How accurate are home blood-glucose meters with special respect to the low glycemic range?

Comparisons were made between four blood-glucose meters (Diascan, Glucometer II, Reflolux II and ExacTech) and a reference method (YSI) for the full, clinical, blood-glucose range and for the subranges < 4.4 mmol/l, 4.4-10.0 mmol/l and > 10.0 mmol/l, respectively. In the low-glucose range, the error-grid analysis was also applied. All the meters showed acceptable agreement with the reference method when the whole glucose range was considered, yielding r-values between 0.96 and 0.99. However, when the results were separated in the different subranges, the outcome was different, in that the Diascan meter displayed systematically high glucose levels and the ExacTech meter showed a great spread of the values within the low-glucose range, whereas the Glucometer II and the Reflolux II meter were less accurate within the high-glucose range. By applying the error-grid analysis, several errors of clinical importance within the low glycemic range were revealed, while other significant errors, which might lead to inadequate therapeutic decisions, were classified as 'clinically accurate'.