Product Info

The device will always alert the user when the CGM system reads that the user is
below 50 mg/dL, regardless of the high threshold, low threshold, or predictive
alerts that the user sets.
Glucose TRUE Alert Rate
The glucose true alert rate is the rate at which the BG confirmed that the CGM
alert was triggered correctly. For example:
True Threshold Hypoglycemic alert rate alerted when the CGM system read that
the user was below the low threshold and the user’s BG was actually below that
low threshold.
True Threshold Hyperglycemic alert rate alerted when the CGM system read that
the user was above the high threshold and the user’s BG was actually above that
high threshold.
True Predictive Hypoglycemic alert rate alerted when the CGM system predicted
that the user would reach below the low threshold and the user’s BG was actually
below that low threshold within 15 or 30 minutes.
True Predictive Hyperglycemic alert rate alerted when the CGM system predicted
that the user would reach above the high threshold and the user’s BG was actually
above that high threshold within 15 or 30 minutes.
The true alert rate is important because it is necessary that users be notified when
their BG is low (or high) so that they can correct the low (or high) BG. A high true
alert rate indicates that when the CGM system says that their glucose values are, or
will reach a specified threshold, the user’s BG is likely to be at or approaching that
threshold.
For example, per the following table, the low glucose alerts would have correctly
indicated that the user was below (i.e. threshold only), or predicted to reach below
the threshold (i.e. predictive only) or both (predictive and threshold) 66.9%, 52.7%,
or 58.3% of the time within 30 minutes (or 66.9%, 47.7%, or 55.2% of the time
within 15 minutes) when the user had BG values lower than 70 mg/dL for a sensor
inserted in the abdomen.
344 Chapter 17