From Heather DeVries, Indiana University: Greetings George!
The labs within our system have been discussing our reportable range for D-dimers. Our vendor’s stated limit is beyond what calculates from our AMR and maximum dilution. We are debating changing our reportable range to what we calculate, and stop using the vendor’s limit so that we truly are within CAP regulations. What do other systems do? Would they choose to stay with the vendor’s limit and refer to them if questioned by CAP, or would they change to what calculates out mathematically? I can give specific numbers if this doesn’t make sense! Thanks, Heather
Thank you, Heather, it definitely seems you are doing the right thing, I will be interested in learning what our other participants are doing in this case.
To define, the reportable range (clinical reportable range, CRR, clinical measurement range, CMR) is the span of test result values over which the laboratory can establish or verify the accuracy of the instrument or test system measurement response, The CRR permits for diluting a specimen whose analyte result exceeds the analytical measurement range, assaying the dilution, and reporting the result after multiplying by the dilution factor. The analytical measurement range (AMR) is the span of test result values in which the results are proportional to the true concentration of the analyte in the sample or the range over which the test can be performed without modification. The AMR is determined locally and may match manufacturer-computed linearity or, as described by Ms. DeVries, may have narrower limits.