Analytical performance evaluation of the Norudia HbA(1c) assay

BACKGROUND: Hemoglobin A(1c) (HbA(1c)) is arguably the most important biomarker used in the diagnosis and treatment monitoring of diabetes mellitus. We evaluated the analytical performance of the Norudia HbA(1c) assay (Sekisui Medical Co., LTD), which uses an enzymatic method incorporated into a fully automated, high‐throughput system. METHODS: The precision, linearity, and carryover of the Norudia HbA(1c) assay were evaluated. Using 60 patient samples, comparative analysis of HbA(1c) measurements with two commonly used HbA(1c) assays, the D100 (Bio‐Rad Laboratories, Inc) and HLC‐723 G11 (Tosoh), was undergone. Thirteen commutable samples with known HbA(1c) concentrations measured using an IFCC reference measurement procedure were used to compare accuracy between methods. Interference of HbA(1c) measurement by Hb variants was evaluated using 16 known Hb variant samples. RESULTS: Repeatability (% CV) for low and high concentrations ranged from 1.12%‐1.50% and 0.66%‐0.75%, respectively, and within‐laboratory precision for low and high concentrations ranged from 1.73%‐2.89% and 0.98%‐1.64%, respectively. For linearity, the coefficient of determination was 0.9987. No significant carryover was observed. When compared to the D100 and HLC‐723 G11 assays, the Norudia HbA(1c) assay showed the best accuracy with the lowest mean bias (−1.72%). Furthermore, the Norudia was least affected by Hb variants and gave the most reliable HbA(1c) measurements. CONCLUSION: The Norudia HbA(1c) showed excellent analytical performance with good precision and linearity, and minimal carryover. When compared to other routine HbA(1c) methods, the Norudia HbA(1c) assay showed the highest accuracy and was least affected by Hb variants.