Table 1.

Research questions and data sources

Research question (RQ)	Data source	Timing of data collection	Variables measured
RQ1: How closely did intervention implementation adhere to the study protocol?	Planograms before and after intervention, provided by the collaborating supermarket	Baseline and after implementation of the placement intervention*	Distance in metres (m) fresh fruit and vegetable section moved forward
	Store-level SKU data on available produce, provided by collaborating supermarket	Baseline and after implementation*	Availability of fresh fruit and vegetables – number of varieties of fresh fruit and vegetables
	Intervention implementation survey	Baseline, 1 month and 6 months after intervention implementation	Proportion of stores with different products available in the first half of the first aisle
RQ2: What contextual factors affect intervention implementation?	Intervention implementation survey	Baseline, 1 month and 6 months after intervention implementation	Proportion of stores with produce placed prominent locations (foyer, checkouts, aisle-ends) Regularity of deliveries of fresh fruit and vegetables
	Semi-structured interviews with store managers and senior store staff	Post-implementation, for most stores these took place at least one year after implementation	Study store manager views and lived experience of implementing the intervention

* at the time of store refit