We perform a molecular test to detect the presence of microorganims in a clinical sample i.e. the presence of salmonella (61370-3 Salmonella enterica DNA [Presence] in Unspecified specimen by Probe & target amplification method). The ordinal result is reported as detected/not detected. However we also perform this test on request of an other microbiology-laboratory. Additional to the ordinal result they require the CT (cycle treshold) value for authorization purposes. The HL7 message has a field for interpretation of test results, however this is clearly not an interpretation of the test result. Should I request a new loinc code for reprting CT values? or should this be defined in an HL7 field?
I agree that the cycle or cross threshold (CT) value for real-time PCR is not an interpretation. I suggest requesting a quantitative code similar to the following since the result is numerical:
Salmonella enterica DNA Threshold Pt XXX Qn Probe.amp.tar