The Use of Internal and External Quality Control Data for the Calculation of Measurement Uncertainty of Glycated Hemoglobin
Hemanth T
, Renuka P* and V. M. VinodhiniDepartment of Biochemistry, SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences, SRM Institute of Science and Technology, Kattankulathur – 603203, Kanchipuram, Chennai, TN, India.
Corresponding Author E-mail:renukap@srmist.edu.in
Abstract: Introduction and Aim: Diabetes mellitus is a burgeoning worldwide problem. For monitoring the glycemic state in diabetes, glycated hemoglobin (HbA1c) is one of the standardized tests. Measurement of uncertainty shows the magnitude of the doubt about a measurement result. The current study aims to estimate the measurement uncertainty (MU) of HbA1c in our laboratory using the method suggested by EURACHEM/CITAC and advocate its utilization as a quality standard in clinical laboratories as part of the quality control program to enhance the reliability of their results. Materials and Methods: The HbA1c levels were measured using a high-performance liquid chromatography method. The “Top Down” technique proposed by EURACHEM/ CITAC was used to calculate the uncertainty of HbA1c. This method allows the inclusion of the bias and imprecision of the HbA1c method. Bias value was calculated from data of external quality assessment results of the EQAS program and two levels of internal quality control results data was used to calculate the imprecision. Results: The measurement uncertainty (95% confidence interval) of HbA1c was estimated to be 4.2%. When measurement uncertainty was taken into account, the acceptable range for an HbA1c value of 6.5% typically used to diagnose DM was between 6.2 to 6.77. Conclusion: The EURACHEM/CITAC method is valuable for calculating MU of HbA1c and is a viable way that can be utilized as an extra analytical target in HbA1c testing. Furthermore, the data can assist clinicians in determining the degree of confidence that may be placed in test results.
Keywords: EURACHEM/CITAC; Glycated hemoglobin; Measurement uncertainty; Top-down approach Back to TOC