Introduction

The 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^®) maintains the SNOMED CT technical design, the content architecture, the SNOMED CT content (including the concepts table, the descriptions table, the relationships table, a history table and ICD mappings), and related technical documentation. This document is intended to give a brief description, background context, explanatory notes on the SNOMED CT International Medical Devices project and the resulting Release package, which is now published every 6 months. This document covers the background to the collaboration between IHTSDO and Global Medical Devices Nomenclature Agency (GMDNA) and goes on to cover the consequent release artefacts. It is not a detailed technical document of SNOMED CT, GMDN or the SNOMED CT International Medical Devices release. Nor does it seek to provide an editorial policy for medical devices, and related technical documentation. 

EDQM (the European Directorate for the Quality of Medicines & HealthCare - a directorate of the Council of Europe) is a leading organisation that protects public health by enabling the development, supporting the implementation and monitoring the application of quality standards for safe medicines and their safe use. These quality standards are recognised as a scientific benchmark and applied worldwide.

This document is intended as release notes for the EDQM Dose Forms map to SNOMED CT map release. This document is a complement to the more general EDQM Dose Form Map User Guide, which describes the map use cases, principles and implementation guidance in detail.

The ALPHA release package is distributed for evaluation purposes only. It must not be used in production clinical systems or in clinical settings, or distributed to Affiliate Licensees or any third parties at this time.  .

Audience for this document

This document should be read by all those (National Release Centers, vendors of electronic health records, terminology developers and regulators) with an interest in the usage of medical device content in the EDQM Dose Forms map to SNOMED CT and its linkage with GMDN. 

Background

The decision of the joint IHTSDO Management Board and General Assembly in October 2010 was to work towards a Cooperation agreement with the Global Medical Devices Nomenclature Agency (GMDNA), owners of the Global Medical Devices Nomenclature (GMDN), with the intention that the content of GMDN be integrated with the basic terminological content of the medical devices component of the International Release of SNOMED CT. In April 2012 the culmination of discussions between the IHTSDO and GMDNA was the signing of a cooperation agreement which now permits the IHTSDO to use the content of GMDN as the basis of the medical device component of SNOMED CT and conversely for the GMDN Agency to use SNOMED CT medical device content to inform GMDN development. The collaboration is consistent with the aims of both organisations to minimize duplication of effort and support international harmonization. EDQM "Standard Terms" is a set of concepts used in the definition and description of medicinal products; these include the Pharmaceutical dose form (i.e. the dosage form), Route or method of administration, and certain important Packaging items such as the Container, Closure and Administration device.  These Terms were initially produced by the European Pharmacopoeia (Ph. Eur.) Commission following a request from the EU Commission prior to being overseen by EDQM.  Now, Standard Terms are managed by EDQM in compliance with the ISO 11239 standard for the description of pharmaceutical dose forms, which is itself part of the IDMP (IDentification of Medicinal Products) suite of standards, and as such, gives them global applicability as opposed previously a European focus.  Regulatory agencies beyond Europe may submit requests to EDQM for new Terms; supporting evidence for all requests for new Terms must be provided.

The Terms are designed to be used in marketing authorisation applications, medicinal product labelling (including the summary of product characteristics (SmPC) and in electronic communications about medicines.  Additionally, in the last 5 years, the Standard Terms have been used for related purposes such as adverse event reporting (pharmacovigilance) and clinical trials.  But, whilst the primary use is in the regulatory domain, the Standard Terms bring information to the patient/user/prescriber through their use in SmPC, and it is this that underpins the requirement to map the EDQM Pharmaceutical Dose Forms to the Pharmaceutical Dose forms in SNOMED CT, where dose form is one of the definitional attributes of the Clinical Drug and Real Clinical Drug concepts.

For further information on EDQM and Standard Terms, please see https://standardterms.edqm.eu/

Scope and Purpose of the collaborative work

Use cases

The scope of the EDQM Dose Forms to SNOMED CT International Medical Devices map project was the delivery of a concept model to support medical devices within SNOMED CT, and the continuous alignment of SNOMED CT with GMDN.  This was managed in phases. We are now in the business as usual (maintenance) phase of the continuous alignment of SNOMED CT with GMDN. We are in the development phase of the delivery of a concept model to support medical devices within SNOMED CT.  

Under the terms of the Cooperation agreement between the IHTSDO and the GMDNA, only active GMDN Preferred Terms were under consideration for inclusion in the SNOMED CT International Release. Of these approximately 11,000 were In Vitro Diagnostic medical device (IVD) terms. These terms are authored to a different level of granularity than the rest of the GMDN content and set them apart in this difference. The level of detail they hold was discussed and the IHTSDO made the decision to not include them in SNOMED CT until a compelling use case for the IVD terms is identified, from the perspective of SNOMED CT users.

Release content

Overview

linkage table that would support the following use cases:

1. Authoring a SNOMED CT drug extension based on authorised medicinal product information (e.g. SmPC) that uses EDQM dose forms.
2. Mapping a national Medicinal Product Dictionary (MPD) to international SNOMED CT medicine concepts for patient care.
3. Facilitating international interoperability of medication information.
4. Maintaining decision support.
5. Mapping an IDMP-compliant regulatory database to SNOMED CT.

A more detailed description of the use cases is available in the User Guide.

The map is distributed as a Simple map with correlation to SNOMED CT type reference set.

The directionality of the map is from EDQM Dose Forms to SNOMED CT.  There are currently no plans to produce a map in the other direction (from SNOMED CT to EDQM Dose Forms) - if you have a strong business case for requiring a map in this direction, however, please let us know by sending an email to support@snomed.org.

The User Guide describes the policies and principles used as guidance to produce the mappings.

Scope: Map Source and Target

Map source: EDQM Pharmaceutical Dose Forms (PDFs)

• Active PDFs at 2021-07-31 that are not ‘Veterinary only’
• A "snapshot" full download of EDQM PDF data was taken via the EDQM API 

Some EDQM PDFs are considered "out of scope" since they either support types of products that are currently out of scope for the SNOMED CT medicinal product hierarchy (e.g., herbal products, blood products), or they are not PDFs within the SNOMED CT definition (e.g., the solvent terms, the living organisms). For a complete list of the excluded PDFs you can refer to the map user guide.

Map target: SNOMED CT 20220731 international edition

• Active concepts that are < 736542009 | Pharmaceutical dose form (dose form) |

Release content

Overview

The EDQM Dose Forms map The medical devices derivative content is released under a project-specific module (466707005|SNOMED CT Medical Devices module) 1237620007 |European Directorate for the Quality of Medicines & Healthcare module (core metadata concept)|) with component identifiers that are within the main IHTSDO (International Release) namespace. The content links into the main International Release Physical Object dose forms hierarchy, and therefore all the fully specified names in target concepts have a ("physical object") semantic tag. All the concepts are primitive i.e. no modeling beyond the subtype relationships, and the hierarchical organisation is based on existing GMDN groupings ('collective terms'). 

Content detail

Each SNOMED CT new concept has at least 2 descriptions (Fully Specified Name and Synonym). Following International Edition editorial policies, GB and US spelling variants were generated as necessary and the preferences reflected in the corresponding language reference sets. A third reference set (608771002|GMDN language reference set) is included to enable the identification of the original GMDN term, as in a small number of cases minor editing has been necessary to align terms to SNOMED CT International Edition naming conventions (i.e. acronyms included in original GMDN terms were expanded in the FSNs derived from them). 

To enable the tracking of the relationship between SNOMED CT concepts and GMDN terms across releases, the preliminary linkage table has been replaced by a simple map reference set between SNOMED CT concepts and GMDN terms (467614008|GMDN simple map reference set). 

From July 2018 onwards, SNOMED International will also process modified and obsolete concepts, rather than just new and inactivated.  Modified GMDN codes which require a new concept to be authored will subsequently be flagged as "no target". Obsolete GMDN codes will have the GMDN target map flagged as "no target".

Language preferences

The original English language used to represent GMDN terms is 'European English' and therefore spellings conform to US derivative in some instances and GB in others. GMDN terms also include spellings with US and GB variants in the same description. New descriptions were created to align content with International Edition practices, including the expansion of acronyms in FSNs. 

Effective date

This release includes 286 map rows, with correlations between the EDQM map source and the SNOMED CT map target defined as either "Equivalent", "Narrower than", or "Broader than".

When an EDQM code was in the scope of the map but no semantically matching concept is present in SNOMED CT this is considered a "No map". In the cases when it has been possible to confirm that the Dose forms were used in pharmaceutical products authorised in member countries this was resolved by creating new content in SNOMED CT during the mapping process. The remaining cases are not part of the release map, these source terms were logged as "No maps" and categorised based on possible mapping approaches in future versions of this product.

Versions of the dependent content

The content in the December 2022 EDQM Dose Forms to SNOMED CT Map package has been updated in line with updates received from EDQM in July 2022, and so the version of EDQM that this ALPHA Release map is based upon is July 2022.  

EDQM has been mapped to the July 2022 International Edition of SNOMED CT.

However, the metadata for the EDQM product was published in the December 2022 International Edition, and so the EDQM map content was upgraded in line with the December 2022 International content.   The maps themselves were not updated, and are still based on July 2022 content, but the release itself is dependent on the December 2022 International Edition.  Therefore, all component states in the December 2022 EDQM Dose Forms to SNOMED CT Map package have been assigned an effectiveTime of 20221231.   

The package will be published in January 2023, and so the version of the Package itself is "ALPHA_20230104" - this is to distinguish the Published date (20230104) from the effectiveTime of the underlying dependent content (20221231).The content in the January 2022 GMDN Simple Map package has been updated in line with updates received from GMDNA in the latest editing cycle.  All component states in the January 2022 SNOMED CT to GMDN Simple Map package have therefore been assigned the value of 20220131 in the effectiveTime field. 

Technical Notes

RF2 package format

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:

1. ...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 
2. ...files that just 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.

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 - https://www.snomed.org/news-and-events/articles/SNOMEDCT-monthly-releases-february-2022. The move towards more frequent releases of SNOMED CT will realize 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 all International, Derivative and Managed Service release packages, including the SNOMED CT to GMDN Simple Map package.  A Delta Generation service is available 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 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 SNOMED CT to GMDN Simple Map package from the March 2022 Release onwards.

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

ALPHA Release Feedback

Feedback should be sent as soon as possible, but no later than the 17th February 2022.

When providing feedback, please include as much detail as possible, incorporating references to, or samples of, specific instances of the issue being reported.  The absence of sufficient information to allow SNOMED International to confirm the reported issue may result in no action being taken prior to the Production release.  Feedback on content related issues will be assessed and prioritized by SNOMED International, and a decision will be made as to whether to address any reported content issues for the Production release or as part of a future release.  

If you have any questions about the EDQM Alpha release, or have difficulties downloading this file, please contact SNOMED International at support@snomed.org with “SNOMED CT EDQM Simple Map package Alpha release question” in the subject line.