Table 5. Summary of steps involved in creation of new EPPIIC.

	Step	Resources/People involved	Results
1	Compile full list of available checklists	CEPPP Database search (PubMed, Google Scholar)	Total checklists identified (n = 20; 11 CEPP and nine database search)
2	Generate full list of themes	All identified checklists; PPI involvement	Total number of items in the first iteration of the checklist = 34
3	Matching each item with a checklist item	All identified checklists	Checklist items were sorted into each identified theme
4	Grouping subthemes into relevant main themes	PPI involvement; research team discussion	Three overarching themes identified
5	Refining the items	PPI involvement; research team discussion	Decision to separate PPI and researcher evaluation
6	Piloting of the checklist	PPI and research team	Adjustments between PPI member and researcher surveys–e.g. change language, merging of items etc.
7	Finalising the checklist	PPI and research team	Number of items–ensuring equal questions between researcher and PPI member survey with appropriate balance of qualitative and quantitative questioning.
8	Application of the checklist	EPPIIC applied to a clinical trial	Results presented below.