| Methods |
CBA. Neither outcome assessment nor the analysis were undertaken blind to treatment group allocation. Some data on completeness of follow‐up are presented but not numbers initially allocated to each group. An assessment of the distribution of confounders is presented. The median household income of the intervention area was USD 58,900 compared to USD 40,600 in the control area. |
| Participants |
328 under 16 year‐olds observed riding bicycles in 2 US counties |
| Interventions |
Subsidised helmets, a helmet education programme and a local media campaign. The control group received none of the above interventions. |
| Outcomes |
Observed helmet wearing. Measured at 9 months. |
| Notes |
Only follow‐up data presented for self reported outcomes which were excluded from the analysis. One additional county included in the report had passed legislation and was therefore excluded. Participating sites probably represent clusters but no adjustment was made for this in the analysis. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
High risk |
Not used |
