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A real-world study of user characteristics, safety and efficacy of open-source closed-loop systems and Medtronic 670G

Research output: Contribution to journalArticlepeer-review

Roshell Jeyaventhan, Geraldine Gallen, Pratik Choudhary, Sufyan Hussain

Original languageEnglish
Pages (from-to)1989-1994
Number of pages6
JournalDiabetes, Obesity and Metabolism
Issue number8
Accepted/In press2021
PublishedAug 2021

Bibliographical note

Funding Information: The authors would like to thank the clinical teams and participants in the study. The authors would also like to thank Prof. John Pickup for helpful comments and feedback on the manuscript. Parts of this study have been submitted in abstract form for consideration for presentation at the 14th International Conference on Advanced Technologies and Treatments for Diabetes (ATTD), Paris, France, 2-5 June 2021. Publisher Copyright: © 2021 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors


We report a real-world evaluation of the first commercially approved automated insulin delivery (AID) system, MiniMed 670G (670G), and open source-automated insulin delivery (OS-AID) systems. This was undertaken as a retrospective observational study in adults with type 1 diabetes using AID systems for 6 months or longer in a publicly funded health service using clinically validated data. Sixty-eight adults (38 670G, 30 OS-AID systems) were included. OS-AID system users were younger, had a shorter diabetes duration and a higher education status. OS-AID systems displayed a significantly better change in HbA1c (median −0.9% [−0.4%, −1.1%] vs. −0.1% [IQR −0.7%, 0.2%], P =.004) and time in range 3.9-10 mmol/L (mean 78.5%, SD ± 12.0% vs. 68.2% ± 14.7%, P =.024) compared with 670G. Both systems showed minimal hypoglycaemia, with OS-AID systems revealing significantly improved secondary outcomes of mean glucose and percentage of time more than 10 mmol/L, with a higher percentage of time of less than 3 mmol/L. OS-AID system users displayed improved glycaemic outcomes with no clinical safety concerns compared with 670G, although higher weight-adjusted insulin dose and weight gain were noted. The study highlights key differences in OS-AID system user characteristics that are important for interpreting real-world findings from recent OS-AID system studies.

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