Preparation of quality control materials for urinalysis in medical technology laboratory

Abstract

Quality control of urine analysis consists of chemical examination and microscopic examination.  External Quality Assessment (EQA) programs in Thailand cannot assess all parts. The aim of this study was to develop the control materials for urinalysis including the production of artificial urine control for chemical examination and preparation of the urine sediment slide for identifying urine sediment. Two levels of artificial urine control (normal and abnormal) samples and urine sediment slide were prepared. Artificial urine controls were tested by automated urine analyzer from 3 companies and tested by the urine strip from 6 companies. In additional, artificial urine controls were tested for homogeneity and stability for 6 months. The urine sediments slide consists of white blood cell, white blood cell with clumping, red blood cell, squamous epithelial cell, calcium oxalate crystal and bacteria. The performance and stability of urine sediment slide was tested for 6 months. The artificial urine samples and urine slides were evaluated from 62 medical technology laboratories. The results from the automated analyzers for all parameters were consistent. The urine strips found that most of the results were consistent. When testing the homogeneity and stability, all test results were stable. The results of urine sediment slide were able to identify correctly after 6 months of storage. Evaluation from medical technology laboratory, the results of normal and abnormal artificial urine samples were reported within target value more than 98.4% and more than 92% respectively, except ketone and leukocyte esterase. In addition, the result of identifying urine sediment slide found that there were 98.4% corrected.  In conclusion, the results of the evaluation of the quality of urinalysis using artificial urine samples and urine sediment slides demonstrate that they are appropriate to be used in external quality control.