Supplementary Material for: T1Drink: Education gaps and safety issues concerning alcohol consumption in young adults with type 1 diabetes mellitus – A JENIOUS-driven international Initiative report

Introduction
Alcohol consumption is common among people with type 1 diabetes mellitus (PwT1D), with prevalence rates similar to the general population. However, it is associated with unique risks – increased risk of (delayed) hypoglycemia, diabetic ketoacidosis, and impaired ability to self-manage diabetes. In this study, we aimed to explore the knowledge and experiences of young (>16 years old) PwT1D concerning safe alcohol use.

Methods
We designed an anonymous survey informed by the clinical expertise of healthcare professionals, the lived experience of people with type 1 diabetes represented within our team, and the perspective of a patient organization, , which was made available in 12 languages on a dedicated website and promoted via social media. We collected data on responders' background, self-perceived safety of alcohol use, experience about the impact of specific alcoholic drinks on one's glycemia, and safety management strategies. Data collection was open from October 2022 to November 2023.

Results
We analyzed complete responses from 216 PwT1D (63.4% females, 54.2% aged 16-21 years old, 29.3% with diabetes duration >15 years), who represented 23 countries (most often Italy, Poland and US). Only 53.2% of PwT1Ds reported feeling safe while consuming alcohol, and 37% assessed their alcohol-related knowledge as average or lower. Only 45.8% reported that the issue of safe alcohol consumption was discussed as part of diabetes education. A total of 48.2% of participants experienced unpredictable effects of alcoholic drinks on blood glucose levels. Alcohol-related severe hypoglycemia episodes were significantly more frequent in those reporting frequent excessive drinking (≥6 drinks ≥1/month, OR 4.19, 95%CI 1.37-12.75) and routinely consuming ≥2 alcoholic drinks per occasion (OR 4.20, 95%CI 1.52-11.61).

Conclusions
The topic of safe alcohol consumption requires more attention in diabetes education. Developing precise, evidence-based, and easy-to-apply strategies tailored to alcohol type, amount, and technology use is essential for reducing the risk of acute diabetes-related complications.