Effectiveness of a state law mandating use of bicycle helmets among children: An observational evaluation

In spring 1999, the authors evaluated the effectiveness of a 1997 Florida l aw requiring helmet use by all bicyclists younger than age 16 years. Sixty- four counties in Florida had enacted the bicycle helmet-use law, while the other three counties had opted out. Using a cross-sectional study design, t he authors conducted unobtrusive observations at bicycle racks at public el ementary schools statewide. Florida children riding bicycles in counties wh ere the state helmet-use law was in place were twice as likely to wear helm ets as children in counties without the law. In counties where the state la w was in place, 16,907 (79%) of 21,313 riders observed wore a helmet, compa red with only 148 (33%) of 450 riders in counties where no such law was in place (crude prevalence ratio = 2.4, 95% confidence interval: 2.1, 2.8). He lmet use by children of all racial groups exceeded 60% under the law. No si gnificant difference in use by gender was found. These data support the pos itive influence of a law on bicycle helmet use among children. The data rei nforce the Healthy People 2010 objective that all 50 states adopt such a la w for children in order to increase helmet use and consequently reduce brai n injury.