Mobile App for Assisting Patients With Type 1 Diabetes in Insulin Dose Adjustment: Development and Usability Study

Background: In resource-limited countries, most patients with type 1 diabetes (T1DM) use basal-bolus insulin therapy. Optimal dosing requires matching insulin to carbohydrate intake, premeal blood glucose levels, and physical activity-a complex process prone to error, particularly for patients with limited health literacy. Objective: This study aimed to develop and pilot-test a new mobile app designed to adjust bolus insulin doses based on the carbohydrate content of the meal, premeal blood glucose, and physical activity, tailored specifically for Iraqi patients with T1DM. Methods: To guide the app's development, a literature search was conducted to identify key features in mobile apps for improving glycemic control in patients with T1DM. Evidence highlighted bolus insulin calculation, blood glucose tracking, and patient education as the most impactful features; consequently, these 3 functionalities were selected as the core components of the app. The scientific content of the app was based mainly on the latest American Diabetes Association guidelines and reviewed by 8 experts to ensure accuracy. After initial app prototype development, a cross-sectional pilot feasibility study was conducted at the Diabetes and Endocrine Center in Basrah, Iraq. A purposive sample of 10 health care professionals (5 endocrinologists, 2 dietitians, 2 clinical pharmacists, and 1 diabetes educator) and 10 patients with T1DM (aged ≥15 y) was recruited. The app was installed on participants' smartphones, and standardized instructions on its functions and usage were provided. After a 10- to 14-day trial period, participants evaluated the usability, satisfaction, and perceived benefits of the app using newly developed and validated 3-point Likert scale questionnaires (one specific to patients and the other to health care professionals), alongside an optional open-ended question for qualitative feedback. Results: Positive feedback was reported across both groups. A favorable usability rating was expressed by 80% of experts and 90% of patients. Regarding app benefits, 90% of experts and nearly all patients considered it effective for adjusting insulin doses, improving treatment adherence, and reducing hypoglycemia. At least 70% of experts noted provider benefits (reduced workload and improved monitoring). All participants were satisfied and would recommend the app. Conclusions: The new app tested in this study demonstrated promising acceptability and usability among patients with T1DM and relevant health care professionals. However, given the small sample size, these findings should be interpreted as preliminary feasibility evidence. A larger, adequately powered clinical trial is warranted to confirm these results and evaluate the app's clinical impact on glycemic outcomes.