Researchers from Columbia University's Mailman School of Public Health, found that drug use is associated with a significantly increased risk of fatal crash involvement, particularly when used in combination with alcohol. The study provides critical data for understanding the joint effect of alcohol and drugs on driving safety.
Data for the study came from two national information systems sources sponsored by the National Highway Traffic Safety Administration: the 2007 National Roadside Survey of Alcohol and Drug Use by Drivers and the Fatality Analysis Reporting System (FARS), a repository of investigation data for all crashes that resulted in at least one fatality within 30 days of the crash and that occurred on a public road.
The second data source also contains detailed information about the crash circumstances as well as individuals and vehicles involved in the crash. This is the first study to use both data sources to quantify relative risks of fatal crash involvement associated with different drugs.
Results of the Mailman School study led by Guohua Li, MD, DrPH, professor of Epidemiology and director of the Center for Injury Epidemiology and Prevention, show that 31.9 percent of the drivers involved in fatal car crashes (cases) and 13.7 percent of the drivers interviewed at the roadside survey (controls) tested positive for at least one non-alcohol drug.
Overall, drivers testing positive for drugs were three times as likely as those testing negative to be involved in a fatal crash. Among the drugs studied, depressants conferred the highest risk, followed by stimulants, narcotics, and marijuana.