Selection of an Acceptable Method for the Measurement of Glycosylated Hemoglobin by Evaluating Three Different Methods

The objective of the study is to compare the analytical performance in terms of precision and accuracy of three methods viz., Immunoturbidimetry (IT), Capillary Electrophoresis (CEP) and High Performance Liquid Chromotography (HPLC) for the measurement of glycosylated haemoglobin (HbA1c). A total of 40 routine patients samples were used for the estimation of HbA1c using the three methods and the results obtained were correlated between the three methods. The correlation coefficient ‘r’ obtained between IT & CEP, IT& HPLC and CEP & HPLC were 0.96, 0.95 & 0.99 respectively, indicating that an ‘r’ value of 0.99 obtained between CEP & HPLC is in agreement with the CLIA guidelines value of > 0.98,while poor ‘r’ values of 0.96 and 0.95 were obtained when IT method was compared with both CEP and HPLC methods. As per this study both CEP & HPLC methods gave good precision and accuracy for Bio-Rad controls. Further, CEP and HPLC methods have provisions to identify interference by Haemoglobin variants present in patient sample. The outcome this study recommends the use of one of the two methods viz., CEP and HPLC for routine measurement of HbA1c.