Sustained HbA1c Improvements Over 36 Months in Youth in the Teamwork, Targets, Technology, and Tight Control (4T) Study.

Context: Youth with type 1 diabetes (T1D) struggle to meet and sustain hemoglobin A1c (HbA1c) targets. Youth enrolled in the Pilot 4T Study improved HbA1c by 0.5%, compared to historical controls at 1-year.

Objective: To assess 3 years of glycemic outcomes in the Pilot 4T Study.

Design: The Pilot 4T Extension cohort was prospectively followed to determine changes in HbA1c and continuous glucose monitoring (CGM) metrics over 3 years.

Setting: Stanford Medicine Children's Health Diabetes Clinic.

Patients or other participants: Youth with T1D in the Pilot 4T Study enrolled in the extension phase.

Intervention: Youth started CGM in the first month of diabetes diagnosis, received intensified education and remote patient monitoring (RPM) weekly for the first year of diabetes diagnosis and monthly RPM in the extension phase.

Main outcome measure: HbA1c and CGM metrics over the first 3 years of diagnosis.

Results: In the Pilot 4T cohort, 78.5% (n=102) of participants enrolled in the study extension phase and were followed through 3 years. The adjusted difference in HbA1c at 3 years was 1.2% (95% CI 0.7-1.7%) lower in the Pilot 4T cohort than in the Historical cohort. In the Pilot 4T cohort, 68% and 37% met the <7.5% and <7% HbA1c targets at 3 years, respectively, compared to 37% and 20% in the Historical cohort.

Conclusions: Youth with T1D in the Pilot 4T extension phase sustained improvements in HbA1c over 3 years. Focusing resources on intensive management during the first year after T1D diagnosis may impact long-term glycemia.