Evaluation of the HbA1c Analytical Performance on the Bio-Rad D-10 Analyzer Using Sigma Metrics at the Clinical Diagnostic Laboratory, USM Medical Centre Bertam
Keywords:
HbA1c, Bio-Rad D-10, high-performance liquid chromatography, Six Sigma, analytical performance, quality controlAbstract
Glycated haemoglobin (HbA1c) is a key biomarker for long-term glycaemic control in diabetes management, necessitating high analytical accuracy and precision. This study evaluated the performance of HbA1c assay on the Bio-Rad D-10 analyzer, which employs high-performance liquid chromatography (HPLC) method, using Sigma metrics at the Clinical Diagnostic Laboratory (CDL), USM Medical Centre Bertam (PPUSMB). A retrospective analysis of two-level internal quality control (IQC) data from February to August 2025 was conducted. Imprecision was calculated and expressed as coefficient of variation (CV%), bias was determined from Unity Interlaboratory Program data, and Sigma scores were calculated according to CLIA 2024 guideline. Results revealed variable performance at QC Level 1, with Sigma scores ranging from 3.30 to 9.01, indicating marginal to world-class quality. The performance variability was attributed to higher bias and imprecision at lower analyte concentrations. In contrast, QC Level 2 consistently demonstrated excellent to world-class performance, with Sigma scores between 5.63 and 14.70, supported by low bias (0.20–0.79%) and CV% (0.50–0.93%). In conclusion, the Bio-Rad D-10 analyzer provides robust analytical performance, particularly at higher HbA1c concentrations. However, lower concentration levels require closer monitoring and strengthen quality control monitoring strategies to maintain results’ reliability. Sigma metrics offer a structured framework for evaluating method performance but should be complemented by additional quality indicators for comprehensive assessment.
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