Did Amendments to the Ontario Highway Traffic Act in 2009-2010 Affect the Proportion of Alcohol-Related Motor Vehicle Collisions Seen at a Level I Trauma Centre over a 10-year Period?

Abstract

Objectives: To determine if changes to the Ontario Highway Traffic Act (OHTA) in 2009 and 2010 had an effect on the proportion of alcohol-related motor vehicle collisions (MVCs) presenting to a trauma centre over a 10-year period. Methods: A retrospective review of the trauma registry at a Level I trauma centre in southwestern Ontario was undertaken. The trauma registry is a database of all trauma patients with an injury severity score (ISS) ≥12 and/or who had trauma team activation. Descriptive statistics were calculated. Interrupted time series analyses with ARIMA modeling were performed on quarterly data from 2004-2013. Results: A total of 377 drivers with a detectable serum ethanol concentration (SEC) were treated at our trauma centre over the 10-year period, representing 21% of all MVCs. The majority (330; 88%) were male. The median age was 31 years, median SEC was 35.3 mmol/L, and median ISS was 21. A total of 29 (7.7%) drinking drivers died from their injuries after arriving to hospital. There was no change in the proportion of drinking drivers after the 2009 amendment, but there was a significant decline in the average SEC of drinking drivers after changes to the law. There was no difference in the proportion of drinking drivers ≤ 21 years after introduction of the 2010 amendment for young and novice drivers. Conclusions: There was a significance decline in the average SEC of all drinking drivers after the 2009 OHTA amendment, suggesting that legislative amendments may have an impact on drinking before driving behaviour. En tout, 29 (7,7 %) conducteurs en état d'ébriété ont succombé à leurs blessures après leur arrivée à l'hôpital. La proportion de conducteurs en état d'ébriété n'a pas changé après les modifications apportées au CR en 2009, mais une diminution importante du TAD moyen a été notée chez les conducteurs en état d'ébriété. Enfin, aucune différence, par rapport aux années antérieures, n'a été relevée en ce qui concerne la proportion de conducteurs en état d'ébriété, âgés de 21 ans ou moins après l'entrée en vigueur des modifications apportées en 2010 visant les jeunes conducteurs et les apprentis conducteurs. Conclusions: Une diminution importante du taux moyen d'alcoolémie a été enregistrée chez tous conducteurs en état d'ébriété après l'entrée en vigueur des modifications apportées au CR de l'Ontario en 2009, ce qui donne à penser que les modifications à la loi peuvent inciter les personnes restreindre leur consommation d'alcool avant de se mettre au volant.