Device Performance Characteristics - Dexcom G4 User Manual

11.2

DEVICE PERFORMANCE CHARACTERISTICS

NOTE:
• We recommend that you review the information in this chapter with your
healthcare provider to understand how well the Dexcom G4 System
performs.
The Dexcom G4 System (the System) uses a glucose sensor to continuously
measure and monitor your glucose levels. The sensor is "calibrated" using a
commercially available blood glucose meter; and once calibrated the System
reports glucose readings up to every 5 minutes. The System was evaluated
in a clinical study in which System readings were compared to blood glucose
values to assess its performance and how well the System readings compare
to a laboratory test method that measures blood glucose values. Additionally,
patients performed self-monitoring blood glucose meter tests at home to
assess the System performance in real use environment.
Although the performance characteristics of the System are presented in the
following, there is no commonly accepted statistical approach for capturing
performance of continuous glucose monitors (CGMs), such as the Dexcom
G4 System.
Clinical Study Overview
The System performance was evaluated in a prospective clinical study; 72
participants were enrolled. All participants had Type 1 or Type 2 diabetes
mellitus, and required insulin or oral medication to manage their diabetes.
About 83% of participants had Type 1 diabetes and about 17% of participants
had Type 2 diabetes. The study included subjects greater than 18 years of
age.
Participants used the System for seven days. Thirty-six participants each
wore 2 sensors. Sensors were calibrated approximately once every 12 hours,
using the self-monitoring blood glucose (SMBG) meter values obtained from
the LifeScan OneTouch Ultra2 meter. Throughout the 7-day wear period, the
sensor was calibrated with an average of 2 fingersticks per day (approximately
once every 12 hours).
All subjects were evaluated in a controlled clinic environment on Day 1, Day
4, and Day 7 of the 7-day wear period. While using the System in the clinic,
participants had their blood glucose measured every 15 minutes with a
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