Facilitating health information exchange for providers, enabling exchange within workflows is the goal of a collaborative agreement between LOINC and SNOMED CT.


The collaboration between LOINC and SNOMED CT could be a big step towards semantic interoperability.

The developers of the SNOMED CT and LOINC terminology standards used in electronic health records are collaborating on a project designed to facilitate a unified approach to implementing the two standards, with the goal of facilitating a broader exchange of health information.

“The goal of the agreement is to deliver a solution that would allow users using both standards to implement and interact in a simple and efficient manner,” said Don Sweete, CEO of SNOMED International.

LOINC is a global standard for identifying health metrics, observations, and HL&ts; it enables the exchange and collection of data between health systems. The coding system identifies laboratory tests and other diagnostic procedures that clinicians order.

SNOMED CT is comprehensive multilingual health terminology; coding captures the care of individuals in an EHR and facilitates information sharing, decision support, and analysis. The codified language for groups of clinical terms can be used, for example, to identify test results.

An important step

The agreement is an important step in the effort to make these standards interoperable so that comprehensive records can be exchanged, says Charles Christian, vice president of technology at Franciscan Health in Indianapolis and former Indiana Health Information executive. Exchange.

“Too many standards may be less useful than no standards at all,” he points out. “As an industry, we have found that interoperability in the clinical setting is, at best, difficult. Therefore, the more we can standardize and harmonize our tools, the more chance we have of getting to a place where we can exchange data in a meaningful way, without the need for additional interpretation.

Christian says the announcement of LOINC and SNOMED “is a big step in this process, and I’m looking forward to what’s next.”

Develop an “extension”

As part of their new collaboration agreement, SNOMED International and Regenstrief Institute, the developer of LOINC, will work to develop a LOINC “extension” that aligns with the SNOMED CT model.

The developers claim that the extension will create SNOMED CT and LOINC codes for all concepts shared between terminologies, making it easier for implementers to have a unified approach to implementing both standards and meeting clinical requirements. and regulatory.

“An easy way to think about how LOINC and SNOMED work together now is that LOINC provides codes that ask a question, and if needed, SNOMED provides codes for the answer,” according to a joint statement from Marjorie Rallins, Executive Director of LOINC, and Stan Huff, MD, chair of the LOINC Clinical Committee.

“A common interaction between LOINC and SNOMED CT occurs in microbiology. For example, when a culture (the question) is ordered, this ordering will be encoded as LOINC. The result (response) would be encoded in SNOMED CT,” the statement explains.

A SNOMED extension, they note, “is a place where domain-specific codes (such as codes for lab results, microbiology results, or radiology results) can be developed by a community and then codes can be shared with other interested users as appropriate.”

Having LOINC and SNOMED together in one extension “provides a structure that connects each terminology to broader and enhanced content in the other, allowing for more robust analysis of patient data,” say the two LOINC experts.

LOINC and SNOMED developers are working on a proof of concept for the extension. “We expect the first iteration to be available to the community in 2023,” says SNOMED’s Sweete.

One of the goals of the effort is “to provide a solution that would allow those using both standards to implement and interoperate in a simple and efficient way,” Sweete adds.

Health Information Exchange

Another goal of the collaborative project, according to the two leaders of LOINC, is to promote the exchange of health information nationally and internationally. The development of the LOINC extension for SNOMED CT is useful, they say, “because it allows interoperability of records/results across entities and jurisdictions that may have different requirements for many standards.”

The new extension will also help support efforts to increase health information exchange that builds on the HL7 FHIR (Fast Healthcare Interoperability Resources) standard, according to the two LOINC experts.

“LOINC and SNOMED codes are already used in the HL7 V2.X standards and in HL7 FHIR,” they point out. “This collaboration will allow LOINC codes (for questions and comments) to be closely coupled with SNOMED codes (for responses and response lists) in the creation of HL7 implementation guides and FHIR profiles. Creating these links makes it possible to precisely define how clinical information should be represented, bringing the process closer to semantic interoperability.

Semantic interoperability facilitates the ability of systems to exchange data with unambiguous shared meaning.

“Users would be able to use either LOINC or SNOMED identifiers in their health records, and the meanings would be semantically equivalent,” says SNOMED’s Sweete.

“The benefit of this agreement is that organizations that don’t use LOINC can take advantage of the LOINC extension, which includes SNOMED CT identifiers, so that SNOMED can be used to represent both the ‘question’ and the ” answer “. Organizations that use LOINC could use LOINC IDs to represent the question and SNOMED CT IDs to represent the answer.