25
SECTION
B
FREQUENTLY ASKED QUESTIONS
1. Can results vary between meters in side-by-side tests?
Yes.
One meter is not a valid reference method for another meter. Readings would likely
vary because of the many variables that can affect the reading including:
• The naturally uneven distribution of glucose in blood between sites
• The time that the blood drop is exposed to the environment
• Whether you had to apply extra pressure to obtain the blood sample
• Inherent 15 to 20% variability of BGMs from laboratory reference methods
• Size of sample
• User technique
Medical studies reveal that it is not uncommon to get differences between the same brand
of test strips or between meters. Small variances are thought by many health professionals
to be perfectly reasonable.¹
Solution:
To confirm the accuracy of your meter, test results should be compared to those
obtained from a laboratory.
2. Can the Assure® Platinum Meter results vary from the laboratory test results?
Yes.
The test result you get with your meter should fall within 15% of the laboratory result.¹
However, the difference might exceed 20% on rare occasions because of the following
important variables:
a. Plasma versus whole blood
While blood glucose meters test whole blood, laboratory blood glucose measurements
are made either from a whole blood sample or from a blood plasma sample (blood
with the red cells removed). Both methods are widely used, and neither is more
“correct” than the other. However, the very nature of these two sample types produces
slightly different glucose measurements from the sample blood specimen. Plasma
measurements are, on average, about 12% higher than their whole blood counterparts.²
Solution:
The Assure Platinum System is “plasma-referenced.” Assure Platinum results
should fall within 15% to 20% of a laboratory result, which is based on testing a plasma
sample. Although the Assure Platinum uses a whole blood sample, we have adjusted
its internal calibration so that it converts results to match a plasma-referenced result.
Assure Platinum results will be, on average, 12% higher than laboratory results based on
whole blood testing. To compare Assure Platinum results with a whole blood referenced
laboratory result, first multiply the laboratory result by 1.12. Then Assure Platinum
results should fall within 15% to 20% of the adjusted laboratory result.
b. Capillary versus venous blood
The blood you use to test from the fingertip is capillary blood, while laboratories
generally use venous blood. Unless the patient is in a fasting state, the blood sugar
level of the capillary blood will be higher than that of the venous blood. Capillary blood
glucose levels may be 20 to 70 mg/dL higher than venous blood glucose after food
intake.³
c. Time test was performed
If the meter test is not done within 30 minutes of the laboratory test, it will result in
variations in the readings as blood glucose levels can change quickly.
For example: Glucose levels of whole blood can drop up to 7 mg/dL each hour because
of glycolysis if the samples are left at room temperature.
Solution:
Assure that the lab test is performed within 30 minutes of the blood being
drawn.