Trends in drug use among drivers killed in U.S. traffic crashes, 1999–2010

• Patterns of drug-involvement among drivers killed in traffic crashes are changing.
• Drug-positive prevalence increased 49% from 1999–2000 to 2009–2010.
• Prescription drug use by drivers in fatal traffic crashes has considerably risen.
• The use of purely illicit drugs (i.e. cocaine) in fatal crashes has declined.

ObjectiveDriving under the influence of drugs is a global traffic safety and public health concern. This trend analysis examines the changes in general drug usage other than alcohol, broad categories, and typical prescription and illegal drugs among drivers fatally injured in motor vehicle crashes from 1999 to 2010 in the U.S.MethodsData from the Fatality Analysis Reporting System were analyzed from 1999 to 2010. Drug prevalence rates and prevalence ratios (PR) were determined comparing rates in 2009–2010 to 1999–2000 using a random effects model. Changes in general drug usage, broad categories, and representative prescription and illegal drugs including, methadone, oxycodone, hydrocodone, barbiturates, benzodiazepines, and cocaine, were explored.ResultsComparing 2009–2010 to 1999–2000, prevalence of drug usage increased 49% (PR = 1.49; 95% confidence interval [CI] 1.42, 1.55). The largest increases in broad drug categories were narcotics (PR = 2.73; 95% CI 2.41, 3.08), depressants (PR = 2.01; 95% CI 1.80, 2.25), and cannabinoids (PR = 1.99; 95% CI 1.84, 2.16). The PR were 6.37 (95% CI 5.07, 8.02) for hydrocodone/oxycodone, 4.29 (95% CI 2.88, 6.37) for methadone, and 2.27 (95% CI 2.00, 2.58) for benzodiazepines. Barbiturates declined in rate over the 12-year period (PR = 0.53; 95% CI 0.37, 0.75). Cocaine use increased until 2005 then progressively declined, though the rate remained relatively unchanged (PR = 0.94; 95% CI 0.84, 1.06).ConclusionsWhile more drivers are being tested and found drug-positive, there is evidence that a shift from illegal to prescription drugs may be occurring among fatally injured drivers in the U.S. Driving under the influence of prescription drugs is a growing traffic concern.