—To rebut criticism of a previous study of motorcycle helmet—use laws through reanalysis with improved measures of exposure, stratification for regional differences in crash risk, and addressing of total motorcycle-related mortality and the grounds for targeting motorcyclists for helmet-use laws.
—Death certificate—based correlational study of motorcycle-related deaths and motorcycle helmet—use laws.
—United States resident deaths from 1979 through 1986.
—Regardless of the denominator used (resident population, motorcycle registrations, or motorcycle crashes), states with full helmet-use laws had consistently lower head injury—associated death rates than states without such laws, even when stratified by region. Total motorcycle-related mortality, however, was similar between law groups. On a registration or crash basis, motorcyclists who died in crashes had a fivefold to sixfold higher risk of head injury than those who died using any other type of motor vehicle.
—Full helmet-use laws were consistently associated with lower rates of head injury—associated death. While disagreement remains on the acceptability of the legislative approach, the scientific basis for motorcycle helmet— use laws as a head injury prevention tool appears sound.(JAMA. 1992;267:1649-1651)