This is an abbreviation for SNOMED CT compositional grammar.

The set of rules that govern the way in which SNOMED CT expressions are represented as a plain text string.

• Compositional grammar

• SCG

snapshot release

A release type in which the release files contain only the most recent version of every component and reference set member released, as at the release date.

Provide Feedback

Provide Feedback

SNOMED CT Affiliate License Agreement

This is the full name for Affiliate License Agreement.

Affiliate License Agreement

The agreement between an Affiliate Licensee and SNOMED International.

Notes

• The agreement allows developers and implementers to use the SNOMED CT International Release and distribute the terminology to their sub-licensees as part of a software system.

Alternatives

• Affiliate License

• SNOMED CT Affiliate License Agreement

SNOMED CT author

A person responsible for creating or editing SNOMED CT concepts, concept definitions, and descriptions.

Alternatives

• Author

• Editor

• Modeler

• SNOMED CT editor

• SNOMED CT modeler

SNOMED CT distribution file

This is a synonym for SNOMED CT release file.

SNOMED CT release file

A computer file used to distribute SNOMED CT content in a form that can be readily imported by a software application.

Notes

• The content is from SNOMED International or from the originator of an Extension._ _

• SNOMED CT release files follow the Release Format 2 (RF2) as defined in the SNOMED CT Release File Specifications.

Alternatives

• Release file

• SNOMED CT distribution file

semantic interoperability

The capability of computer systems to communicate and exchange information.

Notes

• With semantic interoperability , each system should be able to interpret and effectively use received information.__ To achieve this, the meaning of the information must be agreed upon, consistent, and clear.

• Semantic interoperability of electronic health applications __ is achieved through the combination of the information architecture of the application and its terminology.

• SNOMED CT is a clinical terminological designed to support for semantic interoperability between well-designed electronic health records, clinical decision support and data analytics systems.

SCT

This is an abbreviation for SNOMED Clinical Terms.

SNOMED Clinical Terms

This is the full name for SNOMED CT.

SNOMED CT

A clinical terminology owned, maintained and distributed by SNOMED International.

Notes

• SNOMED CT is the most comprehensive clinical terminology in use around the world.

• SNOMED CT was created in 2002 as a result of the merger of SNOMED RT and NHS Clinical Terms Version 3.

Alternatives

• SCT

• SNOMED CT

A software application that provides a user interface through which to explore SNOMED CT content.

• A typical SNOMED CT browser can locate concepts and descriptions by identifiers and by searching the text of description terms.

• Various views of located concepts may be displayed including the set of related descriptions, the hierarchical relationships and other defining relationships.

• Browser

This is an abbreviation for SNOMED CT enabled application.

A software application designed to support the use of SNOMED CT.

• Enabled application

• SNOMED CT application

A clinical idea to which a unique concept identifier has been assigned.

• SNOMED CT concepts are distributed in the concept file.

• Concepts are associated with descriptions that contain human-readable terms describing the concept.

• Concepts are related to one another by relationships and OWL axioms that provide a formal logical definition of the concept.

Is additional information that can be associated to SNOMED CT components and reference set members.

• This extra information may be of value when evaluating a particular change to a SNOMED component or aid in implementation of SNOMED CT.

• Annotations are non-defining, so they do not have any impact on the classification of SNOMED CT concepts.

• Annotations are not mandatory for all components; they can be used as needed for a particular use case.

The process of creating or editing SNOMED CT concepts, concept definitions and descriptions.

• Authoring

• Modeling

• SNOMED CT modeling

A distribution file used to represent the main SNOMED CT components (concepts, descriptions and relationships).

• Previously, the term core was also used to refer to the content of the SNOMED CT International Release, but this usage is deprecated.

• The agreement contains a specific legal definition of the term "SNOMED CT Core", which includes all content controlled, maintained and distributed by SNOMED International.

This is the full name for SNOMED CT.

A clinical terminology owned, maintained and distributed by SNOMED International.

• SNOMED CT is the most comprehensive clinical terminology in use around the world.

• SNOMED CT was created in 2002 as a result of the merger of SNOMED RT and NHS Clinical Terms Version 3.

This is a synonym for SNOMED CT release format.

A file structure used to distribute SNOMED CT content.

• The release format is specified by SNOMED International.

• The current release format is Release Format 2, which superseded Release Format 1 in 2012.

This is a synonym for SNOMED CT author.

A person responsible for creating or editing SNOMED CT concepts, concept definitions, and descriptions.

• Author

• Editor

• Modeler

A software application designed to support the use of SNOMED CT.

• Enabled application

• SNOMED CT application

An implementation of an information system that is able to make effective use of SNOMED CT in an organization or region.

• SNOMED CT enabled implementation has a broader meaning than SNOMED CT enabled application. An implementation involves practical deployment of one or more applications to address personnel and organizational issues that allow the potential benefits to be realized.

• Enabled implementation

• SNOMED CT implementation

A SNOMED CT expression constraint containing template slots that can be populated by specific values when in use.

• An expression constraint template is particularly useful when non-technical users need to create structured constraints or queries. A technically competent designer creates the template and users enter values in the template slots. A form-driven query tool may also be used to create structured constraints or queries.

A computable rule that is used to define a set of clinical meanings.

• SNOMED CT expression constraints are defined using the expression constraint language (ECL).

• Expression constraints can be used for a variety of purposes including:

  • Specifying value set bindings that constrain the values that can be entered in a particular data entry context.

A unique integer identifier applied to each SNOMED CT component (Concept, Description, or Relationship).

• Each SNOMED CT Identifier (SCTID) includes an item identifier, a check-digit, a partition identifier and, depending on the partition identifier, it may also include a namespace identifier.

• Identifier

• SCTID

This is an abbreviation for SNOMED CT enabled implementation.

An implementation of an information system that is able to make effective use of SNOMED CT in an organization or region.

• SNOMED CT enabled implementation has a broader meaning than SNOMED CT enabled application. An implementation involves practical deployment of one or more applications to address personnel and organizational issues that allow the potential benefits to be realized.

• Enabled implementation

The set of SNOMED CT components and reference set members that either belong to a specific module identified by SNOMED International as the focus module for that edition or belong to one of the modules on which that module depends.

• The International Edition includes the foundational content of SNOMED CT on which all other SNOMED CT modules must have dependencies.

• SNOMED International currently identifies the as the focus module for the International Edition. Only the is currently specified as a dependency.

A SNOMED CT extension that is maintained and distributed by SNOMED International.

• Identifiers of components in a SNOMED CT extension are not required to include a namespace identifier.

• A SNOMED CT International extension contains components and reference set members which are dependent on modules in the International Edition, but are not part of the International Edition. The International extensions are, however, considered part of the overall International Release.

A SNOMED CT release package distributed by SNOMED International.

• A SNOMED CT International release package is used to distribute the SNOMED CT International Edition.

The complete set of SNOMED CT components and reference set members distributed by SNOMED International and made available to its Members and Affiliates.

• The International Release , provided by SNOMED International, includes the SNOMED CT International Edition and all supplementary content and derivatives contained in SNOMED CT International Extensions.

• The International Release may be supplemented by extension releases, maintained and distributed by Members and Affiliates, to meet additional national, local, and organizational requirements.

The model that specifies the overall design of SNOMED CT.

• The logical model specifies how the SNOMED CT components and reference sets represent the essential content of the terminology.

This is a synonym for SNOMED CT author.

A person responsible for creating or editing SNOMED CT concepts, concept definitions, and descriptions.

• Author

• Editor

• Modeler

This is a synonym for SNOMED CT authoring.

The process of creating or editing SNOMED CT concepts, concept definitions and descriptions.

• Authoring

• Modeling

• SNOMED CT modeling

A SNOMED CT Extension that is maintained by a Member for use in the territory for which that Member is responsible.

The complete set of SNOMED CT components and reference set members distributed to licensees by a Member.

• The National Release is a set of release files which contain components and derivatives from a National Extension maintained and distributed by a Member.

• A National Release may also include the SNOMED CT International Release on which it depends, in which case it is a release of the National Edition.

• Alternatively, a National Release

A formal language for representing computable queries over SNOMED CT content.

• The SNOMED CT query language is a superset of the SNOMED CT Expression Constraint Language, with the addition of filters , which restrict the results based on the value of specific release file fields.

A standard format for maintaining and distributing a set of references to SNOMED CT components.

• A reference set can be used to represent a subset of components (concepts, descriptions or relationships).

• A reference set may also associate referenced components with additional information such as:

  • Ordered lists of components

A computer file used to distribute SNOMED CT content in a form that can be readily imported by a software application.

• The content is from SNOMED International or from the originator of an Extension._ _

• SNOMED CT release files follow the Release Format 2 (RF2) as defined in the SNOMED CT Release File Specifications.

• Release file

The file structure previously used to distribute SNOMED CT content.

• Release Format 1 was specified by SNOMED International in 2002, but was replaced by Release Format 2 in January 2012.

• Release Format 2 is now the primary format for the SNOMED CT International Release.

• During an overlap period until 2016, both formats were used for the SNOMED CT International Release.

The file structure used to distribute SNOMED CT content and derivatives.

• Release Format 2 was specified by SNOMED International.

• In 2012, Release Format 2 replaced the original SNOMED CT Release Format 1 used between 2002 and 2012.

• During an overlap period until 2016, both formats were used for the SNOMED CT International Release.

A file structure used to distribute SNOMED CT content.

• The release format is specified by SNOMED International.

• The current release format is Release Format 2, which superseded Release Format 1 in 2012.

• Release format

The complete set of SNOMED CT components and reference set members distributed by a specific organization.

A release at a given point in time can be referred to as a SNOMED CT release version.

• The SNOMED CT International Release distributed by SNOMED International.

• A SNOMED CT National Release distributed by a Member National Release Center.

A marked position in a SNOMED CT template that can be removed or replaced an with appropriate values during processing.

• There are two main types of template slots:

  1. Replacement Slots , which are replaced by a SNOMED CT concept, expression or string during template processing

  2. Information Slots , which provide metadata about how the template is to be processed.

A SNOMED CT expression, expression constraint, or query containing one or more SNOMED CT template slots to be populated with values prior to or during processing.

Software that provides access to SNOMED CT through a defined application programming interface.

• A SNOMED CT terminology server __ should enable term-based searches, hierarchy navigation, access to selected concepts and their descriptions and definitions.

• A SNOMED CT terminology server may also provide access to other terminologies, code systems and classifications.

• Terminology server

A set of software functions that interface with and provide effective access to the content and features of one or more SNOMED CT editions.

• Each terminology service is a software function that interfaces with and provides access to information from one or more representations of a terminology.

• The software application that provides SNOMED CT terminology services is known as a SNOMED CT terminology server.

• While terminology services __ may be applicable to several different terminologies, applications that provide SNOMED CT terminology services,

This is an abbreviation for SNOMED CT versioned edition.

A SNOMED CT edition that is published on a specific date.

• A new version of the International Edition of SNOMED CT is released twice a year (in January and July).

• National extensions generally follow this cycle, however it is often with a three-month delay. Some extensions (notably those including medication-related concepts) are released more frequently.

A SNOMED CT edition that is published on a specific date.

• A new version of the International Edition of SNOMED CT is released twice a year (in January and July).

• National extensions generally follow this cycle, however it is often with a three-month delay. Some extensions (notably those including medication-related concepts) are released more frequently.

• The International Edition, 20180131 (dated January 31, 2018).

A clinical terminology owned, maintained and distributed by SNOMED International.

• SNOMED CT is the most comprehensive clinical terminology in use around the world.

• SNOMED CT was created in 2002 as a result of the merger of SNOMED RT and NHS Clinical Terms Version 3.

• SCT

This is a synonym for Affiliate Licensee.

An organization or individual that has been issued a license to use SNOMED CT by SNOMED International.

• Usage must be in accordance with the SNOMED CT Affiliate License Agreement.

• Affiliate

A Member of the International Health Terminology Standards Development Organisation (IHTSDO) in accordance with the IHTSDO Articles of Association.

• IHTSDO trades as SNOMED International.

• IHTSDO Member

• Member

The name of one of the antecedent versions of the SNOMED terminology.

• SNOMED International

• SNOMED International was first released in 1993.

• SNOMED International version 3.5 ,__ released in 1998, was the immediate predecessor of SNOMED RT.

Not to be confused with:

This is the trading name of the International Health Terminology Standards Development Organisation.

The organization that owns, administers, and develops SNOMED CT.

• The purpose of International Health Terminology Standards Development Organisation (IHTSDO) is to support safe, accurate, and effective health information exchange.

• SNOMED International is the trading name for the IHTSDO.

The antecedent version of SNOMED that immediately preceded the release of SNOMED Clinical Terms.

• In SNOMED RT , RT refers to reference terminology.

• SNOMED RT was a source terminology, with CTV3, from which SNOMED CT was developed.

The general name for a series of clinical terminologies owned, managed and licensed by SNOMED International.

• The current version, SNOMED Clinical Terms was first released in 2002 and is actively maintained, licensed and distributed by SNOMED International.

• None of the earlier versions of SNOMED are maintained and since 2017 all antecedent versions are formally deprecated and are no longer licensed for use.

• The SNOMED terminologies were originally developed by the College of American Pathologists (CAP), they were acquired by the International Health Terminology Standards Development Organisation (IHTSDO) in 2007. Since 2017 IHTSDO has traded as SNOMED International.

The concept that is used as a source value in a relationship.

• The source concept is identified by the sourceId in the relationship.

• The relationship represents a defining characteristic of the source concept.

This is an abbreviation for translation source language.

The language in which the original text is written.

• English is the source language for the International Edition of SNOMED CT.

• Source language

A field in the relationship release file containing a SNOMED CT identifier that represents the source concept as defined by the associated relationship.

This is an abbreviation for Structured Query Language.

The standard language for manipulating and querying relational databases.

• Structured Query Language (SQL) is designed for: * managing data in a relational database management system (RDBMS) * stream-processing data in a relational data stream management system (RDSMS)

• Structured Query Language is an ANSI and ISO standard.

This is a synonym for stated view.

A representation of concept definitions consisting only of assertions made or revised by SNOMED CT authors.

• In contrast to the inferred view, the stated view does not include inferences generated by applying a description logic classifier.

• The stated view is represented by axioms, that conform to the OWL functional syntax. These axioms are distributed in the OWL axiom reference set file

A representation of concept definitions consisting only of assertions made or revised by SNOMED CT authors.

• In contrast to the inferred view, the stated view does not include inferences generated by applying a description logic classifier.

• The stated view is represented by axioms, that conform to the OWL functional syntax. These axioms are distributed in the OWL axiom reference set file

• Prior to July 2018 the stated view of concept definitions were represented by relationships in the stated relationship file. During a transitional period between July 2018 and July 2019 the OWL reference sets were introduced. Since the end of that transitional period in July 2019, the stated relationship file is no longer maintained or distributed. More information on the earlier representation of the stated view is provided in a historical note on Representation of the Logical Model - Before July 2018.

The standard language for manipulating and querying relational databases.

• Structured Query Language (SQL) is designed for: * managing data in a relational database management system (RDBMS) * stream-processing data in a relational data stream management system (RDSMS)

• Structured Query Language is an ANSI and ISO standard.

• SQL

A person or group of people to whom healthcare services are delivered.

• healthcare client

• patient

The person, or other identified entity, to which a health record, note or communication primarily relates.

• The subject of record is formally represented in the SNOMED CT concept model by the concept . This is the default value of the attribute that indicates a finding or procedure relates directly to the subject of the record rather than to another person such as a family member or disease contact.

• Usually the subject or record is also the subject of care.

The SNOMED CT content by which an expression constraint is evaluated or a query is executed.

• Two distinct types of substrate are directly relevant to use of SNOMED CT:

  • The substrate for an expression constraint that generates the membership of a subset or reference set.

  • The substrate for a clinical analytics query, consisting of a collection of records either coded in or mapped to SNOMED CT.

A concept that has a direct subtyperelationship to a specified concept.

• See also subtype and subtype descendant.

• The figure below shows an example hierarchy in which concept C has two subtype children ,F and G.

This is the plural form of subtype child.

A concept that has a direct subtyperelationship to a specified concept.

• See also subtype and subtype descendant.

• The figure below shows an example hierarchy in which concept C has two subtype children ,F and G.

A classification hierarchy in which each node is connected to its supertypes.

• Subtype classification allows aggregation of information based on a hierarchy of types.

• Subtype hierarchy

A concept that is a subtype of a specified concept.

• Includes the subtype children and the subtype children of each subtype child and so on recursively.

• The terms subtype and subtype descendant are synonymous. However, it is sometime helpful to use the term subtype descendant to emphasize inclusion of all subtypes not just subtype children.

The figure below shows an example hierarchy in which concept C has eight subtype descendants (F, G, M, N, O, P, U and V).

This is a synonym for subtype classification.

A classification hierarchy in which each node is connected to its supertypes.

• Subtype classification allows aggregation of information based on a hierarchy of types.

• Subtype hierarchy

SNOMED CT Affiliate Edition

A set of SNOMED CT components and reference set members that either belong to a focus module identified by an Affiliate Licensee with an allocated extension namespace identifier, or belong to one of the modules on which that module depends.

Notes

• The focus module is part of the extension for which that Affiliate is responsible.

• An Affiliate Edition may extend the SNOMED CT International Edition or a National Edition.

Provide Feedback

SNOMED CT concept model

The set of rules that determines the permitted sets of relationships between particular types of concepts.

Notes

• The c oncept model specifies the attributes that can be applied to concepts in particular domains and the ranges of permitted values for each attribute. There are additional rules on the cardinality and grouping of particular types of relationships.

Alternatives

• Concept model

Provide Feedback

snapshot view

A view of SNOMED CT that includes the most recent version of all components and reference set members at a specified point in time.

Notes

• The snapshot view at the current date matches the content of the most recent snapshot release.

• A full release can be filtered to provide the snapshot views for the current date or any date in the past.

Provide Feedback

SNOMED CT compositional grammar

The set of rules that govern the way in which SNOMED CT expressions are represented as a plain text string.

Alternatives

• Compositional grammar

• SCG

Provide Feedback

SNOMED CT core

This is an abbreviation for SNOMED CT core file.

SNOMED CT core file

A distribution file used to represent the main SNOMED CT components (concepts, descriptions and relationships).

Notes

• Previously, the term core was also used to refer to the content of the SNOMED CT International Release, but this usage is deprecated.

• The SNOMED CT Affiliate License agreement contains a specific legal definition of the term "SNOMED CT Core", which includes all content controlled, maintained and distributed by SNOMED International.

Alternatives

• Core file

• Core table

• SNOMED CT core

• SNOMED CT core table

semantic equivalence

The relationship between two classes that have the same logical meaning.

Notes

• The equivalent classes may be represented in different ways for example as SNOMED CT concept definitions, SNOMED CT expressions, or axioms expressed using a syntax such as OWL Functional Syntax.

• Semantic equivalence is represented by the Ξ symbol or by a sequence of three equals signs === .

Example

• The expression below asserts that the concept 80146002 | Appendectomy| has semantic equivalence with with method applied to the direct site .

=== : { = , = }

• Concept equivalence

• Equivalence

SNOMED CT edition

A complete set of SNOMED CT components and reference set members that either belong to an identified SNOMED CT module or belong to one of the modules on which that module depends.

Notes

• The module used to define the scope of an edition is referred as the focus module of that edition.

• All SNOMED CT editions (except the International Edition) are a combination of one or more extension modules, together with the modules from the SNOMED CT International Edition.

• A complete SNOMED CT edition may be prepared and released by SNOMED International or by the provider of a SNOMED CT Extension. Alternatively, a SNOMED CT edition may be derived from one or more release packages, by combining the contents of an identified focus module with the contents of the relevant version of all modules on which the focus module depends.

• The dependencies between modules are represented using the .

• A SNOMED CT edition can be identified using a Uniform Resource Identifier (URI) as specified by the URI Standard (2.1 URIs for Editions and Versions).

• The SNOMED CT International Edition consists of the focus module , , and the module on which it depends, .

• The US National Edition (including the US SNOMED to ICD-10-CM maps) consists of the focus module , , and the three modules on which this depends, , and .

• Edition

SNOMED CT expression

A structured combination of one or more concept identifiers that represents an idea.

Notes

• An expression containing a single concept identifier is referred to as a precoordinated expression. An expression that contains two or more concept identifiers is a postcoordinated expression.

• The syntax used to represent SNOMED CT expressions is called the SNOMED CT compositional grammar and is formally defined in the Compositional Grammar - Specification and Guide.

• The concept identifiers in a postcoordinated expression are related to one another in accordance with rules expressed in the SNOMED CT Concept Model. These rules allow an expression to refine the meaning of a concept by applying more specific values to particular attributes of a more general concept.

• The expression 284196006:363698007=770850006 represents a burn to the skin of the left index finger.

• An expression can also include the terms related to each of the identified concepts as shown below:

: =

• Expression

SNOMED CT extension

A set of terminology components and reference set members that add to and are dependent on the SNOMED CT International Edition.

Notes

• An extension is created, structured, maintained, and distributed in accordance with SNOMED CT specifications and guidelines.

• An extension consists of one or more modules. All components and reference set members maintained in an extension include a module identifier that assigns them to a module in that extension.

• SNOMED CT extensions may be created and maintained by SNOMED International itself or by SNOMED International Members or Affiliate licensees to which SNOMED International has assigned a namespace identifier.

• Components that are created by Members or Affiliates are identified using SCTIDs that include the namespace identifier assigned to that organization. This ensures that they do not collide with other SCTIDs, and can be traced to an authorized originator. Identifiers of extension components and reference set members created by SNOMED International are not required to include a namespace identifier.

• Extensions released by SNOMED International contain components and reference set members that extend, rather than being an essential part of, the SNOMED CT International Edition. However, SNOMED CT International Extensions are considered to be part of the overall International Release.

• Members may create, maintain, and distribute extensions to address specific national, regional, and language requirements. SNOMED International Affiliates may also create, maintain, and distribute extensions to meet the needs of particular software solutions and customers.

• Extension

SNOMED CT metadata

SNOMED CT content (including concepts, descriptions, and relationships) that provides additional information about SNOMED content and derivatives (including reference sets).

Notes

• All SNOMED CT metadata concepts are subtypes of 900000000000441003 | SNOMED CT Model Component (metadata)| .

• The top level of the metadata hierarchy represents broad groups of metadata as follows:

Top level of the SNOMED CT metadata hierarchy 900000000000441003 | SNOMED CT Model Component (metadata)|

• Concept enumerations use metadata concepts to represent values that are applied to particular fields in release files.

• Reference set types and reference set names are represented by metadata concepts that are subtypes of .

• metadata

SNOMED CT model component concept

The concept that represents the top of the hierarchy of metadata concepts.

Notes

• This SNOMED CT model component concept has the identifier 900000000000441003 | SNOMED CT Model Component (metadata)| .

• The top level of the metadata hierarchy represents broad groups of metadata as follows:

138875005 |SNOMED CT Concept| ⬅︎ The root concept 900000000000441003 |SNOMED CT Model Component| ⬅︎ The root metadata concept 106237007 |Linkage concept| ⬅︎ Attributes and other linkage concepts 370136006 |Namespace concept| ⬅︎ Concepts representing namespaces 900000000000442005 |Core metadata concept| ⬅︎ Metadata supporting components 900000000000454005 |Foundation metadata concept| ⬅︎ Metadata supporting refsets

Alternatives

• Root metadata code

SNOMED CT module

A group of SNOMED CT components and/or reference set members managed, maintained, and distributed as a unit.

Notes

• Components and reference set members that are part of the same module share the same moduleId "Reference term: moduleId (field)") value.

• All modules , except the 900000000000012004 | SNOMED CT model component module| , have dependencies on other modules specified by the Module Dependency Reference Set.

  • components and reference set members, that are part of the same module, share the same moduleId "Reference term: moduleId (field)") value.

  • components and reference set members are part of only one module , at any given time.

• The organization responsible for maintaining an extension must:

  • create and maintain at least one module identified by a moduleId that it has created;

  • apply a moduleId that it has created to all components and reference set members in its extension ;

• The organization responsible for maintaining an extension may:

  • create and maintain multiple modules ;

  • organize its components and reference set members within the modules it manages in a way that best meets its business needs;

  • move a component or reference set member between its modules by creating a revised version of that component or reference set member with a different

• Components and reference set members may be moved between modules maintained by different organizations. However, such moves must only be made:

  • with the consent of the organizations responsible for both the source and target modules; and

  • in accordance with rules specified by SNOMED International.

• Module

SNOMED CT National Edition

A set of SNOMED CT components and reference set members that either belong to a focus module identified by a National Release Center (NRC), or belong to one of the modules on which that module depends.

Notes

• The focus module is part of the National Release for which that NRC is responsible.

• An NRC may have multiple National Editions with different focus modules for each edition.

• A National Edition may:

  • be part of a National Release distributed to licensees.

  • combine a focus module from the National Release , the relevant versions of modules in the International Edition, and any other extension modules on which the focus module of the National Edition depends.

• United States Edition

• Canadian Edition

• United Kingdom Clinical Edition (does not include UK drug extension modules)

• United Kingdom Edition (includes UK drug extension modules)

• National Edition

SNOMED CT relationship

An association between a source concept and a destination concept.

Notes

• Each relationship is represented by a separate row in the relationship file.

• Each relationship has a unique identifier and contains columns identifying the relationship type and the concepts that are related (sourceId) and destinationId)).

• Each relationship provides defining information about the source concept.

Change Notice

• Since July 2019, OWL axioms the authoritative representation of the stated view of concept definitions are represented by axioms distributed in OWL Expression Reference Sets. Relationships continue to be distributed to represent necessary normal form of the inferred view concept definitions.

• The source, type and destination of one of the relationships for the concept are as follows:

• Relationship

SNOMED CT release package

A single-unit set of release files with SNOMED CT components, reference set members, and/or other related items.

Notes

• A release package

  • Is distributed by SNOMED International, a National Release Center, or another organization authorized to maintain and distribute a SNOMED CT extension

  • May be a complete SNOMED CT Edition or a supplementary extension module, dependent on other modules

  • May be referred to as a release package version, meaning it is distributed at a specific point in time

    • Each release package version is assigned a release packages status: alpha release package, beta release package, or production release package.

  • May also refer to other SNOMED CT products or services, such as those listed in the

• Release

• Release package

statistical classification

A hierarchical organization of terms or ideas that allows aggregation into categories.

Notes

• A statistical classification

  • Allows categories to be counted and compared, without double counting.

  • Is a monohierarchical classification, which mean that each node in the hierarchy is included in only one node in the level above. Although this avoids double counting, it means that arbitrary decisions are made when a node is naturally related to more than one parent.

• In a statistical classification such as ICD-10, bacterial pneumonia is related to lung disorder or infectious disorder , but not to both.

• In contrast, a polyhierarchical classification such as SNOMED CT, enables bacterial pneumonia to be a subtype of both lung disorder and infectious disorder. This enables more inclusive analytics and avoids overlooking conditions that are in a different category from the one being analyzed.

structure-entire-part

A modeling approach used in SNOMED CT to represent anatomical entities such as body organs, systems, or regions.

Notes

• Structure is the most general way to refer to an organ, body system, or region.

• Entire refers to a complete organ, body system, or region.

• Part refers to a part of an organ, body system, or region. Part does not refer to the entire organ, body system, or region.

Example

Figure 1 below illustrates the relationships between the structure , entire , and part concepts applied to the heart.

• SEP

subset

A set of members all of which are members of another set (from set theory in mathematics).

Notes

• In SNOMED CT, the definition of subset applies to SNOMED CT components as follows:

  • A subset of SNOMED CT concepts is a set of concepts taken from a wider set of concepts.

  • A subset of SNOMED CT descriptions is a set of descriptions taken from a wider set of descriptions.

• The members of a subset can be defined in one of two ways:

  • Extensionally, by enumeration, with a simple reference set as the standard distribution format.

  • Intensionally, using rules to determine inclusion, with a query reference set as the standard distribution format.

• A subset of SNOMED CT concepts from all of the concepts in a particular version of a SNOMED CT edition.

• A subset of SNOMED CT descriptions from all the descriptions in a particular version of a SNOMED CT edition.

• Wikipedia

subsume

See subsumption test.

subsumption test

A test to determine if a specified candidate concept or expression is a subtype descendant of another specified concept or expression.

Notes

• Literally speaking a subsumption test determines if one concept is subsumed by another.

• In the context of SNOMED CT a concept is subsumed by its supertypes and subsumes its subtypes. So the following terms are for all practical purposes interchangeable.

• To answer the question "Which patients have an infectious disease?" involves finding all of the patients with records that include a concept or expression that is subsumed by the concept .

• Subtype test

subsumption test

A test to determine if a specified candidate concept or expression is a subtype descendant of another specified concept or expression.

Notes

• Literally speaking a subsumption test determines if one concept is subsumed by another.

• In the context of SNOMED CT a concept is subsumed by its supertypes and subsumes its subtypes. So the following terms are for all practical purposes interchangeable.

• To answer the question "Which patients have an infectious disease?" involves finding all of the patients with records that include a concept or expression that is subsumed by the concept .

• Subtype test

subtype relationship

A relationship that asserts that a concept is a subtype of another concept.

Notes

• Subtype relationships __ are represented by relationship type 116680003 | is a| .

• A subtype relationship asserts that a concept conforms to all the defining characteristics the supertype concept but also has at least one feature or refinement that distinguishes it from that concept.

  • Note that the distinguishing features may or may not be represented in the concept definition of the subtype concept.

• Concepts are defined by a combination of subtype relationships and attribute relationships.

• The table below shows an example of a subtype relationship as it appears in the three significant columns of the relationship file.

• Is a

semantic tag

This is a synonym for hierarchy tag.

hierarchy tag

A parenthetical notation at the end of a fully specified name indicating the relevant domain.

Notes

• The purpose of hierarchy tags is to disambiguate concepts that contain the same commonly used words or phrases.

Examples

• 55903007 | Acute atrophy (morphologic abnormality)| with the hierarchy tag , morphologic abnormality in the body structure domain

• with the hierarchy tag , procedure

• Semantic tag

SNOMED CT description

An association between a human-readable phrase (term) and a particular SNOMED CT concept.

Notes

• Each description is represented by a separate row in the Description File.

• Each description has a unique identifier and connects a concept with a term of a specified description type. All concepts have descriptions with description types fully specified name and synonym. Other description type can be defined and may be applied to some concepts.

Alternatives

• Description

SNOMED CT component

A concept, description, or relationship that conforms with the SNOMED CT logical model.

Notes

• Components are released and distributed in file formats that conform to the Release File Specification.

• Components may be part of the SNOMED CT International Edition or in an authorized extension.

Alternatives

• Component

SNOMED CT concept identifier

A SNOMED CT identifier that uniquely identifies a concept.

Notes

• Each concept represents a defined meaning. Therefore, a concept identifier can be used to refer to that meaning in electronic health records and queries used to analyse those records.

Examples

• The c oncept identifier for the concept 233604007 | Pneumonia (disorder)| is 233604007.

Alternatives

• Concept identifier

• SNOMED code (deprecated)

SNOMED CT derivative

A document, subset, set of maps, or other resource that includes references to, or is derived from, one or more SNOMED CT components.

Notes

• The standard computer processable representation for most types of SNOMED CT derivatives is a reference set.

• The SNOMED CT Affiliate License agreement contains a more specific legal definition of the term "Derivative".

Alternatives

• Derivative

References

SCTID

This is an abbreviation for SNOMED CT identifier.

SNOMED CT identifier

A unique integer identifier applied to each SNOMED CT component (Concept, Description, or Relationship).

Notes

• Each SNOMED CT Identifier (SCTID) includes an item identifier, a check-digit, a partition identifier and, depending on the partition identifier, it may also include a namespace identifier.

Alternatives

• Identifier

• SCTID

A set of one or more axioms that partially or sufficiently specify the meaning of a SNOMED CT concept.

• Concept definitions are represented in two ways in SNOMED CT release files: * As a stated view represented by axioms that conform to the OWL Functional Syntax distributed in the OWL Expression Reference Set file. * As an inferred view represented by defining relationships that are distributed in the relationship file. The inferred view is generated by applying description logic classification to the stated view.

• Concept definitions include two distinct elements

This is a synonym for SNOMED CT core file.

A distribution file used to represent the main SNOMED CT components (concepts, descriptions and relationships).

• Previously, the term core was also used to refer to the content of the SNOMED CT International Release, but this usage is deprecated.

• The agreement contains a specific legal definition of the term "SNOMED CT Core", which includes all content controlled, maintained and distributed by SNOMED International.

This is an abbreviation for structure-entire-part.

A modeling approach used in SNOMED CT to represent anatomical entities such as body organs, systems, or regions.

• Structure is the most general way to refer to an organ, body system, or region.

• Entire refers to a complete organ, body system, or region.

A concept that specifically defines the context of a clinical finding or procedure.

• A situation with explicit context is defined as a subtype of the situation to which it applies with an attribute associating it with the relevant clinical finding or procedure.

• Family history of diabetes mellitus is a situation with explicit context concept. It defines the context as family history by indicating that the is a .

SNOMED CT expression template

A SNOMED CT template that represents an expression in which one or more elements are replaced by SNOMED CT template slots.

Notes

• An expression template includes one or more predefined variables which when replaced by appropriate values creates a conformant expression.

• An expression template can be used to specify how data items entered via several controls in a structured user interface should be combined to represent a composite meaning.

• Expression templates are also used to formally represent meaning bindings associated with different data entry contexts.

• Expression templates are one of several types of templates defined by the SNOMED CT Template Syntax Specification.

• The example expression template below specifies a meaning binding for a family history data entry context. In this context, a subtype of will be interpreted as the value of the attribute. Similarly, the concept or one of its subtypes will be interpreted as the value of the attribute. The template assigns the names @disease and @subject to these slots, which allows them to be referenced from specific user interface controls.

: { = , = [[+id ( < ) @disease ]], = , = [[+id ( << ) @subject ]]}

• If is entered in the @disease slot and is entered in the @subject slot, the result is the expression , shown below, stating that the father of the patient has (or had) .

: { = , = , = , = }

• Expression template