In the other two tubes the evaluation of urine formed elements that were used in the evaluation

A total of 209 patients who came to our hospital's laboratory were studied. They were chosen at random. Prior to enrollment in the study, all patients provided signed written consent, and the research was carried out in accordance with the Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects).

According to European Urinalysis Guidelines 1, the collection, transportation, preparation of specimens, and urinalysis of the samples were all carried out. Mid-stream samples (30 mL) were collected into primary containers that did not pose a risk of spillage during transport, and then transferred to secondary containers (three different conical tubes) in the laboratory. It was necessary to use translucent secondary tubes in order to see the sample clearly. Each tube received a 10 mL urine sample to begin with. Each sample was subjected to three different methods in less than an hour. For manual microscopic examination, the first tube was centrifuged for 5 minutes at 1500 rpm (400 g) for 400 g. Until 0.5 mL urine analyzer remained at the bottom of the tube, the supernatant was decanted several times. Using a light microscope, one drop of sediment was placed on a microscope slide, which was then covered with a cover slip and examined under a bright light. The evaluation of  formed elements was carried out independently by one biochemistry specialist and one biologist, both of whom used the same microscope slide for their work. The examination included scanning at least 10 different microscopic fields at magnifications of 100 and 400 (per low-power field; LPF) and 400 (per high-power field; HPF) during the course of the examination. The results were calculated by taking an average of the formed elements and were reported as cells or particles in a field of data. If there was a discrepancy between the results of the two evaluators, the analysis was repeated with a new sample in order to resolve the discrepancy between the two.

The evaluation of urine formed elements in the other two (uncentrifuged) tubes was carried out on the automatic urine sediment analyzers Iris iQ200 ELITE (Iris Diagnostics, Chatsworth, CA, USA) and Dirui FUS-200 (DIRUI Industrial Co., Changchun, China). The average of formed elements per LPF and HPF was used to calculate the results from the instruments' measurements. The analytical principle of the Dirui FUS-200 analyzer is based on flow cell digital imaging and identification, which is accomplished through the use of artificial intelligence. The Digital Flow Morphology technology employed by the Iris iQ200 ELITE analyzer, in conjunction with the Auto-Particle Recognition (APR) software, serves as the analytical principle. As urine passes through the flow cell, it is illuminated by a special light source, and the images are captured by a digital camera that is placed in the microscope's eyepiece and transmitted to the computer via a computer interface. The images are classified by the software, which then displays them on the screen for the operator to see. These sediment images are accepted, modified, or deleted by the operator.

Since native microscopic urine analysis samples were not stable over the course of 20 days, we used the results of positive controls (Dirui FUS-200 positive control and Iris iQ200 positive control), rather than native urine samples, to calculate the coefficients of variation for between-run imprecision over the course of 20 days. With two different pooled urine specimens containing various concentrations of erythrocytes, leukocytes, and epithelial cells, the imprecision within a run was determined using each analyzer performing a total of 20 runs on each specimen. The results were expressed as the number of particules per high-pressure fluid (HPF).

Both the SPSS Statistics 20.0 (Statistical Package for Social Sciences, IBM Corporation, Armonk, NY) and the Microsoft Excel 2007 (Microsoft Corp. of Seattle, WA) programs were used to conduct the statistical analyses. Semi-quantitative classification of erythrocytes, leukocytes, and epithelial cells was performed (0–5, 6–10, 11–20, >20 cell/HPF) on erythrocytes, leukocytes, and epithelium. Various microorganisms, such as bacteria, yeast, casts, and crystal, were classified as negative or positive. It was also possible to classify semi-quantitative elements as either positive or negative, with positive results being those that exceeded the cutoff values, which were defined as 5/HPF for leukocytes, erythrocytes, and epithelial cells, respectively.

The Cohen's kappa coefficient was calculated to determine whether the methods were in agreement.6. Cohen's kappa coefficient values ranging from 0–0.21 to 0.21–0.40, 0.40–0.60, 0.61–0.80, and 0.81–1.00 are characterized as poor to fair agreement, moderate to good agreement, good agreement, and very good agreement, respectively. The rates of concordance among students in the same grade were calculated. Comparing automated analyzers to manual microscopic examination, the researchers evaluated their analytical sensitivity, specificity, as well as their positive and negative predictive values.