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| {{Use dmy dates|date=June 2019}} | | {{Short description|A clinical coding system used in the UK}} |
| '''Read codes''' were the standard [[Medical terminology|clinical terminology]] system used in [[General Practice]] in the United Kingdom before 1 April 2018, when they were replaced by [[SNOMED CT]]. They are still permitted for use in NHS secondary care settings, such as dentistry and mental health care until 31 March 2020. Read codes support detailed clinical encoding of multiple patient phenomena including: occupation; social circumstances; ethnicity and religion; clinical signs, symptoms and observations; laboratory tests and results; diagnoses; diagnostic, therapeutic or surgical procedures performed; and a variety of administrative items (e.g. whether a screening recall has been sent and by what communication modality, or whether an item of service fee has been claimed). It therefore includes but goes significantly beyond the expressivity of a [[diagnosis code|diagnosis coding]] system. | | |
| | ==Read Code== |
| | The '''Read Code''' system, also known as the Read Clinical Classification, is a comprehensive coding system used primarily within the [[United Kingdom]]'s [[National Health Service]] (NHS) to record clinical information in [[patient]] records. It was developed by Dr. James Read in the 1980s and has been widely adopted across various healthcare settings in the UK. |
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| ==History== | | ==History== |
| Since its origins in the 1980s,<ref>Benson, Tim. "The history of the Read codes: the inaugural James Read Memorial Lecture 2011." ''Informatics in primary care'' 19.3 (2011): 173-182. http://www.ingentaconnect.com/content/bcs/ipc/2011/00000019/00000003/art00008</ref> the system has evolved through three major technical design changes and significantly expanded its content.
| | The Read Code system was initially developed to provide a standardized way of recording [[clinical]] information in [[general practice]]. Dr. James Read, a general practitioner, recognized the need for a consistent method to document patient data, which led to the creation of this coding system. The system was first introduced in the 1980s and has since evolved to accommodate the growing complexity of medical information. |
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| ===Read version 1 (4-byte Read)===
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| The first version was developed in the early 1980s by [[Dr James Read]], a Loughborough general medical practitioner.<ref name="BCS">{{cite web |vauthors=Bentley T, Price C, Brown P |title=Structural and lexical features of successive versions of the Read Codes |url=http://www.phcsg.org/main/pastconf/camb96/readcode.htm |work=The Proceedings of the 1996 Annual Conference of The Primary Health Care Specialist Group of the [[British Computer Society]] |date=13–15 September 1996 |accessdate=2010-04-17 |url-status=dead |archiveurl=https://web.archive.org/web/20100829143656/http://www.phcsg.org/main/pastconf/camb96/readcode.htm |archivedate=29 August 2010 }}</ref> The scheme was structured similarly to [[International Statistical Classification of Diseases and Related Health Problems|ICD-9]]:
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| * each code was composed of four consecutive characters: first character 0-9, A-Z (excepting I and O), remaining three characters 0-9, A-Z/a-z (excepting i,I,o and O) plus up to three trailing period '.' characters
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| * the relative position of one code to another was represented through the code itself: [J...] is the common ancestor of all other codes with 'J' as the first character, and [J1..] in turn the common ancestor of all codes beginning 'J1'.
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| Because of its four character code structure, Read Codes version 1 was more commonly known as 4-Byte Read. The first release was in April 1986; the final official release of 4-Byte Read occurred in April 2009.
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| ===Read version 2 (5-byte Read)===
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| 4-Byte Read could only encode a monoaxial hierarchy with a maximum of 4 hierarchical levels. The operational NHS requirement to provide a direct crossmap to both [[ICD|ICD-9-CM]] and [[OPCS|OPCS-4]] implied an additional hierarchical level was required. Accordingly, a new scheme was devised with exactly the same technical properties as 4-Byte Read except that the code structure was extended to 5-Bytes. This became known as Read2, or 5-Byte Read. The first release of 5-Byte Read occurred sometime prior to January 1991. The October 2010 release contained 82,967 discrete 5-byte codes (although the actual number of discrete clinical concepts that may be represented is estimated to be slightly lower - 82,593 - because of duplicate entries).
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| A later extension of Read version 2 product family was the co-publication of a drug and appliance dictionary. This follows the same technical structure (5-character alphanumeric codes with first character lower case alpha organised in a monohierarchy). Released every four weeks, the October 2010 release contained 52,316 codes.
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| A popular misconception is that all 4-Byte codes are also present in 5-Byte, where they will also carry the same meaning. Whilst in the majority of cases any 4-Byte code of the general form 'wxyz' will be equivalent to a 5-Byte code of the form 'wxyz.', there are notable exceptions. The 4-Byte code [E333 Fear of flying], for example, corresponds to 5-Byte [E202A Fear of flying]; no [E333.] code exists in 5-Byte Read at all.
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| ===NHS mandation===
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| In 1988 a joint conference of the [[Royal College of General Practitioners]] and the [[British Medical Association]] recommended standardisation of the system in general practice [[Electronic medical record|Electronic Medical Record (EMR)]] systems and the [[National Health Service]] mandated this in April 1999.<ref name="NHS-CfH">{{cite web |title=Frequently Asked Questions about Clinical Terms (The Read Codes) |url=http://www.connectingforhealth.nhs.uk/systemsandservices/data/readcodes/faqs/index_html#1 |publisher=NHS Connecting for Health |accessdate=2010-04-17}}</ref> The intellectual property of the codes themselves was purchased outright by the UK government, and they have therefore been published under [[Crown Copyright]] ever since.
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| ===Read version 3 (Clinical Terms Version 3 or 'CTV3')===
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| A third and more radically progressive version was devised through the 1990s in an attempt to address some of the more serious technical limitations of the earlier designs, including:
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| * Although codes remain 5-bytes in length, the hierarchical relationship between codes is no longer represented through the codes themselves but rather through a separate table listing all binary parent-child relations; this allows for a [[polyhierarchy]] of indefinite depth.
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| * Codes exist independently from the terms associated with them; terms now have their own 5-Byte code identifier, usually beginning with the letter 'Y'
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| * Both concept codes and term codes have a release status, thus allowing authoring errors to be corrected: concepts and terms may be moved to different places in the polyhierarchy between releases, or retired from the scheme (and hierarchy) altogether.
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| * A large scale professional consultation exercise, the 'Clinical Terms Project', was conducted to identify clinically valuable concepts that were not codable within version 2. This led to a significant expansion in the content of CTV3, including improved support for the various 'professions allied to medicine', such as speech therapy, physiotherapy and community nursing.
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| * CTV3 concepts can be qualified or 'post-coordinated' by the addition of further codes, to form compound expressions with more detailed semantics than may be expressed by any single code alone. For example, a procedure code can be associated via a laterality attribute code with a laterality value (left/right/bilateral).
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| * Many concepts were provided with partially modelled definitions. Thus, many surgical procedures have a 'site' relationship linking to the code for the anatomical target(s) of the procedure:
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| e.g. 70266|Repair of acoustic nerve|:X9019|Site|=7N031|Vestibulocochlear nerve|
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| 73143|Myringostapediopexy|:
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| X9019|Site|=Xa18W|Tympanic membrane structure|,
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| X9019|Site|=Xa8RI|Stapes structure|
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| The first release of Clinical Terms Version 3 occurred in the late 1990s. The October 2010 release contained 298,102 discrete concept codes of which 55,829 were marked as inactive, and 58,130 were pharmaceutical products or devices. | |
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| ==Production and license==
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| Both actively maintained versions of the Read codes are now maintained by the UK Terminology Centre, a division within NHS Data Standards and Products (currently in turn a division of [[NHS Connecting for Health]]).
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| Both versions are released biannually, in October and April, under the [[Open Government Licence]].
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| License application, and distribution, are now electronic only via the UKTC [https://www.uktcregistration.nss.cfh.nhs.uk Terminology Reference data Update Distribution] service.
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| ==Read and SNOMED==
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| [[SNOMED CT]] was created in 2001 out of a technical, editorial and content merger of CTV3 and [[Systematized Nomenclature of Medicine|SNOMED RT]], an American system. A significant part of the International Core content of SNOMED CT derives directly from CTV3; most of this content is identifiable as those SNOMED ConceptIDs where the CTV3ID column in the sct_concept table cites a code NOT beginning with the characters 'XU'.
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| Although CTV3 continues to be released biannually by the NHS independently of SNOMED CT, maintenance of both occurs in parallel; most concepts required to be added to CTV3 are as a matter of course simultaneously dual-authored into both CTV3 and the UK extension of SNOMED CT.
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| The NHS in England has committed to a strategic move to [[SNOMED CT]], and systems using SNOMED are now being deployed within the NHS primary and secondary care estates. At the end of 2010, however, READ versions 2 and 3 remained the core clinical terminology used in UK primary care, with roughly 90% of the primary care estate still using version 2. | | ==Structure== |
| | Read Codes are alphanumeric codes that represent specific clinical terms. The system is hierarchical, allowing for detailed and specific coding of medical conditions, procedures, and other healthcare-related information. Each code corresponds to a specific term or concept, enabling healthcare professionals to accurately record and retrieve patient information. |
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| ==Deprecation and withdrawal==
| | The Read Code system is divided into chapters, each representing a different category of medical information, such as [[diagnosis]], [[symptoms]], [[procedures]], and [[medications]]. This hierarchical structure allows for both broad and detailed coding, depending on the level of specificity required. |
| In preparation for the whole health system moving to SNOMED CT by April 2020, [[primary care]] systems are to have adopted the new [[nomenclature]] by April 2018.<ref>{{cite web|title=SNOMED CT Implementation in Primary Care|url=https://digital.nhs.uk/SNOMED-CT-implementation-in-primary-care|publisher=NHS Digital|accessdate=1 October 2017}}</ref> Secondary care, including Mental Health and Dentistry, is mandated to move to SNOMED by April 2020.<ref>{{cite web|title=SNOMED CT |url=https://digital.nhs.uk/snomed-ct|publisher=NHS Digital|accessdate=1 October 2017}}</ref>
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| The former Information Standards Board for Health and Social Care (ISB) set December 2010 as the deprecation date for Read version 2, but did not set a date for its withdrawal at the time.<ref>{{cite web|title=Information Standards Notice – Deprecation|url=http://www.hscic.gov.uk/media/15868/1553disn/pdf/1553disn.pdf|publisher=Standardisation Committee for Care Information|accessdate=15 May 2015}}</ref> In August 2014 the ISB's successor, the Standardisation Committee for Care Information (SCCI), formalised the withdrawal time frame of Read version 2: A final updated release for Read version 2 is to be made available on 1 April 2016, and will be withdrawn completely on 1 April 2020.<ref name=HSCIC-Read>{{cite web|title=Deprecation of Read Version 2 and Clinical Terms Version 3|url=http://systems.hscic.gov.uk/data/uktc/readcodes|publisher=Health & Social Care Information Centre|accessdate=15 May 2015}}</ref>
| | ==Usage== |
| | Read Codes are used extensively in [[electronic health records]] (EHRs) within the NHS. They facilitate the standardized recording of patient data, which is essential for effective [[clinical management]], [[research]], and [[healthcare planning]]. By using a common coding system, healthcare providers can ensure consistency and accuracy in patient records, improving the quality of care. |
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| The deprecation and withdrawal time frame for Read version 3 was also agreed by the SCCI in August 2014. The deprecation date was set at 1 September 2014,<ref>{{cite web|title=Information Standards Notice – Deprecation|url=http://www.hscic.gov.uk/media/15869/1552disn/pdf/1552disn.pdf|publisher=Standardisation Committee for Care Information (SCCI)|accessdate=15 May 2015}}</ref> with a final updated release for 1 April 2018, and complete withdrawal on 1 April 2020.<ref name=HSCIC-Read />
| | ==Transition to SNOMED CT== |
| | In recent years, the NHS has been transitioning from the Read Code system to [[SNOMED CT]] (Systematized Nomenclature of Medicine Clinical Terms), a more comprehensive and internationally recognized coding system. SNOMED CT offers greater detail and interoperability, allowing for improved data sharing and integration across different healthcare systems. |
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| The Read Codes Drug and Appliance Dictionary (DAAD) was published for the final time on 1 April 2016, with data since being pulled from public circulation<ref>{{cite web|title=Read Codes|url=https://digital.nhs.uk/article/1104/Read-Codes|publisher=NHS Digital|accessdate=1 October 2017}}</ref>. The intent of [[NHS Digital]] is to migrate users to the Drugs and Medicines Dictionary (dm+d), which itself is based upon SNOMED CT.
| | Despite the transition, Read Codes remain in use in some areas, particularly where legacy systems are still operational. The transition process involves mapping Read Codes to their corresponding SNOMED CT terms to ensure continuity of patient data. |
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| ==See also== | | ==Advantages== |
| *[[Pathology Messaging Implementation Project]] | | The Read Code system offers several advantages, including: |
| | * '''Standardization''': Provides a consistent method for recording clinical information. |
| | * '''Flexibility''': Allows for both broad and detailed coding, accommodating various levels of specificity. |
| | * '''Integration''': Facilitates integration with electronic health records, improving data management. |
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| ==References== | | ==Limitations== |
| {{reflist}}
| | While the Read Code system has been widely used, it has certain limitations: |
| | * '''Complexity''': The hierarchical structure can be complex, requiring training for effective use. |
| | * '''Limited Scope''': Compared to SNOMED CT, Read Codes have a more limited scope and detail. |
| | * '''Transition Challenges''': Moving from Read Codes to SNOMED CT involves significant effort in mapping and data conversion. |
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| {{Medical classification}}
| | ==Related pages== |
| | * [[SNOMED CT]] |
| | * [[Electronic health record]] |
| | * [[National Health Service]] |
| | * [[Clinical coding]] |
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| [[Category:National Health Service]] | | [[Category:Medical classification]] |
| [[Category:Diagnosis classification]]
| | [[Category:Healthcare in the United Kingdom]] |
| [[Category:General practice]]
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| [[Category:Clinical procedure classification]]
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| [[Category:Electronic health record software]] | |
A clinical coding system used in the UK
Read Code[edit]
The Read Code system, also known as the Read Clinical Classification, is a comprehensive coding system used primarily within the United Kingdom's National Health Service (NHS) to record clinical information in patient records. It was developed by Dr. James Read in the 1980s and has been widely adopted across various healthcare settings in the UK.
History[edit]
The Read Code system was initially developed to provide a standardized way of recording clinical information in general practice. Dr. James Read, a general practitioner, recognized the need for a consistent method to document patient data, which led to the creation of this coding system. The system was first introduced in the 1980s and has since evolved to accommodate the growing complexity of medical information.
Structure[edit]
Read Codes are alphanumeric codes that represent specific clinical terms. The system is hierarchical, allowing for detailed and specific coding of medical conditions, procedures, and other healthcare-related information. Each code corresponds to a specific term or concept, enabling healthcare professionals to accurately record and retrieve patient information.
The Read Code system is divided into chapters, each representing a different category of medical information, such as diagnosis, symptoms, procedures, and medications. This hierarchical structure allows for both broad and detailed coding, depending on the level of specificity required.
Read Codes are used extensively in electronic health records (EHRs) within the NHS. They facilitate the standardized recording of patient data, which is essential for effective clinical management, research, and healthcare planning. By using a common coding system, healthcare providers can ensure consistency and accuracy in patient records, improving the quality of care.
Transition to SNOMED CT[edit]
In recent years, the NHS has been transitioning from the Read Code system to SNOMED CT (Systematized Nomenclature of Medicine Clinical Terms), a more comprehensive and internationally recognized coding system. SNOMED CT offers greater detail and interoperability, allowing for improved data sharing and integration across different healthcare systems.
Despite the transition, Read Codes remain in use in some areas, particularly where legacy systems are still operational. The transition process involves mapping Read Codes to their corresponding SNOMED CT terms to ensure continuity of patient data.
Advantages[edit]
The Read Code system offers several advantages, including:
- Standardization: Provides a consistent method for recording clinical information.
- Flexibility: Allows for both broad and detailed coding, accommodating various levels of specificity.
- Integration: Facilitates integration with electronic health records, improving data management.
Limitations[edit]
While the Read Code system has been widely used, it has certain limitations:
- Complexity: The hierarchical structure can be complex, requiring training for effective use.
- Limited Scope: Compared to SNOMED CT, Read Codes have a more limited scope and detail.
- Transition Challenges: Moving from Read Codes to SNOMED CT involves significant effort in mapping and data conversion.
Related pages[edit]
