Analytical performance of a dry chemistry analyzer designed for in‐clinic use

Abstract

The Heska Dri-Chem 4000 uses dry slide technology to evaluate serum or plasma. No previous independent performance evaluation is published to the authors' knowledge. The objectives were to (1) characterize analytical performance of a Dri-Chem 4000 by measuring precision and bias, (2) compare analytical performance of that Dri-Chem 4000 unit with a predetermined quality requirement, and (3) determine whether statistical QC of the Dri-Chem 4000 is possible using the 13s control rule. Sixteen analytes were measured using plasma from dogs, cats, and horses. Coefficient of variation (CV), bias, and observed total error (TEobs ) were calculated. TEobs was compared with allowable total error (TEa ). Sigma metric and quality goal index were calculated where relevant. QC validation was performed. Bias and TEobs calculated using quality control material (QCM) data were smaller than those calculated using method comparison data. Using TEobs calculated from species-specific CV and QCM-based bias, 100% of analytes in each species met ASVCP-recommended TEa . Desired error detection and false rejection rates were achievable using the 13s control rule and ASVCP-recommended TEa values for 9/16 (56%) of analytes in dogs, 9/14 (64%) of analytes in cats, and 8/13 (62%) of analytes in horses. Analytical performance of the Dri-Chem 4000 is comparable to that reported by other authors for other small benchtop biochemistry analyzers. Statistical QC using a simple control rule is possible for most analytes in dogs, cats, and horses.