Impacts of the minimum legal drinking age on motor vehicle collisions in Québec, 2000-2012.

ABSTRACT

BACKGROUND: International debates are occurring about the effectiveness of minimum legal drinking age laws. Most minimum legal drinking age evaluation studies have focused on motor vehicle collision outcomes, but this literature is primarily based on naturalistic experiments involving legislation changes in the U.S. in the mid-1980s. Few studies have provided up-to-date estimates of the impacts of Canadian drinking age laws on motor vehicle collisions to inform current policy discussions. PURPOSE: To estimate the impacts of minimum legal drinking age legislation on motor vehicle collisions occurring in 2000-2012 in Québec, a province with a minimum legal drinking age of 18 years. METHODS: Using Québec Ministry of Transportation records of police-reported motor vehicle collisions in 2000-2012, regression-discontinuity analyses were employed to assess the impacts of the minimum legal drinking age on motor vehicle collisions. All data were analyzed in 2013. RESULTS: Relative to individuals slightly younger than the minimum legal drinking age, male and female drivers just older than the minimum legal drinking age had a significant and abrupt increase of approximately 6% (men, 6.3%, p=0.003; women, 5.9%, p=0.047) in population-level motor vehicle collisions, as well as a significant 11.1% (p=0.001) rise in nighttime motor vehicle collisions (a proxy for alcohol-related collisions). CONCLUSIONS: Drinking-age laws continue to be an integral component of contemporary alcohol-control and driving-related policies designed to limit motor vehicle collisions among youth. In addition, the regression-discontinuity approach can guide future work to estimate potential minimum legal drinking age impacts on other health outcomes.