Research Finds Half of Young Victims of Fatal Crashes in Nine States Used Either Alcohol or Marijuana

Half of teens and young adults who died in car crashes in nine states were under the influence of either alcohol or marijuana, or both, according to statistics of fatal road accidents involving 16- to 25-year olds between 1999 to 2011.

Researchers at Columbia University’s Mailman School of Public Health analyzed the statistics to gauge how possible policy changes could influence substance use among teens and young adults. The study, led by Katherine M. Keyes, PhD, assistant professor of Epidemiology, was published online in the journal Injury Epidemiology.

Keyes and researchers analyzed 7,191 fatal crashes involving the young drivers from 1999 to 2011 who died within one hour of the crash in California, Connecticut, Hawaii, Illinois, New Hampshire, New Jersey, Rhode Island, Washington State and West Virginia. These nine states were chosen for the study because all routinely perform toxicological tests on the blood or urine specimens of drivers who die in car crashes, according to a news release.

Information was drawn from the Fatality Analysis Reporting System, a census of fatal traffic crashes occurring within the U.S. More than half of the crashes (54.7 percent) occurred in California.

Overall, 50.3 percent of the deceased tested positive for alcohol, marijuana or both. Of these, 36.8 percent were under the influence of alcohol, 5.9 percent used marijuana and 7.6 percent used both drugs.

The researchers further tested whether there were any changes in patterns of alcohol and marijuana use among those aged 21 years and older who were legally allowed to consume alcohol, versus those younger than 21. It was found that alcohol consumption increased by 14 percent, but such prominent changes in marijuana use were not seen. fter reaching age 21, use of alcohol in combination of marijuana increased slightly.

Co-author Guohua Li, MD, DrPH, Mailman School professor of Epidemiology and director of the Center for Injury Epidemiology and Prevention, said availability seems to be at the crux of the problem.

“Taken together, we found no significant substitution effect between alcohol and marijuana. Rather, an uptick in availability seems to increase the prevalence of concurrent use of alcohol and marijuana,” Li said.

The study was supported by the National Institute on Alcohol Abuse and Alcoholism, National Institute on Drug Abuse, and the Centers for Disease Control and Prevention.