A framework for structuring digital health intervention research: insights from a systematic review

Abstract Background Digital health interventions (DHIs) are complex and rapidly evolving, posing challenges for research programme design. Using the UK Medical Research Council's four-phase research framework (development, feasibility, evaluation, implementation) as a reference, this study examines how researchers select and progress through phases when evaluating DHIs, to inform future programme design. Methods A systematic review identified DHIs promoting health among adolescents and young adults, implemented between 2017 and 2023. For each intervention, we analysed research phases conducted and mechanisms guiding progression between phases. Results Of the 31 included interventions, 26 reported a development (D) phase, 24 feasibility (F), 31 evaluation (E), and 6 implementation (I). Three phase arrangements were identified: sequential (>), iterative (i), and overlapping ([+]). Progression mechanisms included: automatic progression, conditional progression based on qualitative appraisal of findings, and conditional progression based on quantitative criteria. Five main research programme structures (combination of arrangements and progression mechanisms) were observed across 28/31 interventions: 1) strictly linear (8/28, e.g. D>F>E>I); 2) iterative development (8/28, e.g. D(i)>F>E); 3) iterative feasibility (3/28, e.g. D>F(i)>E); 4) overlapping development and feasibility (4/28, e.g. [D+F]>E>I); 5) overlapping evaluation and implementation (5/28, e.g. D>F > [E+I]). Conclusions This study proposes a new operational framework to practically guide planning and communication of future DHI research programmes in terms of phase arrangements and progression mechanisms. Applying this framework may reduce research waste by preventing premature evaluations of underdeveloped or unfeasible interventions and by ensuring sufficient evidence generation throughout the research cycle to support endorsement from decision-makers, funders, and regulatory authorities. Key messages • Typologies of research phase arrangements and progression mechanisms provide an operational framework to design and document digital health intervention research programmes. • Application of this framework will reduce research waste by preventing premature evaluations of underdeveloped interventions and supporting robust evidence generation throughout the research cycle.