Coding & Terminology Systems
What is Terminology?
Clinical terminology is a structured collection of descriptive terms which are used in clinical practice at the point of care. Terminology includes items such as treatments, diagnoses, administrative terms, social and environmental factors.
What is coding?
Coding is the translation of clinical terminology into an (alpha) numeric code to make it easier to analyse data for management and epidemiological purposes. By supporting the process of collecting better quality information through accurate coding we contribute to the decisions that inform health care policy which ultimately leads to improvements in patient health.
Clinical and health related data are collected on various national patient based datasets (e.g. Scottish Morbidity records, Scottish Cancer Registry). To ensure data is recorded consistently and accurately, nationally agreed coding systems are used.
These are:
- The International Classification of Diseases, Tenth Revision (ICD-10) for diagnoses
- Office of Population Censuses and Surveys, Fourth Revision (OPCS4) for procedures and interventions
- Read codes for primary care
- Clinical Imaging Procedure codes
SNOMED-CT will eventually become the terminology of choice covering both primary and secondary care. It will encompass all coding systems mentioned above, allowing NHS Scotland to progress towards an electronic patient record.
The International Statistical Classification of Diseases and Related Health Problems (ICD) is a detailed index of diseases and injuries that is developed and released by the World Health Organisation (WHO). Details of a diagnosis are recorded by a clinician in the patient's medical notes. These are translated into ICD-10 codes by a clinical coder. This allows consistency when selecting and comparing conditions. It is possible to select and compare conditions consistently, not only in Scotland but also across the world wherever ICD-10 is used. The information can be used for epidemiological purposes, health service planning and clinical audit at both a national and local level.
ICD is revised periodically and is currently in its tenth edition. ICD-10 was developed in 1992 to track morbidity statistics and Scotland adopted its use in 1995. Since its launch there have been 2 major updates and minor annual updates which are published by WHO.
Help and information on ICD-10 is available from the Terminology Advisory Service helpdesk on 0131 275 7283 or via email.
The Office of Population Censuses and Surveys' Classification of Surgical Operations version-4 (OPCS-4) was first issued in September 1987 to record operations and procedures carried out in the acute sector although coding of surgical procedures had been ongoing since 1944. It is now in its fourth revision with the latest release, OPCS-4.5, implemented in April 2009 and was expanded to include interventions. In Scotland OPCS codes are used in SMR returns to record operations, procedures and interventions.
Connecting for Health co-ordinate the update of OPCS in the UK. OPCS-4.5 was implemented on 1st April 2009 in NHS Scotland.
Additions or enhancements to the OPCS codes can be requested via Connecting for Health via their OPCS-4 Requests Portal.
Help and information on OPCS Codes is available from the Terminology Advisory Service helpdesk on 0131 275 7283 or via email.
Read codes originated as a thesaurus designed specifically to enable general practitioners to code and record all relevant information arising from a patient encounter. Read codes have become widely used in general practice and primary care. The Read codes enable a summary of the medical record to be coded and stored in a computer system and contain mapping fields/tables which can provide mapping to IDC10 (International Statistical Classification of Diseases and Health Related Problems, Tenth Revision) and OPCS4 (Office of Population Censuses and Surveys, Fourth Revision) codes. We would recommend that you consult our advisory service if you require advice on these mappings.
The de facto standard for Scotland is 5-byte Version 2 Read Codes (Scottish). Connecting for Health currently also support other versions of Read: UK READ Codes Version 2 and Clinical terms (The Read Codes) Version 3 which are used in England. Scottish users downloading the browser from the TRUD download site should choose the option offering the Scottish variation.
Read codes are updated twice yearly, in April and October, and code requests in Scotland are co-ordinated by the Terminology Service. All updates can be downloaded by registering on their website.
Help and information on Read Codes is available from the Terminology Advisory Service helpdesk on 0131 275 7283 or via email.
SNOMED-CT
The Systematised Nomenclature of Medicine - Clinical Terms, SNOMED-CT, is a result of a collaboration between the College of American Pathologists and the NHS in the UK. In January 2002 SNOMED-CT® was created by the merger, expansion and restructuring of SNOMED RT ® (Reference Terminology) and the UK NHS Clinical Terms Version 3 (also known as the Read Codes). The historical strength of SNOMED RT was its terminologies for speciality medicine, while the strength of Clinical Terms Version 3 was its terminologies for General Practice. By combining these two systems, SNOMED-CT is the most comprehensive clinical vocabulary available covering most aspects of clinical medicine with over 414,000 concepts covering diseases, clinical findings and procedures. It also allows a consistent way to index, store, retrieve and aggregate clinical data across specialities and sites of care. It also helps structure and computerise the medical record, reducing the variability in the way data is captured, encoded and used for clinical care of patients and research. SNOMED-CT created a common clinical language that is a necessary element of a health care information infrastructure.
SNOMED-CT content is updated twice a year in the UK in April and October and the Terminology Service co-ordinate code requests from users in Scotland.
Help and information on SNOMED-CT is available from the Terminology Advisory Service helpdesk on 0131 275 7283 or via email.
The National Interim Clinical Imaging Procedure Codes are code and term descriptions of Clinical Imaging Procedures in electronic systems in the NHS. They can be downloaded by registering on the NHS TRUD download site.
Help and information on Clinical Imaging Procedure Codes is available from the Terminology Advisory Service helpdesk on 0131 275 7283 or via email.
