Alarms based on real-time sensor glucose values alert patients to hypo- and hyperglycemia: the guardian continuous monitoring system.

The purposes of this study were to demonstrate the accuracy and effectiveness of the Guardian Continuous Monitoring System™ (Medtronic MiniMed, Northridge, California) and to demonstrate that the application of real-time alarms to continuous monitoring alerts users to hypoand hyperglycemia and reduces excursions in people with diabetes. A total of 71 subjects with type 1 diabetes, mean hemoglobin A1c of 7.6 ± 1.1%, age 44.0 ± 11.4 years, and duration of diabetes 23.6 ± 10.6 years were enrolled in this two-period, randomized, multicenter study. Subjects were randomized into either an Alert group or a Control group. The accuracy of the Guardian was evaluated by treating the study data as a single-sample correlational design. Effectiveness of the Guardian alerts was evaluated by comparing the Alert group with the Control group. The mean (median) absolute relative error between home blood glucose meter readings and sensor values was 21.3% (17.3%), and the Guardian, on average, read 12.8 mg/dL below the concur...