@article{ref1,
title="Helmet laws, helmet use, and bicycle ridership",
journal="Journal of Adolescent Health",
year="2016",
author="Kraemer, John D.",
volume="59",
number="3",
pages="338-344",
abstract="PURPOSE: To assess bicycle helmet laws' effect on helmet and bicycle use among U.S. high school students in urban jurisdictions. <br><br>METHODS: Log-binomial models were fit to Youth Risk Behavior Survey data from five jurisdictions. Adjusted helmet and bicycle use proportions were calculated with post-regression marginal effects. Difference-in-differences were estimated, comparing intervention to concurrent controls. A placebo outcome was used to falsify possible confounding or selection effects. <br><br>RESULTS: In San Diego and Dallas, helmet use increase increased 10.6 (95% confidence interval [CI] 6.5 to 14.7, p <.001) and 8.1 (95% CI 4.3 to 12.0, p <.001) percentage points more than out-of-jurisdiction controls. Increases in Florida counties were 5.0 (95% CI 1.8 to 8.2, p =.003) and 4.0 (95% CI -.7 to 8.8, p =.098) points against age-based and out-of-jurisdiction controls, respectively. Bicycle use fell 5.5 points in both San Diego (95% CI -9.8 to -1.1, p =.015) and the Florida counties (95% CI -11.5 to.5, p =.075) against out-of-jurisdiction controls, but other comparisons had no significant changes. The placebo outcome never changed significantly. <br><br>CONCLUSIONS: Laws increased helmet use in all jurisdictions, with limited evidence of reduced cycling. Although sound health policy, laws should be coupled with physical activity promotion.<br><br>Copyright © 2016 The Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.<p /> <p>Language: en</p>",
language="en",
issn="1054-139X",
doi="10.1016/j.jadohealth.2016.03.009",
url="http://dx.doi.org/10.1016/j.jadohealth.2016.03.009"
}