Abstract: We included 29 studies in the review, 21 of which were included in at least one meta-analysis. Non-legislative interventions increased observed helmet wearing (11 studies: OR 2.08, 95% CI 1.29 to 3.34). The effect was most marked amongst community-based interventions (four studies: OR 4.30, 95% 2.24 to 8.25) and those providing free helmets (two studies: OR 4.35, 95% CI 2.13 to 8.89). Significant effects were also found amongst school-based interventions (eight studies: OR 1.73, CI 95% 1.03 to 2.91), with a smaller effect found for interventions providing education only (three studies: OR 1.43, 95% CI 1.09 to 1.88). No significant effect was found for providing subsidised helmets (seven studies: OR 2.02, 95% CI 0.98 to 4.17). Interventions provided to younger children (aged under 12) may be more effective (five studies: OR 2.50, 95% CI 1.17 to 5.37) than those provided to children of all ages (five studies: OR 1.83, 95% CI 0.98 to 3.42). Interventions were only effective in increasing self reported helmet ownership where they provided free helmets (three studies: OR 11.63, 95% CI 2.14 to 63.16). Interventions were effective in increasing self reported helmet wearing (nine studies: OR 3.27, 95% CI 1.56 to 6.87), including those undertaken in schools (six studies: OR 4.21, 95% CI 1.06 to 16.74), providing free helmets (three studies: OR 7.27, 95% CI 1.28 to 41.44), providing education only (seven studies: OR 1.93, 95% CI 1.03 to 3.63) and in healthcare settings (two studies: OR 2.78, 95% CI 1.38 to 5.61). Non-legislative interventions appear to be effective in increasing observed helmet use, particularly community-based interventions and those providing free helmets. Those set in schools appear to be effective but possibly less so than community-based interventions. Interventions providing education only are less effective than those providing free helmets. There is insufficient evidence to recommend providing subsidised helmets at present. Interventions may be more effective if provided to younger rather than older children. There is evidence that interventions offered in healthcare settings can increase self reported helmet wearing. Further high-quality studies are needed to explore whether non-legislative interventions increase helmet wearing, and particularly the effect of providing subsided as opposed to free helmets, and of providing interventions in healthcare settings as opposed to in schools or communities. Alternative interventions (e.g. those including peer educators, those aimed at developing safety skills including skills in decision making and resisting peer pressure or those aimed at improving self esteem or self efficacy) need developing and testing, particularly for 11 to 18 year olds. The effect of interventions in countries with existing cycle helmet legislation and in low and middle-income countries also requires investigation.

Plain-language summary: This review focused on encouraging children to wear helmets, as distinct from compelling them to do so through laws. The authors wanted to find out which sort of helmet programmes work best, particularly with children from poor families who are less likely to own helmets. They found 29 helmet promotion programmes that had been studied. The programmes varied widely with regard to where they were carried out, age of the children, programme methods, etc. The results were also very varied but overall 11 studies found that after a helmet programme children were more likely to be observed wearing helmets than other children. More research is still needed but it seems likely that the best schemes are based in the community and involve both education and providing free helmets. Promotion of helmets in schools also seems to be effective. Promoting helmets appears to be more effective for younger children (aged 12 years and under) than for older children and young people. The studies reviewed did not look at the impact of helmet programmes on injury rates, or assess whether programmes had any negative effects such as reducing cycling. Most of the studies were undertaken in higher-income countries and the additional effect of helmet promotion above existing legislation was not explored. More research is needed to understand more about whether providing subsidised helmets is as effective as providing free helmets and whether programmes in healthcare settings are as effective as those in schools or communities. Other types of helmet programmes (e.g. those including peer educators, those developing skills such as decision making and resisting peer pressure, or improving self esteem or self efficacy) need developing and testing, particularly for 11 to 18 year olds. The effect of helmet programmes in countries with existing cycle helmet legislation and in low and middle-income countries also requires investigation.