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Published on: September 21, 2017
Adolescent noncompliance with age-specific versus universal US motorcycle helmet laws: Systematic review and
Jon Berrick1, Konstantina Gkritza2
1Science Division, Yale-NUS College, 10 College Avenue West #01-101, Singapore 138609, Singapore.
Introduction:
The U.S. experience with motorcycle helmets affords an important insight into the responses of adolescents to age-specific laws. Political contention has led to a number of U.S. state law changes back and forth between universal and age-specific laws. Because both kinds of law require adolescent motorcyclists to wear helmets, relatively few studies have focused on how the law type affects their behavior.
Method:
Differential behavior is tested by a systematic review of literature, leading to a meta-analysis, in relation to the experience of various states' motorcycle helmet laws. An electronic search was conducted for before-and-after studies in U.S. states that include data on adolescent helmet usage - both with a universally applicable motorcycle helmet law, and with an age-restricted law (usually, under-21 or under-18) - from observational, injury or fatality records for a certain period (e.g., 12 months) pre and post the state law change.
Results:
The search yielded ten studies, including two that compared a set of age-specific law states with a set of universal law states over the same time period. Heterogeneity analysis of seven single-state studies with raw data revealed an acceptable fit for a random-effects model. Additional noncompliance with age-restricted laws was indicated by an attributable percentage among exposed of over 65% and odds ratio exceeding 4.
Conclusions:
About two-thirds of adolescent noncompliance with age-restricted motorcycle helmet usage laws disappears with universal applicability. Evidence from numerous international studies of youth reaction to helmet laws suggests that a large part of the greater compliance with universal laws is due to their conveying a more convincing message that helmets afford protection against injury. Practical Applications: The meta-analysis provides fresh, young-rider perspective on the continuing debate over motorcycle-helmet laws. Broader insight into adolescent psychology suggests considering alternatives to age-restricted laws more widely in safety and health policy.
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