Primary Care-Initiated Continuous Glucose Monitoring in Adults With Insulin-Treated Diabetes

Most diabetes care is managed in primary care settings, which represent a critical yet underutilized site for continuous glucose monitoring (CGM) adoption. Whether CGM initiation by primary care clinicians improves glycemic outcomes and reduces acute health care utilization remains understudied.

To evaluate the association of primary care-initiated CGM with changes in hemoglobin A1c (HbA1c) levels and rates of hospitalizations and emergency department (ED) visits among adults with insulin-treated diabetes.

This cohort study was performed at 18 primary care clinics within Montefiore Medical Center, a large safety-net health system in the Bronx, New York. Adults 18 years or older with any insulin-treated diabetes who had at least 1 primary care visit between August 1, 2022, and August 1, 2025, were included. Patients were excluded if they were uninsured, if they had a CGM prescription in the prior 2 years, or if their first CGM during follow-up was prescribed outside primary care.

First CGM prescription by a primary care clinician.

The primary outcomes were HbA1c level trajectories, which were analyzed using mixed-effects models, and hospitalizations and ED visits, which were analyzed using recurrent event frailty models.

The study included 8502 insulin-treated CGM-naive adult patients with diabetes (mean [SD] age, 62.3 [14.6] years; 4764 [56.0%] female; 3618 [42.6%] with Medicare and 2854 [33.6%] with Medicaid coverage). Of these, 2392 patients (28.1%) were prescribed CGM by primary care clinicians. Patients who initiated CGM were younger, more often English-speaking and commercially insured, and had higher baseline HbA1c levels and more microvascular complications. At 12 months, HbA1c levels decreased by 0.66 (95% CI, 0.57-0.75) percentage points (pp) in patients who initiated CGM vs 0.17 (95% CI, 0.08-0.27) pp in those who did not, with a between-group difference of -0.49 (95% CI -0.62 to -0.35) pp. CGM initiation was associated with lower risk of recurrent hospitalizations (hazard ratio, 0.87 [95% CI, 0.77-0.98]) and ED visits (hazard ratio, 0.82 [95% CI, 0.74-0.91]).

In this cohort study of adults with insulin-treated diabetes, initiation of CGM by primary care clinicians was associated with clinically meaningful improvements in HbA1c and significant reductions in recurrent hospitalizations and ED visits. These findings support expanding CGM implementation in primary care settings as a scalable strategy to improve diabetes outcomes and reduce acute care utilization, particularly in underserved populations.