PRODUCES+: Guidance for co-creation in public health informed by evidence and user experience.

Objectives: Despite the growing popularity of co-creation to develop complex interventions, there is limited guidance on planning and implementing a co-creation process in public health. This study aims to critically review and update one such guidance, the PRODUCES framework, to develop a more comprehensive, user-friendly guide for public health researchers and practitioners. Study design: Evidence- and user-informed guideline development. Methods: A multi-method, evidence-informed approach was used to identify strengths, gaps, and areas for improvement. This included a snowballing review of peer-reviewed articles citing the PRODUCES framework, followed by in-depth interviews and a mixed-methods survey with lead authors identified through the review. Data from included studies, interviews, and survey responses were analysed thematically. Results: The search identified 96 studies, of which 21 were included. Four interviews and nine survey responses were obtained. Strengths included flexibility, clear foundational guidance, and practical applicability, while limitations related to clarity, overlapping stages, and terminology. Participants suggested strengthening implementation guidance and methods and highlighted the value of complementary frameworks. These findings informed the development of the PRODUCES+ guideline. Conclusions: Building on user input, the original framework, and contemporary co-creation literature, the PRODUCES+ Guideline provides an expanded, step-by-step resource for planning co-creation in public health.