Introduction and Objective: Our randomized crossover trial in adolescents/young adults with T1D on automated insulin delivery (AID) showed a simple bolus approach (simple; entering 30/60/90g) achieved non-inferior time-in-range (TIR) vs carbohydrate counting (CC). We describe bolus behaviors and compare self-reported burden and related outcomes. Methods: Participants (age 14-26) using AID completed 4 weeks of simple and 4 weeks of CC. Surveys were collected at baseline and after each study period. Results were summarized as means; higher scores indicated worse outcomes (frequency, burden, worry, difficulty, or negative impact). Survey items were compared using a Friedman test. Results: Thirty-one participants (17.4 years; 51.6% female; T1D duration 8.3 years; baseline TIR 63.8%) delivered 4.6 user-initiated boluses/day at baseline, 4.5 during simple, and 5.1 during CC. Baseline bolus habits included educated guessing (90.3%), entering similar values each meal (6.5%), or using labels/resources to CC (3.23%). After the trial, 40.6% preferred simple, 31.3% CC, and 28.1% baseline habits. Meal bolusing felt significantly less burdensome during simple (baseline 2.0, simple 1.6, CC 2.4; p = 0.0007). Need for compensatory behaviors (extra eating or correction insulin) did not differ. Conclusion: A simple meal bolus strategy can reduce perceived burden for some adolescents and young adults on AID without an impact on glycemic outcomes, supporting its use as a pragmatic alternative to CC. Disclosure A. Sawyer: None. A.B. Stein: None. L. Towers: None. S. Lange: None. C. Berget: Consultant; Current; Insulet Corporation. Consultant; Ended; Medtronic. Advisory Panel; Current; Tandem Diabetes Care, Inc. Consultant; Current; Tandem Diabetes Care, Inc. Advisory Panel; Current; Sequel. G. Forlenza: Other - Research Support, Speaker, Ad Board Member; Current; Medtronic. Other - Research Support, Speaker, Consultant; Current; Dexcom, Inc. Research Support; Current; Abbott. Other - Research Support, Speaker, Consultant; Current; Insulet Corporation, Tandem Diabetes Care, Inc. Research Support; Current; MannKind Corporation. Other - Research Support, Consultant; Current; Sequel. Funding NIDDK (T32: 2T32DK063687)
Sawyer et al. (Fri,) studied this question.