D-Dimer Calculated Values

[ccarter]

HEM.37923 D-Dimer Calculated Values

If calculations (including conversion of units) are used to obtain d-dimer results, the lab documents checks or at least annually to ensure that the calculations are correct.

Note: The d-dimer may be a calculated value. In some institutions, the D-dimer result may be calculated by the coagulation analyzer, while in others it may be calculated by the LIS. The accuracy of calculations should be verified at least annually.

We use mini-Vidas for d-dimer. Are there other Vidas user that have a response to this question?.

[Bill]

By virtue that your controls "work" for the D-dimer test is a check of the calculation as well as the reagent and instrument.

[SMILLER]

If the lab uses a "converted" value (such as taking the analyzer's ng/ml result and multiplying by 2 to report it in FEUs), and this calculation is done manually, I am not sure that checking the analyzer results for QC would satisfy any documentation requirements that patient results are also calculated properly. If both are automatically converted by the LIS, or by the analyzer (like INRs), then I suppose you would be covered by just documenting that the analyzer's calculation setup is correct once a year.

The answer would be to drop reporting in FEUs altogether, if this is the case here, and just report as ng/ml like most labs do. On the other hand, if you are getting FEUs from the analyzer, I guess you are stuck with all of this calculation validation stuff.