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.
Autoanalysis/methods ; Humans ; Quality Control ; Sensitivity and Specificity ; Urinalysis/*instrumentation ; Urine/*cytology/microbiology