974-P: High Time in Closed Loop for Control-IQ Technology with New Interoperable iCGM Sensors

Background: The FDA defines medical device interoperability as “the ability to safely, securely, and effectively exchange and use information among one or more devices⋯ technologies, or systems.” Interoperability helps address barriers to diabetes device use such as lack of access, high cost, and preferences for use, by offering users choice for their diabetes care.  The t:slim X2 with Control-IQ technology is the first automated insulin delivery (AID) system in the U.S. with an interoperable continuous glucose monitor (iCGM) option. In late 2023, Tandem users participated in a first access launch and remote software update of their AID system, enabling use of iCGMs including the Dexcom G7, G6, and Abbott Freestyle Libre 2 Plus (FSL2Plus). Here we report on system performance and perceptions on usefulness, and ease of use.  

Methods: 154 existing Tandem pumpers elected to update their pump software to use the Dexcom G7 or FSL2Plus integrated with their t:slim X2 pump. These users had 1+ sensor changes and ≥ 18 days of system use at time of analysis. Daily qualitative feedback from email surveys were analyzed along with back-end system performance data. 

Results: The t:slim X2 pump median time in automation was ≥92% (excluding CGM warm-up time) irrespective of CGM brand. User satisfaction was high, and primary qualitative themes included ease of use and perceptions of performance. Specifically, ease of the software update process and device pairing, as well as perceptions around system connectivity and accuracy were main contributors to positive user feedback.

Conclusion: This is a first report of people with diabetes using an AID system with multiple iCGMs in the U.S. Time in automation was high in this real-world setting, and users reported positive experiences, in line with published evidence for Control-IQ technology. An AID system with the ability to choose sensor type enables people with diabetes to optimize their device experience, and reduces barriers due to cost, access, or wearability.