title: Three of 7 hemoglobin A1c point-of-care instruments do not meet generally accepted analytical performance criteria.
abstract: BACKGROUND
  In 2009, we investigated the conformance of 8 hemoglobin A(1c) (Hb A(1c)) point-of-care (POC) instruments. Since then, instruments have improved and new devices are available on the market. In this second study, we evaluated the performance of DCA Vantage, Afinion, InnovaStar, Quo-Lab, Quo-Test, Cobas B101, and B-analyst Hb A(1c) POC instruments.
  
  
  METHODS
  Clinical and Laboratory Standards Institute protocols EP-5 and EP-9 were applied to investigate imprecision, accuracy, and bias. We assessed bias using the mean of 3 certified secondary reference measurement procedures (SRMPs). Assay conformance with the National Glycohemoglobin Standardization Program (NGSP) certification criteria was also evaluated. Interference of common Hb variants was investigated for methods that could work with hemolysed material.
  
  
  RESULTS
  The total CVs for all instruments, except for the DCA Vantage at a high Hb A(1c) value, were ≤3.1% in SI units and ≤2.1% in Diabetes Control and Complications Trial (DCCT) units. Afinion, DCA Vantage, B-analyst, and Cobas B101 instruments passed the NGSP criteria with 2 different reagent lot numbers. Quo-Test, Quo-Lab, and InnovaStar instruments had a negative bias compared to the mean of the 3 SRMPs and failed NGSP criteria. Most of the common Hb variants did not interfere with the investigated instruments, except Hb AE for the Cobas B101.
  
  
  CONCLUSIONS
  Afinion, DCA Vantage, Cobas B101, and B-analyst instruments met the generally accepted performance criteria for Hb A(1c). Quo-Test, Quo-Lab, and InnovaStar met the criteria for precision but not for bias. Proficiency testing should be mandated for users of Hb A1c POC assays to ensure quality.
authors.affiliation: Department of Clinical Chemistry, Isala, Zwolle, the Netherlands; European Reference Laboratory for Glycohemoglobin, Zwolle, the Netherlands. w.b.lenters@isala.nl.
authors.forename: Erna
authors.initials: E
authors.lastname: Lenters-Westra
authors.affiliation: Department of Clinical Chemistry, Isala, Zwolle, the Netherlands; European Reference Laboratory for Glycohemoglobin, Zwolle, the Netherlands.
authors.forename: Robbert J
authors.initials: RJ
authors.lastname: Slingerland
mesh_terms: D006442:Glycated Hemoglobin / Q000032:analysis* / Q000592:standards; D006801:Humans; D019095:Point-of-Care Systems / Q000592:standards*; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human