Performance evaluation of the BC-720 auto hematology analyzer and establishment of the reference intervals of erythrocyte sedimentation rate in healthy adults

BACKGROUND: Erythrocyte sedimentation rate (ESR) is a new reporting parameter of the BC-720 auto hematology analyzer; however, no biological reference interval for healthy adults has been established for this parameter. METHODS: Outpatients or hospitalized patients with ESR test orders were selected. The ESR was measured by the standard method of ESR (Westergren) recommended by the International Council for Standardization in Hematology (ICSH), the BC-720 hematology analyzer, and the LBY-XC40B auto ESR analyzer. The data were statistically analyzed and compared among different methods. The repeatability and carryover rate (CR) of the BC-720 were assessed in randomly selected samples for each range segment. Blood Samples from three hospitals in China were collected, and the reference interval of the BC-720 ESR was determined. RESULTS: The ESR results measured by the BC-720 correlated well with the Westergren method (r=0.957, y = 0.359 + 1.016x), and there was no significant difference between these two methods (P>0.05). The correlation between LBY-XC40B auto ESR analyzer and Westergren was y = 1 + 1.25x and r=0.856. The BC-720 ESR has good repeatability [standard deviation (SD) ≤1 mm/h, coefficient of variation (CV) ≤5%], and the CR was less than 1%. The 95th percentile of the biological reference interval for BC-720 ESR is 15 mm/h for men and 24 mm/h for women. CONCLUSIONS: The Mindray BC-720 ESR showed high accuracy and good repeatability, which provided a faster, safer, and more reliable method to measure ESR. The reference intervals for BC-720 ESR could guide better clinical decisions for the laboratories utilizing this new method.