TREC units = copies/uL

[shamm]

Newborn screening programs in the USA are reporting a component using "copies/uL". From one of the program directors: "All newborn screening programs I am aware of express this marker as copies/uL. In the publication Newborn screening for severe combined immunodeficiency in 11 screening programs in the United States (JAMA. 2014 Aug 20;312(7):729-38. doi: 10.1001/jama.2014.9132.), results are expressed and compared as copies/uL."

However, as a CAP accredited laboratory, we are expected to comply with general checklist question GEN.41440 which states "information directly related to the interpretation must be copied as reported by the reference laboratory".

Further compounding this issue is the 2014 Edition EHR Technology (MU2) requirement for exclusive use of UCUM resulting units.

"copies" is not sufficient as it carries no concentration property. "copies/mL" is not acceptable as it requires us to manipulate data from our reference lab which goes against our accrediting agency. "/uL" by itself does not convey what is being counted per microliter, and also is not a copy of what was reported by our reference laboratory.

We cannot be the only clinical laboratory with this issue.

[Gunther Schadow]

These copies and log copies are a problem. We need expertise or a good metrologically oriented discussion paper on this.

#90, #143, #165, #173

[Brenée Mitchell]

Note from Clem: "This is vary common kind of units which represent coutns per voumne ( an NCNC propert). I UCUM we would suggest {copies}/uL or {#}/ul If it is important to report the native units string In FHIR one can eport both and I elieve that in V2 there is also way to do that. THEre are some new data types that not exper on. but think there is another component vof codd value. "