Lee 2000.

Methods	CBA. Outcome assessment was not undertaken blind to treatment group allocation. Data relating to completeness of follow‐up are not clear. An assessment of the distribution of confounders is not presented.
Participants	500 eleven to 15 year‐olds from intervention and control areas completed questionnaires at the beginning and end of the campaign each year for 3 years (6000 children in total). Control and intervention areas were both UK cities.
Interventions	Subsidised helmets and an education programme. The control group received none of the above interventions.
Outcomes	Self reported helmet wearing
Notes	Data from this study have not been included in the meta‐analysis because we could not obtain them in a form that would allow the calculation of odds ratios.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	Not used