User`s guide

134 | Dexcom G4 Continuous Glucose Monitoring System
11
Calibrations Stability
The System must be calibrated every 12 hours. To demonstrate performance
of the System over a 12-hour calibration period, 42 Sensors were evaluated to
verify that performance remains consistent over the 12-hour calibration period.
Systems were evaluated in 2-hour increments after calibration. Performance was
estimated at each 2-hour interval and stratied by glucose concentrations by
calculating the percentage of System readings within 20 mg/dL (1.1 mmol/L) or
20%, 30 mg/dL (1.7 mmol/L) or 30% and greater than 40 mg/dL (2.2 mmol/L) or
40% of the YSI values in Table 5.
Table 5. Percentage of CGM System Readings within YSI Laboratory Values
with data stratied in 2-hour increments after calibration
Time from
Calibration
Number
of Paired
YSI-CGM
Readings
Percent
within 20%*
Percent
within 30%*
Percent
greater than
40%*
0-2 hours 348 83% 93% 2%
2-4 hours 308 74% 94% 1%
4-6 hours 293 84% 96% 1%
6-8 hours 276 75% 92% 3%
8-10 hours 203 81% 96% 2%
10-12 hours 40 78% 93% 5%
12-14 hours 9 100% 100% 0%
*For YSI less than 80 mg/dL (4.4 mmol/L), the absolute difference is presented as the
difference between the System and YSI, rather than the percent.