Accuracy Performance of the Medtronic NexSensor® for 6 Days in an Inpatient Setting Using Abdomen and Buttocks Insertion Sites

Abstract

Background:

Users of continuous glucose monitoring are concerned with product accuracy and choice of insertion site. The Medtronic NexSensor® was evaluated for accuracy during 6 days of wear when inserted in the abdomen and buttocks areas.

Methods:

Adults (ages 18–75) with type 1 diabetes wore two sensors simultaneously for 6 days, one each inserted in the abdomen and buttocks. Subjects underwent a frequent blood sampling study for 12 hours, during which time reference blood glucose values were obtained every 15 minutes and compared to sensor values.

Results:

Sixty-three subjects were enrolled, and 61 subjects completed the study. The mean agreement rate between sensor and blood glucose values was 75.5% [95% confidence interval (CI), 69.5, 81.4] at the abdomen site, 73.8% (95% CI, 68.8, 78.8) at the buttocks site, and 75.6% (95% CI, 70.8, 80.4) when sensor and reference data were combined between sites. Over 90% of paired sensor-reference values on Clarke error grids were within the A and B ranges. The mean absolute relative differences were 17.1% at the abdomen site, 16.5% at the buttocks site, and 16.8% when sites were combined.

Conclusion:

The NexSensor was accurate for inpatient, frequent-sample testing for 6 days when inserted into the abdomen and buttocks. The results of this study also provide evidence that both the abdomen and buttocks are suitable as sensor insertion sites.

Keywords

accuracy blood glucose continuous glucose monitoring subcutaneous glucose sensor

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