We recently received an email from a laboratory system that sends us results. They currently send laboratory tests to us that are coded using "local vocabulary." They asked us if we could accept LOINC codes (http://loinc.org/) in the alternate codes.
What they are proposing is adding LOINC codes to the OBX-3 Observation Identifier field. The OBX-3 data type is Coded With Exceptions (CWE), The structure of this field is:
<Identifier (ST)> ^ <Text (ST)> ^ <Name of Coding System (ID)> ^ <Alternate Identifier (ST)> ^ <Alternate Text (ST)> ^ <Name of Alternate Coding System (ID)> ^ <Coding System Version ID (ST)> ^ <Alternate Coding System Version ID (ST)> ^ <Original Text (ST)>
So, they are proposing to send their local code in the first "triplet" of the CWE and the LOINC code in the second "triplet". This would change:
OBX|1|CWE|xxxxx^Local Test Value||result goes here.....
OBX|1|CWE|xxxxx^LocalTestValue^L^yyyyyy-y^Loinc Test Name^LN||result goes here.....
The first three subfields of obx-3 (aka the first triplet) are the local code (xxxxx), description (LocalTestValue), and the "L" indicates a local code. The second set of subfields (aka the second triplet) are the alternate identifiers and are the LOINC code for the test (yyyyyy-y), the description of the test from LOINC, and "LN" which specifies that the alternate code comes from LOINC.
This lab has been sending local codes for its tests for many years. The meaningful use requirements of ARRA/HITECH are nudging them to use LOINC.
Who says that we are not making progress :-)