Target Trial Emulation Links CGM to 44% Lower One-Year Mortality in Basal Insulin Users

Abbott researchers emulated a target trial within the Truveta database of 140 million U.S. records, matching 13,935 first-time CGM users to an equal number of controls on 29 baseline covariates including HbA1c, diabetes duration, comorbidities, and prior healthcare utilization. Prescription fill data from 2017-2024 yielded consistent reductions in all-cause death, incident macrovascular events, recurrent events, and heart failure hospitalizations at both one and two years. The absolute mortality reduction of 0.93 percentage points at 12 months implies a number-needed-to-treat near 108, with larger relative effects on heart failure (54% lower). Sensitivity analyses excluding the COVID period and deaths before 90 days left estimates materially unchanged, yet the design still relied on filled prescriptions rather than verified sensor wear. Because the study remains observational despite emulation methods, healthier-user bias and unmeasured socioeconomic factors could explain part of the association. No prior large RCT has tested mortality as a primary endpoint in basal-insulin-treated type 2 diabetes, leaving causality unproven. An adequately powered randomized trial with five-year follow-up and objective adherence monitoring would be required to determine whether CGM itself alters survival.