Accuracy of portable blood glucose monitoring. Effect of glucose level and prandial state.

Glucose was determined on capillary and venous blood samples from 274 adult diabetics by three different methodologies: the Glucoscan 2000 and Accu-Check II portable glucose meters (capillary) and the Kodak Ektachem 700 analyzer (venous). Both glucose meters correlated significantly with the Ektachem results. A significant positive bias was found for the Glucoscan compared with Ektachem, not found with the Accu-Check II. The Accu-Check performed better than the Glucoscan at venous plasma glucose levels less than 1 g/L. The mean error of Glucoscan determinations was significantly greater and biased positive when the measurement was performed within 4 hours of eating, whereas no such effect was seen with Accu-Check error. Multiple regression analysis revealed that the Glucoscan measurement was independently influenced by both venous plasma glucose and prandial state, whereas the Accu-Check II measurement was not dependent on either variable. The within-run precision for both glucose meters were comparable.