User-centered development of a digitally-delivered dietary intervention for adults with type 2 diabetes: The T2Diet study

Background: Web-based interventions can help address challenges of accessibility and availability of dietary support for people with type 2 diabetes (T2D). However, concerns regarding adherence and engagement in web-based interventions have been noted. Implementing a user-centered approach to intervention development has been shown to encourage better participant engagement. The overarching aim of this paper was to describe the user-centered approach used in the T2Diet Study to develop a new web-based dietary intervention for adults with T2D, exploring strategies for enhancing adherence and engagement. Methods: Intervention development was based on a flexible iterative user-centered approach to enable new product development. Twenty-one adults with T2D were engaged in six guided discussion groups across four iterative development phases, alongside reference to evidence and theory throughout the process. The phases of user inquiry progressed from broad discussion on areas to support dietary needs; to design feedback on aspects of site layout; through to further feedback on aesthetics and functionality; then into a two-week field test followed by final user inquiry and participation in user experience polls. A hybrid approach of thematic data analysis was used, incorporating both a data-driven inductive approach and a deductive approach based on a priori identification of themes. Results: Group discussion across the four phases highlighted factors the participants considered may motivate them to adhere and engage, which predominantly included relevance of resources, clear and simple positive communication, and flexibility for personal tailoring. Participant feedback provided an actionable list of intervention developments and input to inform intervention structure and theoretical framework. The two-week field test highlighted factors participants valued in terms of the user experience, most notably usability and accessibility. Additionally, the field test indicated a positive user experience, with no significant usability issues identified. Conclusion: This paper provided the first detailed report of a user-centered approach to iterative development in the context of a web-based T2D dietary intervention. The insights will be useful to inform future digitally-delivered dietary interventions for adults with T2D or to inform a similar user-centered approach for other chronic health conditions.