Evaluation of the Quo-Test A1c assay: the Oxford experience

The John Radcliffe Hospital was opened in the 1970s and is Oxfordshire’s main accident and emergency site. With over 700 in-patient beds and nearly 100 day case beds, it also provides acute medical and surgical services, trauma, intensive care, cardiac, diabetes and women’s services. The largest of the
trust’s hospitals, it houses many departments of Oxford University Medical School and is the base for most of the medical students training throughout the trust.

The Quo-Test assay is primarily intended for the measurement of HbA1c at the point of care by clinicians or other healthcare staff using fingerprick or venous blood samples.  The purpose of this evaluation is to establish the performance characteristics of the Quo-Test system when used by an independent evaluator. To that end, 40 patient samples were analysed on two Quo-Test analysers and the results are compared with those reported by the Menarini HA-8160 analyser, which is the system used by the hospital laboratory. The results will then be analysed for accuracy, precision and bias.

When comparing two (or more) systems for the measurement of HbA1c, it is important to consider the methodological variability derived from the type of assay used to measure the patient samples.1,2 There are four main methods commonly used in the measurement of HbA1c: electrophoresis, high-performance liquid chromatography (HPLC), antibody affinity and boronate affinity. While all these methods are accepted and standardised for the measurement of HbA1c,3,4 it is also accepted that small discrepancies will be found between these methods when measuring HbA1c values in a patient population. The Menarini HA-8160 uses HPLC with reverse-phase cation exchange chromatography to separate HbA1c from other types of haemoglobin. The Quo-Test A1c assay is a boronate affinity method.