concept definition

This is an abbreviation for SNOMED CT concept definition.

SNOMED CT concept definition

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

Notes

• 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

  • Axioms that assert that a concept is a subtype of one or more other concepts. In the inferred view these are represented as subtype relationships.

  • Axioms that assert characteristics of a concept that distinguish it from its supertypes. In the inferred view these are represented as attribute relationships.

• Prior to July 2018 the stated view of concept definitions were represented by relationships in the Stated Relationships 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 Since the end of that transitional period in July 2019, the stated relationship file is no longer maintained or distributed.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.

• Concept definition

A set of SNOMED CT concept identifiers used to represent values for a property of a SNOMED CT component or reference set member.

Notes

• Concept enumeration serves the same purpose as more general approaches to providing enumerated lists of values (i.e. assigning a number to a value). However, the use of SNOMED CT concept identifier allows access to the human readable meaning of each enumeration using descriptions in the same way for other concepts.

• The SNOMED CT concepts used to represent concept enumerations are usually subtype children (or descendants) of concepts in the SNOMED CT metadata hierarchy. Each possible value is represented by a single child concept. This allows updates to the permitted values to be tracked using the component history mechanism.

Example

• Concept enumerations for description.typeId:

concept

This is an abbreviation for SNOMED CT concept.

SNOMED CT concept

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

Notes

• 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.

• Concept

Not to be confused with:

• Concept , in its more general dictionary usages, referring to an idea or to a class of real-world entities. When working with SNOMED CT, the words "idea" or "meaning" are suggested instead of this more general use of concept.

• Concept identifier. For clarity when referring to the identifier of a SNOMED CT concept, specifically refer to the "concept identifier", "concept id" or "code" rather than using the word concept.

This is an abbreviation for SNOMED CT concept model.

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

• 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.

• Concept model

A SNOMED CT identifier that uniquely identifies a concept.

• The concept identifier uniquely identifies the clinical idea represented by the concept.

• The concept identifier is used in expressions and other information artefacts to represent the identified concept.

concept equivalence

This is a synonym for semantic equivalence.

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 has semantic equivalence with with method applied to the direct site .

=== : { = , = }

• Concept equivalence

• Equivalence

concept model range

A set of values that the concept model permits to be applied to a specific attribute.

Notes

• The range of permitted values that can be applied to an attribute is formally specified using the expression constraint language.

• The range is typically limited to concepts that are subtypes of one concept. However, in some cases a range may be specified to include subtypes of several concepts or members of a specified reference set.

Example

• The concept model range for the attribute is limited the concept and its subtypes. This is specified by the following constraint:

<<

• Range

concept model attribute

A characteristic of the meaning of a concept or the nature of a refinement.

Notes

• An attribute is assigned a value (attribute value pair) when used in the definition of a concept or in a postcoordinated expression.

• The attributes that can be used in definitions or refinements are represented by a concepts that are subtypes of the concept 410662002 | Concept model attribute (attribute)| .

• The SNOMED CT concept model specifies:

  • The concept model domains which each specific attribute can be applied; and

  • The concept model range of values that can be applied to each specific attribute.

• The attribute

  • is one of the attributes that can be applied to concepts in the domain; and

  • its range includes and its subtypes.

• Attribute

• Role

A set of concepts which the concept model permits to be defined or refined, using a particular set of attributes and ranges.

• A domain to which an attribute can be applied typically includes concepts in one or more branches of the subtype hierarchy.

• Section Procedure Attributes Summary of the SNOMED CT Editorial Guide defines the domain , attributes and ranges for | Procedure| .

• The domain