Acceptability of blinded continuous glucose monitoring for people with serious mental illness and type 2 diabetes: findings from an exploratory mixed-methods study

Introduction People with serious mental illness (SMI) experience a disproportionately high prevalence of type 2 diabetes and a reduced life expectancy of 15 to 20 years. While continuous glucose monitoring (CGM) has revolutionised diabetes self-management in the general population, its feasibility and acceptability among individuals living with co-existing SMI remain largely unexamined. Methods The study was embedded within the DIAMONDS feasibility study. Community-dwelling adults with SMI and type 2 diabetes (N = 21 eligible) were invited to wear a blinded CGM sensor (FreeStyle LibrePro) for 14 days. Quantitative metrics evaluated uptake, wear duration, data completeness, and adverse events. Semi-structured qualitative interviews (n = 9) explored user experiences. The qualitative analysis used a hybrid human-AI framework approach to map findings onto the Theoretical Framework of Acceptability (TFA) and the Theoretical Domains Framework (TDF), followed by data integration using a convergence coding matrix. Results Sixteen participants agreed to wear the device (76.2% uptake), achieving a mean wear duration of 11 days. Of the returned sensors with data, 92.8% captured ≥5 days of readings, and no adverse events were reported. Qualitative analysis demonstrated highly positive affective attitudes and a significantly lower perceived burden compared with traditional finger-stick testing, despite minor challenges with sensor adhesion. Cross-framework integration revealed that high acceptability was driven by the device’s low-friction physical layout, positive participant beliefs about data consequences, and alignment with a proactive, research-contributing identity. Discussion The use of blinded CGM is both feasible and acceptable for people living with SMI and type 2 diabetes. These findings offer a robust foundation for developing structured, low-burden, and theory-informed physical health interventions aimed at closing the mortality gap in this underserved population.