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The Bigfoot Unity
™
Diabetes Management System User Guide | Appendix C
Alert Performance
The tables in this section show the accuracy of the Libre 2 Sensor’s
Low Glucose Alert. The Alert Rate tells you how often the alert is right
or wrong. The Detection Rate tells you how often the Libre 2 Sensor is
able to recognize and notify you about a low glucose event.
Low Glucose Alert Performance
Tables 5a and 5b
display the percentages for these parameters:
True Alert Rate
Tells you: When you got a Low Glucose Alert, were you actually low?
Definition: Percentage of time the alert issued and blood glucose was
below the alert level within 15 minutes before or after the alert.
False Alert Rate
Tells you: Did you get a Low Glucose Alert that you shouldn’t have?
Definition: Percentage of time the alert issued and blood glucose was
not below the alert level within 15 minutes before or after the alert.
Detection Rate
Tells you: When you were low, did you get a Low Glucose Alert?
Definition: Percentage of time blood glucose was below the alert level
and the alert issued within 15 minutes before or after the glucose
event.
Missed Detection Rate
Tells you: When you were low, did you miss a Low Glucose Alert?
Definition: Percentage of time blood glucose was below the alert level
and the alert didn’t issue within 15 minutes before or after the glucose
event.
For example, the Adult study found that for a Low Glucose Alert level
set to 70 mg/dL:
86.0% of the time a Low Glucose Alert was received when blood
glucose was indeed below the alert level but 14.0% of the time a Low
Glucose Alert was received when blood glucose wasn’t actually below
the alert level. 89.3% of the time blood glucose was below the alert
