Evaluation of two HbA1c point-of-care analyzers

Clin Chem Lab Med. 2011 Apr;49(4):653-7. doi: 10.1515/CCLM.2011.101. Epub 2011 Feb 17.

Abstract

Background: Measurement of HbA1c is the most important parameter to assess glycemic control in diabetic patients. Different point-of-care devices for HbA1c are available. The aim of this study was to evaluate two point-of-care testing (POCT) analyzers (DCA Vantage from Siemens and Afinion from Axis-Shield). We studied the bias and precision as well as interference from carbamylated hemoglobin.

Methods: Bias of the POCT analyzers was obtained by measuring 53 blood samples from diabetic patients with a wide range of HbA1c, 4%-14% (20-130 mmol/mol), and comparing the results with those obtained by the laboratory method: HPLC HA 8160 Menarini. Precision was performed by 20 successive determinations of two samples with low 4.2% (22 mmol/mol) and high 9.5% (80 mmol/mol) HbA1c values. The possible interference from carbamylated hemoglobin was studied using 25 samples from patients with chronic renal failure.

Results: The means of the differences between measurements performed by each POCT analyzer and the laboratory method (95% confidence interval) were: 0.28% (p<0.005) (0.10-0.44) for DCA and 0.27% (p<0.001) (0.19-0.35) for Afinion. Correlation coefficients were: r=0.973 for DCA, and r=0.991 for Afinion. The mean bias observed by using samples from chronic renal failure patients were 0.2 (range -0.4, 0.4) for DCA and 0.2 (-0.2, 0.5) for Afinion. Imprecision results were: CV=3.1% (high HbA1c) and 2.97% (low HbA1c) for DCA, CV=1.95% (high HbA1c) and 2.66% (low HbA1c) for Afinion.

Conclusions: Both POCT analyzers for HbA1c show good correlation with the laboratory method and acceptable precision.

MeSH terms

  • Bias
  • Blood Chemical Analysis / instrumentation
  • Blood Chemical Analysis / methods*
  • Blood Chemical Analysis / standards
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Glycated Hemoglobin A / analysis*
  • Humans
  • Laboratories / standards
  • Point-of-Care Systems* / standards
  • Reference Values
  • Reproducibility of Results

Substances

  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human