Drug Testing Blog

Marijuana on the road

Marijuana on the road: Real but rare risks
Study from France finds nearly 9% of at-fault drivers with detectable cannabis levels in fatal crashes.

Nearly 1 in 10 drivers in France involved in fatal crashes had detectable cannabis levels, according to a study released early by BMJ (formerly the British Medical Journal), but the proportion of fatalities attributed to marijuana was dwarfed by those caused by alcohol-intoxicated drivers.

Looking at the October 2001 through September 2003 time period, Bernard Laumon of the French National Institute for Transport and Safety Research and colleagues identified 10,748 drivers with known drug and alcohol concentrations who were involved in fatal crashes. The 6,766 drivers who were considered at fault were compared with 3,006 of the other drivers in a population case–control design.

While 8.8% of cases were positive for cannabis, only 2.8% of control drivers had detectable marijuana levels. The odds ratio increased from 2.18 at low THC levels to 4.72 among those with high levels of this active ingredient of marijuana. But overall, only 2.5% of fatal crashes were attributable to cannabis, compared with 26.8% where alcohol was the likely cause.

posted by Dr. Farm @ 10:44 PM