Meta-Analysis of a Decade of Studies Assessing Accuracy of Abbott FreeStyle Libre Continuous Glucose Monitor

Background and Aims: This meta-analysis provides a summary of research publications over a decade since the FreeStyle Libre device was first launched by Abbott in 2014. This includes research publications in which the Libre freestyle glucose measurements have been evaluated for accuracy or compared to other glucose devices. Methods and Results: The dichotomy is organized into six sections: (1) Comparing Libre to Dexcom CGM, (2) Assessing Libre accuracy, (3) Efficacy for diabetes, (4) Ease of use, (5) Direction of change trend arrows, (6) Exercise while wearing Libre. A comprehensive meta-analysis of studies comparing Libre and Dexcom is presented. Main results include: Libre and Dexcom give close matching glucose measurements. Libre and Dexcom are both clinically acceptable. Libre efficacy is worse for glycemic variability and does not reduce the risk of recurrent hypoglycemia. Our comprehensive meta-analysis integrates data from these key studies; our results demonstrate that the accuracy of Libre was not significantly different from accuracy of Dexcom when compared with a gold standard comparator. Conclusions: Several factors reduce Libre accuracy: hypoglycemia, rapid glucose changes, night time, exercise, the first and last days of the 14-day sensor life, placing on abdomen instead or arm or thigh, and variation between left and right arms. The direction of change arrows need more consideration before integrating with clinical decisions. Libre can also perform well when used by children and pregnant women. This provides a current overview of Libre, highlighting open questions for future research direction.