Q: What is required for daily QC in hematology for an analyzer with two sample modes?
A: Since there are two distinct sample pathways, QC is required for each sample mode according to the parameters established in the hematology standards.
Specifically, the hematology standards require:
- Performance of at least one control every eight hours of patient testing
- Performance of at least two levels of commercial controls every 24-hours of patient testing
- The controls used in the 24-hour period test the entire range of reported results
As noted in the standards manual, patient controls may be used to supplement the commercial controls if an acceptable level of precision has been defined.
For a single or primary mode, a 24-hour laboratory with three 8-hour shifts could perform one level of commercial control for two shifts (a different level on each shift) and a patient control for the third shift and be minimally compliant with the standards. In addition, the combination of controls must span the reportable patient range. Many laboratories still choose to perform three levels of commercial controls, with at least one level run on each 8-hour shift.
In lieu of using commercial controls for QC of the secondary mode, laboratories may instead use patient controls whose values have been established in the primary mode when commercial controls were within acceptable ranges. For satisfactory compliance, patient controls should test the reportable range and have acceptable levels of precision defined in policy.