Automated urinalysis combining physicochemical analysis, on-board centrifugation, and digital imaging in one system: A multicenter performance evaluation of the cobas 6500 urine work area

• Published in: Practical laboratory medicine 2019-11, Vol.17, p.e00139-e00139, Article e00139
• Main Authors: Cobbaert, Christa M., Arslan, Figen, Caballé Martín, Imma, Serra, Antoni Alsius, Picó-Plana, Ester, Sánchez-Margalet, Víctor, Carmona-Fernández, Antonio, Burden, John, Ziegler, André, Bechel, Walter
• Format: Article
• Language: English
• Subjects: Automated biology—high-throughput screening; Clinical automation; Laboratory management—workflow
• ISSN: 2352-5517; 2352-5517
• DOI: 10.1016/j.plabm.2019.e00139

We evaluated the analytical performance of the fully automated cobas® 6500 urine work area and its automated components—cobas u 601 and cobas u 701. The study was conducted at three European centers using un-centrifuged surplus routine urine samples; all measurements were performed within 2 h of sample collection. Precision, sample carry-over, and method comparisons were evaluated per Clinical and Laboratory Standards Institute guidelines. Method comparisons: cobas u 601 versus Urisys 2400 and cobas u 411 urine test strips; and cobas u 701 versus KOVA® visual microscopy and iQ200 analyzer. Operability and functionality were assessed using questionnaires. Precision of the entire cobas 6500 system was within predefined acceptance limits and no significant carry-over was observed. Erythrocytes, leukocytes, nitrites, and protein were in good agreement (≥93%) with cobas u 411 reflectometry. High correlation was shown between the cobas u 701 analyzer and KOVA visual microscopy for red blood cells (RBC; slope, 0.89; Pearson’s r, 0.95) and white blood cells (WBC; slope, 0.96; Pearson’s r, 0.96), demonstrating equivalence of test results. The 97.5% percentile reference values on the cobas u 701 analyzer were 5.3 cells/μL (RBC) and 6.2 cells/μL (WBC). The cobas 6500 system showed good sensitivity for small bacteria (>1 μm) and pathological casts, and the user interface, maintenance wizards, and system design were highly rated by operators. The fully automated workflow, high precision, and high throughput of the cobas 6500 system have the potential to facilitate standardization of urine screening. •The cobas u 601 analyzer showed good agreement with cobas u 411 reflectometry.•cobas u 701 analyzer results were highly correlated with KOVA® visual microscopy.•The combined cobas® 6500 system showed excellent precision across laboratories.•No significant carry-over was observed.•The cobas 6500 system design and interface were highly rated by operators.