An Evaluation of the Automated Cobas u 701 Microscopy Analyzer for the Routine Screening of Urine to Identify Negative Samples.

Background: Urinalysis based on microbiological culture and manual microscopy requires expertise and is labor intensive. Automated screening could save time and improve patient management in clinical settings. Methods: We evaluated the fully automated cobas u 701 analyzer for identifying infection-negative urine samples using 2,046 anonymized samples from a routine pathology laboratory. Samples containing >= 40 white blood cells (WBC)/mu L and/or >= 100 bacteria/mu L were considered positive. For microbiological cultures: pure growth of >= 10(8) colony-forming units (cfu)/L was considered significant; > 10(7) cfu/L was considered significant for pregnant women, children < 12 years, immune-compromised/critical care patients or patients with > 100 WBC/mu L. Results: The cobas u 701 analyzer identified 1,346 positive samples, giving a 65.7% culture rate. Sensitivity and negative predictive value were high (> 99%). Most replicates were within two standard deviations of the original measurement. Conclusions: The cobas u 701 analyzer is an effective screening tool for routine urinalysis and demonstrates rapid turnaround times, thus benefiting patients and clinicians.