Comparison and Standardization of the Urine Microscopic Examination

Abstract

The purpose of this study was to determine which of three methods of urine sediment preparation and examination achieves the best accuracy and precision. A comparison of the Kova System, the T-System, and an “inhouse” system using a conical plastic centrifuge tube was performed. Ninetyeight urine specimens were examined. The mean values of the number of white blood cells, red blood cells, and casts were calculated and false-negative findings were identified. Ten technologists performed urine sediment examinations of aliquots of the same urine by the three systems. Reproducibility of one specimen by the ten technologists for each method was determined by calculating the mean, standard deviation, and coefficient of variation. Of the three systems studied, only the T-System demonstrates the accuracy, sensitivity, and precision required for standardization of the urine microscopic examination.