P.L. Johnson1, M.R. Hemmila1, R.A. Jean1 1University of Michigan, Surgery, Ann Arbor, MI, USA
Introduction: Despite motorcycle helmets reducing crash-related morbidity, an increasing number of states are repealing motorcycle helmet mandates. The impact of motorcycle helmet law repeal on clinical outcomes and healthcare economics is unknown.
Methods: We evaluated the impact of the 2012 repeal of Michigan’s mandatory motorcycle helmet law on motorcycle crash associated outcomes and economics using data from the Healthcare Cost & Utilization Project State Inpatient Database. We also evaluated the rate of unfavorable discharge (discharge disposition other than home, excluding deaths). A difference-in-difference regression analysis method was used to evaluate clinical outcomes and inpatient costs before and after policy repeal (2009-2011 vs 2013-2015). Wisconsin was chosen as a control based on sociodemographic and regional similarity.
Results: 10,285 patients ≥18 years old were identified. On unadjusted analysis, there was an increase in mortality (2.1 vs 2.6%, p=0.01), neurosurgical interventions (5.6 vs 7.3%, p=0.05), unfavorable hospital disposition (35 vs 40%, p<0.001), and inflation-adjusted inpatient hospital costs ($19,833 vs 25,608, p<0.001) in Michigan after repeal. On difference-in-difference regression analysis, helmet law repeal was associated with a 1.7 percentage-point rise in mortality (95% CI: 0.1 to 3.3, p=0.04) after policy enactment, representing a 24% relative increase (Table).
Conclusion: Motorcycle helmet mandate repeal is associated with worse clinical outcomes and higher hospital costs. The rise in repeal of mandatory state helmet laws may have important downstream impacts on population health and healthcare costs.