Uninterrupted continuous glucose monitoring access is associated with a decrease inHbA1cin youth with type 1 diabetes and public insurance

Objective Continuous glucose monitor (CGM) use is associated with improved glucose control. We describe the effect of continued and interrupted CGM use on hemoglobin A1c (HbA1c) in youth with public insurance. Methods We reviewed 956 visits from 264 youth with type 1 diabetes (T1D) and public insurance. Demographic data, HbA1c and two-week CGM data were collected. Youth were classified asnever user,consistent user,insurance discontinuer, andself-discontinuer. Visits were categorized asnever-user visit,visit before CGM start,visit after CGM start,visit with continued CGM use,visit with initial loss of CGM,visit with continued loss of CGM, andvisit where CGM is regained after loss. Multivariate regression adjusting for age, sex, race, diabetes duration, initial HbA1c, and body mass index were used to calculate adjusted mean and delta HbA1c. Results Adjusted mean HbA1c was lowest for theconsistent usergroup (HbA1c 8.6%;[95%CI 7.9,9.3]). Delta HbA1c (calculated fromvisit before CGM start) was lower for visit after CGM start(-0.39%;[95%CI -0.78,-0.02]) andvisit with continued CGM use(-0.29%;[95%CI -0.61,0.02]), whereas it was higher forvisit with initial loss of CGM(0.40%;[95%CI -0.06,0.86]),visit with continued loss of CGM(0.46%;[95%CI 0.06,0.85]), andvisit where CGM is regained after loss(0.57%;[95%CI 0.06,1.10]). Conclusions Youth with public insurance using CGM have improved HbA1c, but only when CGM use is uninterrupted. Interruptions in use, primarily due to gaps in insurance coverage of CGM, were associated with increased HbA1c. These data support both initial and ongoing coverage of CGM for youth with T1D and public insurance.