Co-design and usability testing in the development of a digital health intervention for the secondary prevention of cardiovascular disease: The INTERCEPT Study (Preprint)

Abstract

Secondary prevention is an important strategy to reduce the burden of cardiovascular disease (CVD), a leading cause of death worldwide. Despite the growing evidence for the effectiveness of digital health interventions (DHI) for the secondary prevention of CVD, the majority are designed with minimal input from target end users, resulting in poor uptake and usage.

The objective of this study was to optimise the acceptance and effectiveness of a DHI for the secondary prevention of (CVD) through co-design, integrating end-users perspectives throughout.

A theory driven, person-based approach using co-design was adopted for the development of the DHI, known as INTERCEPT. This involved a four-phase iterative process using online workshops. In phase one, a stakeholder team of healthcare professionals, software developers and public and patient involvement members was established. Phase two involved identification of the guiding principles, content and design features of the DHI. In phase three, DHI prototypes were reviewed for clarity of language, ease of navigation and functionality. To anticipate and interpret DHI usage, phase four involved usability testing with participants who had a recent cardiac event (<2 years). Improvements in usability of the DHI were assessed pre- and post-acceptance testing with the System Usability Scale (SUS). The ‘Guidance for reporting intervention development studies in health research’ (GUIDED) checklist was used to report the development process.

Five key design principles were identified: simplicity and ease of use; behavioural change through goal setting and self-monitoring; personalisation; system credibility and social support. Usability testing resulted in 64 recommendations for the app of which 51 were implemented. Significant improvements in SUS scores were observed comparing before and after implementation of recommendations (61 vs 83, P=.02).

Combining both behaviour change theory with a person based, co-design approach facilitated the development of a DHI for the secondary prevention of CVD that optimsed responsiveness to end-users needs and preferences, thereby potentially improving future engagement.