Autopsy study of motorcyclist fatalities: the effect of the 1992 Maryland motorcycle helmet use law.

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 10000 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.