Azeredo 2003.

Methods	CBA
Participants	6300 children from kindergarten to grade 2 in 12 schools in Oklahoma, US
Interventions	Bicycle fairs were held during assemblies. Free helmets given to those who filled in an application form. The study also addressed seat belt use and smoke alarm awareness.
Outcomes	Self reported helmet use and observed helmet use measured at 18 and 27 weeks
Notes	Not included in meta‐analysis as denominators not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	High risk	Not used