Common Terminology Services

The HIT Standards Committee has tirelessly focused on content, vocabulary and transport standards.   When it comes to vocabularies, they've tried to do three things

1.  Select one vocabulary per domain of medicine (problems, medications, laboratories, demographic elements, structured data questionnaires etc.), which they've achieved n the 2014 edition of the standards and certification NPRM recommendations.

2.  Recommend that  the National Library of Medicine is the optimal organization for doing content review of value sets, offering feedback to value set and measure developers.

3.  Recommend that a government "value set hosting entity"  distribute all the necessary vocabularies and code sets, making them available for download or real time query.

For #3, we'll need a body of standards to enable the sharing of value sets.   From our investigation thus far, the Common Terminology Services (CTS) family of standards seems like the leading candidate to enable automated exchange of vocabulary resources.

What is CTS?

It is the work of some 20 years, merging early terminology services work (Pathak, et al; LexGRID, JAMIA) and the 3M/Intermountain work into the LexGrid environment .  It has evolved through three standards organizations  CTS1 (in HL7 and ISO)  and CTS2  (in  the Object Management Group).  It is now an industry standard through OMG.

What does it do?

The core principle is that we should not have different ways (Custom programming, REST protocols, SPARQL queries  , etc) of accessing terminologies.  CTS2 is a unifying access method for terminologies, and ontologies that is an Application Programming Interface (API) specification, and easily deployed through REST or SPARQL queries.  It supports things as simple as word/code pairs, and full ontologies such as OWL.  It forms the backbone of  the National Center for Biomedical Ontologies (NCBO) and earlier versions of at the National Cancer Institute LexEVS services.  General Electric has adopted it, as the core terminology services in their work with Intermountain Healthcare (Huff et al).  The specification is public and an open-source reference implementation will soon be available.  Any company or group is free to establish as CTS2 service.

NLM is working on CTS2 support for its terminology services.

Although you may not have heard of CTS, it will be an important mechanism for EHRs to download and query the curated vocabularies and code sets required for Meaningful Use in 2014 and beyond.

Thanks to Chris Chute and the folks at Mayo for briefing me about it.