Ann Clin Microbiol.  2021 Sep;24(3):83-96. 10.5145/ACM.2021.24.3.3.

Evaluation of Five Automated Urine Analyzers as Screening Instruments for Enhancing Diagnostic Efficiency in Urinary Tract Infection

• Cho J
• Byun JH
• Lee SG
• Oh K
• Jeon B
• Yong D
• Kim JH

• KMID: 2520133
• DOI: http://doi.org/10.5145/ACM.2021.24.3.3

Abstract

Background
Although urine culture is considered a reference standard for the diagnosis of urinary tract infection (UTI), it is time-consuming, labor-intensive, and expensive. Here, we evaluated the performance of five recent automated urine analyzers for UTI diagnosis.
Methods
For the 510 specimens analyzed, the criterion for ‘significant bacteriuria’ was defined as ≥ 10⁴ CFU/mL in the inoculated plate for all specimens or ≥ 10³ CFU/mL for specimens from patients using a Foley catheter or with urinary symptoms. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of UTI were analyzed using indicators individually, in different combinations, or with various cut-off values.
Results
Seventy-one specimens (13.9%) exhibited ‘significant bacteriuria’. In the eceiver operating characteristics curve analysis, UF-5000 (Sysmex Corp., Japan) showed the highest area under the curve values for both males and females (0.876 and 0.846, respectively). The PPVs for specimens from males with all indicators positive increased up to 100% after adjusting the cut-off values. NPVs for specimens with all indicators negative were 94.3%– 98.2% in males and 78.1%–93.8% in females after adjusting the cut-off values.
Conclusion
As a rapid and accurate diagnostic tool, urine sediment analyzers can be valuable for UTI diagnosis by reducing unnecessary culture and can help clinicians determine a treatment plan.

Keyword

Automated urine analyzer; Screening test; Urine culture; , Urinary tract infections