A realist-informed conceptualization of lived experience engagement in implementation science: the how and the why

Successful implementation in health care depends on understanding that interventions operate within complex adaptive systems shaped by context, relationships, and power. Lived experience perspectives provide critical insights into contextual determinants that influence implementation success, such as barriers, facilitators, and sociocultural dynamics. However, lived experience engagement is often inconsistently operationalized and insufficiently theorized within implementation research.Inclusive implementation begins with an equitable research design and continues through intervention development, the selection of implementation strategies, and the evaluation of implementation outcomes. Embedding lived experience across these stages may trigger mechanisms that increase the likelihood of improved acceptability, feasibility, fidelity, and sustainability, while strengthening relevance and reach across populations and settings.This paper presents a principle-based, realist-informed approach to integrating lived experience into implementation science. Drawing on established frameworks, including the Consolidated Framework for Implementation Research (CFIR), i-PARIHS, RE-AIM, and Proctor's implementation outcomes, the paper conceptualizes lived experience engagement as a context-sensitive process. This process introduces resources capable of triggering mechanisms that operate through three generative principles: navigating power, building relational resilience, and adopting a learning mindset. We propose that these mechanisms are activated through evidence-informed implementation strategies such as shared governance, facilitation, equitable remuneration, capacity-building, and iterative learning cycles.Evaluation of lived experience engagement is essential for understanding whether inclusive approaches lead to meaningful change. This requires examining processes within the research group, external influences, and broader system-level factors. Evaluating lessons learned, impact achieved, and long-term sustainability ensures that lived experience engagement contributes not only to better implementation, but also to more equitable and effective health care. SPANISH ABSTRACT: http://links.lww.com/IJEBH/A598.