Dexcom G4 Platinum User Manual page 136

11
Precision of System Readings
In the study, 36 participants wore two Systems. This was to look at how similarly
two Systems function on the same patient (sensor precision). Precision was
evaluated by comparing the glucose readings from the two Systems worn on
the same subject at the same time. Results showed that System readings from
the two sensors generally agreed with each other within 9% (absolute percent
difference) with a 7% coefficient of variation.
Sensor Life
Sensors may be worn for up to 7 days (168 hours). To estimate how long a
sensor will work over 7 days, 108 sensors were evaluated to determine how
many days/hours of readings each sensor provided. Ninety-four percent (94%)
of the sensors lasted until Day 7 (145-168 hours). There were 6 (4%) sensors
that ended early, four of which lasted more than 3 days.
Number of Readings Provided
The System is capable of providing a reading up to every 5 minutes, or up to 288
readings per day. For a variety of reasons, the System may not display a glucose
reading and readings are "skipped." Adjusted within each system wear-day, the
System provided an average of 97% of all expected glucose readings (288).
Agreement and Accuracy Relative to SMBG
During the study, agreement between the System and blood glucose values
is also characterized using paired System and SMBG results. The System
and SMBG values were compared by pairing the comparative SMBG value
to a System glucose reading that occurred immediately after the SMBG was
collected. These results characterize the performance patients expect during
real-time use of the system in their daily diabetes management when comparing
the system readings to their home blood glucose meter results.
Table 6. System Agreement to SMBG within CGM Glucose Ranges
CGM Glucose
Ranges mg/dL
(mmol/L) CGM-SMBG
40-400
(2.2-22.2)
40-80
(2.2-4.4)
136 | Dexcom G4 PLATINUM Continuous Glucose Monitoring System
Percent
Number of
within
paired
20/20%
SMBG
7508 81%
1699 85%
Percent Percent
within within
30/30% 40/40%
SMBG SMBG
94% 98%
94% 97%