Object Identifiers (OIDs) for LOINC

Legacy general-discussion
1

Hi,

In the HL7 OID registry (http://www.hl7.org/oid/index.cfm), there is an OID defined for LOINC: 2.16.840.1.113883.6.1 (although curiously there appears to be another candidate there too: 2.16.840.1.113883.11.16492).



My question is, how are different versions of LOINC code sets represented? If there is a single OID to identify LOINC, something else in an HL7 message must convey the version. Alternately, perhaps there are several OIDs, one for each version of the LOINC?



Thanks

Andrew

2

Hi Andrew,

The HL7 OID ending with …6.1 is appropriate when using LOINC codes in HL7 messages and documents. I don’t know about the other OID, and had not seen it before your post.



As far as I know, there is no versioning of LOINC codes. RELMA is versioned, and the LOINC database as a full distribution is versioned; however, the individual LOINC codes are not versioned. Once a code is assigned to a concept, the code always represents that concept (although the code may be deprecated in favor of some other LOINC code when duplicate concepts are found).



-mike

3

Hi Mike

So just to be absolultely clear, I think you’re saying that there is a single OID for LOINC regardless of the LOINC release version (e.g 2.24, 2.21). How would a receiving system know to which LOINC version the LOINC codes conveyed in the message belong?



Thanks

Andrew Cripps.

4