Forecasting Injuries Prevented and Costs Averted by Cambodia's 2015 Passenger Helmet Law

Background/Purpose

In 2013 motorcyclists accounted for about 1,340 deaths in Cambodia, equal to two-thirds of all road traffic deaths.  Motorcycle helmet use varies substantially by rider type, with approximately 60% of drivers and 7% of passengers helmeted. These differences align with helmet laws, which prior to 2015 required that drivers, but not passengers, wear helmets.  In January 2015, Cambodia passed a new law mandating motorcycle helmet use for drivers and passengers.  This project quantifies the potential injuries and costs averted by increased helmet use between 2015 and 2020.

Methods

We projected the number of injuries and deaths between 2015 and 2020 using multiple helmet uptake scenarios. Potential injuries and deaths prevented were based on Cochrane review estimates for the safety value of wearing a motorcycle helmet.  Costs—including medical, property damage, and work loss—were calculated for each helmet use scenario.

Results/Outcomes

Assuming passenger helmet use increases to 15%, over 70 deaths and 1,000 head injuries could be prevented over 5 years, accounting for $11 million US dollars in costs averted. Should passenger helmet use reach 80%, over 550 lives could be saved, 10,000 head injuries prevented, and nearly $100 million saved over 5 years.  

Conclusions

The new helmet law in Cambodia may increase helmet use, resulting in substantial injuries prevented and costs averted.  Increases in helmet use are contingent on many factors including communication about and enforcement of the new law.   Government and non-governmental efforts to encourage proper motorcycle helmet use for all riders will likely be critical for achieving these potential increases.