Characterising the design and methods of continuous glucose monitoring used in behavioural interventions to inform future research in prediabetes.

Digital health feedback technologies are expected to help address the projected 630 million individuals with prediabetes worldwide by 2045. This Viewpoint article characterises the historical use of continuous glucose monitoring (CGM) systems in behavioural research with a focus on the prediabetic population. We identified 19 peer-reviewed studies through a pragmatic literature review and reported key methodological features, including study design, sensor wear protocols, data masking strategies, the role of CGM in behavioural interventions, and approaches to generate CGM metrics. Based on our literature review, we propose four directions to advance CGM in behavioural intervention research in prediabetes: refining sampling strategies to focus recruitment on individuals with prediabetes to better understand metrics in this population; improving transparency in CGM feedback delivery protocols; reporting a comprehensive and targeted set of CGM metrics; and articulating principles that account for the effects of CGM use within behavioural interventions. This methodological characterisation of CGM is a starting point to enhance research quality and behavioural intervention effectiveness, particularly when integrating CGM systems aimed at supporting dietary, physical activity, or lifestyle modifications among people with prediabetes.