Effects of state helmet laws on bicycle helmet use by children and adolescents.

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.