A comparison of blood glucose meters in Australia.

OBJECTIVE: To assess the accuracy and precision of the five currently available blood glucose meters in Australia.

DESIGN AND SETTING: Control solutions from manufacturers were used to determine the precision for each meter. Glucose levels in capillary blood samples from 49 patients attending a diabetes clinic were measured with each meter and with a laboratory reference method.

OUTCOME MEASURES: The coefficient of variation was calculated to determine precision. Bias, Error Grid analysis, and Bland-Altman plots were used to determine accuracy.

RESULTS: The CVs of most meters were acceptable at <5%. Bias ranged from 4.0 to 15.5% with only 1 meter satisfying the American Diabetes Association recommendation of <5% bias. Error Grid analysis showed that 94-100% of readings were clinically accurate, and that none of the differences from the reference method would lead to clinical errors. Bland-Altman plots showed that for two meters the magnitude of the difference between the meter and the reference method increased with increasing glucose values, but did not change significantly with glucose level for the other 3 meters.

CONCLUSIONS: Currently available blood glucose meters show acceptable precision, and any errors (with respect to a laboratory method) are highly unlikely to lead to clinical errors. However, only the CareSens meter achieved a bias of less than 5%.