The Effect of Analytic Variation on Empirical Biological Variation-Derived Analytical Performance Specifications in the Veterinary Clinical Pathology Laboratory.

Abstract

Background: The empirical biologic variation (EBV) method to derive analytical performance specifications (APSs) has been provisionally evaluated for use in the veterinary clinical pathology laboratory. Analytical performance can affect EBV APSs. It has been argued that this effect is minimal, but the effect has not been evaluated for the range of performance found in veterinary laboratories.

Objective: Model and compare EBV APSs derived across a range of analytical CV (CV_A) observed in veterinary clinical pathology laboratories.

Method: Published data on biochemistry measurand CV_A in veterinary clinical pathology laboratories and dog reference intervals (RIs) were used to model EBV APSs using Monte Carlo simulation. The modeled EBV APSs were compared with analogous APSs from total allowable error (TE_A) and traditional BV models.

Results: Generally, the EBV-recommended permissible CV_A (pCV_A) was smaller than the observed CV_A when analytical performance was poor. The EBV APSs did not have a consistent relationship with analogous APSs from TE_A or traditional BV systems when analytical performance was judged acceptable using TE_A or BV APSs. When analytical performance was unacceptable, the resulting EBV APSs increased dramatically (sometimes by > 200%) and lost their initial relationship with TE_A or traditional BV-derived APSs. Using log-normal calculations for measurands with a Gaussian distribution produced wider EBV APSs.

Conclusion: The EBV method produces growth-oriented APSs under all modeled conditions and can produce notably more lenient APSs for poorly performing labs than better performing labs. The EBV method can produce acceptable APSs under some conditions and may not be suitable for use in veterinary medicine.