Accuracy of the EasyTouch blood glucose self-monitoring system: a study of 516 cases.

BACKGROUND

Self-monitoring blood glucose device is an important tool for diabetes patients to efficiently control their blood glucose concentrations. We evaluated the accuracy of EasyTouch glucose monitoring system.

METHODS

Capillary blood glucose concentrations measured using EasyTouch and the reference values obtained from Yellow Springs Instruments (YSI) 2300 STAT were performed in the Department of Laboratory Medicine, Wei-Gong Memorial Hospital. Results were evaluated using (1) linear regression analysis, (2) Clarke Error Grid analysis, (3) percentage of readings within a defined range of deviation from the reference value, (4) bias plots, and (5) coefficients of variation (CVs) calculated from 60 measurements in series.

RESULTS

The window of the 516 EasyTouch readings covered a range from 42 to 555 mg/dl. Linear regression analysis yielded a regression slope 0.9972, intercept 1.899 mg/dl, r2 0.9571, and Syx 14.89 mg/dl. A Clarke Error Grid analysis showed 100% of the EasyTouch readings in clinically acceptable zones A and B. Of the EasyTouch readings, 98.3%, 91.9%, 78.3% and 46.9% were found within +/-20%, +/-15%, +/-10%, and +/-5%, respectively, of the reference values. Further analysis showed that the percentage of EasyTouch readings within the defined intervals was similar in three glucose ranges (< or =100, 101-200, and > or =201 mg/dl). The CVs for the four lots of strips (lot 1 to lot 4) ranged from 3.5 to 5.5%, 2.1 to 4.8%, 1.8 to 3.6%, and 3.0 to 5.7%, respectively.

CONCLUSIONS

EasyTouch provides high accurate and precise glucose readings over a wide range of glucose concentrations.