Ease of administration: All four CGMs were easily affixed to the back of my arm using a plunger device held against the skin. (I must admit that I’m not sure I could have done this on my own, at least the first few times. I engaged the help of my mechanical-engineering husband, who found administration straightforward.) All four sensors have a short monofilament that remains embedded in the skin.
Event Tracking: All four allow tracking of food and exercise in the companion app and include a notes feature to track meal details and other important factors, like stress and sleep. Event tracking is critical for diagnosing what led to spikes, dips, or blood sugar variability, since individuals react to foods differently. Mahmood Kazemi, chief medical officer for Abbott’s diabetes care arm, says “there are no absolutes in terms of eating; what works for you may be different than what works for others.” He adds that “CGMs provide information needed to make educated decisions, since the impact of food choices can be different for each person.”
Summary Reports: All four provide summary graphs that are useful for monitoring glucose range and trends, along with user-supplied notes. Daily reports that show actual blood glucose graphs, along with meals and notes about food, exercise, and stress, are very helpful for determining what behaviors and situations impact blood glucose.
Water resistance: The FreeStyle Libre sensors are water resistant and work as long as they are not submerged more than 3 feet or kept underwater for over 30 minutes at a time. The Dexcom G7 is waterproof and may be submerged under 8 feet of water for up to 24 hours. I showered and worked out with all four CGMs without any issue.
Support: All four systems provided user videos, phone support, and explanations about app functionality.
Cost: Cash prices vary widely, so be sure to compare prices. I took advantage of substantial savings by checking prices and using online prescription discount services. Also, it’s worth remembering that the sensors have to be replaced periodically. Sensor prices are included below.