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Integration of clinical terminology

Data sets can benefit significantly from implementing clinical terminologies and classifications within their data model (where applicable).

Why we are continuing to integrate clinical terminologies within national data sets

Data sets can benefit significantly from implementing clinical terminologies within the data model

Providers can choose between multiple schemes to submit patient information. Providers can also submit what they record over and above specific national information requirements. This enables commissioner information requirements to be better met through the data set

Using SNOMED CT to capture outcome measures reduces the need for individual tables for each measure. A single table can capture multiple measures using a common structure. For example, multiple different scored assessments can be submitted in a coded scored assessment table, rather than a separate table being needed for each type of scored assessment.

Data sets can respond more quickly to changes in clinical practice and information requirements. Terminology is updated at regular intervals and the data set can automatically capture the latest terms without the need to change the structure or content of the data set through the DAPB process.

How we have integrated clinical terminologies within data sets

We have been working closely with the UK Terminology Centre (UKTC) to restructure the data set to further cater for clinical terminology recording.

Within the MHSDS 

  • diagnoses can now be submitted using a select choice of schemas
  • assessment tools must now be submitted using SNOMED CT. There are multiple ways to link this data within the data set such as against a specific referral, care contact or anonymously
  • more detailed care activity information can now be submitted, using a select choice of schemas.
  • procedures, observable entities and findings are all recordable
  • social and personal circumstances can now be submitted using SNOMED CT, which will allow the flow of MHS001 data items and personal information in line with published SNOMED CT subsets
  • the MHS010 assistive technology table also follows this same convention, which will allow the flow of SNOMED CT concepts to identify the findings related to the assistive technology a person uses

Within the MSDS v2.0:

  • diagnoses for the mother can be submitted using MSD105 Provisional Diagnosis (Pregnancy), MSD106 Diagnosis (pregnancy) and MSD107 Medical History (previous diagnosis) tables.
  • diagnoses for the baby can be submitted using MSD403 Provisional Diagnosis (Neonatal) and MSD404 Diagnosis (Neonatal) tables
  • assessment tools must be submitted using SNOMED CT. There are multiple ways to link this data within the data set such as against a specific booking (in the MSD104 Coded Scored Assessment (pregnancy) table), care contact (in the MSD203 Coded Scored Assessment (contact) or MSD406 Coded Scored Assessment (Baby) tables) or anonymously (in the MSD601 anonymous self-assessment table)
  • more detailed care activity information can be submitted, using a select choice of schemas. Procedures, observable entities and findings are all recordable in the MSD202 Care Activity (pregnancy), MSD302 Care Activity (labour and delivery), and MSD405 Care Activity (baby) tables. Observations and findings can be submitted in the MSD109 Finding and Observation (mother) table.
  • social and personal circumstances can be submitted using SNOMED CT, which will allow the flow of demographic data items and personal information in line with published SNOMED CT subsets.

How clinical terminology data should be captured and submitted

Data providers should flow activity as recorded in their systems for primary record purposes. This activity may consist of clinical terms that have been recorded in systems which have been used to record the treatment of the patient during their care as part of the relevant care pathway.

The data set development service will not author or release specific subsets of clinical SNOMED CT codes for secondary uses purposes. However, other bodies such as royal colleges may choose to publish clinically relevant subsets for specific areas. These same codes can then be submitted to the data sets for national reporting purposes. We may create subsets to govern areas of the data set that are subject to copyright, like  scored assessments. Details of these subsets will be made available in specific user guidance for each data set.

We will not prohibit the flow of specific SNOMED CT codes using validation, except where codes cannot be submitted in an identifiable form for patient confidentiality, governance, or legal reasons (for example HIV status data).

The majority of clinical terminology fields within the national data sets will accept multiple forms of terminology and classifications, such as SNOMED CT, ICD-10 and OPCS-4 codes, where these are used in local systems. It is acceptable to submit a mixture of different classifications and terminologies within a single submission file, for example SNOMED CT codes and ICD-10 codes, provided you identify which type of code you are submitting using the relevant scheme in use data item.


SNOMED CT is the standard clinical terminology for the NHS to support recording of clinical information, in a way that supports data management and analysis to support patient care, while enabling data extraction and data exchange. 

SNOMED CT provides a comprehensive set of clinical phrases or terms; this is called a terminology. SNOMED CT is much more than just a set of clinical phrases, for example it also includes groups with relationships between terms. It is the most comprehensive international terminology currently available and can be used across all care settings and all clinical domains.

SNOMED CT is managed and maintained internationally by SNOMED International and in the UK by the UK National Release Centre (part of NHS Digital).

SNOMED CT is specified as the single terminology to be used across the health system in Personalised Health and Care 2020: A Framework for Action. SNOMED CT was specified as the single terminology to be used across the health system in Personalised Health and Care 2020: A Framework for Action.

The SCCI0034: SNOMED CT Information Standard requires local systems to move to using SNOMED CT as the single standard for holding data locally for primary use in all care settings.

SNOMED CT benefits

As the NHS moves to paperless records and the exchange of data electronically across the NHS, it is critical that all systems share the same clinical vocabulary. 

The use of an international terminology enables system suppliers to design their system to a common terminology that can be implemented with less country specialisation across a number of countries. The last few years has seen a shift by suppliers from developing country specific solutions to global solutions with local configuration.

Further SNOMED CT resources

Learn more about  SNOMED CT  including information about


The UK is a SNOMED International member country. Use of SNOMED CT in the UK is free; however, the use of SNOMED CT does require a licence. All SNOMED CT licensing enquiries can be sent to


NHS Digital offer a range of ways for individuals to learn more about SNOMED CT and its uses. For those who feel they need more understanding of SNOMED CT, NHS Digital provide a number of training and education resources. For an overview of SNOMED CT, the two live webinars provide a good introduction; you will also find case studies, brochures and technical guidance detailed on this web page. For system suppliers, you may also be interested in the more technical guidance provided through our recorded webinar on the release files.

SNOMED CT browser

The NHS Digital SNOMED CT browser enables users to search for SNOMED CT concepts and subsets.

ICD codes

An ICD-10 code is the International Classification of Diseases (ICD) 10th Revision code, which can be submitted to some NHS Digital data sets. ICD-10 diagnostic codes are at least four characters in length. The first character is always alphabetic. Where an undivided three-character code is used, the fourth character must be filled with 'X'. Further guidance regarding ICD-10 codes is available in the NHS Data Model and Dictionary.

NHS Digital data sets do not currently allow the submission of ICD-11 codes.

Read version 2 and clinical terms version 3

Read v2 and CTV3 were withdrawn from use in April 2020. Reference to them is made within some NHS Digital data sets, which allow the submission of these codes, but they should not be used for any new circumstances. Please refer to additional guidance on the Read Codes .


OPCS-4 is also used in some national data sets. OPCS-4 is a statistical classification for clinical coding of hospital interventions and procedures undertaken by the NHS. The classification is mandatory for use by health care providers to support various forms of data collections for secondary uses. Further information is available on the OPCS-4 Information Standard web page.

Last edited: 20 December 2021 4:45 pm