SNOMED International Website

Get Terms for a Concept

Overview

Each concept is associated with descriptions. Each description is an association between a human-readable phrase (term) and a particular SNOMED CT concept.

There are different types of descriptions and there may be descriptions of each of the following types in several languages:

  • A synonym is a word or phrase that expresses the meaning of a SNOMED CT concept in a specified language.

    • Synonyms are terms that represent the meaning of the concept in a way that is familiar and readily understandable. However, when taken out of context a synonym may not be unambiguous and in some cases the same term may be associated with more than one concept.

    • Each concept has at least one synonym and a concepts may have several synonyms. One of the synonym descriptions in each language is marked as the preferred term for the associated concept and others may be marked as acceptable for use. The preferred term is the term deemed to be the most clinically appropriate way of expressing a concept in specified language context.

  • A fully specified name is a description that represents the meaning of a concept in a way that is unambiguous and independent of the context in which it is used.

    • Fully specified names are essential for disambiguation of the meaning of a concept. These term used in the fully specified name includes a hierarchy tag that specifies the branch of the SNOMED CT hierarchy the concept is in. The hierarchy tag is enclosed in brackets at the end of the term.

    • There is only one fully specified name in each language. In some languages there may not be a fully specified name, in which case the English fully specified name may be used where necessary for disambiguation.

  • A text definition is a narrative text explanation of the meaning of a concept that may exceed the maximum permitted length for a fully specified name.

    • Text definitions are only included for some concepts where longer terms are deemed to be necessary or useful to add clarity to the meaning of the concept.

Requirements and Options

Terminology services must enable access to the term in each active description associated with an identified concept. They should also be able to selectively filter the descriptions for which terms are returned based on the following criteria:

  • Active status (description.active)

    • Inactive descriptions associated with a concept should not be returned unless explicitly requested.

  • Description type (description.typeId)

    • Fully specified name

    • Synonyms (including the preferred term)

    • Textual definitions (and other types where these are used)

  • Acceptability in a specified Language Reference Set

    • Preferred: To access the fully specified name or preferred term

    • Acceptable: To access synonyms

The required services are listed in the table below.

The services described in Get a Concept, Description or Relationship require access to data about individual components based on their unique identifiers. Therefore, a service that gets a description is only required to return the data in the identified description. However, some implementations of those services may also meet some of the requirements for getting terms associated with a concept.

  • Services that get concepts may also return some or all of the terms associated with the selected concept.

    • For example, the Snowstorm service that retrieves an identified concept also returns the fully specified name and preferred term for that concept in one language.

    • Similarly, the FHIR service returns a single display term and may optionally also return other associated terms as designations.

  • Services that get relationships may also return terms associated with the concepts identified by those relationships.

Services Required

Service Name and Status
Input
Output

  • Get the fully specified name of a concept in US English (or in a specified language reference set).

REQUIRED

  • Edition and version

  • Concept identifier

  • Language refset set identifier (optional)

  • Description not found: Return appropriate error message

  • Description found: Return data associated with the description:

  • Get the preferred term of a concept in US English (or in a specified language reference set).

REQUIRED

  • Edition and version

  • Concept identifier

  • Language refset set identifier (optional)

  • Description not found: Return appropriate error message

  • Description found: Return data associated with the description:

Get all terms for a concept

  • Get the terms from all descriptions associated with a concept

REQUIRED

  • Edition and version

  • Concept identifier

  • Include inactive descriptions (optional)

  • Descriptions not found: Return appropriate error message

  • Descriptions found: Return data associated with each of the descriptions found

    • This data must include the id, term, active status, description type, language code and case sensitivity

    • It should also include the acceptability of the term in one or more language reference sets

  • Get terms from descriptions associated with a particular concept filtered by one or more of the following

    • Status of the description (active: 1=true, 0=false)

    • Term (term: matching a phrase or pattern)

    • Description type (typeId: fully specified name, synonym, textual definition)

    • Language (languageCode)

    • Acceptability in a specified language reference set (refset.acceptabilityId: preferred, acceptable)

CONDITIONAL

  • Edition and version

  • Concept identifier

  • Filters

    • Active

    • TypeId

    • Language code

    • Language refset identifier

    • Language refset acceptability

  • Descriptions not found: Return appropriate error message

  • Descriptions found: Return data associated with the descriptions found

    • This data must include the id, term and case sensitivity

    • It must also include the term, active status, description type, language code

Interdependencies

Required By

Depends On

This service requires access to description acceptability data in a language reference set. This could be regarded as a dependency on Get Data from a Reference Set. However, access to language reference set data is an essential part of the process of displaying appropriate terms for a concept. Therefore access to the language reference set is included as an integral part of this service and is not declared as a distinct dependency.

Service Examples

The Snowstorm and FHIR examples are presented in plain text and URL encoded versions. Always use the "Encoded URL" when testing the example service requests. The plain text version is included to aid readability but using this version in a service request may result in errors. These errors result from characters that have to be encoded as they are not permitted in a URL (see IETF RFC1738).

Snowstorm API

Service Name
API Call
Result

Get fully specified name of a concept Get preferred term of a concept

GET [snowstorm]/[branchPath]/concepts/[conceptId]

for example

GET [snowstorm]/MAIN/2020-01-31/concepts/6025007

Encoded URL

GET [snowstorm]/MAIN%2F2020-01-31/concepts/6025007

Returns a JSON representation of data about the selected concept. This include both the fully specified name and the preferred term.

This is the same Snowstorm API call used in Get a Concept, Description or Relationshipto get the concept by identifier. If the fully specified name and/or preferred term there is no need for a specific service to get these terms.

Get all terms for a concept

GET [snowstorm]/[branchPath]/concepts/[conceptId]/descriptions

for example

GET [snowstorm]/MAIN/2020-01-31/concepts/6025007/descriptions

Encoded URL

GET [snowstorm]/MAIN%2F2020-01-31/concepts/6025007/descriptions

Returns a JSON representation of data about all descriptions in the selected edition and version that are associated with the concept specified.

The descriptions returned include:

  • Active and inactive descriptions

  • All types of descriptions

  • Descriptions in all languages that are present in the selected edition

The data return for each description includes all data present in the description release file and acceptability data derived from language reference sets. The following items have specific roles in filtering descriptions and presenting the terms they contain:

  • The active value (true or false) can be used to exclude inactive descriptions.

  • The typeId value can be used to filter descriptions of specific types.

    • The additional a text token type provides a human readable representation.

  • The lang value contains the language code and this can be used to filter descriptions.

  • The acceptabilityMap contains text tokens for the acceptability of the description in one or more language reference sets.

  • The caseSignificance value contains a text token indicate whether all or part of a term is case-sensitive. This can be used to enable the case of a term to be adjusted to fit the context of use except in when this would be incorrect or liable to alter the meaning.

Get filtered terms for a concept

Use the API call above to get all terms for a concept and then filter using the returned data.

Same as above

Snowstorm supports selection of the language(s) in which terms will be returned. This is specified using HTTP request header Accept-Language. The values used with this include the identifiers of the language reference sets to be applied.

For example

{ "Accept": "application/json", "Accept-Language": "en-X-900000000000509007,en-X-900000000000508004,en" }

FHIR API

Service Name
API Call
Result

Get all descriptions for a concept

GET [fhir]/CodeSystem/$lookup?system=http://snomed.info/sct&code=[conceptId]

for example

GET [fhir]/CodeSystem/$lookup?system=http://snomed.info/sct&code=6025007

Returns a JSON representation of data about the selected concept. This include both the fully specified name and all synonyms of the concept.

This is the same FHIR API call used in Get a Concept, Description or Relationship to get concept by identifier. If the fully specified name and/or preferred term there is no need for a specific service to get these terms.

MySQL Example Database

Service Name
API Call
Result

Get fully specified name of a concept

SELECT term,caseSignificanceId FROM snap_fsn WHERE conceptId=[conceptId]

for example

SELECT term,caseSignificanceId FROM snap_fsn WHERE conceptId=6025007

Returns the fully specified name of a specified concept and its caseSignificanceId.

Get preferred term of a concept

SELECT term,caseSignificanceId FROM snap_pref WHERE conceptId=[conceptId]

for example

SELECT term,caseSignificanceId FROM snap_pref WHERE conceptId=6025007

Returns the preferred term of a specified concept and its caseSignificanceId

Get all synonyms of a concept

SELECT term,caseSignificanceId FROM snap_synall WHERE conceptId=[conceptId]

for example

SELECT term,caseSignificanceId FROM snap_synall WHERE conceptId=6025007

Get all terms for a concept

SELECT * FROM snap_description WHERE conceptId=[conceptId]

for example

SELECT * FROM snap_description WHERE conceptId=6025007

Returns all descriptions of all concepts together with all the data for each of those descriptions in the concept file.

CALL setLanguage([configId],[languageCode]);

for example

CALL setLanguage(0,'en-GB');

After this setting is made all references to views including the prefix snap_ and the suffixes _fsn, _pref, _syn, _synall will use the language reference set for GB English (rather than the default language US English).

Other languages supported by the the installed Edition can also be specified in a similar way.

The SNOMED CT MySQL example database is not designed as a terminology server and is not intended for use in a live system . It is referenced in this guide as an illustration that some readers may find helpful. For more information about the SNOMED CT example database see the SNOMED CT - SQL Practical Guide.

PreviousGet a Concept, Description or RelationshipNextGet Definition of a Concept

Last updated