Objectives <p>Mindfulness-based interventions are effective in supporting a range of mental health outcomes for breast cancer survivors, yet they are not routinely offered as part of cancer care in Australia. Economic evaluations can support uptake decisions but are often limited by lack of context specific information on outcomes. This study conducted structured stakeholder engagement to inform a meta-analysis to generate relevant effect estimates of mindfulness-based interventions for breast cancer survivors.</p> Method <p>A literature review identified seven studies published since 2007. A workshop was convened to present information on the study population and characteristics of the mindfulness-based interventions to clinical experts to consider the relevance of the study populations to the local population and the impact of intervention characteristics on published effect estimates. Responses informed the inclusion of relevant primary studies and subgroup meta-analyses based on important elicited differences in intervention characteristics.</p> Results <p>Structured stakeholder engagement provided context- and intervention-specific insights on factors expected to affect the relevance, feasibility and effectiveness of mindfulness-based interventions in the local context. These insights informed exclusion criteria for primary studies and relevant subgroups for meta-analyses, including an additional 6-hr session, encouragement of home practice and instructor training and experience.</p> Conclusions <p>This paper outlines a systematic method for contextualising published evidence for a specific context through structured stakeholder engagement. It explores strategies to address uncertainties, including broadening review criteria for meta-regression, expert elicitation to refine effect estimates and the use of economic evaluation to evaluate the magnitude of incremental effects required to demonstrate cost-effectiveness.</p> Preregistration <p>This study is not preregistered.</p>