| Methods |
CBA. Neither outcome assessment nor the analysis were undertaken blind to treatment group allocation. Completeness of follow‐up not applicable because of population‐based design. An assessment of the distribution of confounders is presented. Intervention and control schools were similar with respect to average family income, university education, owner occupation of dwellings and one‐parent families. |
| Participants |
5 to 14 year‐olds from 3 schools in areas of low average family income in a large urban Canadian city and 3 low‐income areas in the same city served as control areas. 1415 children received the intervention. |
| Interventions |
Subsidised helmets and an education programme. The control group received none of the above interventions. |
| Outcomes |
Observed helmet wearing. Self reported helmet ownership also mentioned but full data not presented. Measured at approximately 2 months. |
| Notes |
This study included a subgroup analysis comparing the observed helmet wearing rates post‐intervention in high versus low‐income groups. No adjustment for clustering in the analysis. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
High risk |
Not used |
