Domain	Risk of bias	Support for judgement
Random sequence generation (selection bias)	Low risk	Computerised random number function in Microsoft Excel used to generate random number sequence
Allocation concealment (selection bias)	Low risk	Statistician not involved in the project allocated the services to groups using a computerised program
Blinding of participants and personnel (performance bias)	High risk	Assume through nature of the intervention that centre staff and study personnel delivering the intervention not blind to the study allocation and therefore potential high risk of performance bias
Blinding of outcome assessment (detection bias)	Low risk	Child physical activity: Measured using pedometers with research staff blind to group allocation
	High risk	Adverse effects: service manager self‐report via interview
Incomplete outcome data (attrition bias)	Low risk	Child physical activity: Although there was 48% and 44% loss to follow‐up in intervention and control groups respectively, sensititvity analysis imputing missing data showed no difference in outcome analysis.
Selective outcome reporting (reporting bias)	Unclear risk	There are no unreported outcomes according to those planned in published protocol.
Recruitment bias	Low risk	For the physical activity measure, children were recruited by supervisors at the centre selecting a day of the week for measurement to occur. Allocation was not revealed to services until after baseline data collection.