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

concept model domain

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

Notes

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

Examples

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

• The domain is defined as follows:

<< /* the concept "Procedure" or any of its subtypes */

• The table row below shows how , one of the many attributes applicable to the domain, is specified together with its range of permitted values.

• Domain

CTUF expression

This is a synonym for close to user form expression.

close to user form expression

The faithful representation of the information as it was entered, and the primary stored and communicated view of clinical information encoded using SNOMED CT.

Notes

• The close to user form expressio n includes refinements applied by an application based on selections made in an entry form as well as those made explicitly

• The close to user form expression does not include any additional relationships that are added based on classifier rules to make the expression complete or to normalize it

• CTUF expression

canonical form

A serialized representation of a SNOMED CT expression produced by applying a set of rules that ensure a single unique representation for any expression.

Notes

• Expressions that contain exactly the same concept identifiers and refinements, may differ from one another in the following ways:

  • Inclusion of whitespace between elements

  • Inclusion of specific terms associated with identified concepts.

  • The order in which focus concepts, refinements, attributes, and attribute groups appear.

• The canonical form is generated by removing whitespace and terms from an expression and arranging the focus concepts, refinements, attributes, and attribute groups in a standard order.

• If canonical form rules are applied to a normal form expression, the result is a single unique rendering of the meaning represented by that expression.

• Canonical representation

• Wikipedia

A record of creation or modification of a component between SNOMED CT versions.

CEN

This is an abbreviation for European Committee for Standardization.

European Committee for Standardization

A standards organization whose mission is to foster the economy of the European Union in global trading, the welfare of European citizens, and the environment.

Notes

• The European Committee for Standardization is a major provider of European standards and technical specifications.

Alternatives

• CEN

• Comité Européen de Normalisation

• Europäiches Komitee für Normung

• CEN TC251 - Health informatics

CDS

This is an abbreviation for clinical decision support.

clinical decision support

A service that assists clinicians, caregivers, or patients in healthcare and/or treatment decisions.

Notes

• A clinical decision support system is a computer system or software application designed to assist clinicians, caregivers, or patients in healthcare and/or treatment decisions.

Alternatives

• CDS

An operator used to assert that two (or more) parts of a concept definition or expression constraint must both be true.

• Conjunction can be represented by theAND operator. A conjunction of A with B , means that both A AND B must be true.

• Conjunction gives the same result as an intersection**** between the set of concepts or

Common Terminology Services 2

An application programming interface (API) specification of the basic functional requirements used to query and access terminological content.

Notes

• CTS2 * Is an abbreviation for Common Terminology Services 2. * Is used by healthcare software implementers. * Defines the functional requirements of a set of service interfaces to allow the representation, access, and maintenance of terminology content either locally, or across a federation of terminology services nodes._ _ * Is specified as an API, rather than a set of data structures. This enables a wide range of terminological content to be integrated within a common framework, without the need for significant migration or revision. * Was developed from the original HL7 CTS specification and is now a joint initiative between HL7 and the Object Management Group (OMG).

Alternatives

• CTS2

• HL7 CTS2

Clinical Terms Version 3

This is an abbreviation for NHS Clinical Terms Version 3.

NHS Clinical Terms Version 3

A source terminology used to develop SNOMED CT.

Notes

• SNOMED RT was also used with NHS Clinical Terms Version 3 to develop SNOMED CT .

• NHS Clinical Terms Version 3 is UK Crown Copyright, distributed by the United Kingdom National Health Service (NHS), and is integrated into SNOMED CT.

Alternatives

• CTV3

• Read Codes Version 3

A syntactically valid and concept model compliant representation of the close-to-user form expression.

• The classifiable form expression serves as the input to the classifier, enabling compositional expressions to be classified with SNOMED CT content

• In the classifiable form expression , ungrouped attributes and role groups have been validated and appropriately applied to the definition of the focus concept

Superseded by - Beta release package.

A SNOMED CT release package made available for review and testing only.

• Implementers and other stakeholders review and test the beta release.

• The beta release package is made available prior to the production release. It must not be used in production clinical systems or in clinical settings. This includes Affiliate Licensees or any third parties, except those who have formally committed to test it.

CF expression

This is a synonym for classifiable form expression.

classifiable form expression

A syntactically valid and concept model compliant representation of the close-to-user form expression.

Notes

• The classifiable form expression serves as the input to the classifier, enabling compositional expressions to be classified with SNOMED CT content

• In the classifiable form expression , ungrouped attributes and role groups have been validated and appropriately applied to the definition of the focus concept

Alternatives

• CF expression

component

This is an abbreviation for SNOMED CT component.

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

This is an abbreviation for Common Terminology Services 2.

An application programming interface (API) specification of the basic functional requirements used to query and access terminological content.

• CTS2 * Is an abbreviation for Common Terminology Services 2. * Is used by healthcare software implementers. * Defines the functional requirements of a set of service interfaces to allow the representation, access, and maintenance of terminology content either locally, or across a federation of terminology services nodes._ _ * Is specified as an API, rather than a set of data structures. This enables a wide range of terminological content to be integrated within a common framework, without the need for significant migration or revision. * Was developed from the original specification and is now a joint initiative between HL7 and the .

compositional grammar

This is an abbreviation for SNOMED CT compositional grammar.

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

Related Links

• Specification

  • Compositional Grammar Specification and Guide

close to user form expression

The faithful representation of the information as it was entered, and the primary stored and communicated view of clinical information encoded using SNOMED CT.

Notes

• The close to user form expressio n includes refinements applied by an application based on selections made in an entry form as well as those made explicitly

• The close to user form expression does not include any additional relationships that are added based on classifier rules to make the expression complete or to normalize it

Alternatives

• CTUF expression

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:

C-NPU

A coded terminology used in clinical laboratory sciences.

Notes

• C-NPU is maintained by the International Federation of Clinical Chemists (IFCC) in collaboration with the International Union of Pure and Applied Chemistry (IUPAC).

Alternatives

• IFCC-IUPAC

• Nomenclature, Properties and Units

• NPU

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

clinical situation

This is a synonym for situation with explicit context.

situation with explicit context

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

Notes

• 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.

Example

• 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 .

• In contrast, diabetes mellitus itself is not a situation with explicit context. It can be used in many different situations including family history , past medical history or current diagnosis.

• Clinical situation

• Context

• Explicit context

CDSS

This is an abbreviation for clinical decision support system.

clinical decision support system

A computer system or software application designed to assist clinicians, caregivers, or patients in healthcare and/or treatment decisions.

Notes

• Typically a clinical decision support system responds to triggers, such as specific signs or symptoms, diagnoses, laboratory test results, medication selections, or complex combinations of such triggers. The system then provides information or recommendations relevant to the specific patient.

Alternatives

• CDSS

classifier

This is an abbreviation for description logic classifier.

description logic classifier

A software tool that applies the rules of description logic to a set of axioms to infer additional relationships between concepts.

Notes

• SNOMED CT concept definitions are processed by a description logic classifier to generate inferred subtype hierarchies.

• SNOMED CT expressions can also be processed by a description logic classifier to make inferences that enable more complete and precise selective retrieval to support analytics.

• Classifier

core table

This is a synonym 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

References

• ** **

This is an abbreviation for clinical information system.

A computer-based system that collects, stores, manipulates, and supplies clinical information to support the delivery of healthcare services to individual people and populations.

• CIS

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 model

This is an abbreviation for SNOMED CT concept model.

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

This is an abbreviation for SNOMED CT concept.

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.

The set of elements that are not in a specified set.

Notes

• In set theory, the complement of set ** A** refers to all elements not in set ** A**.

• In SNOMED CT, the complement of a _subset _of concepts consists of all concepts that are not in that subset.

Example

• The following expression constraint language defines the set of concepts that are subtypes of that are also part of the complement of the . The "MINUS" instruction excludes members of the reference set, so only concepts that are part of the complement of that set are included.

< MINUS ^

Related Links

• Wikipedia

child

This is an abbreviation for subtype child.

subtype child

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

Notes

• See also subtype and subtype descendant.

Example

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

• Child

• Children

• Subtype children

A representation of a SNOMED CT component at a particular point in time.

Notes

• In SNOMED CT release files each component version is represented as a single row with a unique combination of component.id and component.effectivetime.

• The component.id uniquely identifies the component and is shared by other versions of that component.

• The component.effectiveTime distinguishes different versions of the same component. It indicates the point in time at which that version became the authoritative version of that component. The effectiveTime of the first version of a component represents the time when it first became available for use. The effectiveTime of each subsequent version of a component represents the time when that version superseded the previous version.

A rule that limits the attributes, values, and associations that may be applied to a particular component.

• A modeling constraint may limit the permissible defining relationships applied to a particular type of concept.

• An instance data constraint may limit the permissible refinements that may be applied to a particular concept.

context

The circumstances that form the setting in which a concept can be appropriately interpreted.

Notes

• Clear recording and appropriate interpretation of context is essential for safe use and accurate analysis of electronic health records.

• The context in which a concept is used can be represented in various ways. Some of the possible representation are shown in the examples section below.

• Appropriate interpretation of different representations of context can be facilitated by terminology binding techniques that resolve multiple models of use into a common model of meaning.

• A disease such as "asthma" might be referred to in various contexts.

  • A current presenting problem needing treatment

  • A past history recorded during assessment for treatment of another condition

: { = }

Family History Record Section )

Confluence

This is the system that currently provides the SNOMED International collaborative space.

collaborative space

A web resource that assists organizations with communication and collaboration.

Notes

• SNOMED International collaborative spaces powered by Confluence:

  • Support communication within the organization and with its Members, Affiliates, and Advisory Groups.

  • Enable maintenance and publication of the SNOMED CT Document Library containing specifications, guides and other documents related to SNOMED CT.

current snapshot view

A snapshot view for the date of the most recent release.

Notes

• A snapshot view is generated by filtering a full view so that it only includes the most recent version of each SNOMED CT component as at a specified date.

• The content the current snapshot view __ should match the content of the most recent snapshot release.

• Access to a current snapshot view is essential for data entry.

A web resource that assists organizations with communication and collaboration.

Notes

• SNOMED International collaborative spaces powered by Confluence:

  • Support communication within the organization and with its Members, Affiliates, and Advisory Groups.

  • Enable maintenance and publication of the SNOMED CT Document Library containing specifications, guides and other documents related to SNOMED CT.

children

This is an abbreviated plural for subtype child.

subtype child

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

Notes

• See also subtype and subtype descendant.

Example

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

• Child

• Children

• Subtype children

code

Disambiguation

• Meanings of the word code commonly used in connection with SNOMED CT and the services, applications and organizations that use SNOMED CT include:

  1. SNOMED CT concept identifiers and expressions used to represent clinical meanings may sometimes be informally referred to as "SNOMED codes".

  2. Codes in code systems or classifications that are used with or mapped to/from SNOMED CT.

  3. Software code written in a computer programming language (or compiled as machine executable code) that determines the operation of an application or device.

  4. Codes used to represent characters and symbols in computer storage and communication (e.g. UTF-8).

  5. Cryptographic codes used to support secure access to and/or communication of data.

context wrapper

The part of the SNOMED CT expression specifying the context of the focus concept.

Examples

• Family history of asthma can be represented by an expression in which the 195967001 | Asthma| is nested within a context wrapper indicating family history.

281666001 |Family history of disorder (situation)| : ⬅︎ Context wrapper { 246090004 |Associated finding| = 195967001 |asthma| ⬅︎ Focus concept }

• Addition information can be added in the context wrapper to specify the family member affected by asthma.

: ⬅︎ Context wrapper { = , ⬅︎ ... = ⬅︎ Focus concept }

core file

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

References

• ** **

current delta view

A delta view for the date range between the most recent release date and the immediately preceding release date.

Notes

• Delta views allow changes to the terminology content to be reviewed.

• A current delta view is generated by filtering a full view so that it only contains rows with effectiveTime greater than the immediately preceding release date.

• The content the current delta view __ should match the content of the most recent delta release.

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 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

clinical decision support

A service that assists clinicians, caregivers, or patients in healthcare and/or treatment decisions.

Notes

• A clinical decision support system is a computer system or software application designed to assist clinicians, caregivers, or patients in healthcare and/or treatment decisions.

Alternatives

• CDS

cardinality

The actual or permitted number of elements in a set or other grouping.

Notes

• Modeling rules include constraints on the minimum and maximum cardinality of particular attributes or associations between classes.

Example

• A cardinality of [1..5] means that all clinical meanings that satisfy the given expression constraint must have at least one and at most five attributes, that match the given attribute criteria.

Provide Feedback

clinical decision support system

A computer system or software application designed to assist clinicians, caregivers, or patients in healthcare and/or treatment decisions.

Notes

• Typically a clinical decision support system responds to triggers, such as specific signs or symptoms, diagnoses, laboratory test results, medication selections, or complex combinations of such triggers. The system then provides information or recommendations relevant to the specific patient.

Alternatives

• CDSS

A computer-based system that collects, stores, manipulates, and supplies clinical information to support the delivery of healthcare services to individual people and populations.

• CIS

The last digit of a SNOMED CT Identifier, which is used to validate the identifier.

• Applications can use the check-digit to identify SNOMED CT codes that have been entered or communicated incorrectly.

• The check-digit is calculated using the Verhoeff algorithm.

cardinality in group

This is a synonym for attribute in group cardinality.

attribute in group cardinality

The number of times that a specific attribute is included in the same attribute group.

Notes

• This term may sometimes be used as an informal abbreviation for attribute in group cardinality constraint which is defined as follows:

  • A constraint on the number of times that a specific attribute may be included in the same attribute group.

• Attribute in group cardinality is not the same as attribute cardinality or attribute group cardinality.

• Cardinality in group

cardinality in group constraint

This is a synonym for attribute in group cardinality constraint.

attribute in group cardinality constraint

A constraint on the number of times that a specific attribute may be included in the same attribute group.

Notes

• Constraints on attribute in group cardinality apply only to non-redundant attributes. A redundant attribute is an attribute with a value that is subsumed by another attribute in the same group.

• Cardinality constraints are represented by square brackets containing a minimum value value represented as an integer, optionally followed by two dots and a maximum value represented as an integer or as an asterisk *****.

  • If the maximum is omitted then the maximum cardinality is the same as the minimum cardinality.

  • If the maximum is an asterisk ***** the maximum cardinality is unlimited.

• Attribute in group cardinality is NOT the same as attribute group cardinality constraint.

Attribute group cardinality constraint is defined as:

__

• The following expression constraint restricts cardinality in-group and would require a clinical finding whose definition has no more than one finding site in each group. However, it permits multiple groups to exist as there are cardinality constraints on the group.

< : {[0..1] = < }

• In contrast, the following expression constraint is satisfied by any clinical finding whose definition has two or more non-redundant finding sites, irrespective of the attribute group in which they are contained.

< : [2..*] = <

• A clinical finding could satisfy both the above constraints by have two or more groups each of which contains one finding site.

CEN TC251

A technical committee of the European Committee for Standardization (CEN) with a focus on Health Information and Communications Technology (ICT).

Notes

• The full name of this committee is CEN/Technical Committee 251 - Health informatics.

• The goal of CEN TC251 is to achieve compatibility and interoperability between independent systems and to enable modularity in Electronic Health Record systems.

Related Links

CTV3

This is an abbreviation for NHS Clinical Terms Version 3.

NHS Clinical Terms Version 3

A source terminology used to develop SNOMED CT.

Notes

• SNOMED RT was also used with NHS Clinical Terms Version 3 to develop SNOMED CT .

• NHS Clinical Terms Version 3 is UK Crown Copyright, distributed by the United Kingdom National Health Service (NHS), and is integrated into SNOMED CT.

Alternatives

• CTV3

• Read Codes Version 3

cross mapping

This may sometimes be used to refer to mapping.

mapping

The process of converting data from one code system, classification, or terminology to another code system, classification, or terminology.

Notes

• The mapping process includes the preparation and maintenance of resources used for converting data.

• SNOMED CT mapping resources are distributed as mapping reference sets.

Alternatives

• Cross mapping