Abstract

Background: While evaluating the diagnostic performance of venous blood glucose measured with blood glucose meters in diagnosis of gestational diabetes, we had the opportunity to assess the accuracy of the blood glucose meters. Objectives: To assess the accuracy of blood glucose meters using venous blood in the glucose tolerance test in pregnant women. Methods: 230 pregnant women at 24 - 32 weeks of gestation were tested for 75 gr oral glucose tolerance test with blood samples at 0, 1 and 2 hours. Venous plasma glucose concentrations were quantified in the laboratory by a biochemistry analyzer and measured with 2 blood glucose meters (GMT) Contour TS and One Touch VerioPro Plus. The modified Bland – Altman chart, the mean of the absolute values of the relative differences (MARD) and the ISO 15197: 2013 standards were used to evaluate the accuracy of the meters when taking the laboratory venous plasma glucose concentrations as the reference values. Results: The relative bias of the Contour TS meter measurements was -8.5% with the 95% confident interval and 95% agreement limits of -7.4% to -9.6% and -23.0% to +5.9%, respectively. The relative bias of One touch VerioPro Plus meter measurements was -5.6%, statistically significantly lower than that of Contour TS meter (p < 0.001), with the 95% confident interval and 95% agreement limits of -4.7 to -6.5% and -20.5% to +9.4%, respectively. The MARD of the Contour TS meter and the One touch VerioPro Plus meter was 9.44 ± 6.15%, and 7.60 ± 5.61%, respectively, and the former’s was statistically significantly higher than the latter’s (p < 0.001). The proportions of samples that met the standards according to ISO 15197: 2013 of the Contour TS meter in the venous plasma glucose range < 5.6 mmol/L, ≥ 5.6 mmol/L and in the whole range were 91.4%, 83.8% and 86.7%, respectively; the corresponding values of the One touch VerioPro Plus meter were 95.3%, 90.8% and 92.5%,respectively. Conclusions: The bias of both GMT measurements was significant and both did not meet ISO 15197: 2013 requirements