Evaluation of Sysmex XT-2000iV analyzer performance across a network of five veterinary laboratories using a...

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.

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.

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.

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.

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