Accuracy of the IDEXX SediVue Dx analyzer for quantifying RBC and WBC indices in the urine sediments of cats and dogs compared with manual microscopic evaluations

Abstract

Background:The IDEXX SediVue Dx (SediVue) is an automated, in-clinic urine sediment analyzer for veterinary patients. The bias between the results from manual microscopy and the SediVue is currently unknown.Objectives: To assess the diagnostic accuracy of the SediVue, we aimed to determine the bias between the SediVue (index test) and manual microscopy (reference standard) for the quantification of RBCs and WBCs in urine.Methods: Urine remnant samples were collected from cats and dogs that contained RBCs (n = 462) and WBCs (n = 510). Retrospective analysis of results from urine sediment examinations using both manual microscopy (using a KOVA and DeciSlide system) and the SediVue (1.0.1.3) was performed. Bias was determined with Bland-Altman plots. SediVue-captured images from high-bias samples were reviewed, and biases were compared. Results:The median bias for semi-quantitative RBC and WBC counts was determined for RBC and WBC counts. The cutoffs were RBC ≤ 5/HPF, 0.3; RBC 5.1-10/HPF, 10.1;

Analytical performance evaluation of two automated urine sediment analysers using two levels of commercially available quality control material

“…ASVCP guidelines recommend that the high and low amounts of microscopic elements observed over 10 fields should be reported, or that a 0 to 3+ or 0 to 4+ (semiquantitative) grading system may be used (Arnold et al 2019). Although multiple studies have evaluated automated urine sediment analysers designed for human samples, to date only a few studies have evaluated the accuracy of a urine sediment analyser in the veterinary setting or reported the sensitivity and specificity of Analyzer S for specific cellular and formed elements when compared with manual microscopy (Ince et al 2016, Laiwejpithaya et al 2018, Hernandez et al 2019, Yalcinkaya et al 2019, Vasilatis et al 2021, Blanco et al 2022, Seigner et al 2022. Instrument manufacturers provide minimal quality specifications and an independent investigation evaluating in-clinic automated urine sediment analysers using quality specifications has not been published (Lepage et al 2006, Lem & Rosenfeld 2018.…”

A review of Bland–Altman difference plot analysis in the veterinary clinical pathology laboratory

“…Current ASCVP guidelines for method comparison recommend pairing regression evaluation with BA‐plot analysis 9 . The method is commonly used in the veterinary clinical pathology laboratory and published in Veterinary Clinical Pathology manuscripts 10–14 . Others have noted that the composition and interpretation of BA‐plots are not always appropriate 7,8,15 .…”

“…9 The method is commonly used in the veterinary clinical pathology laboratory and published in Veterinary Clinical Pathology manuscripts. [10][11][12][13][14] Others have noted that the composition and interpretation of BA-plots are not always appropriate. 7,8,15 This work seeks to review the common…”