A new study published in the journal Addiction includes an interesting analysis of alcohol- and drug-impaired drivers in fatal car accidents. The study also highlights the need for more detailed data if we are to understand more completely the magnitude of the health risks associated with drunk and drugged driving.
The researchers looked at toxicology screen results from fatally injured drivers in 14 states, one of which was West Virginia, covering the period from 2005 to 2009. The data shows that 57 percent of the 20,150 drivers killed had at least one drug in their system at the time of the crash. One in five tested positive for multiple drugs. While less than 50 percent of the female victims tested positive for drugs, 60 percent of the male victims had drugs in their system at the time of their fatal accidents.
The most common drug to show in those tox screens was alcohol, with marijuana and stimulants coming in second and third. The stimulants included amphetamines and Adderall, a drug used to treat attention deficit hyperactivity disorder that contains amphetamine and dextroamphetamine.
What the test results do not show is how much of any given drug was present in each victim's system. As a result, the researchers cannot determine how many of the drivers who died were impaired by drugs. Marijuana, for instance, is just one drug that will show up in blood or urine samples days or weeks after a person last used it.
Alcohol does not linger in the system the same way. The researchers say that tox screen results are reasonably related to the level of impairment in the driver. For drug levels, though, the relationship is not quite as direct -- and the researchers say this is a key area for more work, especially when it comes to drug interactions.
The study also showed that not all states collect the same data from toxicology screens, and not all states test for drugs or alcohol in a fatal car accident. Again, the full extent of the problem of impaired driving is difficult to know without consistent and complete data.
What researchers and health and safety professionals do know is that during 2010 more than 10,000 people died in accidents involving a driver whose blood alcohol concentration was above the nationwide legal limit of 0.08 percent. That translates into one third of all motor vehicle fatalities that year. Even without the data on drivers impaired by drugs, the number is far too high.
Source: CNBC.com, "Alcohol, drugs common in fatal crashes," Sept. 6, 2012