in the March 2020 INTERIM release of SNOMED Clinical Terms^® (SCT) International Release.

It also includes technical notes detailing the known issues which have been identified and agreed to be released. 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.

The SNOMED International Release Notes are available alongside the INTERIM March 2020 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.

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 INTERIM March 2020 International Edition release.

Content Development Activity

Summary

This INTERIM International Edition Release has been created as part of the ongoing global effort to tackle the Coronavirus outbreak, and as such includes the updated Coronavirus descriptions for Members and implementers. This is a full International Edition Release package containing changes to the content detailed in the news item (https://www.snomed.org/news-and-events/articles/changes-coronavirus-descriptions) under the following conditions:

- following SNOMED International's critical incident policy, there will NOT be a recall of the January release, simply an update in response to international renaming, to ensure that SNOMED CT is current when assisting with the global Coronavirus effort
- implementers are encouraged to update to the new edition, however, they are NOT obliged to do so as the concept modelling and identifiers are not being modified
- the entirety of these changes will also be incorporated into the upcoming July 2020 International Edition Release

Content development activity summary

The map is a directed set of relationships from SNOMED CT source concepts to ICD-10 target classification codes.  The SNOMED CT source domains for the MAP are limited to subtypes of 404684003 |clinical finding|, 272379006 |event| and 243796009 |situation with explicit context|.  The target classification codes are ICD-10 2016 release. 

Mapped content for March 2020

The map provided for the March 2020 release has been updated in line with the Coronavirus changes for both the January 2020 and March 2020 International Edition releases:

We would welcome feedback on any issues that users of the map may detect when using the map. Issues should be submitted via mapping@snomed.org

Technical Guide Exemplars

The Technical Guide Exemplars document has now been moved from the International Edition release package to a Confluence page.  This page can be found as part of the ICD-10 Mapping Technical Guide (see Appendix B), which is hosted here:  http://snomed.org/icd10map

ICD-O Map

No changes to the ICD-0 map were required for this Interim release.

SNOMED CT to OWL conversion and classificationThe repository containing the toolkit enabling simple SNOMED CT to OWL conversion and classification can be found here, including documentation on its use: https://github.com/IHTSDO/snomed-owl-toolkit

Please contact SNOMED International at support@snomed.org if you would like to provide any feedback on ways to extend and improve the new toolkit.

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 the SNOMED CT March 2020 International edition, the following Known Issues were identified, and agreed to be resolved in future editing cycles:

Resolved Issues

Resolved issues are Known Issues which were not fixed as part of the previous release lifecycle, but which have now been resolved in the latest release.  They can also be issues found during the Alpha and Beta testing of the current release, which were resolved before the final deployment of the associated Member release.  Finally they can be issues which were reported or found during the testing phase, but which have been closed without any action taken.  

The Resolved Issues for the Snomed CT March 2020 International edition can be found here:

Technical updates

RF2 package format

For future reference, the RF2 package convention dictates that it contains all relevant files, regardless of whether or not there is content to be included in each particular release.  Therefore, the package contains a mixture of files which contain both header rows and content data, and also files that are intentionally left blank (including only a header record).  The reason that these files are not removed from the package is to draw a clear distinction between files that:

• have been deprecated (and therefore removed from the package completely), due to the content no longer being relevant to RF2 in this or future releases, and 
• happen to contain no data in this particular release (and are therefore included in the package but left blank, with only a header record), but are still relevant to RF2, and could therefore potentially contain data in future releases.

This allows users to easily distinguish between files that have purposefully been removed or not, as otherwise if files in option 2 above were left out of the package it could be interpreted as an error, rather than an intentional lack of content in that release.

RF2 file consumption

The changes are delivered in the usual Delta, Full + Snapshot files, with the Delta relative to the January 2020 International Edition release.

Early visibility of impending change in the July 2020 International edition

Please see the following page for details of all upcoming changes planned for July 2020 and beyond:  July 2020 Early Visibility Release Notice - Planned changes to upcoming SNOMED International Release packages

Document links

All links provide information that is correct and current at the time of this Release.  Updated versions may be available at a later date, but if so these will need to be requested from the relevant SNOMED International teams.