Abstract
OBJECTIVE: To evaluate the effectiveness of state helmet laws in increasing the use of bicycle helmets by children and adolescents under age 16. SETTING: United States. METHODS: A cross sectional study of factors associated with the likelihood of helmet use by children and adolescents. Data were derived from a national random digit dial telephone survey of bicycle riders. A multiple logistic regression analysis was used to quantify the independent effect of the state helmet laws on helmet use. RESULTS: Helmet use was systematically related to the presence of state helmet laws (odds ratio 2.65; 95% confidence interval (CI) 1.29 to 5.44). The increase in the average probability of helmet use attributable to state helmet laws was 18.4% (95% CI 17.8% to 19.0%). CONCLUSIONS: State helmet laws significantly increase helmet use by children and play an important part in any comprehensive effort designed to achieve this goal.