School regulations governing bicycle helmet use and head injuries among Japanese junior high school students.

We examined the effectiveness of school regulations concerning bicycle helmet use in reducing head injuries among student bicycle commuters to junior high schools in the Japanese prefecture of Saitama. This was done by comparing the rates of head injuries and the ratios of head injuries to non-head injuries between junior high schools with and without school regulations concerning helmet use. Bicycle injury data were derived from school insurance records. Information relating to numbers of bicycle commuters and demographics was collected for each school. We identified that the head injury rate was significantly higher in schools that had no regulations governing the use of bicycle helmets (rate ratio 2.97, 95% confidence interval (CI) 1.03-8.56; odds ratio 2.46, 95% CI 0.80-7.60). The observed trend was more prominent in male students than in female students. The actual rate of bicycle injuries did not significantly differ between the schools with and without regulations concerning helmet use. This suggests that students at schools with regulations were no more cautious in riding their bicycles than their counterparts in schools with no regulations, and that there was no significant difference in the traffic environments surrounding each school. Thus implicating that the observed difference in the head injury rate was most accounted for by the presence of school regulations governing helmet use.