The Pharmaceutical Journal
Vol 280 No 7500 p534
3 May 2008

This article
Reprint   Photocopy

PDF 30K, Acrobat Reader

For the NHS Care Records Service the future’s bright, it’s SNOMED CT

By Monica Kapoor

SNOMED CT, the Systematised Nomenclature of Medicine — Clinical Terms, is the medical language of the future, where computer systems in both primary and secondary care will communicate with each other and the NHS Care Records Service.

It is the terminology that is envisaged to be used to code all health-related information in England.

In 1965, what we now know as SNOMED began as SNOP (the Systematised Nomenclature of Pathology). It was not until over 30 years later, in 1999, that SNOMED CT was developed jointly between the College of American Pathologists and NHS Connecting for Health.

In 2001, the Audit Commission recommended a national system of coding for medicines. A year later, the Department of Health published “Delivering 21st century IT support for the NHS: national strategic programme”, which discussed the NHS Care Record System, booking appointments, the electronic transfer of prescriptions and the IT infrastructure.

In November 2005, NHS Connecting for Health and the College of American Pathologists announced their intention to establish the International Health Terminology Standards Development Organisation (IHTSDO) and transfer ownership of SNOMED CT from the college to this organisation and, in March 2007, IHTSDO was formally registered.

Currently in primary care, healthcare professionals record information using terminologies such as Read codes or Clinical Terms Version 3 (CTV3). In secondary care, clinical coders record information using classifications such as the International Statistical Classification of Diseases and Health Related Problems, 10th revision (ICD-10) or Office of Population, Censuses and Surveys Classification of Surgical Operations and Procedures, 4th revision (OPCS-4).

Are you still with me? Terminologies are used to populate electronic patient records and describe concepts relating to individuals; classifications categorise concepts relating to populations or groups of patients. SNOMED CT — set to replace these current terminologies and classifications — is the product of the combination of the College of American Pathologists’ SNOMED Reference Terminology and the NHS’s CTV3.

What this means is that early adopters have been implementing the NHS Care Records Service and, therefore, using SNOMED CT, since spring 2007. These early adopters consist of GP surgeries from five primary care trusts, namely Bolton PCT, Bradford and Airedale Teaching PCT, Bury PCT, Dorset PCT and South Birmingham PCT.

Since the NHS Care Records Service is fundamental to the functioning of the electronic patient record, all currently used terminologies and classifications must be mapped to their corresponding SNOMED CT concepts for electronic patient records to be functional.

“Concepts” form the crux of SNOMED CT, concepts being units of thought, such as clinical disorders or procedures and interventions. Each concept has a unique number associated with it, known as the concept identity. Each concept also has a phrase associated with it that describes it in an unambiguous manner. This is known as its fully specified name (FSN). FSNs have preferred terms and synonymous terms.

Preferred terms are the most appropriate way of expressing concepts within a clinical record whereas synonymous terms are acceptable alternatives. For example, “myocardial infarction (disorder)” is an FSN, myocardial infarction is its preferred term, and heart attack is one of its synonymous terms.

Each concept is linked to at least one other by an “is a” relationship or by an “attribute” relationship. Concepts can be grouped together with descriptions and relationships to form subsets, which is useful when catering for individual medical specialties.

The IHTSDO acquired the intellectual property rights of SNOMED CT from the College of American Pathologists in April 2007. The organisation comprises nine countries (Australia, New Zealand, Canada, the Netherlands, Denmark, Sweden, Lithuania, the UK and the US) and “seeks to improve the health of humankind generally by owning, distributing, operating and developing suitable health terminology products”.

In the UK, the IHTSDO is managed by the NHS Terminology Service via the UK Terminology Centre.

Many benefits are cited to support the uptake of SNOMED CT, including:

• Patients will take comfort in the fact that everyone in the NHS will be “speaking the same language”.

• A patient will be able to travel anywhere in the UK (and abroad) and know that his or her medical history will be retrievable in the event of an emergency.

• Use of SNOMED CT may encourage more detailed documentation by users.

• Members of multidisciplinary teams will be able to use a single source to document patient information, preventing duplication.

• More accurate recording of information will aid audits, research, etc.

• Medical language will be organised in a structured framework.

• One language, maintained and updated centrally, will be better than several different languages being used.

• Accurate searches for specific clinical information in a patient’s record will become possible.

The final step in the chain is the dictionary of medicines and devices (dm+d). This consists of unique identifiers and textual descriptions for medicines and devices. Clinical systems not currently using the dm+d descriptions are required to map their descriptions to those of the dm+d to enable inter-operability between different clinical systems. The link to SNOMED CT is that these unique identifiers are also SNOMED CT codes.

Connecting for Health plans to deliver the dm+d in a SNOMED CT-like format and monthly releases aim to translate the nine-table dictionary of the dm+d into the three-table terminology of SNOMED CT. Monthly releases are licensed and distributed by the Terminology Reference-data Update Distribution Service on behalf of the UK Terminology Centre.