Analytical performance evaluation of the Norudia HbA1c assay

Abstract Background Hemoglobin A1c (HbA1c) is arguably the most important biomarker used in the diagnosis and treatment monitoring of diabetes mellitus. We evaluated the analytical performance of the Norudia HbA1c 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 HbA1c assay were evaluated. Using 60 patient samples, comparative analysis of HbA1c measurements with two commonly used HbA1c assays, the D100 (Bio‐Rad Laboratories, Inc) and HLC‐723 G11 (Tosoh), was undergone. Thirteen commutable samples with known HbA1c concentrations measured using an IFCC reference measurement procedure were used to compare accuracy between methods. Interference of HbA1c 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 HbA1c 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 HbA1c measurements. Conclusion The Norudia HbA1c showed excellent analytical performance with good precision and linearity, and minimal carryover. When compared to other routine HbA1c methods, the Norudia HbA1c assay showed the highest accuracy and was least affected by Hb variants.