A Pilot Study of Youth With Type 1 Diabetes Initiating Use of a Hybrid Closed-Loop System While Receiving a Behavioral Economics Intervention.

Objective: Many youth do not use the hybrid closed-loop system for type 1 diabetes effectively. This study evaluated the impact of financial incentives for diabetes-related tasks on use of the 670G hybrid closed-loop system and on glycemia.

Methods: At auto mode initiation and for 16 weeks thereafter, participants received a flat rate for wearing and calibrating the sensor ($1/day), administering at least 3 mealtime insulin boluses per day ($1/day), and uploading ($5/week). Weekly bonuses were given for maintaining at least 70% of the time in auto mode, which were increased for persistent auto mode use from $3/week to a maximum of $13/week. If a participant failed to maintain auto mode for a week, the rewards were reset to baseline. Data from 17 participants aged 15.9 years ± 2.5 years (baseline hemoglobin A1c [HbA1c] 8.6% ± 1.1%) were collected at 6, 12, and 16 weeks. The reinforcers were withdrawn at 16 weeks, with a follow-up assessment at 24 weeks.

Results: With reinforcers, the participants administered an average of at least 3 mealtime insulin boluses per day and wore the sensor over 70% of the time. However, auto mode use waned. HbA1c levels decreased by 0.5% after 6 weeks, and this improvement was maintained at 12 and 16 weeks (P < .05). Upon withdrawal of reinforcers, HbA1c levels increased back to baseline at 24 weeks.

Conclusion: Compensation for diabetes-related tasks was associated with lower HbA1c levels, consistent administration of mealtime insulin boluses, and sustained sensor use. These results support the potential of financial rewards for improving outcomes in youth with type 1 diabetes.