JMIR Publications

ABSTRACT

Background:

Digital multidomain interventions hold promise for dementia risk reduction; however, populations at higher dementia risk, including those experiencing socioeconomic and educational disadvantage, remain underrepresented in trials, and engagement with digital interventions often declines over time. Co-production and blended models that combine digital tools with human support may improve reach, acceptability, usability, and sustained engagement. Designing interventions that are usable and acceptable for individuals facing structural, educational, or digital barriers (underserved groups) is therefore likely to produce solutions that are both accessible and scalable for the wider older adult population.

Objective:

To describe the co-production process used to develop ENHANCE—a coach-supported digital intervention targeting ten modifiable dementia risk factors in older adults from underserved groups—and report key outputs and lessons learned for equitable digital prevention design.

Methods:

We co-produced ENHANCE between July 2023 and February 2025 using a multi-stage development process guided by the Medical Research Council framework for complex interventions and the Double Diamond design model. The Person-Based Approach informed user-centred guiding principles (key design objectives), while behaviour change content was operationalised using behavioural change theories. Co-production followed four phases. The Discovery phase explored barriers to engagement with existing digital materials and identified candidate components for each dementia risk-factor module. The Define phase translated these insights into guiding principles and blueprints of each risk-factor module integrated with behavioural change components. The Design phase involved iterative co-production and usability testing of prototypes. The Delivery phase evaluated a high-fidelity prototype through a one-week usability study with coaching support. Contributors included 162 research participants recruited from underserved community settings, 33 patient and public involvement contributors, and 4 human–computer interaction experts. Throughout development, co-production focused on reducing literacy, digital confidence, and cultural barriers to maximise usability across diverse older adult populations.

Results:

Co-production produced (1) evidence-informed module strategies for targeted dementia risk factors; (2) a set of guiding principles to ensure low-literacy, culturally relevant, and accessible content, supporting both equity of access and wider population usability; (3) a meadow-themed app integrating tailored check-ins, educational videos, cognitive training games, and in-app messaging; and (4) a structured coaching model, including onboarding, brief follow-up, and accompanying coaching manuals. Iterative testing and refinement improved navigation, simplified language, reduced text burden, and ensured the use of familiar and accessible game formats, resulting in a feasibility-ready prototype.

Conclusions:

: ENHANCE is a co-produced, coach-supported digital intervention designed to be accessible for underserved older adults at increased dementia risk, with design features intended to support accessibility, engagement, and scalability across the wider ageing population. The development process illustrates how integrating co-production with behavioural science and usability methods can support principled intervention design for equitable digital dementia prevention. Clinical Trial: ISRCTN17060879