Evaluation of the Analytical Performance of Five Assays in Measurement of Hemoglobin A1c in Iran

Background: Hemoglobin A1c (HbA1c) testing devices are widely used to evaluate glycemic control in diabetic patients. Despite international effort on standardization of HbA1c tests, different levels of variation in different assay results are still present. Objectives: The purpose of this study was to investigate the comparability of the results of various HbA1c instruments used in Iran. Materials and Methods: This cross-sectional study was conducted in the endocrine and metabolic institute of Tehran University of Medical Sciences from October 2013 to December 2013. Fresh blood samples taken from 45 diabetic type 2 patients with different HbA1c levels (4.8 - 12.7%) were tested with five assays; NycoCard Reader II (Axis-Shield), CERA STAT 2000 (Ceragem Medisys Inc), DS5 (Drew Scientific inc), Biosystems (BioSystems S.A.) and Pars Azmoon (Pars azmoon), and the results were compared to those obtained from TOSOH G8 Ion exchange (Tosoh Bioscience) as a reference method. Clinical Laboratory Standardization Institute (CLSI) protocols (EP-15A2 and EP-9A2) were used for designing the study and evaluation of the results. Microsoft Excel 2007 and SPSS version 15 packages were used for computation and analysis of the data. Results: Interassay imprecision of all assays was less than 3.4%. There was a significant linear correlation between test methods and TOSOH G8 results (r: 0.86 to 0.96). The mean values of all different methods were significantly different from the reference method (P value 0.01). Conclusions: Although the results obtained with the use of different methods show an excellent correlation, when one particular sample is tested by different assays, the results are significantly different. It can be concluded that the national standardization program of HbA1c measurement is necessary.