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What GPs need to know about SNOMED CT

What is it?

SNOMED CT is the clinical terminology chosen to replace Read codes in the NHS. It is a structured clinical vocabulary for use in an electronic health record; it includes diagnoses, procedures, symptoms, family history, allergies, assessment tools, observations, devices and other content to support care delivery to individuals.

SNOMED CT (Systematized Nomenclature of Medicine – Clinical Terms) is the fundamental standard for care terminology in England approved by the Standardisation Committee for Care Information (SCCI). 

Why is it being introduced?

SNOMED CT has an improved selection of terms to choose from, so clinical information can be captured in more detail, with reduced ambiguity.

Currently there are three different dictionaries in use across the NHS. SNOMED CT will align with national plans for a single coding scheme across all health and care systems.

As electronic health and care records are introduced throughout the NHS and social care, these will also need to use SNOMED CT. This will enable better and safer patient care, facilitate seamless data exchange and improve the analysis and reporting of clinical data.

How does it differ from Read v2 or CTV3?

To an end user clinical terms on screen will in most cases be very similar. However, SNOMED CT has a more logical structure and a much richer vocabulary, thus allowing improved and clearer recording of patient information.

The identifiers themselves differ and SNOMED CT’s are not memorable – they are all numeric and much longer than Read codes. SNOMED CT is international but can be extended with UK-specific content. Read v2 codes were developed just for general practice and while CTV3 was expanded for use in hospitals, SNOMED CT is more extensive and provides content for all clinical professions and specialties.

When will practices need to migrate to SNOMED CT? 

It must be adopted by all general practice systems and in use by GP service providers from 1 April 2018. NHS Digital is working closely with all the system suppliers to coordinate the transition. The suppliers have completed various aspects of the work and we will keep practices informed of progress.

Do the main GP IT system suppliers support it?

All main suppliers are adapting their systems for SNOMED CT. Deployment schedules are being developed now. Medications already use SNOMED CT codes, as does the Summary Care Record and e-Referrals.

A number of the suppliers are already sending clinical data in SNOMED CT along with the Read codes. The changeover has therefore been happening for some time; the next transition is to make that final change – to use a single clinical vocabulary across the NHS.

How do practices update their existing software?

The main GP suppliers will deploy their clinical system to practices as a system update in much the same way updates are currently provided. CCGs will provide any training and support required, and suppliers will make information available to practices on system changes through eLearning and documentation.

However, it is anticipated that any changes to the system will be intuitive and that end users will not see substantial changes when entering data.

Will SNOMED CT change GPs’ practice?

SNOMED CT has its origins in Read codes and many of the clinical phrases already present in Read are within SNOMED CT. End users will find significant similarity between the two but are advised to gain familiarity with SNOMED CT in advance of the transition. Some suppliers have released demo browsers, but you can also use the NHS Digital SNOMED CT browser.1

GPs will add data into the clinical system in much the same way as they do now. Suppliers are indicating that their browsers will look very similar to those in use now and will be intuitive to users.

Local reports and functions that currently use Read/CTV3 will continue to work after migration to SNOMED CT. However, over time they will need to be updated to include new codes required by processes such as the QOF.

Using SNOMED CT will in time enable documents received in coded form from other care settings to be quickly brought into the GP system. This electronic exchange of data is planned to improve the way GPs work and over time reduce re-entering of data.

How will SNOMED CT affect QOF or DES data extraction?

The end-of-year QOF will be undertaken using the Read codes for 2017/18, and SNOMED CT for 2018/19.

This means practices will be working to the business rules for 18/19 expressed in SNOMED CT.

All legacy or historical Read/CTV3 data will be mapped by the system to a SNOMED CT code, so will always be available for future specifications expressed in SNOMED CT.

How can practices be sure they will not miss payments during the switchover?

For a limited period, systems will associate newly entered SNOMED CT codes with corresponding Read codes, and systems will be able to process data in both. This enables local searches or business protocols to still be run in Read if needed. 

NHS Digital is working with suppliers to agree how long this period will last; the dual coding period will help to ensure there is no significant impact on the business of the practice.

What training in SNOMED CT is available to practice staff?

System suppliers will provide training to their end users using their preferred training tools.

NHS Digital is providing awareness for those transitioning from Read to SNOMED CT, for example offering help on how to find clinical terms and develop reports, and hints and tips on preparation.2

Dr Neill Jones is a GP and senior clinical advisor at NHS Digital


1 NHS Digital. SNOMED CT demo browser.

2 NHS Digital. SNOMED CT Implementation in primary care.