title: Six of eight hemoglobin A1c point-of-care instruments do not meet the general accepted analytical performance criteria.
abstract: BACKGROUND
  Hemoglobin A(1c) (Hb A(1c)) point-of-care (POC) instruments are widely used to provide rapid-turnaround results in diabetic care centers. We investigated the conformance of various Hb A(1c) POC instruments (In2it from Bio-Rad, DCA Vantage from Siemens, Afinion and Nycocard from Axis-Shield, Clover from Infopia, InnovaStar from DiaSys, A1CNow from Bayer, and Quo-Test from Quotient Diagnostics) with generally accepted performance criteria for Hb A(1c).
  
  
  METHODS
  The CLSI protocols EP-10, EP-5, and EP-9 were applied to investigate imprecision, accuracy, and bias. We assessed bias using 3 certified secondary reference measurement procedures and the mean of the 3 reference methods. Assay conformance with the National Glycohemoglobin Standardization Program (NGSP) certification criteria, as calculated from analyses with 2 different reagent lot numbers for each Hb A(1c) method, was also evaluated.
  
  
  RESULTS
  Because of disappointing EP-10 results, 2 of the 8 manufacturers decided not to continue the evaluation. The total CVs from EP-5 evaluations for the different instruments with a low and high Hb A(1c) value were: In2it 4.9% and 3.3%, DCA Vantage 1.8% and 3.7%, Clover 4.0% and 3.5%, InnovaStar 3.2% and 3.9%, Nycocard 4.8% and 5.2%, and Afinion 2.4% and 1.8%. Only the Afinion and the DCA Vantage passed the NGSP criteria with 2 different reagent lot numbers.
  
  
  CONCLUSIONS
  Only the Afinion and the DCA Vantage met the acceptance criteria of having a total CV <3% in the clinically relevant range. The EP-9 results and the calculations of the NGSP certification showed significant differences in analytical performance between different reagent lot numbers for all Hb A(1c) POC instruments.
authors.affiliation: Department of Clinical Chemistry, Isala klinieken, Zwolle, The Netherlands. w.b.lenters@isala.nl
authors.forename: Erna
authors.initials: E
authors.lastname: Lenters-Westra
authors.forename: Robbert J
authors.initials: RJ
authors.lastname: Slingerland
mesh_terms: D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D019095:Point-of-Care Systems / Q000592:standards*; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results
chemical_list: D006442:Glycated Hemoglobin; D011933:Reagent Kits, Diagnostic; C517652:hemoglobin A1c protein, human