Considerable confusion has been generated by the SNOMED CT requirements verbiage recommended in the LRI
Vocabulary WG Consensus Statement which has resulted in multiple negatively balloted submissions for the LRI
Implementation Guide. The IG Analysis workgroup (along with the LRI Pilots and Validation Suite workgroups) has requested a review and clarification of our recommendations in order to reconcile the negative ballots. In an effort to clarify our Consensus Statement, a draft proposal is being presented for consideration.
SNOMED CT is a required vocabulary for communicating coded results when reported as Coded With Exception
(CWE) data types in OBX.5 for specific result categories as defined below.
It is also recommended for specimen source terms in SPM.4.
Further information on SNOMED can be found at the National Library of Medicine.
OBX.5
SNOMED CT is a required vocabulary for communicating Microbiology related results reported as Coded With
Exception (CWE) data types in OBX.5 (and identified as CWE in OBX.2), when a SNOMED code has been published.
It is not intended as a required vocabulary for any other specialty. For results other than Microbiology, the use of
SNOMED would need to be negotiated between trading partners. If a SNOMED code is not published for a
Microbiology coded result, it is acceptable to use an alternate coding system (and identified as CWE in OBX.2). If results are reported as text only and not coded, the string (ST) data type should be used in OBX.5 (and identified as ST in OBX.2). When SNOMED CT is used in OBX.5, CWE.9 shall contain the laboratory’s original text which is used for printing and/or display.
For Microbiology coded results, the following hierarchies are applicable. a.
Organism identification using SNOMED CT organism hierarchy b.
Organism-related substances (e.g. toxin, DNA, RNA, antigen, antibody, etc.) from the SNOMED CT substance hierarchy c.
Organism presence and absence findings using SNOMED CT qualifier values (e.g. positive, negative, present, absent)

General Format for OBX.2 = CWE (SNOMED CT required when published)
OBX|1|CWE| LOINC code^Loinc Longname^LOINC code sytemID || CWE.1=SNOMED CT
ConceptID^CWE.2=description^CWE.3=SNOMED CT code systemID ^ CWE.4=alt. code ^CWE.5=alt. description
^CWE.6=alt. code system ^ CWE.7=SNOMED CT code system version ^ CWE.8=alt. code system version
^ CWE.9=original text ||||||F|||200808151030-0700|||0086^Bacterial identification^OBSMETHOD^^^^501-
20080815||200808161030-0700||||Reliable Labs,
Inc^L^^^^CLIA&2.16.840.1.113883.19.4.6&ISO^XX^^^1236|3434 Industrial Loop^^Ann
Arbor^MI^99999^USA^B|9876543^Slide^Stan^S^^^^^NPPES&2.16.840.1.113883.19.4.6&ISO^L^^^NPI
1.
SNOMED-Specific Format for OBX.2 = CWE (SNOMED CT required when available code is published) a.
Example of organism finding with generic LOINC in Nominal scale:
OBX|1|CWE| 626-2^ Bacteria identified in Throat by Culture^LN || 413643004^Beta-hemolytic Streptococcus, group A^SCT ^ bstrep^beta hemolytic Streptococci^L ^ 20110731 ^ 1 ^ beta-hemolytic streptococcus isolated ||||||F|||200808151030-0700|||0086^Bacterial identification^OBSMETHOD^^^^501-
20080815||200808161030-0700||||Reliable Labs,
Inc^L^^^^CLIA&2.16.840.1.113883.19.4.6&ISO^XX^^^1236|3434 Industrial Loop^^Ann
Arbor^MI^99999^USA^B|9876543^Slide^Stan^S^^^^^NPPES&2.16.840.1.113883.19.4.6&ISO^L^^^NPI b.
Example of substance finding with generic LOINC in Nominal scale:
OBX|1|CWE| 6551-6 ^Streptococcus agalactiae Ag [Presence] in Throat by Immunofluorescence^LN ||
260208006^Group B Streptococcus antigen^SCT ^ bstrepAG^beta hemolytic Streptococci Antigen identified^L ^ 20110731 ^ 1 ^ beta-hemolytic streptococcus antigen detected ||||||F|||200808151030-
0700|||0086^Bacterial identification^OBSMETHOD^^^^501-20080815||200808161030-0700||||Reliable Labs,
Inc^L^^^^CLIA&2.16.840.1.113883.19.4.6&ISO^XX^^^1236|3434 Industrial Loop^^Ann
Arbor^MI^99999^USA^B|9876543^Slide^Stan^S^^^^^NPPES&2.16.840.1.113883.19.4.6&ISO^L^^^NPI c.
Example for presence finding with organism specific LOINC in O rdinal scale:
OBX|1|CWE| 546-2^Streptococcus.beta-hemolytic [Presence] in Throat by Organism specific culture^LN || 46651001^isolated^SCT ^ bstrep^beta hemolytic Streptococci^L ^ 20110731 ^ 1 ^ beta-hemolytic streptococcus isolated ||||||F|||200808151030-0700|||0086^Bacterial identification^OBSMETHOD^^^^501-
20080815||200808161030-0700||||Reliable Labs,
Inc^L^^^^CLIA&2.16.840.1.113883.19.4.6&ISO^XX^^^1236|3434 Industrial Loop^^Ann
Arbor^MI^99999^USA^B|9876543^Slide^Stan^S^^^^^NPPES&2.16.840.1.113883.19.4.6&ISO^L^^^NPI
2. General Format for OBX.2 = ST (SNOMED CT not required)
OBX|1|ST|546-2^Streptococcus.beta-hemolytic [Presence] in Throat by Organism specific culture^LN^^^^|| betahemolytic streptococcus isolated ||||||F|||200808151030-0700|||0086^Bacterial identification^OBSMETHOD^^^^501-20080815||200808161030-0700||||Reliable Labs,
Inc^L^^^^CLIA&2.16.840.1.113883.19.4.6&ISO^XX^^^1236|3434 Industrial Loop^^Ann
Arbor^MI^99999^USA^B|9876543^Slide^Stan^S^^^^^NPPES&2.16.840.1.113883.19.4.6&ISO^L^^^NPI

SPM.4
SNOMED CT is a suggested vocabulary for specimen source terms in SPM.4 when a SNOMED CT code is available for the specimen source, pending the outcome of pilot testing. Specimen type/source terms in SPM.4 should be drawn from the specimen hierarchy in SNOMED CT or may be drawn from HL7 table 0487 as it is a commonly used vocabulary, for example in use with NAACCR (until deprecated by HL7).
NOTE: Pending the outcome of successful pilot testing, the workgroup anticipates that SNOMED CT would be the required vocabulary for specimen type/source concepts in the long term.
Further information on SNOMED CT can be found at the National Library of Medicine.