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Unified Medical Language System® (UMLS®)

SNOMEDCT_US (US Edition of SNOMED CT) Source Information

Click on a topic below the Source Synopsis section to display details.

Source Synopsis

Web site:
https://www.nlm.nih.gov/healthit/snomedct/us_edition.html

Authority
The U.S. National Library of Medicine (NLM) produces the US Edition of SNOMED CT.

The Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT®) was originally created by the College of American Pathologists by combining SNOMED RT and Clinical Terms Version 3. SNOMED CT intellectual property rights were transferred to the SNOMED Standards Development Organisation (SDO) in the formal creation of the IHTSDO (International Health Terminology SDO). IHTSDO is now SNOMED International.

Purpose
SNOMED CT aims to improve patient care through the development of systems to record health care encounters accurately.

The US Edition of SNOMED CT facilitates the use of SNOMED CT as a primary coding terminology for clinical information in electronic health records, research and clinical trials. It is used with RxNorm and LOINC to cover medications and laboratory tests needs in the US.

Description
The US Edition of SNOMED CT combines the International Release of SNOMED CT and the US Extension of SNOMED CT

SNOMED CT provides the core general terminology for the electronic health record (EHR). The concepts have unique meanings and formal logic-based definitions organized into hierarchies. Each International Release includes the core of the terminology (concepts, descriptions, and relationships), together with works to support the implementation and use of SNOMED CT, including subsets, cross maps to existing classifications and coding schemes, and an extensive set of guidelines.

The US Extension to SNOMED CT includes the concepts, descriptions, and relationships accepted by NLM as a formal extension to the SNOMED CT International Release. NLM no longer releases the standalone US Extension.

The US Edition of SNOMED CT includes more than 300,000 unique concepts. There are over 1,000,000 descriptions in SNOMED CT, including synonyms that can be used to refer to a concept. In addition, there are approximately 903,000 links or semantic relationships between the SNOMED CT concepts.

UMLS licensees may download the US Edition release and International Release files.

As of 2013AB, the Metathesaurus includes the US Edition and no longer includes the separate International Release and US Extension.

RxNorm Scope
RxNorm includes filtered content from the following SNOMEDCT_US hierarchical categories:

  • Pharmaceutical / biologic product (ConceptID 373873005)
  • Biological substance (ConceptID 115668003)
  • Drug or medicament (ConceptID 410942007)

Both Biological substance and Drug or medicament categories are children of Substance (ConceptID 105590001). RxNorm also includes the SNOMEDCT_US relationships that exist between concepts meeting the above criteria.

Audience
SNOMED CT is used by standards setting organizations and in a variety of health care applications. It is also utilized by developers of electronic health data exchange applications.

Update Frequency
The US Edition is updated in March and September.

RxNorm Update Frequency
The US Edition is typically updated in the March and September RxNorm monthly releases.

Sites Consulted

  1. SNOMED International [Internet]. England and Wales: SNOMED International; [cited 2018 Dec 7]. Available from: https://www.snomed.org/; About SNOMED CT: https://www.snomed.org/snomed-ct/five-step-briefing; Why SNOMED CT?: https://www.snomed.org/snomed-ct/why-snomed-ct; Get SNOMED CT: https://www.snomed.org/snomed-ct/get-snomed.
  2. US Edition of SNOMED CT® [Internet]. Bethesda (MD): National Library of Medicine (US); 2013 May 16 [reviewed 2014 Mar 03; updated 2014 Mar 03; cited 2014 Apr 16]. Available from: //www.nlm.nih.gov/research/umls/Snomed/us_edition.html
  3. US Extension to SNOMED CT® [Internet]. Bethesda (MD): National Library of Medicine (US); 2011 Mar 22 [reviewed 2012 May 15; updated 2012 May 15; cited 2012 June 12]. Available from: //www.nlm.nih.gov/research/umls/Snomed/us_extension.html
  4. SNOMED CT FAQs [Internet]. Bethesda (MD): National Library of Medicine (US); 2016 July 11 [reviewed 2018 May 23; updated 2018 May 23; cited 2018 Dec 7]. Available from: https://www.nlm.nih.gov/healthit/snomedct/faq.html.

Metadata

Field Value
Short NameUS Edition of SNOMED CT
FamilySNOMEDCT
Source Restriction Level9
LanguageENG
License ContactNLM Customer service
NLM is a Charter Member of SNOMED International on behalf of the U.S.
National Library of Medicine
8600 Rockville Pike
Bethesda
MD
United States
20894
1-888-FIND-NLM (1-888-346-3656)
https://support.nlm.nih.gov/support/create-case/
Content ContactNLM Customer Service
NLM is a Charter Member of SNOMED International on behalf of the U.S.
National Library of Medicine
8600 Rockville Pike
Bethesda
MD
United States
20894
1-888-FIND-NLM (1-888-346-3656)
https://support.nlm.nih.gov/support/create-case/

Source Representation (currently unavailable)

RxNorm Representation (currently unavailable)

Data Examples with Sample Database Queries

This section lists source terminology specific data examples and sample database queries using Structured Query Language (SQL) to obtain the data. For more information about RxNorm data and files, see the RxNorm Technical Documentation.

Names and Codes in RXNCONSO.RRF

Here are sample source terminology code, source string, RxNorm Concept Unique Identifier (RXCUI), RxNorm string, RxNorm term type (TTY), and suppress values.

SOURCE_CODE SOURCE_STR RXCUI RXNORM_STR RXNORM_TTY SUPPRESS
329652003 Ibuprofen 200 mg oral tablet 310965 Ibuprofen 200 MG Oral Tablet SCD N
329652003 Product containing precisely ibuprofen 200 milligram/1 each conventional release oral tablet (clinical drug) 310965 Ibuprofen 200 MG Oral Tablet SCD N
329652003 Product containing precisely ibuprofen 200 milligram/1 each conventional release oral tablet 310965 Ibuprofen 200 MG Oral Tablet SCD N

Here is a sample database query to retrieve the data above:

SELECT distinct rc1.code as source_code, rc1.str as source_str, rc1.rxcui, rc2.str as rxnorm_str, rc2.tty as rxnorm_tty , rc2.suppress
FROM rxnconso rc1, rxnconso rc2
WHERE rc1.code = '329652003'
     AND rc1.sab = 'SNOMEDCT_US'
     AND rc1.rxcui = rc2.rxcui
     AND rc2.sab = 'RXNORM'
     AND rc2.tty in ('SCD','SBD','GPCK','BPCK');

Names and Relationships in RXNCONSO.RRF and RXNREL.RRF

Here are sample source terminology code, source string, RXCUI, relationship name, RxNorm term type (TTY), brand name, and suppress values.

SOURCE_CODE SOURCE_STR RXCUI RELA RXNORM_TTY BN SUPPRESS
387207008 p-Isobutylhydratropic acid 5640 has_tradename BN Genpril N
387207008 p-Isobutylhydratropic acid 5640 has_tradename BN Vicoprofen N
387207008 Ibuprofen (substance) 5640 has_tradename BN Advil N
387207008 Ibuprofen (substance) 5640 has_tradename BN MIdol Cramps & Bodyaches N

Here is a sample database query to retrieve the data above:

SELECT distinct rc1.code as source_code, rc1.str as source_str, rc1.rxcui, rr.rela, rc2.tty as rxnorm_tty, rc2.str as bn, rc2.suppress
FROM rxnconso rc1, rxnrel rr, rxnconso rc2
WHERE rc1.code = '387207008'
     AND rc1.sab = 'SNOMEDCT_US'
     AND rc1.rxcui = rr.rxcui2
     AND rr.rela = 'has_tradename'
     AND rr.rxcui1 = rc2.rxcui
     AND rc2.sab = 'RXNORM'
     AND rc2.tty = 'BN'
     ORDER BY suppress;

Last Reviewed: March 31, 2020