CGMs are probably going to still be more accurate, so the watch may not be ideal for Type 1, but could be nice for people with pre-diabetes who are trying to optimize their health. I'm also curious how accurate they will be.
CGMs themselves are still inaccurate compared to needles. And even needle based meters have a lot of different levels of accuracy. A CGM, even once calibrated, may be off by as much as 10%.
The value is in clinical application though. For closed loop systems, making a clinical decision for insulin dosing every 5 minutes is life-changing, even if the dosage is 10% off. I’d say even with compression lows, most systems are self-balancing enough to produce better results than a self-monitoring person could.
Besides, 10% off doesn’t often matter:
At 0-70 mg/dl the pump should suspend insulin either way. At 110-600 mg/dl the pump should ensure enough IoB by bolus, increase basal, and monitor either way. In that 70-110mg/dl the 10% MARD kind of matters for clinical decision-making, but not much. 90mg/dl is about as healthy as 81 and 99.
Patients are sometimes fussy by this inaccuracy but forget the tremendous benefit of trend indicators, let alone closed loop systems. Both of these have a much much larger positive impact to health than blood glucose being 10% above or below target impacts health negatively.
CGM with <=10% MARD, whether in wrist form factor or sensor form, is good enough for treatment. Of course, same as most readers, I have my doubts about this article.
My understanding is that CGMs shine at having a large volume of good data. You can see how your biometrics are trending over time much better than the <10/day readings someone with manual testing will receive.
It's both. The volume of data is helpful in making adjustments to insulin basal rates or dosing ratio. The instantaneous data is useful for making immediate decisions, either manually or automated, about insulin or sugar intake. Seeing a trend line can be much more useful than a single reading from finger stick too.
