Executive Overview
Individuals living with severe mental illness (SMI)—such as schizophrenia, bipolar disorder, and psychosis—face a stark, internationally recognized health disparity: they are two to three times more likely to develop type 2 diabetes than the general population. Compounded by systemic barriers, unintegrated healthcare structures, and a distinct lack of tailored physical health interventions, this vulnerable patient group experiences a reduced life expectancy of 15 to 20 years.
While continuous glucose monitoring (CGM) technology has revolutionized diabetes management globally by offering real-time, actionable visual feedback, its implementation remains largely out of reach for individuals with SMI. Standard diabetes education programmes, such as DESMOND, often fail to accommodate the cognitive, psychological, and systemic complexities of managing a dual diagnosis.
To address this pressing clinical gap, a pioneering research team at the University of York conducted an accelerated, experience-based co-design study. Bringing together service users, family carers, and healthcare professionals (HCPs), the study successfully mapped out a logic model and programme theory for a structured, patient-centered CGM intervention tailored specifically to adults living with SMI and type 2 diabetes. This initiative proves that traditionally "hard-to-reach" populations can actively and effectively collaborate on healthcare innovation when provided with respectful, flexible, and supportive environments.
Detailed Chronology of the Co-Design Study
The research project unfolded systematically between June and August 2024, utilizing an accelerated co-design framework informed by health psychology, behavior change theory, and experience-based co-design (EBCD) principles.
Phase 1: Rapid Evidence Synthesis and Discovery Sessions
The project kicked off with the rapid synthesis of existing evidence on CGM and SMI, resulting in a comprehensive catalyst slide deck and fictional persona sketches (such as "Andy" and carer "Noori"). These tools allowed participants to explore sensitive health scenarios safely without needing to disclose potentially traumatic personal experiences. Discovery sessions were conducted via Zoom, dividing participants into distinct groups for healthcare professionals and service users/carers. These workshops established foundational insights into the daily emotional and practical burdens of managing diabetes alongside psychiatric conditions.
Phase 2: Journey Mapping and Joint Co-Design Breakouts
Following initial synthesis, the project team structured the CGM user experience into three distinct, overlapping phases: set-up, early days, and living with CGM. Using healthcare journey-mapping techniques, a hybrid joint co-design event was held where stakeholders split into breakout groups to dissect systemic bottlenecks—such as administrative referral failures, information overload during initial device fitting, and the critical need for a reliable "SMI flag" within medical records to prevent patients from falling through the cracks.
Phase 3: Prototyping, Showcase, and Logic Model Finalization
In the final stages, the research team developed a prototype intervention tested against a new case study persona. During a hybrid showcase and celebration event, participants prioritized key components—such as personalized technical training, drop-in clinics, phone check-ins, and structured relapse support. Iterative refinement by the study team yielded a definitive logic model and programme theory grounded in the Behaviour Change Wheel (BCW) and the COM-B model (Capability, Opportunity, Motivation, and Behaviour).
Supporting Context, Key Findings, and Metrics
The study engaged a dedicated cohort of 10 participants (comprising four healthcare professionals, four service users, and two carers) across multiple interactive workshops. Qualitative analysis of these sessions revealed several critical thematic insights regarding why standard diabetes interventions fail this demographic and how CGM can be optimized.
Identified Barriers to Care
- Systemic Inefficiencies: Rigid clinical booking systems, administrative errors, and missed referral appointments frequently lead to months of delays, during which a patient’s physical health can deteriorate unchecked.
- Fragmented Care: A persistent disconnect between mental health services and primary physical healthcare leaves patients feeling alienated. Treating diabetes in isolation from an individual’s psychiatric state breeds mistrust in the healthcare system.
- Technological and Data Overload: Unassisted CGM adoption can overwhelm patients. Without proper support interpreting real-time data, devices can induce anxiety rather than foster positive behavioral change.
Core Components of the Co-Designed Intervention
To resolve these obstacles, the co-designed intervention was structured around three operational phases, incorporating specific active ingredients linked to behavior change techniques (BCTs):
- Set-Up Phase: Features an initial introductory conversation, exploration of personal needs, implementation of reasonable adjustments (such as flexible appointment types or home visits), and a streamlined first set-up appointment.
- Early Days Phase: Focuses on intensive early support, including 1-week and 2-week follow-up appointments, proactive phone calls to prevent early drop-off, and tailored technical troubleshooting lessons.
- Living with CGM (Ongoing Maintenance): Emphasizes long-term sustainability through regular communication, structured support networks, rapid-response pathways during mental health relapses, and integrated annual reviews.
Official Statements and Theoretical Foundations
The integration of rigorous health psychology frameworks was central to the study’s validity. By mapping participant-prioritized components onto the Theoretical Domains Framework (TDF) and established Mechanisms of Action (MoAs), the researchers ensured that the intervention was not merely acceptable, but mechanistically sound.
Lead researcher Dr. Jennifer V. E. Brown and senior collaborators emphasized the empowering nature of the co-design process:
"Our study highlights that people with serious mental illness can take an active interest in their physical health and see the potential for continuous glucose monitoring to improve diabetes management, provided they receive appropriate, flexible, and empathetic support."
The research underscores that building a trusted relationship with a consistent healthcare provider directly targets the psychological mechanism of beliefs about capabilities (self-efficacy). Similarly, hands-on technical training directly operationalizes behavioral instructions, bridging the gap between clinical innovation and daily patient execution.
Future Outlook and Clinical Implications
While the study successfully demonstrated the feasibility and acceptability of co-designing a structured CGM intervention for individuals with SMI and type 2 diabetes, the authors note several limitations and directions for future research.
Addressing Remaining Unknowns and Diversity Gaps
The current sample predominantly represented White British demographics, pointing to a critical need for future iterations to incorporate intersectional cultural adaptations. Minoritized ethnic groups living with SMI face compounded health inequalities that require targeted, culturally sensitive investigation. Furthermore, real-world implementation trials must evaluate the cost-effectiveness, scalability, and optimal component combinations of the proposed intervention across diverse geographic and clinical settings.
Paving the Way for Systemic Reform
By proving that rapid, respectful, and inclusive co-design is entirely achievable with populations historically deemed "hard to reach," this study establishes a vital benchmark. As healthcare systems look toward precision medicine and digital health integration, deploying tailored CGM pathways offers a tangible mechanism to shrink the tragic mortality gap, alleviate chronic health disparities, and restore dignity and longevity to individuals managing the complex intersection of severe mental illness and type 2 diabetes.
