SNOMED CT UK Drug Extension

The history of the development of the NHS Dictionary of Medicines and Devices (dm+d) required that a stand alone entity be produced to allow implementation in systems independent of the strategic clinical terminology solution the NHS was committed to - SNOMED Clinical Terms (SNOMED CT). However, even in taking this decision the importance of seamless integration with the SNOMED CT strategic solution was recognised and the decision to use SNOMED CT content and identifiers was made. (All unique identifiers used in dm+d are SNOMED CT codes)

Developers of clinical systems that do not need to provide users with access to clinical terms may consider the stand-alone implementation of dm+d to provide users with access to standard codes and terms for medicines and devices. It should however be recognised that proposals for increased involvement of clinicians in patient care (e.g. through access to centrally held clinical records) and the widening clinical roles for users (e.g. supplementary /independent prescriber status for nurses, pharmacists etc) may result in the need for their clinical systems to be able to receive clinical information from external sources (e.g. NHS Care Records Service) and to provide clinical information to fully record the detail of their clinical interactions with patients. Where this is the case, provision of SNOMED CT will be required.

Feedback from Local Service Providers (LSP's) and the Independent System Vendors (ISV's) sub-contracted to the LSP's has consistently shown that implementation of a single terminological structure would simplify the task when both dm+d and SNOMED CT are required. In response to this NHS Connecting for Health has undertaken to deliver the SNOMED CT UK Drug extension containing components of dm+d in a SNOMED CT format.

At its simplest SNOMED CT is a three table terminology (Concepts, Descriptions and Relationships) designed to comply with all the principles of good terminology practice; at its simplest dm+d is a nine table dictionary designed to support the business processes of the NHS and comply with good vocabulary practice wherever possible. Translating components of dm+d into SNOMED CT format to produce content for the SNOMED CT UK Drug Extension involves representing these nine tables in the three table SNOMED CT format.

Conversion of dm+d information to form part of the SNOMED CT Drug Extension means addition of the following to the original data:

  • Fully Specified Name (to follow SNOMED CT naming convention) and UK preferred term for each concept
  • A valid SNOMED CT Description Id for each description (e.g. FSN, PreferredTerm etc) associated with a dm+d concept
  • Relationships to core SNOMED CT. Each dm+d concept will have a SNOMED CT defined relationship either to an appropriate supertype concept in the SNOMED CT core or to another dm+d concept that is itself linked (directly or indirectly) to a SNOMED CT core concept.
  • Inherited defining relationships (where appropriate)
  • Specific defining relationships. Relationships to other core defined concepts.
  • Historical relationships.

The aim is to turn the terminology aspects of dm+d into a fully, structurally compliant extension of SNOMED CT (i.e. the SNOMED CT UK Drug Extension) thus supporting the NHS Connecting for Health intention of adopting a common approach to clinical terminology.

Please note:

  • The SNOMED CT UK Drug Extension contains content other than just original dm+d data. More concept classes, subsets and other aspects of SNOMED CT hierarchy are also incorporated.
  • Not all dm+d content is taken into the SNOMED CT UK Drug Extension. For example reimbursement information is not incorporated.

The first release of the SNOMED CT UK drug extension incorporating dm+d data was in October 2006.

Documents giving information about the SNOMED CT UK Drug Extensions including the Editorial policy and Release Notes are contained in the documentation folder of the SNOMED CT UK Drug Extension download data. To gain access to the download data please register by completing the form on the NHS Connecting for Health TRUD Service website at https://www.uktcregistration.nss.cfh.nhs.uk

Four-weekly Release of the SNOMED CT UK Drug Extension

SNOMED CT UK Drug extension data is now published on a four-weekly cycle starting from 10th February 2010 as a release within the "NHS_SNOMED" sub-pack. The subsets and bonus files supplied as part of the SNOMED CT UK Drug Extension are also updated and released on a four weekly basis in the same sub-pack. The SNOMED CT UK Drug extension will no longer be released as part of the UKTC Combined biannual release. These changes are being made in order to facilitate closer synchronisation of the SNOMED CT UK Drug extension with the weekly released XML format dm+d data.

To gain access to the SNOMED CT UK Drug Extension please register by completing the form on the NHS Connecting for Health TRUD Service website at https://www.uktcregistration.nss.cfh.nhs.uk

The release schedules can be accessed via the TRUD application.

If you have any difficulties please contact the Data standards helpdesk datastandards@nhs.net.