Comparison of WBCs and RBCs Concordance between the Cobas u 701 Analyzer and Three Manual Microscopy Methods in Urine Sediment

Abstract

Urine sediments are performed by a microscopic examination of centrifuged urine by medical technologists. This study examined different urine sediment preparation procedures. The 107 fresh urine specimens that tested positive from white blood cells (WBCs) and red blood cells (RBCs) in the urine dipstick test and the cobas u 701 analyzer, respectively, were selected for manual microscopy. This study evaluated an automated urine sediment analyzer and three manual microscopy methods for WBCs and RBCs. The methods were performed according to the test guidelines. The coefficients of determination between the cobas u 701 analyzer and the Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) for WBCs and RBCs were r2=0.977 and r2=0.970, respectively. The concordance rates between the cobas u 701 analyzer and KAQACL for WBCs and RBCs were 74.8% and 77.6%, respectively. A good correlation and concordance with the automatic analyzer were shown when the specimens were prepared and examined using the KAQACL method. Consequently, the differences in the urine sediment preparation procedures affected the sediment concentrations, influencing the cell number per high power field (HPF).

Keywords

• concordance
• manual microscopy
• sediment preparation procedure