April Flowers for redOrbit.com – Your Universe Online
The number of fatally-injured drivers in the US that test positive for non-alcohol drugs has been steadily rising. From 1999 to 2010, the number tripled for drivers who tested positive for marijuana, which is the most commonly detected non-alcohol drug. This increase suggests that drugged driving may be playing an increasing role in fatal motor vehicle collisions.
Researchers at Columbia University’s Mailman School of Public Health used toxicological testing data from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System to understand these trends. The research team looked at 23,591 drivers who died within one hour of the crash, finding that 39.7 percent tested positive for alcohol and another 24.8 percent tested positive for other drugs. The results showed that the alcohol-related deaths remained stable, while the prevalence of non-alcohol drugs rose significantly — from 16.6 percent in 1999 to 28.3 percent in 2010. For marijuana specifically, fatality rates rose from 4.2 percent to 12.2 percent.
The study, published online in the American Journal of Epidemiology, is based on data collected from six states that routinely perform toxicological testing on drivers involved in fatal crashes. The six states are California, Hawaii, Illinois, New Hampshire, Rhode Island, and West Virginia.
According to the findings, men were more prone to alcohol being involved (43.6 percent) than women (26.1 percent), although the trends remained stable for both sexes. The substantial increase in marijuana, in contrast, was consistent across all ages and genders.
“Although earlier research showed that drug use is associated with impaired driving performance and increased crash risk, trends in narcotic involvement in driver fatalities have been understudied,” said Guohua Li, MD, DrPH, professor of Epidemiology and Anesthesiology and director of the Center for Injury Epidemiology and Prevention. “Given the increasing availability of marijuana and the ongoing opioid overdose epidemic, understanding the role of controlled substances in motor vehicle crashes is of significant public health importance.”
Prior research from 2003 to 2013 revealed an increase in drivers testing positive for marijuana in roadside surveys, according to Joanne Brady, PhD candidate in epidemiology, as well as for California drivers involved in fatal accidents. Marijuana use also increased in Colorado during this time among patients treated in healthcare settings. “The marked increase in its prevalence as reported in the present study is likely germane to the growing decriminalization of marijuana,” noted Ms. Brady. During the last two decades, 20 states and Washington, DC have enacted legislation to decriminalize marijuana for medical use, and four more states have legislation pending. “Although each of these states has laws that prohibit driving under the influence of marijuana, it is still conceivable that its decriminalization may result in increases in crashes involving marijuana.”
The authors note that while their results provide evidence that non-alcohol drugs in fatally injured drives has increased significantly, there are some limitations to the results that must be considered. The study is based on data collected in only six states, and the effects of drugs on driving performance and crash risk vary by drug type, dosage, and the driver’s physiological response and tolerance level. Another limit of the data is that it is possible to test positive for marijuana in the blood for up to one week after use.
Dr. Li said, “it is important to interpret the prevalence of non-alcohol drugs reported in this study as an indicator of drug use but not necessarily as a measurement of drug impairment. To control the ongoing epidemic of drugged driving, it is imperative to strengthen and expand drug testing and intervention programs for drivers.”