Discussion
This work takes the important step of scaling evidence from pilot programs through to a multisite intervention, drawing on implementation science theory through use of i-PARIHS framework and the MRC guide for complex interventions. Steps like the intervention deconstruction process (into core and adaptable elements), assessment of feasibility and sustainability, and the development of detailed context assessment tools are key to the process of scale-up, and the subsequent ability to tailor the intervention to each RAC home without compromising fidelity. Our inclusion of these steps are supported by the most recent version of the MRC guide (2021)—published during our implementation of the EDDIE + trial but after the development phase—highlighting economic feasibility and understanding the process of change as key to maximising the impact of complex interventions [There has been some recent discussion on the limited applicability of theories, models or frameworks in practice and seemingly incongruent nature of implementation science theory in pragmatic trials [Detail around the final intervention is further described in the Supplementary Files (Files We recognize that the development and refinement of the intervention could have been further enhanced and contextualized by including aged care residents and their families, or local clinicians (e.g. general practitioners) in the IWG or through local resident committees, but was not supported by the aged care provider at the time. Further, the EDDIE + trial was developed in a single Australian state and may require future refinement and adjustment to context if the intervention is to be scaled nationally or internationally.