Research Reports - Motorcycle helmet effectiveness in reducing head, face and brain injuries by state and helmet law
Inj Epidemiol. 2016;3:8. Epub 2016 Mar 7.
Olsen CS(1), Thomas AM(1), Singleton M(2), Gaichas AM(3), Smith TJ(4), Smith
GA(5), Peng J(6), Bauer MJ(7), Qu M(8), Yeager D(9), Kerns T(10), Burch C(10),
BACKGROUND: Despite evidence that motorcycle helmets reduce morbidity and
mortality, helmet laws and rates of helmet use vary by state in the U.S.
METHODS: We pooled data from eleven states: five with universal laws requiring
all motorcyclists to wear a helmet, and six with partial laws requiring only a
subset of motorcyclists to wear a helmet. Data were combined in the Crash Outcome
Data Evaluation System's General Use Model and included motorcycle crash records
probabilistically linked to emergency department and inpatient discharges for
years 2005-2008. Medical outcomes were compared between partial and universal
helmet law settings. We estimated adjusted relative risks (RR) and 95 %
confidence intervals (CIs) for head, facial, traumatic brain, and moderate to
severe head/facial injuries associated with helmet use within each helmet law
setting using generalized log-binomial regression.
RESULTS: Reported helmet use was higher in universal law states (88 % vs. 42 %).
Median charges, adjusted for inflation and differences in state-incomes, were
higher in partial law states (emergency department $1987 vs. $1443; inpatient
$31,506 vs. $25,949). Injuries to the head and face, including traumatic brain
injuries, were more common in partial law states. Effectiveness estimates of
helmet use were higher in partial law states (adjusted-RR (CI) of head injury:
2.1 (1.9-2.2) partial law single vehicle; 1.4 (1.2, 1.6) universal law single
vehicle; 1.8 (1.6-2.0) partial law multi-vehicle; 1.2 (1.1-1.4) universal law
CONCLUSIONS: Medical charges and rates of head, facial, and brain injuries among
motorcyclists were lower in universal law states. Helmets were effective in
reducing injury in both helmet law settings; lower effectiveness estimates were
observed in universal law states.