Evaluation of Sysmex XT-2000iV analyzer performance across a network of five veterinary laboratories using a commercially available quality control material

Abstract

Background: Laboratory and instrument harmonization is seldom reported in the veterinary literature despite its advantages to clinical interpretation, including the use of interchangeable results and common reference intervals within a system of laboratories.

Objectives: A three-step process was employed to evaluate and optimize performance and then assess the appropriateness of common reference intervals across a network of six Sysmex XT-2000iV hematology analyzers at 5 commercial veterinary laboratory sites. The aims were to discover if harmonization was feasible in veterinary hematology and which quality parameters would best identify performance deviations to ensure a harmonized status could be maintained.

Methods: The performance of 10 measurands of a commercially available quality control material (Level 2-Normal e-CHECK (XE)-Hematology Control) was evaluated during three 1-month time periods. Precision and bias were assessed with Six Sigma, American Society of Veterinary Clinical Pathology (ASVCP) total error quality goals and biologic variation (BV)-based quality goal approaches to performance measurement.

Results: Instrument adjustments were made to 1 analyzer twice and 3 analyzers once between evaluations to improve performance and achieve harmonization. Sigma metrics improved from 37/50 > 6 to 58/60 > 6 and to all >5 over the course of the harmonization project. BV-based quality goals for desirable bias and for laboratory systems of 0.33 × CV_I (within-subject biologic variation) were more sensitive and useful for assessing performance than the ASVCP total error goals.

Conclusions: Optimization and harmonization were achieved, and because BV-derived bias goals were achieved, common reference intervals could be implemented across the network of analyzers.

Keywords: Sysmex; analytical performance; biologic variation; hematology; quality system; sigma metrics; veterinary.