Long-term efficacy and safety of Control-IQ technology in younger children with type 1 diabetes in Italy (2020–2023): a longitudinal multicentre real-world study

Background Automated insulin delivery (AID) systems have demonstrated significant improvements in glycemic control in children and adults with type 1 diabetes, but long-term real-world data in preschool-aged children remain limited, particularly in Europe, where Control-IQ is not approved for children under 6 years. This study aimed to evaluate the long-term effectiveness and safety of the t:slim X2 insulin pump with Control-IQ technology in children aged 0.5-5 years compared with those aged 6-10 years in a real-world multicenter Italian cohort. Methods In this longitudinal, observational study conducted from 2020 to 2023, data were collected from 32 Italian centers on children <11 years diagnosed with type 1 diabetes for at least six months and using the t:slim X2 with Control-IQ technology (CIQ). Participants were grouped into 0.5-5 years or 6-10 years at CIQ initiation. Primary endpoints were the percentage of time spent in range (TIR, 70-180 mg/dL) and in tight range (TITR, 70-140 mg/dL) in the two age groups, evaluated according to children's demographic, socioeconomic, and clinical characteristics using mixed-effects models for repeated measures. Findings We evaluated 253 children with 18-month follow-up, 131 into the 0.5-5-year group and 122 in the 6-10-year group. In the 0.5-5-year group, TIR and TITR increased significantly from baseline to 6 months and were then maintained through 18 months. In the 6-10-year group, similar improvements were observed, with no statistically significant differences between age groups in the TIR or TITR trajectories. In the adjusted mixed-effects models, TIR increased from baseline to 6 months by 5.45% (95% CI 3.78-7.11) and TITR increased by 5.56% (95% CI 3.60-7.51), with stabilization thereafter. Children of parents with a high level of education had a significantly greater mean TIR. A longer interval between T1D diagnosis and CIQ initiation was associated with a lower mean TITR (-1.21%, 95% CI-2.32 to-0.10). During observation, there were no episodes of severe hypoglycemia in younger children and only one episode in a 6-10-year-old. One episode of DKA occurred after the start of CIQ in a younger child. Interpretation CIQ was associated with sustained improvements in glycemic outcomes, especially within the first six months. Adverse events were rare. These findings support potential supervised off-label use in young children. Funding No specific funds were received for this study. Copyright (c) 2026 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).