Comparison of a point-of-care analyser for the determination of HbA1c with HPLC method

As the use of Point of Care Testing (POCT) devices for measurement of glycated haemoglobin (HbA1c) increases, it is imperative to determine how their performance compares to laboratory methods. This study compared the performance of the automated Quo-Test POCT device (EKF Diagnostics), which uses boronate fluorescence quenching technology, with a laboratory based High Performance Liquid Chromatography (HPLC) method (Biorad D10) for measurement of HbA1c.

Whole blood EDTA samples from subjects (n=100) with and without diabetes were assayed using a BioRad D10 and a Quo-Test analyser. Intra-assay variation was determined by measuring six HbA1c samples in triplicate and inter-assay variation was determined by assaying four samples on 4 days. Stability was determined by assaying three samples stored at -20 °C for 14 and 28 days post collection.

Median (IQR) HbA1c was 60 (44.0-71.2) mmol/mol (7.6 (6.17-8.66) %) and 62 (45.0-69.0) mmol/mol (7.8 (6.27-8.46) %) for D10 and Quo-Test, respectively, with very good agreement (R²=0.969, P<0.0001). Mean (range) intra- and inter-assay variation was 1.2% (0.0-2.7%) and 1.6% (0.0-2.7%) for the D10 and 3.5% (0.0-6.7%) and 2.7% (0.7-5.1%) for the Quo-Test. Mean change in HbA1c after 28 days storage at -20 °C was -0.7% and +0.3% for D10 and Quo-Test respectively. Compared to the D10, Quo-Test showed 98% agreement for diagnosis of glucose intolerance (IGT and T2DM) and 100% for diagnosis of T2DM.

Good agreement between the D10 and Quo-Test was seen across a wide HbA1c range. The Quo-Test POCT device provided similar performance to a laboratory based HPLC method.