INTRODUCTION: Glycated hemoglobin (HbA1c) is a commonly used laboratory test for screening, monitoring, and diagnosing diabetes mellitus (DM). Uncertainty is a statistical expression that shows the effects of factors arising during measurement processes and affecting the reported results. It is important to give reliable laboratory results. This study aims to estimate the measurement uncertainty (MU) of HbA1c at Siemens Atellica Solutions.
METHODS: Internal and external quality control results of 6 months data were used to calculate the MU according to the Clinical & Laboratory Standards Institute (CLSI) document EP29-A. The coefficient of variation (CV%) of the two levels of internal quality control materials was calculated. The external quality control results of 6 months data obtained from the EQAS program of Bio-Rad were used to calculate the bias.
RESULTS: The precision results of the assay were within the current National Glycohemoglobin Standardization Program requirement of ≤4%. The HbA1c level above 6.5% is one of the diagnostic criteria of DM. We estimated the expanded uncertainty as 6.40% for HbA1c at the level of 6.5%. It is presented as 6.5±0.4%.
DISCUSSION AND CONCLUSION: It is important that laboratorians report accurate and reliable test results as clinicians make their decisions based on laboratory data. Laboratories should add measurement uncertainty results as a part of quality control programs. The laboratory tests with clinical decision limits should be presented with measurement uncertainty results.