Additional studies may be required by the manufacturer, accreditation agencies, and state or local agencies. Some of these studies are:
- Verification of accuracy of automated differentials -- Comparison of automated counts to manual differentials. A comparison of the results yields any issues or shortcomings. This may be conducted during a comparison of a current method for testing and the new method.
- Instrument Flags (Sensitivity and Specificity) -- Instruments have built-in algorithms that trigger flags to refer the testing personnel to the need for further intervention. The triggers are frequently for cell morphology, clumping, and other atypical findings. Each laboratory should verify that these flags are working as expected without increased sensitivity, leading to unnecessary follow-up studies.
- Adequate mixing -- mixing studies may need to be performed to verify that adequate mixing of samples is completed before analysis. Mixing studies are most beneficial for verification or analyzers with auto-mixing functions. They are comparing the analysis of thoroughly mixed samples and analysis of the same samples after being allowed to sit without mixing for a specified period.
- Interference -- Commonly known interfering substances that have the potential to produce erroneous or spurious test results. Common offenders include cold agglutinins, lipemia, hemolysis, and EDTA platelet clumping. When possible, include these samples in validation studies and provide procedures to address these interferences.
