Dexcom G4 Platinum User Manual page 138

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Participants used the System for seven days; each participant wore 2 sensors.
Sensors were calibrated approximately once every 12 hours, using the SMBG
values obtained from the Lifescan® OneTouch® Verio™ IQ meter. Throughout
the 7-day wear period, the Sensor was calibrated with an average of 2
fingersticks per day. The study took place at home, the System performance
was also paired with the comparative meter results, and that is referred to as the
reference 'SMBG'.
Agreement
Agreement between the System and blood glucose values is characterized using
paired sensor and SMBG values. The sensor and SMBG results were compared
by pairing the SMBG to a sensor glucose reading that occurred immediately
after the SMBG was collected within 5 minutes. These results present 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.
The agreement of the sensor to reference glucose value was assessed by
calculating the percentage of sensor readings that were within 20%, 30%, and
greater than 40% of the SMBG values. For readings less than or equal to 80
mg/dL (4.4 mmol/L) the absolute difference in mg/dL (mmol/L) between the two
glucose results was calculated. For values greater than 80 mg/dL (4.4 mmol/L)
the absolute percent difference (%) from the SMBG values was calculated. The
percentages of total readings within 20 mg/dL (1.1 mmol/L) or 20%, 30 mg/dL
(1.7 mmol/L) or 30%, or within 40 mg/dL (2.2 mmol/L) or 40%, within glucose
measurable ranges were then calculated (Table 1).
The total number of data pairs considered in this analysis was 1882. Of these,
seventy-seven percent (77%) of the sensor readings fall within 20 mg/dL (1.1
mmol/L) of the SMBG glucose values (≤ 80 mg/dL, i.e. 4.4 mmol/L) and within
20% of SMBG glucose values (>80 mg/dL, i.e. 4.4 mmol/L).
Table 1. Percentage of CGM Readings Within SMBG Values
Glucose
Number of
Ranges
Matchec
mg/dL
Pairs (n)
(mmol/L)
40-400
(2.2-22.2)
138 | Dexcom G4 PLATINUM Continuous Glucose Monitoring System
Percent
within 20/20
1882 77%
Percent Percent
within 30/30 within 40/40
90% 95%