INS and diabetes mellitus: This trial of real-time CGM initiators (N = 3,806) vs. non-initiators (N = 37,947) who received care in Northern California (2014–2019) for insulin-treated diabetes reported a decrease in mean HbA1c from 8.2% to 7.8% in the CGM group and 8.3% to 8.2% in the control group over 12 months (difference-in-differences estimate, −0.4%; 95% CI, −0.5% to −0.3%; P < 0.001).