Table 1.

The four iterative steps used to search, find, extract and synthesise evidence to generate initial programme theories that explain how implementation strategies work in large-scale hospital interventions

Step	Purpose	Research questions	Activities
1 2	To conceptualise implementation of large-scale hospital interventions.	What are the key concepts and features of large-scale hospital initiatives and their implementation? What mechanisms might these suggest are key to driving the programme?	Build an initial list of concepts and associated features based on research team’s research and clinical experience. Add to the list through a search of published literature on implementation of large-scale hospital interventions. Consider antecedents and outcomes of each feature to identify putative relevant mechanisms.
	To scope suites of implementation strategies used with large-scale hospital interventions.	What implementation strategies are used for large-scale hospital initiatives? How do they fit with Step 1? What do they tell us about possible mechanisms, contexts and the underlying programme theories?	Collation of implementation strategies extracted from Step 1 literature. Search of additional published literature including extracted studies from systematic reviews. Grey literature search: targeted websites and search terms. Strategies aggregated and sorted then mapped to ERIC implementation strategies.
3 4	Identify potential initial programme theories.	What formal theories might explain the mechanisms of action for the strategies listed?	Identification of formal theories from the published literature. Consideration of theories in the context of implementation strategies we have listed. Refinement of the initial programme theory-implementation strategy pairing through research team workshops using all data generated from the project.
	Focus on a promising implementation strategy-theory pairing and development of CMOs.	What context–mechanism–outcome configurations can we develop and test with the literature around implementation strategies linked to Organisational Readiness Theory?	Research team workshop to develop initial CMO statements. Testing and refinement of CMO statements through review of literature from Steps 1–3. Final iterations of CMOs.

CMO, context–mechanism–outcome configurations; ERIC, Expert Recommendations for Implementing Change.