Question from Malta:

Are home blood glucose monitors reliable instruments? Some are rated as accurate, and, later, this accuracy turns out to be +/- 20%. Then, compared to each other, they give very different results (at same time and under the same conditions). At times, meters differed by as much as 50% from each other. Once, the reading was only 50% of my real blood sugar.”Real” values, as I understand them, are those obtained by professional hospital equipment. I am taking into consideration that hospitals often use plasma for tests.

While tables comparing various meters are easily obtained, all tables I came across leave out the “margin of error” or test precision that one would expect from any particular meter. They mention price, ease of use and testing time and leave out what all users would want to know first, the true value of the blood glucose level. Does this data exist and is it available to the prospective buyer? Very often patients have to buy blindly relying only on the manufacturer information. For obvious reasons, doctors are often reluctant to promote any particular brand.