@article{ref1,
title="Concurrent use of alcohol and marijuana and fatal motor vehicle crashes: a case-control study (Safety-2016 abstract #297)",
journal="Injury prevention",
year="2016",
author="Li, Guohua and Chihuri, Stanford",
volume="22",
number="Suppl 2",
pages="A108-A109",
abstract="BACKGROUND About one third of fatally injured drivers in the United States test positive for non-alcohol drugs and 20% test positive for two or more drugs. Alcohol-marijuana is the most commonly detected poly-drug combination. The role of concurrent use of alcohol and marijuana in crash causation has not been well understood.    METHODS Using a case-control design, we assessed the individual and joint effects of alcohol and marijuana on fatal crash risk. Cases (n = 2613) were drivers who were involved in fatal motor vehicle crashes in the continental United States during specific time periods in 2006, 2007, and 2008 and controls (n = 7719) were participants of the 2007 National Roadside Survey of Alcohol and Drug Use by Drivers.    RESULTS Overall, 53.3% of the cases and 8.9% of the controls had elevated blood alcohol concentrations (BAC ≥ 0.01 g/dL), and 6.0% of the cases and 3.0% of the controls tested positive for marijuana. Compared to drivers testing negative for both alcohol and marijuana, the estimated odds ratios of fatal crash involvement were 11.77 [95% confidence interval (CI): 10.78, 12.84] for those testing positive for alcohol and negative for marijuana, 2.16 (95% CI: 1.85, 2.54) for those testing negative for alcohol and positive for marijuana, and 25.46 (95% CI: 21.25, 30.51) for those testing positive for both alcohol and marijuana.    CONCLUSIONS Alcohol and marijuana are each associated with a significantly increased risk of fatal crash involvement. When alcohol and marijuana are used together, there exists a positive interaction effect on the risk of fatal crash involvement on the additive and the multiplicative scales.   Abstract from Safety 2016 World Conference, 18-21 September 2016; Tampere, Finland.   Copyright © 2016 The author(s), Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions   <p /> <p>Language: en</p>",
language="en",
issn="1353-8047",
doi="10.1136/injuryprev-2016-042156.297",
url="http://dx.doi.org/10.1136/injuryprev-2016-042156.297"
}