Continuous glucose monitoring (CGM) provides real-time glucose data for people with diabetes. However, detailed knowledge of its use in daily life remains limited. We aim to investigate the interaction between people with type 1 diabetes (T1D) and their CGM data and the impact of the interaction on glycaemia and diabetes distress.

This is a two-centre observational study of adults (n=500) with T1D using FreeStyle Libre 2. Over a period of 14 days, participants will continue their regular CGM use, record insulin doses and timing with smart insulin pens, track activity and sleep with an activity tracker, log all food intake in the LibreLink app and answer questions about quality of life and hypoglycaemia two times per day. Before the study period, the participants will complete a survey of 11 validated questionnaires assessing diabetes distress, hypoglycaemia awareness and other patient-reported outcomes (PROs). After the study period, the participants will complete two additional questionnaires assessing diabetes distress and health literacy.

The collected data will be used in two substudies with the overall aims of:

Substudy 1: to investigate how CGM is used in practice and the impact of the interaction on diabetes distress and glycaemia.

Substudy 2: to investigate whether and how CGM functions as a technological substitute for impaired awareness of hypoglycaemia, focusing on alarm data.

Endpoints will include CGM metrics, alarm data and PROs.

The Danish Data Protection Agency approved the study (P-2024–15985), and the regional committee on health research ethics has granted an ethical waiver (H-24014662). All participants have signed written informed consent forms before participating. The results will be published in an international peer-reviewed scientific journal by the study investigators and shared via www.clinicaltrials.gov. Participants who agreed to receive information about the study will be sent the results after publication.

ClinicalTrials.gov (NCT06453434).