User guide

Table Of Contents
low blood glucose can be obtained by setting the Low Glucose Alert level higher. For example, setting the
Low Glucose Alert at 90 mg/dL (5.0 mmol/L), instead of 70 mg/dL (3.9 mmol/L), increases the ability to
detect low blood glucose levels from 24% to 70% (see the following table).
Sometimes the Guardian RT will alert when the blood glucose levels are not low. When the Guardian RT
Low Alert was set at 70 mg/dL (3.9 mmol/L) in this study, 48% of the results were considered false alerts
(actual blood glucose values are greater than 85 mg/dL (4.7 mmol/L)). This percentage may be
exaggerated because blood glucose may be dropping when the Guardian RT alerts.
The table below shows the percent of Low Glucose readings correctly identified by the Guardian RT for
specific settings.
Guardian RT Low Alert
Setting (mg/dL)
Guardian RT Low Alert
Setting (mmol/L)
True Alert Rate
a
False Alert Rate
b
70 3.9 24% 48%
80 4.4 52% 46%
90 5.0 70% 52%
100 5.6 85% 57%
a. True Alert Rates are the % of times when the glucose level was at or below the alert setting and the alert sounded.
b. False Alerts Rates are the % of times when the Guardian RT Sensor alarmed but the blood glucose level was greater
than the alert setting.
Increasing the Low Alert settings will improve the ability to detect low blood glucose events, but it will
also increase the frequency of Guardian RT false alerts for blood glucose levels not below the target value.
You should consider this trade-off between the improved ability to detect true low blood glucose versus
the increased number of false alerts when setting the low alert threshold.
The High Glucose Alert
The High Glucose Alert was evaluated for its ability to detect glucose levels at 250 mg/dL (13.8 mmol/L),
or above, using the blood glucose meter. As a reference, with the High Glucose Alert set at 250 mg/dL
(13.8 mmol/L), 64% (404/632) of high glucose events were detected by the Guardian RT. Better detection
of high blood glucose can be obtained by setting the High Glucose Alert level lower. For example, setting
the High Glucose Alert at 190 mg/dL (10.6 mmol/L), instead of 250 mg/dL (13.8 mmol/L), increases the
ability to detect high blood glucose levels from 64% to 94% (see the following table).
Appendix A152