Towards meaningful engagement: theoretical approaches guiding the participation of people living with multiple long-term conditions in health research - a scoping review.

The rising prevalence of multiple long-term conditions (MLTCs), largely driven by non-communicable diseases (NCDs), presents complex healthcare challenges. Evidence suggests that meaningful engagement of people with lived experience can improve intervention relevance, health outcomes and equity. Theories, frameworks and models (TFMs) may provide structured approaches to support such engagement among people living with MLTC (PLwMLTC). Objectives: To identify TFMs informing engagement strategies for PLwMLTC. Design: Scoping review followed the Arksey and O'Malley and Levac Data sources: PubMed, Scopus, CINAHL and Embase databases were searched on 20 December 2024 without date restrictions. Eligibility criteria: Studies describing TFMs adopted to support engagement and involvement of PLwMLTC and community members. Data extraction and synthesis: Data were extracted using a predefined charting form and synthesised narratively. Results: Of 756 articles screened, 25 met inclusion criteria. Commonly adopted TFMs included the Chronic Care Model, Collaborative Care Model, Health Belief Model, Transtheoretical Model, Patient-Centred Medical Home, Improving Mood-Promoting Access to Care Model and Patient-Centred Care Model. These TFMs facilitated meaningful engagement through patient education, behaviour change programmes, community-based care, peer support and coordinated provider-patient interactions. Evidence linked several TFMs to improvements in clinical outcomes (eg, blood pressure and depression), while others primarily influenced sociobehavioural dimensions. Persistent challenges concerned heterogeneity in integrating engagement within health systems and limited evidence on contextual adaptation across diverse settings, particularly in relation to NCD-driven MLTC. Conclusions: TFMs provide structured approaches to engage PLwMLTC meaningfully, through behaviour change strategies, multidisciplinary care coordination and community network strengthening. Effective implementation relies on ensuring cultural relevance and alignment with local health system capacities. Future research should focus on adaptation, implementation, sustainability, scalability and equity across diverse settings.