User`s guide

162 | Dexcom G4 PLATINUM Continuous Glucose Monitoring System
14
Low and High Glucose Alerts
The ability of the System to detect high and low glucose levels is
assessed by comparing System results to YSI results at low and high
blood glucose levels and determining if the alert may have sounded. The
System and YSI values were compared by pairing the System reading
that occurred immediately after the YSI value was collected. We suggest
that you ask your doctor what alert settings would be best for you.
The Low Glucose Alert
Estimates of how well the adjustable Low Glucose Alert performs are
presented in Table 5.
Hypoglycemia Alert Rate
The Alert Rate shows how often the alert is right or wrong. The True
Alert Rate is the % of time the device alarmed when the blood glucose
level was at or below the alert setting within 15 minutes before or after
the device alarmed. The False Alert Rate is the % of time the device
alarmed when the blood glucose level was above the alert setting within
15 minutes before or after the device alarmed.
For example, if you set the Low Glucose Alert to 70 mg/dL and your
alarm sounds, how often can you expect your blood sugar to actually
be low? Based on the Original Study, if your alarm sounds, you can
expect your blood sugar to be below 70 mg/dL approximately 79% of the
time and not be below 70 mg/dL approximately 21% of the time within
the 15 minute period before or after your alarm sounds. Based on the
Software 505 Study, if your alarm sounds, you can expect your blood
sugar to be below 70 mg/dL approximately 92% of the time and not
be below 70 mg/dL approximately 8% of the time within the 15 minute
period before or after your alarm sounds.
Hypoglycemia Detection Rate
The Detection Rate shows how often the device recognizes and alerts
you to an episode of hypoglycemia or how often it misses such an event.
The Hypoglycemia Detection Rate is the % of time the blood glucose
level was at or below the alert setting and device alarmed within 15
minutes before or after the blood glucose was at or below the alert