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[Prevalence of helmet use in children and adolescents in Germany and preventable bicycle-related head injuries].

INTRODUCTION
Head injuries are the main cause of death in bicycle-related accidents among children and adolescents. According to a Cochrane Review, the risk of head injury (OR 0.31; 95% CI 0.26-0.37) or brain injury (OR 0.31; 95% CI 0.23-0.42) decreases by 69% if a helmet is worn. This study presents the prevalence of helmet use in cycling children and adolescents in Germany and the proportion of head injuries that could be prevented by wearing helmets. The potential effects of increased helmet wearing rates on the population attributable risk percentage for head injuries (PAR%) are demonstrated.


METHODS
The prevalence of helmet use in children aged 3-17 years was analysed using data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). The percentage of head injuries preventable by helmet use in this group is estimated by calculating PAR%. Prevalence rates of helmet use and odds ratios from a Cochrane Review about the effectiveness of bicycle helmets for the prevention of head injuries were used for analysis. The potential effect of increased helmet use is shown in 3 scenarios by means of differences of PAR% values in the most relevant age groups.


RESULTS
The older the children, the less likely they are to wear a helmet: 89.5% (95% CI 88.0%-90.8%) of the 3- to 6-year-old children wear a helmet when cycling but only 11.0% (95% CI 9.3%-12.9%) of 14- to 17-year-old adolescents do. In the youngest group (3-6 years) 19% of bicycle-related head injuries are attributable to the non-use of helmets, but this proportion rises to 67% in the oldest group (14-17 years). The PAR% of head injuries associated with not wearing a helmet may be reduced by more than a third by increasing the helmet wearing rate to 67% (2 out of 3) among adolescents, and may be reduced to half if 75% of adolescents wore a helmet.


CONCLUSION
Particularly older children and adolescents hardly use bicycle helmets, hence the rate of preventable head injury is high. Efforts towards increasing helmet use should address all age groups with a particular focus on school-aged children and adolescents.