Evaluation and application of two methads for the determination of red blood cells in urine

Abstract

Objective: This study was aimed to evaluate the accuracy and conformity of the dry chemical urine analyzer UA-5800 and the urine formed element analyzer EH-2080Cused in the detection of urine red blood cells, and establish screening and retesting standards for urine red blood cell testing. Methods: Automatic urine analysis line EU-8000 (composed of dry chemical urine analyzer UA-5800 and urine formed element analyzer EH-2080C) was used to conduct hematuria and urine erythrocyte test in 2336 fresh urine samples from occupational medical examinations in our hospital, the sensitivity (true positive rate) , specificity (true negative rate) and the positive coincidence rate (positive rate) and negative coincidence rate (negative rate) of the corresponding test results were analyzed tow instruments. Results: The sensitivity of urinary occult blood detected by UA-5800 and urinary erythrocytes examined by EH-2080C were 98.33% and 95.00%, there was no statistical significant between the two results (χ(2)=0.50、P>0.05) ; specificity was 82.47% and 97.45% respectively, which existed statistical significant (χ(2)=337.05、P<0.01) . Comparing the two methods, the statistical significant remained (χ(2)=339.05、P<0.01) . Among all results of urinary occult blood detected, the EH-2080C had the highest urinary erythrocyte negative coincidence rate (99.89%) ; while in the comparison of urinary occult blood positive grades at 3+, the highest positive coincidence rate of urinary erythrocyte in EH-2080C was 85.76%; when the urine occult blood levels were weakly positive, 1+, 2+, the positive coincidence rate of EH-2080C examination was low (8.97%, 14.40% and 36.48%) , which increased with elevated positive grade. Conclusion: The positive specimens screened by automatic urine analysis line were examined by gold standard microscope combining with with the criteria of urine red blood cell screening and retesting in our laboratory, which can ensure high accuracy and high efficiency of urine erythrocyte analysis.