ABSTRACT
BACKGROUND: We aimed to evaluate the performance of the CLINITEK Novus urine chemistry analyzer (Siemens, UK). METHODS: The precision, correlation, and carryover study were performed using two kinds of commercial quality control materials and 40-55 freshly collected patient specimens. We calculated exact and within-1-block agreement, along with kappa agreement, to compare the semi-quantitative results between urine chemistry analyzers. The urine specific gravity taken by a refractometer was compared with the analyzer results. Moreover, we analyzed additional urine specimens for protein to evaluate the agreement of results between those of the CLINITEK Novus and the AU680 analyzers (Beckman Coulter, Japan). RESULTS: The precision study showed acceptable results; within-1-block agreement was 100% in all tested items. The urine chemistry results from the CLNITEK Novus analyzer demonstrated ≥85.1% within-1-block agreements with those of the Uriscan Super, and the kappa test results were ≥0.81. The comparison of specific gravity with manual refractometer showed a good correlation (r=0.991), and the protein comparison with the AU680 analyzer also showed a good correlation (with exact and within-1-block agreements being 75.9% and 100.0%, respectively). The carryover rates were 0% in all tested items, except specific gravity and heavy blood tests. CONCLUSIONS: The CLINITEK Novus analyzer showed good performance in terms of precision, comparison, and carryover in this study. Therefore, the CLINITEK Novus automated urine analysis is expected to be useful for routine urinalysis in a clinical laboratory.
Subject(s)
Humans , Chemistry , Hematologic Tests , Quality Control , Specific Gravity , UrinalysisABSTRACT
Aim: Although urine culture is used as the reference standard to determine presence or absence of urinary tract infection (UTI), culture is an expensive and time-consuming method. The objectives of the study were to compare automated dipstick urinalysis with microscopic urinalysis and form an algorithm to reduce time and labour of the pathologist and faster initiation of treatment to the patient. Method: 500 morning urine samples were analysed by using automated dipstick analyser( Cobas u 411) and those samples showing abnormal results were subjected to microscopy. Leucocyte esterase and nitrite positivity were taken into consideration as predictive indicators of UTI. Result: 34% of the samples showed abnormal results on automated urine analyser. Total 28% samples showed positive results for leucocytes, nitrite, protein and RBC’s were sent for urine culture. 5% samples grossly turbid were sent for culture. Conclusion: Automated urinalysis method can be used for the rapid diagnosis of UTI. The algorithm presented in this study will guide the pathologist to decide when culture should be advised after urinalysis. Urine culture is an expensive test for routine use and should not be applied unless the result of nitrite, leukocyte or RBC’s are positive on automated dipstick/ microscopic examination.
ABSTRACT
BACKGROUND: Microscopic examination of urine sediment is one of the most commonly performed tests in the clinical laboratory. However, manual microscopic sediment examination is labor-intensive, time-consuming and imprecise. In this study, we evaluated the analytical performance and clinical usefulness of a recently introduced image-based automated urinalysis system, Iris iQ200 (Iris Diagnostics, USA). METHODS: We assessed the iQ200 for linearity, precision and carryover rate using patient's samples and quality control materials. On 337 urine samples, urine sediment analyses performed by the iQ200 were compared with manual microscopy results. RESULTS: The iQ200 showed a good linearity (r2>0.99) for all cellular components analyzed. Within-run and total CVs on urine specimens and quality control samples were less than 10% except for within-run CV for the samples with low concentration of the squamous epithelial cells. The carryover rates were 0.21% for RBCs and 1.92% for WBCs. The agreement rates within one grade between the iQ200 and manual microscopy for RBCs, WBCs, and squamous epithelial cells were 93.8%, 94.2% and 96.9%, respectively. CONCLUSIONS: Since the iQ200 showed a reliable analytical performance and good concordance with manual microscopy, it could be useful in the clinical practice as a screening procedure.