Impact of Helmet Law Repeal on Motorcycle Crash Incidents Attended by EMS in Missouri

About this Research Project

Authors: Morgan K. Anderson¹, Lori L. Boland^1-2, Peggy Huddleston, AAS, CADS³

¹Clincial and Research Services, ImageTrend Inc.
²Allina Health Emergency Medical Services
³Missouri Department of Health and Senior Services

Background

Previous research has shown that motorcycle helmets save lives, reduce serious injuries, and lower the costs associated with healthcare, lost productivity, and other economic impacts. The state of Missouri repealed its universal helmet use law for motorcyclists aged 26 and older with valid health insurance on August 28, 2020. This study aimed to compare characteristics of motorcycle crashes (MCC) attended by emergency medical services (EMS) in Missouri before and after the repeal of the helmet use law.

Methods

Inclusion criteria for this study were 9-1-1 EMS responses involving a MCC injury where the patient was either a driver or passenger on a motorcycle and was at least 26 years of age. MCC injuries were identified using ICD-10 injury cause codes V20-V29. Occupant safety equipment use, provider impressions, chief complaint anatomical location, and patient care narratives were used to categorize helmet use and head injuries. Incidents were ascertained for two time periods: March 1, 2020, through August 27, 2020 (before helmet law repeal) and March 1, 2021, through August 27, 2021 (after helmet law repeal). Patient demographics, urbanicity, helmet use, head injury, patient acuity, Glasgow Coma Score (GCS), and trauma team activations were examined. Categorical variables were compared for the two time periods with chi-square tests to assess differences in proportions.

Results

There were 682 MCCs (7% of all motor vehicle incidents) before the helmet law repeal and 1,031 MCCs (8% of all motor vehicle incidents) that occurred after the helmet law repeal. Of note, the number of incidents increased in 2021, most likely due to the COVID-19 shelter-in-place order that had led to less travel, being lifted from the prior year. The age, sex, and race distributions of MCC patients did not differ by time period. After the repeal, there was a 53% decrease in the proportion of MCC patients who were helmeted (77.3% vs 36.2%, p<0.01). In addition, the prevalence of documented head injuries, patients with critical injuries, patients with GCS <8, and trauma team activations increased by 50%, 64%, 64%, and 20%, respectively (all p<0.001) after the law was repealed. There was no significant difference in the proportion of MCC incidents that resulted in patient deaths reported by EMS before and after the law repeal (2.5% vs 2.2%, p=0.363), but not all roadway deaths were documented by EMS.

Conclusion

Based on these results, the repeal of the mandatory helmet law in Missouri has been associated with an increase in head injuries, injury severity, and subsequent trauma team activations among MCC patients attended to by EMS. Long-term monitoring is necessary to track the impacts of helmet use in MCCs on EMS resources and costs. There was also a decrease in helmet use documentation by EMS providers after the helmet law was repealed, which may be an indicator in the perception that helmet use documentation is no longer relevant; This has not been well studied, but additional research should be performed to see if these results are similar in other states where helmet use laws are changed. Additionally, training for providers on the importance of documenting safety equipment used by patients may also be necessary, especially when laws change related to incidents seen by EMS.