New Guidelines Offer Advice for Clinicians as Open-Source Automated Insulin Grows in Popularity

Clinicians should be willing to work with patients eager to try “do-it-yourself” insulin systems, but should also warn them of the risks, the guidelines state.

Automated insulin delivery (AID) systems have remarkable potential to re-shape diabetes care by increasing the percentage of time patients spend in their target blood glucose range.

However, the mere existence of the technology does not mean it is widely available to patients.

In the absence of easy availability, some patients are turning to do-it-yourself models. In a new review article in The Lancet Diabetes & Endocrinology, corresponding author Rayhan A. Lal, MD, of the Stanford University School of Medicine, and colleagues offered insights into what is known about these technologies, and gave recommendations for health care professionals as they see patients who might be interested in these technologies.

The idea behind AID is simple: the systems continuously monitor a patient’s blood glucose levels and provide automatic, tailored insulin doses based on a data-driven algorithm. In trials, these systems have shown significant promise. However, Lal and colleagues said they have yet to transform day-to-day patient care because few such systems have been approved by national or international regulatory agencies.

“These commercial systems are constrained by device ecosystem options and are not universally available, as approval, access, regulatory, and reimbursement policies for diabetes technologies vary considerably between countries,” they wrote.

Those limits on access have led some non-medical professionals and patients to develop AID systems using open-source, publicly available software code. So far, the number of users of these technologies is relatively small, the authors said, at an estimated 10,000 worldwide. Yet, they said those numbers appear to be growing, and with it, the need for health care professionals to understand how to help people who are interested in using these technologies.

The authors noted a number of potential issues. For one, most open-source AID systems are backed mostly by real-world evidence, rather than by randomized controlled trials. Yet, while the authors said randomized controlled trials are the gold standard, they also argued that there should be a place for real-world evidence in regulatory decisions.

The authors also discussed a number of differences in terms of user experience for people that use open-source systems. For example, open-source systems do not have call-in lines to help users the way that commercial device-makers do. On the other hand, those call-in lines can sometimes require lengthy weight times, and users of open-source tools can often find help from online communities and websites.

Lal and colleagues added that open-source technologies also bring up issues like transparency, since commercial device-makers are not typically transparent about their algorithms and underlying technology. Transparency can make it easier to improve software, though it also opens up safety risks, such as harm caused by unintentional errors in code.

Justice also comes into play, as open-source systems can enable access to life-changing technologies that patients in some parts of the world might not otherwise be able to utilize, the authors noted.

In their recommendations, Lal and colleagues wrote that providers should make sure patients are aware that open-source systems are unregulated, and also inform patients about any options that are approved by regulators. However, physicians should also respect the decisions of patients and provide guidance and support so that patients can optimize whichever system they choose. They said clinicians should carefully document the decisions made and the disclaimers given. Providers should also be prompt and thorough in reporting adverse events to local health and regulatory agencies, they said.

“Health care professionals have an important role in facilitating and supporting people with diabetes to obtain beneficial outcomes from AID systems,” they concluded. “Although we do not suggest that open-source AID systems be universally recommended over commercial options, strong ethical reasons support the use of open-source AID systems, with safety and effectiveness data derived from real-world evidence.”


Braune K, Lal RA, Petruželková L, et al. Open-source automated insulin delivery: international consensus statement and practical guidance for health-care professionals. Lancet Diabetes Endocrinol. Published online November 13, 2021. doi:10.1016/S2213-8587(21)00267-9