Accuracy of three hemoglobin A1c point-of-care systems for glucose monitoring in patients with diabetes mellitus.

Objective: Use of hemoglobin A1c point-of-care devices in physician offices provides immediate results and reduces inconveniences for the patients. We compared the analytical performances of 3 point-of-care HbA1c analyzers to high pressure liquid chromatography (HPLC).

Methods: We preselected a pool of 40 EDTA-preserved whole blood samples from our laboratory with HbA1c results obtained by HPLC (mean 6.6% [49 mmol/mol] and range: 4.6-9.9% [27-87 mmol/mol]). Aliquots of theses samples were tested by Afinion AS100, DCA Vantage and In2it point-of-care systems. According the Clinical Laboratory Standards Institute EP-09 protocol we determined linearity (linear regression and correlation coefficient between point-of-care and reference methods), bias (Bland-Altman analysis) and coefficient of variation (%). We used the acceptability criteria endorsed by the National Glycohemoglobin Standardization Program.

Results: The calculated correlation coefficients (r) were 0.98, 0.98 and 0.83 for Afinion AS100, DCA Vantage and In2it systems, respectively. The 95% confidence interval of the error between point-of-care systems and the reference method was -0.41% and +0.34% (p =.22) for Afinion AS100, -0.62% and +0.05% (p =.57) for DCA Vantage, and -1.15% and +1.26% (p<.001) for the In2it. The coefficients of variation for Afinion AS100, DCA Vantage and In2it systems were 1.80, 3.74 and 7.14%, respectively.

Conclusions: Only the Afinion AS100 point-of-care system met all NGSP performance criteria.