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. , and related technical documentation. 

EDQM (the European Directorate for Quality of Medicines and 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 to give a brief description, background context, explanatory release 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 devicesEDQM Dose Forms map to SNOMED CT map release. This document is a complemente to the more general EDQM Dose Form Map User Guide, which describes the map use cases, principles and implementation guidance in detail.

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

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

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 a 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.

The map is distributed as a Simple map with correlation to SNOMED CT type reference set SNOMED CT until a compelling use case for the IVD terms is identified, from the perspective of SNOMED CT users.

Release content

Overview

The medical devices EDQM Dose Forms map derivative content is released under a project-specific module (46670700500000000|EDQM Dose Forms to SNOMED CT Medical Devices map module|) 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. 

Content detail

This release includes 412 map rows, with 126 rows where no map was available.

Effective date

The content in the January 2022 GMDN Simple December 2022 EDQM Dose Forms to SNOMED CT Map package has been updated in line with updates received from GMDNA in the latest editing cycleEDQM in July 2022.  All component states in the January 2022 SNOMED CT to GMDN Simple December 2022 EDQM Dose Forms to SNOMED CT Map package have therefore been assigned the value of 20220131 20221201 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.

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 time within the new monthly editing cycles, 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 current SNOMED CT International edition, the following Known Issues were identified, and agreed to be resolved in future editing cycles: