Impact of mandatory helmet legislation on bicycle-related head injuries in children: a population-based study.

OBJECTIVE Childhood bicycle-related head injuries can be prevented through the use of helmets. Although helmet legislation has proved to be a successful strategy for the adoption of helmets, its effect on the rates of head injury is uncertain. In Canada, 4 provinces have such legislation. The objective of this study was to measure the impact of helmet legislation on bicycle-related head injuries in Canadian children. METHODS Routinely collected data from the Canadian Institute for Health Information identified all Canadian children (5-19 years) who were hospitalized for bicycling-related injuries from 1994-1998. Children were categorized as head or other injury on the basis of International Classification of Diseases, Ninth Revision, codes. Rates of head injuries and other injuries were compared over time in provinces that adopted legislation and those that did not. RESULTS Of the 9650 children who were hospitalized because of a bicycle-related injury, 3426 sustained injuries to the head and face and the remaining 6224 had other injuries. The bicycle-related head injury rate declined significantly (45% reduction) in provinces where legislation had been adopted compared with provinces and territories that did not adopt legislation (27% reduction). CONCLUSION This country-wide study compared rates of head injury in regions with and without mandatory helmet legislation. Comparing head injuries with other non-head-injured children controlled for potential differences in children's cycling habits. The strong protective association between helmet legislation and head injuries supports the adoption of helmet legislation as an effective tool in the prevention of childhood bicycle-related head injuries.