AUTHOR=Black Daniel , Bates Geoff TITLE=Stakeholder analysis in urban-planetary health research: The Key Group Approach JOURNAL=Frontiers in Public Health VOLUME=Volume 13 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2025.1629249 DOI=10.3389/fpubh.2025.1629249 ISSN=2296-2565 ABSTRACT=IntroductionThere is growing recognition of the importance of ensuring that research involves stakeholders who both affect and are affected by the problems under investigation. However, this presents significant challenges for researchers seeking to solve global problems such as disease prevention and planetary health, and for many reasons: e.g. scale and complexity of systems, high number and inaccessibility of stakeholders, and the range of understandings of what ‘the problem’ is. Methods are needed to help research teams ensure that those recruited are as representative as possible.MethodsThis approach was developed as part of a programme of research in the United Kingdom that sought to improve decision-making in order to prevent diseases linked to unhealthy urban environments including those linked to climate change. The work evolved over the 8 years of research, but was prompted ultimately by the final year of the programme in order to improve the quality of the programme-level stakeholder evaluation workshops. The method was developed by integrating a narrative review of the literature with foundational programme theory and emergent theory of change in order to develop key principles, criteria and conceptual understandings. This led to the development of 16 core stakeholder typologies, a comprehensive database structure and simplified partner-focused checklist, and 14 points for discussion. These were refined through the stakeholder identification and recruitment process into the final approach presented here, which includes a retrospective gap analysis.FindingsThe final approach and toolkit includes a step-by-step process over three rounds of iterative and integrated research activity, combined with supporting checklists, principles, categories and questions. Teams seeking to involve stakeholders in urban development or similar planetary health research can use these to interrogate their samples in order to understand both representativeness and alignment to programme theory and mission. No context is the same, so each approach needs to be tailored to suit. We describe common principles, and an example of how the toolkit was applied in our research study. We reflect on the process using the points for discussion identified, and demonstrate how analysing our sample in this way helped us to understand and identify both strengths and limitations.