EKF Diagnostics, a global in vitro diagnostics company, has announced that, in a recently published paper (Lenters-Westra E, English, E. Understanding the use of sigma metrics in hemoglobin A1c analysis. Clin Lab Med 2017; 37: 57–71.) its Quo-Test point-of-care (POC) haemoglobin A1c (HbA1c) analyser has been confirmed as meeting International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) performance criteria. Using sigma-metrics data modelling, scientists from the European Reference Laboratory for Glycohemoglobin, demonstrated that Quo-Test easily met IFCC accepted quality targets of >2 sigma at 10% total allowable error (TAE) at 48 mmol/mol HbA1c. This is essential for the effective monitoring of glycaemic control in diabetes patients.
Under strict evaluation conditions, Quo-Test was shown to perform well against routine laboratory analysers, certified as secondary reference measurement procedures (SRMPs), but also when compared to six other POC HbA1c analysers. The authors explained that sigma-metrics is a quality management strategy that provides a universal benchmark for analytical performance, effectively placing all analysers on a level playing field. Using sigma-metrics, analytical characteristics (bias and imprecision) are placed in the form of TAE within a framework of clinical requirements. An IFCC Task Force in 2015 advocated the use of sigma-metrics quality targets for HbA1c to standardise analytical quality at a global level.
This latest study follows the release of critical evaluation data by the European Reference Laboratory for Glycohemoglobin, published in a White Paper in 2016, which also demonstrated Quo-Test’s strong performance. In the White Paper, Quo-Test’s performance in sigma-metrics was very good. Sigma was shown to be >2 at 48 mmol/mol and >4 at an HbA1c value of 75 mmol/mol. Examining the coefficients of variation (CVs) of all duplicates, one lot number showed sigma >6.