Collaborative Development and User Testing of a Digital Frailty and Aging Screener for Marginalized Older Adults Using Audio Computer Assisted Self Interview (ACASI): Lessons From the ASCAPE Project (Preprint)

BACKGROUND Older adults facing social or structural marginalization for reasons such as lower literacy, digital exclusion, financial constraints, restricted living environments or complex health histories, often face persistent barriers to much-needed health screening. Digital health tools, particularly those using audio computer-assisted self-interview (ACASI) technology, offer potential to overcome these barriers, but their integration and application to marginalized populations remain underexplored. Moreover, guidance is limited for developing such evidence-based digital health tools which require ongoing input and commitment from highly cross-disciplinary teams. This paper presents development insights and user testing findings from the ASCAPE project, which aimed to develop digital health apps for health screening of older people in Australian prisons. OBJECTIVE To describe in detail the collaborative development of the ASCAPE-HS prototype, a tablet-based ACASI-delivered frailty and ageing screener, and to synthesize key lessons from the project that can inform equitable digital health tool development in hard-to-reach older adults. Also, to present findings on usability and acceptability of ASCAPE-HS in a diverse community sample. METHODS The ASCAPE-HS prototype was developed through an iterative process involving researchers, clinicians, software developers, and justice system end-users. The prototype included a self-administered, audio-delivered frailty index, alongside other items relevant to ageing. The design process prioritized accessibility, sociocultural relevance, and technical feasibility, with regular multidisciplinary consultation and iterative refinement. Exploratory user testing with twenty older adults (aged 47–93, including n=5 who had not finished secondary schooling, n=3 people with previous imprisonment history, and n=9 with mild or moderate cognitive impairment) provided feedback on usability and acceptability. RESULTS A 50-item frailty index was developed, alongside an additional selection of holistic health and sociodemographic questions that could meaningfully capture age-related health, and transferred to an IOS app, with ACASI features (audio delivered and self-administrable). Key elements included lay wording, consistent blue and white interface, simple ‘tapping’ response options with repeatable audio feedback, a tutorial, and AI-generated audio guidance. Successful strategies for the collaborative design process included diverse teams abreast of emerging literature and policy with varying expectations for engagement at different times during development, organizational proximity with software developers, and dedicating time to flexible, iterative development processes. Acceptability (Median scores ≥4 out of 5 across six constructs) and usability (Mean System Usability Scale score =79.0, SD 8.8) scores were high. CONCLUSIONS This project demonstrates that a collaborative approach can produce digital, ACASI-based health screening tools that are well-received by older adults. It highlights the feasibility of integrating frailty and ageing assessment into an accessible digital tool, and offers actionable principles for collaborative, evidence-based development. The ASCAPE experience provides a model for future development of equitable health screening tools in diverse, hard-to-reach populations.