Dubois Sacha, Mullen Nadia, Weaver Bruce, Bédard Michel
Research Department, St. Joseph's Care Group, 580 North Algoma Street, Thunder Bay, ON, Canada P7B 5G4; Centre for Research on Safe Driving, Lakehead University, 955 Oliver Road, Thunder Bay, ON, Canada P7B 5E1; Department of Health Sciences, Lakehead University, 955 Oliver Road, Thunder Bay, ON, Canada P7B 5E1; Northern Ontario School of Medicine, Human Sciences Division, Lakehead University, 955 Oliver Road, Thunder Bay, ON, Canada P7B 5E1.
Centre for Research on Safe Driving, Lakehead University, 955 Oliver Road, Thunder Bay, ON, Canada P7B 5E1.
Forensic Sci Int. 2015 Mar;248:94-100. doi: 10.1016/j.forsciint.2014.12.018. Epub 2014 Dec 25.
BACKGROUND/OBJECTIVES: Driving under the influence of alcohol or cannabis alone is associated with increased crash risk. This study explores the combined influence of low levels of alcohol (BAC≤0.08) and cannabis on crash risk.
Drivers aged 20 years or older who had been tested for both drugs and alcohol after involvement in a fatal crash in the United States (1991-2008) were examined using a case-control design. Cases were drivers with at least one potentially unsafe driving action (UDA) recorded in relation to the crash (e.g., weaving); controls had none recorded. We examined the prevalence of driving under the influence of alcohol, cannabis, and both agents, for drivers involved in a fatal crash. Adjusted odds ratios of committing an UDA for alcohol alone, THC alone, and their combined effect were computed via logistic regression and adjusted for a number of potential confounders.
Over the past two decades, the prevalence of THC and alcohol in car drivers involved in a fatal crash has increased approximately five-fold from below 2% in 1991 to above 10% in 2008. Each 0.01 BAC unit increased the odds of an UDA by approximately 9-11%. Drivers who were positive for THC alone had 16% increased odds of an UDA. When alcohol and THC were combined the odds of an UDA increased by approximately 8-10% for each 0.01 BAC unit increase over alcohol or THC alone.
Drivers positive for both agents had greater odds of making an error than drivers positive for either alcohol or cannabis only. Further research is needed to better examine the interaction between cannabis concentration levels, alcohol, and driving. This research would support enforcement agencies and public health educators by highlighting the combined effect of cannabis at low BAC levels.
背景/目的：单独在酒精或大麻影响下驾驶会增加撞车风险。本研究探讨低水平酒精（血液酒精浓度≤0.08）和大麻对撞车风险的综合影响。
采用病例对照设计，对1991 - 2008年在美国发生致命撞车事故后接受过毒品和酒精检测的20岁及以上驾驶员进行研究。病例为与撞车事故相关记录中至少有一项潜在不安全驾驶行为（UDA）的驾驶员（例如， weaving）；对照则无此类记录。我们研究了涉及致命撞车事故的驾驶员在酒精、大麻以及两者共同影响下驾驶的患病率。通过逻辑回归计算单独酒精、单独四氢大麻酚（THC）以及它们的联合作用导致发生UDA的调整比值比，并对一些潜在混杂因素进行了调整。
在过去二十年中，涉及致命撞车事故的汽车驾驶员中THC和酒精的患病率从1991年的低于2%增加到2008年的高于10%，增加了约五倍。血液酒精浓度每增加0.01单位，发生UDA的几率增加约9 - 11%。仅THC呈阳性的驾驶员发生UDA的几率增加16%。当酒精和THC同时存在时，相对于单独的酒精或THC，血液酒精浓度每增加0.01单位，发生UDA的几率增加约8 - 10%。
两种物质均呈阳性的驾驶员比仅酒精或仅大麻呈阳性的驾驶员犯错几率更高。需要进一步研究以更好地检验大麻浓度水平、酒精与驾驶之间的相互作用。这项研究将通过强调低血液酒精浓度水平下大麻的联合作用，为执法机构和公共卫生教育工作者提供支持。
