SNOMED International

Regenstrief and the SNOMED International are working together to link LOINC and SNOMED CT

Regenstrief Institute and SNOMED International (formerly IHTSDO) have formed a long-term collaborative relationship with the objective of developing coded content to support order entry and result reporting. The two organizations are building closer links between the SNOMED CT and LOINC terminologies, reducing duplication of effort, and making electronic health records more effective at improving health care. By aligning how the two terminologies represent the attributes of laboratory tests and some types of clinical measurements, this collaboration will provide users a common framework within which to use LOINC and SNOMED CT.

In July 2013, Regenstrief and SNOMED International (then known as The International Health Terminology Standards Development Organisation, IHTSDO) signed an agreement to begin the cooperative work.

Read Full Agreement
Read press release announcing the collaboration.

Now, with the agreement in place, the cooperative work is just beginning. In brief, it involves these broad activities:

  1. LOINC Parts that are used in the Cooperative Areas and SNOMED CT Concepts that are used in the “Observables Model” will be mapped to one another to the extent necessary to enable convergence towards a common semantic foundation.
  2. Existing SNOMED CT Concepts that are subtypes of Observable Entity or Evaluation Procedure (and fall with the scope of Cooperative Areas) will be mapped to LOINC Terms.
  3. LOINC Terms that are not already represented by SNOMED CT Concepts will be associated with post-coordinated expressions.
  4. Where appropriate, LOINC Terms that represent observables with ordinal or nominal answer values will be mapped to SNOMED CT Concept names and codes in the LOINC Answer record.

To prioritize the effort, Regenstrief and SNOMED International have agreed to focus the work on these domain areas (which may later be expanded into other areas of mutual interest):

  1. Laboratory, including discrete orders and observations and panel names for orders (excluding panel structure)
  2. Anthropomorphic measurements and evaluations
  3. Vital signs and physiological measurements

The details of how this work will proceed, including a schedule for producing and distributing the end products, are now being worked out by the organizations.

LOINC/SNOMED CT Collaboration Files

This Technology Preview (and future Production versions) is only available in the official SNOMED International RF2 release format. The additional file formats (OWL and Excel) that were published for the Alpha releases will not be provided. Read more information.

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LOINC/SNOMED CT Expression Association and Map Sets File - Production release (RF2 Format)

The LOINC/SNOMED CT Expression Association and Map Sets File was generated as part of the cooperative agreement signed between the Regenstrief Institute and the IHTSDO in July 2013. The agreement details how SNOMED and LOINC will be linked through: 1) a map of LOINC terms to post-coordinated SNOMED CT expressions; 2) a map of LOINC parts to SNOMED concepts; 3) a map between LOINC terms and existing pre-coordinated SNOMED concepts; 4) LOINC Answer sets mapped to SNOMED codes; and 5) addition of new content in either terminology. This Production release includes artifacts related to items 1, 2, and 5 above.

This file contains a LOINC Term to SNOMED CT Expression Reference Set and a LOINC Part to SNOMED CT Reference Set. It is based on the 20170731 version of the SNOMED CT International release and Version 2.58 of LOINC released December 2016. Please read the Release Notes contained in the zip archive for more information.