1625-P: Smartphones Everywhere but Apps Rarely Used for Carb Counting: Insights from Adults with Type 1 Diabetes

Introduction and Objective: Accurate carbohydrate (carb) counting remains difficult for many with type 1 diabetes (T1D), despite its central role in insulin dosing. Smartphone applications (apps) offer a potential tool to support carb counting, yet real-world uptake is not well characterized. Methods: We conducted a cross-sectional survey of 1,026 adults with T1D at a large academic health system, assessing prandial insulin dosing strategies and app use for carb counting. Results: Participants had a mean age of 46 years and T1D duration of 23 years; were mostly White (60%) with a bachelor’s degree or higher (61%). Continuous glucose monitoring (CGM) was used by 882 participants (86%). Insulin pumps were used by 631 participants (62%), while 288 (29%) reported insulin injections. For prandial insulin dosing, 48% reported formal carb counting, 31% reported “guesstimating” carb content, and 7% used fixed dosing strategies. Despite widespread smartphone ownership in the US, 63% of respondents reported never or rarely using an app for carb counting. Among participants who had previously used carb-counting apps, the most reported reasons for discontinuation were apps being too time-consuming or burdensome (37%), difficulty finding commonly eaten foods (29.5%), reluctance to use an additional app (31%), and concerns about inaccurate carb counts (20%). Conclusion: Carb counting apps are infrequently used by adults with T1D, and many rely on imprecise prandial dosing strategies. These findings emphasize the ongoing challenge of accurate carb counting and the need for person-centered strategies that reduce cognitive burden and better support insulin dosing decisions. Disclosure E.M. Everett: None. L. Wisk: None. T. Moin: None. Funding RWJF Harold Amos Medical Faculty Development Program