Dexcom SEVEN PLUS User Manual page 108

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Participants enrolled in the clinical study and certain conditions of the study tend to result in above
average glucose control. This, in turn, may result in the appearance that the SEVEN PLUS agrees
with blood glucose levels better than it does under typical conditions. The following are some
examples of why performance of the SEVEN PLUS might be idealized in this study.
The average Hemoglobin A1c among the 53 participants was 7.4%. Many people with diabetes
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have higher A1c levels, indicating poorer control of their glucose levels.
While subjects participated in the clinic portion of the study, they were more limited in their
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activities than someone at home. They were also provided with all their meals. Subjects who are
more active, or with poor eating habits, may create more challenging conditions for the SEVEN
PLUS.
Blood Glucose meters used in the study were well maintained. Because the meter is used to
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calibrate the SEVEN PLUS, performance may be poorer if the meter is not well maintained. It is
important to carry out quality-control checks on the meter and code the meter according to the
manufacturer's instructions to optimize performance of the SEVEN PLUS.
Clinical Study Results
To evaluate performance of the SEVEN PLUS, 53 participants were enrolled in a clinical study
conducted at 3 clinics. All participants had Type 1 or Type 2 diabetes mellitus, and required insulin
to manage their diabetes. About 81% of participants had Type 1 diabetes and about 19% had Type 2
diabetes. Subjects ranged in age from 23 to 72 years old.
Participants used the SEVEN PLUS for approximately 7 days (each participant wore 1 or 2 Sensors for 7
days.) Receivers were calibrated approximately 2 times per day, on average, over the 7-day period using
the Lifescan OneTouch Ultra meter. Throughout the 7-day wear period, the Receiver was calibrated
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the most on day 1, with an average of 3 fingersticks per day (2 to start up and 1 in the evening), and was
calibrated with an average of 2 fingersticks per day for days 2-7 (approximately every 12 hours).
All participants used the SEVEN PLUS in a controlled clinic environment on Day 1, Day 4, or Day 7
of the 7-day wear period. The remainder of the study took place at home. While using the SEVEN
PLUS in the clinic 49 of the 53 participants had their blood glucose measured every 15 minutes
with a reliable laboratory method, the Yellow Springs Instrument 2300 STAT Plus glucose analyzer.
This instrument is referred to as the "YSI." Readings from the SEVEN PLUS were paired with YSI
readings in order to characterize how well SEVEN PLUS results agreed with blood glucose results.
For the remainder of the study, participants used the SEVEN PLUS at home and results were paired
with OneTouch Ultra blood glucose meter results. During Start-Up Calibration (see Chapter 4), all
participants (100%) were able to calibrate successfully after the 2 hour Start-up period. For Calibration
Updates/Re-Calibration (see Chapter 4) 97% of the time participants only needed one attempt to
update calibration. Two-percent (2%) of Calibration Updates required a second attempt, and less than
one-percent (<1%) of Calibration Updates needed more than three attempts.
108 | SEVEN PLUS Continuous Glucose Monitoring System