The percentage of fatally injured drivers in the U.S. who tested positive for prescription opioids climbed from 1% in 1995 to more than 7% in 2015, according to a new study from Columbia University's Mailman School of Public Health.  

“Prescription opioids as potent pain medications can cause drowsiness and impair cognitive functions. The 700% rise in the prevalence of prescription opioids detected in fatally injured drivers is cause for great concern,” said Dr. Guohua Li, the study’s principal investigator and a professor of epidemiology at the Mailman School of Public Health.

The study’s findings appear online in the American Journal of Public Health.  

Annual prescriptions of opioids, such as oxycodone, hydrocodone and methadone, quadrupled from 76 million in 1991 to nearly 300 million in 2014. According to the latest estimates, about 3,900 people start nonmedical prescription opioid use daily. Opioid abuse has become a national public health crisis.

“The opioid epidemic has been defined primarily by the counts of overdose fatalities. Our study suggests that increases in opioid consumption may carry adverse health consequences far beyond overdose morbidity and mortality,” noted Li, who is also director of the Center for Injury Epidemiology and Prevention at Columbia.  

Li and co-author Stanford Chihuri in the Department of Epidemiology examined two decades of data from the Fatality Analysis Reporting System, a database maintained by the National Highway Traffic Safety Administration. They focused on drivers who died within one hour of a motor vehicle crash in California, Hawaii, Illinois, New Hampshire, Rhode Island and West Virginia — states that routinely conduct toxicological testing on injury fatalities. Of the 36,729 drivers in the analysis, 24% tested positive for non-alcohol drugs, including 3% who tested positive for prescription opioids.  

Of drivers testing positive for prescription opioids, 30% also had elevated blood alcohol concentrations and 67% tested positive for other drugs.  

Prescription opioid prevalence was higher in female drivers than in male drivers, 4.4% compared to 3%. The prevalence of prescription opioids increased from 0.9% during 1995-1999 to 5.2% during 2010-2015 in male drivers, and from 1.4% to 7.3% in female drivers.  

Currently, all states and the District of Columbia operate prescription drug monitoring programs that collect and report opioid prescription data.

“Although the effect of these programs on opioid prescription misuse has been studied extensively, little is known about their effectiveness in reducing driving under the influence of opioids,” Chihuri said. “In light of our findings, evaluations of these programs should be expanded to study opioid involvement in traffic injuries in particular and even take into account the role of specific types and doses of opioids in crash causation.”  

The study was supported by the National Center for Injury Prevention and Control, part of the Centers for Disease Control and Prevention.