We appreciate the efforts of Wong et al. (1) in analyzing continuous glucose monitoring (CGM) use and benefits in the T1D Exchange Clinic Network registry database. Unfortunately, the data reported are reflective of experiences with prior CGM devices, not CGM as it exists today. This disparity may cause readers to draw incorrect conclusions based on the article. Both CGM systems currently available in the U.S. are significantly improved (2,3) compared with the Dexcom SEVEN PLUS and Medtronic Paradigm systems used when these data were collected from the T1D Exchange registry.

Differences between CGM systems significantly impact the CGM value proposition and persistence rates of CGM use (4). Given that sustained use of CGM appears to be a major predictor of patient benefit, system differences are significant (5,6). Accuracy, reliability, usability, and sustained use are major determinants of quality-of-life benefits derived from CGM (7). The authors acknowledge that 41% of CGM users have discontinued use possibly due to the older devices, but they fail to distinguish between types of devices. These categorical statements do not benefit clinicians, payors, or patients. Given the evolution of CGM technologies, it is likely that today’s more accurate CGM systems will result in improved patient trust and reduced alert fatigue, translating into more sustained CGM use, greater use of the CGM data, and better outcomes. As CGM technologies are rapidly improving, future assessment of CGM use and benefit analyses based on T1D Exchange data should exclude antiquated devices and be limited to applicable current technologies.

Duality of Interest. D.P., T.W., and C.G. are employees and shareholders of Dexcom, Inc. in San Diego, CA. No other potential conflicts of interest relevant to this article were reported.

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