Six of Eight Hemoglobin A1c Point-of-Care Instruments Do Not Meet the General Accepted Analytical Performance Criteria

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 56; no. 1; pp. 44 - 52
• Main Authors: Lenters-Westra, Erna, Slingerland, Robbert J
• Format: Journal Article
• Language: English
• Published: Washington, DC Am Assoc Clin Chem 01.01.2010; American Association for Clinical Chemistry
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Glycated Hemoglobin A - analysis; Humans; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Molecular biophysics; Point-of-Care Systems - standards; Reagent Kits, Diagnostic; Reproducibility of Results; Performance evaluation; Instruments; Criterion; Hemoglobin A1c; Point of care testing; Clinical biology; Biochemistry; Molecular biology; Performance
• ISSN: 0009-9147; 1530-8561; 1530-8561
• DOI: 10.1373/clinchem.2009.130641

Background: Hemoglobin A1c (Hb A1c) point-of-care (POC) instruments are widely used to provide rapid-turnaround results in diabetic care centers. We investigated the conformance of various Hb A1c 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 A1c. 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 A1c 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 A1c 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 A1c POC instruments.