Objectives: This study sought to determine the impact of Maryland's all-rider motorcycle helmet law (enacted on October 1, 1992) on preventing deaths and traumatic brain injuries among motorcyclists.
Methods: Statewide motorcyclist fatalities occurring during seasonally comparable 33-month periods immediately preceding and following enactment of the law were compared.
Results: The motorcyclist fatality rate dropped from 10.3 per 10 000 registered motorcycles prelaw to 4.5 postlaw despite almost identical numbers of registered motorcycles. Motorcyclists wearing helmets had a lower risk of traumatic brain injury than those not wearing helmets (odds ratio = 0.31, 95% confidence interval = 0.14, 0.68).
Conclusions: Maryland's controversial motorcycle helmet law appears to be an effective public health policy and may be responsible for saving many lives.