BACKGROUND
Translating evidence-informed interventions into sustained population-level impact remains a major challenge across public health systems, including cancer prevention, treatment and supportive care. While many interventions demonstrate effectiveness in pilot or controlled settings, their successful scale-up is often constrained by system complexity, limited implementation guidance, insufficient adaptation to the context and inadequate consideration of scalability during early design stages. For example, digital and home-based models of care, such as virtual wards, are increasingly being implemented to support hospital-at home pathways and reduce pressure on acute services. However, as models such as these, expand, including potential future application to oncology and palliative care, there is a growing need for structured, transferable approaches to guide scalable implementation across diverse settings. Existing scalability frameworks rarely provide tools that policy makers can apply flexibly across sectors.

OBJECTIVES
The aim of this research is to develop a cross-sectoral scalability framework to support policy makers, practitioners and researchers in planning, implementing the scale-up of complex interventions across health and other public policy sectors. The current presentation focuses on Phase One of this research. In this phrase, the aim is  to synthesise and analyse evidence from literature on existing scalability frameworks, models and tool. This will enable the identification of core constructs and approaches that can be used to inform the development of a transferable scalability framework, applicable to cancer-related and broader public health interventions.

METHODS
A scoping review guided by Joanna Briggs Institute (JBI) methodology has been undertaken in order to identify scalability frameworks, models and tools used across health and other sectors that are used in the scaling up of real-world interventions. Searches were conducted across PubMed, Embase, CINAHL, Web of Science and Scopus, with grey literature from social science databases and other policy-related sources identified. Screening, data extraction and initial synthesis and analysis of data has been undertaken using descriptive and qualitative analytical methods to identify scalability constructs across sectors.

RESULTS
Preliminary findings indicate substantial variation across existing frameworks in how scalability is conceptualised, including distinctions between horizontal and vertical scale-up, spontaneous scaling up, and diversification. Identified frameworks also differ in form, ranging from conceptual frameworks and process models to practical assessment tools. Emphasis on system capacity, stakeholder engagement, contextual fit and sustainability, alongside inconsistent attention to equity and long-term institutionalisation is observed.

IMPLICATION
This research contributes to implementation science by advancing a systematic, cross-sectoral approach to scalability that is transferable to cancer-related service innovations and other health and non-health sector interventions. Phase two will involve stakeholder engagement to explore experiences of scaling up real world interventions across multiple real-world implementation projects, including a national health service implementing a virtual ward programme. The programme is currently operational in two sites with both horizontal expansion to additional sites and vertical expansion to oncology and palliative care pathways planned. These stakeholders will contribute insights to inform the co-design of the scalability framework, alongside stakeholders from other sectors, ensuring cross-sectoral applicability.