title: Accuracy and clinical utility of a point-of-care HbA1c 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 (HbA1c) 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; HbA1c 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 HbA1c levels were within -0.55% to +0.50% for the 3 reagent lots, which is well within the currently acceptable limits of ±0.75% HbA1c 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.
  
  
  CONCLUSIONS
  The A1CNow + provides accuracy and precision when performing POCT of HbA1c as an aid in diabetes management. Ongoing improvements in this and other HbA1c POCT devices may lead to a greater global acceptance of the role of POCT of HbA1c in diabetes management.
authors.affiliation: Scientific Affairs Liaison, Diabetes Care, Bayer HealthCare LLC, Sunnyvale, CA 94085, USA. jennifer.knaebel@bayer.com
authors.forename: Jennifer
authors.initials: J
authors.lastname: Knaebel
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Irvin
authors.forename: Charles Z
authors.initials: CZ
authors.lastname: Xie
mesh_terms: D001322:Autoanalysis / Q000592:standards; D003920:Diabetes Mellitus / Q000097:blood; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D019095:Point-of-Care Systems / Q000592:standards; D015203:Reproducibility of Results
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human