I have a question for which I haven’t found an answer in de LOINC manual sofar. In the Netherland most labs use an enzym calibrator (SKML Kalibrator 2000) to calibrate routine enzym assays in serum/plasma. This specially made calibrator is commutable over all assay platforms from different vendors making test results exchangeble. Using this calibrator our upper reference limit for LDH (lactate dehydrogenase; LOINC 2532-0) is < 250 U/l. However, the very same reagent and analyser is used by a lab in Belguim were they don't use Kalibrator 2000. This lab has calibrated the assay using the molecular extinction coeffficient of the reaction product. Anyway their upper reference limit is < 480 U/l.
If our labs exchange data based on LOINC codes, how are we to know that our assays have a different calibration? Must this be solved by sending reference limits in the HL7 message? That the solution I was thinking about.
I would like to ask for clarification of a few items in your question. When you refer to relaying the “reference limits” in the message, are you alluding to a low to high reference range of normalcy, or the linear cut off level of the assay? Secondly, what version of HL7 are you using?