Department of Epidemiology, Biostatistics and Occupational Health, School of Population and Global Health, McGill University, Montreal, Quebec, Canada; Institute for Health and Social Policy, School of Population and Global Health, McGill University, Montreal, Quebec, Canada.
Department of Epidemiology, Biostatistics and Occupational Health, School of Population and Global Health, McGill University, Montreal, Quebec, Canada.
Am J Prev Med. 2022 Dec;63(6):1037-1052. doi: 10.1016/j.amepre.2022.07.012. Epub 2022 Sep 25.
There is substantial debate concerning the impact of cannabis decriminalization and legalization on road safety outcomes.
Seven databases were systematically searched: Embase, MEDLINE, and PsycINFO through Ovid as well as Web of Science Core Collection, SafetyLit, Criminal Justice Database (ProQuest), and Transport Research International Documentation (from inception to June 16, 2021). Eligible primary studies examined group-level cannabis decriminalization or legalization and a road safety outcome in any population.
A total of 65 reports of 64 observational studies were eligible, including 39 that applied a quasi-experimental design. Studies examined recreational cannabis legalization (n=50), medical cannabis legalization (n=22), and cannabis decriminalization (n=5). All studies except 1 used data from the U.S. or Canada. Studies found mixed impacts of legalization on attitudes, beliefs, and self-reported driving under the influence. Medical legalization, recreational legalization, and decriminalization were associated with increases in positive cannabis tests among drivers. Few studies examined impacts on alcohol or other drug use, although findings suggested a decrease in positive alcohol tests among drivers associated with medical legalization. Medical legalization was associated with reductions in fatal motor-vehicle collisions, whereas recreational legalization was conversely associated with increases in fatal collisions.
Increased cannabis positivity may reflect changes in cannabis use; however, it does not in itself indicate increased impaired driving. Subgroups impacted by medical and recreational legalization, respectively, likely explain opposing findings for fatal collisions. More research is needed concerning cannabis decriminalization; the impacts of decriminalization and legalization on nonfatal injuries, alcohol and other drugs; and the mechanisms by which legalization impacts road safety outcomes.
关于大麻非刑罪化和合法化对道路安全结果的影响，存在大量争议。
系统检索了 7 个数据库：通过 Ovid 检索的 Embase、MEDLINE 和 PsycINFO 以及 Web of Science 核心合集、SafetyLit、刑事司法数据库（ProQuest）和交通研究国际文献（从创建到 2021 年 6 月 16 日）。合格的主要研究考察了群体层面的大麻非刑罪化或合法化以及任何人群中的道路安全结果。
共有 64 项观察性研究的 65 份报告符合条件，其中 39 项采用了准实验设计。研究考察了娱乐性大麻合法化（n=50）、医用大麻合法化（n=22）和大麻非刑罪化（n=5）。除了 1 项研究外，所有研究都使用了来自美国或加拿大的数据。研究发现，合法化对态度、信念和自我报告的影响有混合影响。医用合法化、娱乐性合法化和非刑罪化与驾驶员阳性大麻检测率的增加有关。很少有研究考察对酒精或其他药物使用的影响，尽管研究结果表明医用合法化与驾驶员阳性酒精检测率的下降有关。医用合法化与致命机动车碰撞的减少有关，而娱乐性合法化则相反，与致命碰撞的增加有关。
阳性大麻检测率的增加可能反映了大麻使用的变化；然而，它本身并不能表明驾驶能力受损的增加。医用和娱乐性合法化分别影响的亚组可能解释了致命碰撞的相反结果。需要更多的研究来了解大麻非刑罪化；非刑罪化和合法化对非致命伤害、酒精和其他药物的影响；以及合法化影响道路安全结果的机制。
