Accuracy and Clinical Utility of a Point-of-Care HbA_1c, Testing Device

Abstract

Background: Point-of-care testing (POCT) is widely used to measure blood glucose levels in people with diabetes, although its use in measuring glycated hemoglobin (HbA_1c) levels is less common, perhaps due to perceived performance issues and access to the technology. Methods: Forty blood samples were analyzed in duplicate using Bayer's A1CNow+® Multi-Test A1C system (A1CNow⁺) with 3 different reagent lots; HbA_1c levels of the samples spanned the clinically relevant range of 4% to 10%. Corresponding samples were sent to a National Glycohemoglobin Standardization Program (NGSP) secondary reference laboratory (University of Missouri Secondary Reference Laboratory #9), which analyzed the samples with a Tosoh Automated Glycohemoglobin Analyzer HLC-723G8 (Tosoh G8; Tosoh Bioscience, Inc). Results: Glycated hemoglobin levels measured with the A1CNow⁺ aligned with measurements obtained using the laboratory method, with correlation coefficients of 0.985, 0.987, and 0.989 for the 3 lots, respectively. The 95% CIs for the differences between the A1CNow⁺ levels and the mean HbA_1c, levels were within −0.55% to +0.50% for the 3 reagent lots, which is well within the currently acceptable limits of ±0.75% HbA_1c required by the NGSP. Results were further analyzed per the new tighter NGSP performance criteria effective September 1, 2012, requiring that 37 of 40 results be within ±7% (relative bias) of the NGSP reference laboratory measures. All 3 lots met the tighter NGSP criteria. Conclusion: The A1CNow⁺ provides accuracy and precision when performing POCT of HbA_1c as an aid in diabetes management. Ongoing improvements in this and other HbA_1c POCT devices may lead to a greater global acceptance of the role of POCT of HbA_1c in diabetes management.

Keywords:

• point-of-care testing
• glycated hemoglobin
• diabetes management
• HbA_1c measuring devices