Analytic Performance of the iQ200 Automated Urine Microscopy Analyzer and Comparison With Manual Counts Using Fuchs-Rosenthal Cell Chambers

Abstract

Automated instruments that can examine urine for cells and particles have reduced the need for labor-intensive manual microscopy. We evaluated the performance of the Iris iQ200 Automated Urine Microscopy Analyzer (Iris Diagnostics, Chatsworth, CA) and compared results with manual cell and particle counts using Fuchs-Rosenthal counting chambers. Within-run imprecision (coefficient of variation) of the iQ200 for urine samples ranged from 3.0% to 45% for RBC counts between 1,029 and 3 × 106 cells/L, 3.4% to 40% for WBC counts between 1,006 and 4 × 106 cells/L, and 8.9% to 35% for epithelial cell counts between 93 and 4 × 106 cells/L. Between-run imprecision was 3.3% at 1,017 × 106 cells/L and 19.2% at 28 × 106 cells/L. There was good agreement between the iQ200 and manual cell counts (r ≥ 0.94); however, the iQ200 produced lower results based on slopes of 0.92 (RBC count), 0.81 (WBC count), and 0.94 (epithelial cell counts). The iQ200 has satisfactory performance and correlates well with manual cell counts. Most urine samples containing RBCs, WBCs, and epithelial cells can be reported without review of captured images.