Advanced hybrid closed-loop (HCL) insulin delivery systems are being developed and used to minimize fluctuations in blood glucose levels associated with insulin therapy in people with diabetes. Usability of these systems is critical for their effectiveness.
The objective was to assess the usability and safety of a touchscreen, wearable insulin pump with an operating system that automatically adjusts insulin delivery based on a) predicted continuous glucose monitor (CGM) readings and b) user input that informs the pump of food intake and activity levels.
70 participants, composed of insulin pump users and MDI users, completed the usability studies. The participants were given real-life scenarios as context for simulated use tasks and knowledge tests. Tasks and tests were designed to assess the safety and ease of use of a Tandem t:slim X2 pump designed with a HCL insulin delivery system. Task success rates were collected, and a Systems Usability Scale (SUS) questionnaire was administered at the end of each session.
The formative study gave its 10 adult pump users a 10-minute orientation to the system. The summative study gave its 60 pump and MDI users real-world training, with a decay period before testing.
The average SUS scores were identical at 84 indicating a high user satisfaction (typical scores 65-75). Task completion rates of 93% and 96% were observed, respectively.
The findings indicate that the Tandem t:slim X2 insulin pump with a hybrid closed-loop (HCL) insulin delivery system was both intuitive and safe to use.