In 2019, SNOMED International and HL7 International announced the formalization of a license agreement in which a relevant “Free for Use” Set of SNOMED CT coded concepts will be used within the HL7 implementation of the International Patient Summary (IPS). The collaboration is consistent with the aims of both organizations to support international harmonization.
The SNOMED CT International Patient Summary (IPS) Free Set is international in scope and, in addition to harmonization with the HL7 IPS implementation guides, is aligned with CEN’s Technical Specification for the implementation of the IPS in Europe. The IPS Free Set consists of more than 8,000 SNOMED CT terms for use in implementations of the IPS in conformance with both the HL7 CDA R2 and FHIR IPS Implementation Guides worldwide. The SNOMED CT IPS free set contains concepts that can record the following data:
- General information about the patient (e.g. gender)
- Medical summary of most important clinical data (e.g. allergies, current medical problems, major surgical procedures)
- A list of current medications
The SNOMED CT IPS Free Set is available for non-affiliates of SNOMED International, either directly from HL7, or as part of the Global Patient Set, a package that collects different free sets released by SNOMED International. These releases consist of a list of concept identifiers, fully specified names, preferred terms (in international English) and active/inactive status flags. The SNOMED CT IPS Free Set is designed to support data sharing. However, it lacks the additional capabilities of the SNOMED CT terminology, which is available via a full SNOMED CT release. The HL7 IPS Free Set is also available for Members and Affiliates as a reference set, distributed in a RF2 release package via a National Release Center or the international MLDS service. This reference set is maintained and updated annually, in line with the July SNOMED CT International Release. For more information, please contact firstname.lastname@example.org.
SNOMED International’s IPS Terminology represents an evolution of the HL7 IPS Free Set, providing advanced terminology features for non-affiliates to use in their IPS solutions. In particular, it adds a hierarchy, defining relationships and extra synonyms from the SNOMED CT international edition, to form a sub-ontology of SNOMED CT. A sub-ontology is a functional set of concepts and relationships extracted from the full SNOMED CT ontology that provides the following features:
- It can be loaded in a SNOMED CT compatible terminology server
- It includes all the active concepts from the HL7 IPS Free Set
- The concepts are organized into the same hierarchies as the SNOMED CT International Edition (e.g. Clinical Findings, Procedures)
- The content is expanded to include a minimal set of additional grouper concepts
- The content also includes (inferred) relationships that define the meaning of the included concepts
- The US-English and GB-English language reference sets are included just like in the complete International Edition
- ECL (Expression Constraint Language) queries can be executed over the IPS Terminology to support value set definitions and simple data analytics
Please note that the IPS Terminology contains only a subset of the full international release of SNOMED CT, and therefore the features above are limited to this restricted content.
The IPS Terminology is made available as an RF2 package, with a similar format to other SNOMED CT releases. However the package is not fully RF2 compatible, the content is available only in “snapshot” format (i.e. the current state of each component) and it includes only components that are active at the time the terminology is extracted. The relationship ids are published using temporary ids. Each IPS Terminology release replaces the previous one, providing a new snapshot of active content.
The Beta release of the IPS Terminology was published on April 30th, 2022. The first official production release is planned for the fourth quarter of 2022. The IPS Terminology package will not include historical information (which is normally available to licensed Affiliates in full SNOMED CT releases).
The IPS Terminology package can be loaded into SNOMED International’s Snowstorm, a freely available, open-source, terminology server maintained by SNOMED International. SNOMED International also provides a browser for the IPS Terminology.