Performance Evaluation of the BC-6800Plus Hematology Analyzer for ESR Measurement: Comparison with the Westergren Method and TEST1

Background: Automated erythrocyte sedimentation rate (ESR) measurement streamlines laboratory workflow and shortens turnaround time.This study evaluated the analytical performance of the Mindray BC-6800Plus (BC-6800P, Mindray Bio-Medical Electronics Co., Ltd., Shenzhen, China), a fully automated hematology analyzer with integrated ESR testing capability, and compared its performance with those of the Westergren reference method and the TEST1 analyzer (Alifax S.r.l., Polverara, Italy) in a Korean clinical laboratory setting.Methods: Sixty residual EDTA whole-blood specimens were analyzed by all three methods within 4 hours of collection.The analytical performance of the BC-6800P, including precision, carryover, and reference interval verification, was evaluated in accordance with CLSI EP15-A3 and International Council for Standardization in Haematology (ICSH) recommendations.Agreement between methods was assessed using Passing-Bablok regression, Bland-Altman analysis, Spearman's rank correlation, and range-stratified subgroup analyses.Results: The BC-6800P exhibited excellent precision (intra-run CV ≤ 8.2%, inter-run CV ≤ 1.9%) and negligible carryover (-0.18%).All reference interval verification specimens fell within the sex-specific manufacturer-provided intervals.Comparison with the Westergren method demonstrated strong overall agreement (ρ=0.891,P <0.001) with a small negative bias (-3.61 mm/h).However, absolute bias increased markedly at higher ESR values, rising from 3.5 mm/h at ESR 0-20 to 18.2 mm/h at ESR >60.Comparison with TEST1 showed substantial method-dependent disagreement (proportional bias; limits of agreement, -43.1 to 33.6 mm/h), consistent with platform-dependent measurement differences also observed in the TEST1-Westergren comparison.Conclusions: The BC-6800P demonstrated acceptable analytical performance for routine ESR testing.However, the marked increase in absolute bias at higher ESR values necessitates cautious clinical interpretation, and results from different automated platforms should not be considered interchangeable, particularly for longitudinal patient monitoring.