Three continuous glucose monitoring systems were shown to provide similar accuracy in adults with type 1 diabetes compared with self-monitoring blood glucose, according to findings published in the Journal of Diabetes Science and Technology.
“Since some CGM systems are already intended for nonadjunctive use, that is, as a replacement for SMBG measurements, and may therefore be used for therapeutic decisions, accuracy and reliability of CGM values have also become important in terms of patient safety,” Guido Freckmann, MD, head of research and development for the Institute of Diabetes Technology, Research and Development at the University of Ulm, Germany, and colleagues wrote.
The three devices tested by Freckmann and colleagues in an open, prospective study were the Dexcom G5 Mobile CGM system, the Guardian Connect system (Medtronic) and the Roche CGM system. Fifty-four adults with type 1 diabetes for an average duration of 23 years (mean age, 45 years; 52% women) were recruited from two sites in Austria and Germany to participate in the study. Each participant wore all three devices in parallel, with 4 home use days and 2 days at the study site. Participants also completed questionnaires to help evaluate usability of each device.
The mean absolute relative difference in glucose concentration was lowest in the Dexcom system compared with SMBG in routine measurements (10.1), followed by the Guardian system (11.5) and the Roche system (11.9). In dynamic phases, which were induced during on-site visits, the Dexcom system had the lowest mean absolute relative difference in glucose concentration compared with SMBG (10.1), followed by the Guardian system (11.2) and the Roche system (11.3), according to the study. The Roche system had lower differences in hypoglycemia both in routine use (8.4) and during dynamic phases (7.9) compared with the Dexcom system (10.1 and 11, respectively) and the Guardian system (12.1 and 13, respectively). The Dexcom system had lower differences in hyperglycemia both in routine instances (9.5) and dynamic phases (9.9) compared with the Guardian system (9.9 and 10.2, respectively) and the Roche system (12.5 and 12.6, respectively).
The Guardian system had the highest detection rate for high glucose values (84%) compared with the Dexcom system (79%) and Roche system (61%), whereas the Dexcom system had the highest detection rate for high glucose values (88%), followed by the Roche system (83%) and the Dexcom system (82%), the researchers wrote.
In terms of usability, participants reported a higher use rate for the Roche system (92.6%) compared with the Dexcom (77.4%) and Guardian (68.5%) systems. However, more problems were reported for the Roche system (n = 25) vs. the Dexcom (n = 8) and Guardian (n = 20) systems, primarily related to connecting the transmitter and receiver.
“Generally, all systems were rated positively by most users, but with differences in individual preferences based on usability aspects,” the researchers wrote. – by Phil Neuffer
Disclosures: The study was funded by Roche Diabetes Care GmbH. Freckmann reports he is the general manager of the Institute of Diabetes Technology, Research and Development. He and the institute have received speakers honoraria or consultant fees from Abbott, Ascensia, Bayer, LifeScan, Menarini Diagnostics, Novo Nordisk, Roche, Sanofi, Sensile and Ypsomed Please see the study for all other authors’ relevant financial disclosures.