Carol J. Levy, Lauren Kanapka, Sue A. Brown, Sheryl Marks, Tamara Spaic, Devin Steenkamp, Victor M. Lu, Peter Zhao, John W. Lum, Roy W. Beck, Jordan E. Pinsker, for the 2IQP Study Group
Objective: To characterize simplified meal bolus strategies in adults with insulin-treated type 2 diabetes using automated insulin delivery (AID). Research Design and Methods: In the 2IQP study, a 13-week randomized, controlled trial comparing Control-IQ+ AID to continuation of pre-study insulin regimen with continuous glucose monitoring, 201 participants in the AID arm were classified by meal bolus strategy. Glycemic outcomes were compared to baseline. Results: 68 participants’ meal bolus strategies (33.8%) were classified as Carbohydrate Counting, 79 (39.3%) were classified as Preset Carbohydrate Amounts, 27 (13.4%) were classified as Fixed Insulin Doses, and 27 (13.4%) as Other Methods. All bolus strategies were associated with similar, significant improvements in HbA1c from baseline: −0.9% for Carbohydrate Counting ( P < 0.001), −1.1% for Preset Carbohydrate Amounts ( P < 0.001), −0.8% for Fixed Insulin Doses ( P < 0.001), and −0.9% for Other Methods ( P = 0.003). Hypoglycemia rates were low at baseline and remained low for all bolus strategies. As participants gained experience with the Control-IQ+ AID system, more participants opted to use a simplified bolus strategy in the second half of the study compared with the first half (63% vs. 52%). Conclusion: Simplified bolus strategies worked well for adults with type 2 diabetes using Control-IQ+ in the 2IQP trial. All bolus strategies led to substantial HbA1c improvements, without safety concerns.