Monday, April 23, 2012

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.


Keith W. Boone said...

See my notes from the clinical quality workgroup.

Russell Hamm said...

It is exciting to see the hard work of the HL7 and OMG communities being discussed.

More information on CTS 2 and links to available CTS 2 artifacts and implementations can be found here.


Russell Hamm
Apelon, Inc.
HL7 Vocabulary WG Co-chair

David Clunie said...

I am a bit confused about who is actually responsible for CTS and CTS2, Mayo, OMG or HL7 ?

One of the reasons I ask is that it would be highly desirable to be able to obtain the standard, and more importantly use it, without having to pay the HL7 organization a membership or license fee on an ongoing basis for the "privilege".

I would not want to see CTS(2) be yet another open standard that got "assimilated" under the HL7 label and then ceased to be open any more.


Russell Hamm said...

HI David,

CTS2 was developed jointly between HL7 and the OMG with HL7 owning the Service Functional Model (SFM) and the OMG owning the Platform Independent Model (PIM). Mayo Clinic lead the effort in the OMG community, and has mode the PIM (essentially the technical specification) open source.

- russ

Russell Hamm
Lantana Consulting Group
HL7 Vocabulary WG Co-chair