Prevalence of psychoactive substances, alcohol and illicit drugs, in Spanish drivers: A roadside study in 2015.

A survey was conducted during 2015 to monitor psychoactive substance use in a sample of drivers in Spanish roads and cities. Traffic police officers recruited drivers at sites carefully chosen to achieve representativeness of the driver population. A brief questionnaire included the date, time, and personal and driving patterns data. Alcohol use was ascertained through ethanol breath test at the roadside and considered positive if concentrations >0.05mg alcohol/L were detected. Four drug classes were assessed on-site through an oral fluid screening test that, if positive, was confirmed through a second oral fluid sample at a reference laboratory. Laboratory confirmation analyses screened for 26 psychoactive substances. To evaluate the association between drug findings and age, sex, road type (urban/interurban), and period of the week (weekdays, weeknights, weekend days, weekend nights), logistic regression analyses were done (overall, and separately for alcohol, cannabis and cocaine). A total of 2744 drivers, mean age of 37.5 years, 77.8% men, were included. Overall, 11.6% of the drivers had at least one positive finding to the substances assessed. Substances more frequently testing positive were cannabis (7.5%), cocaine (4.7%) and alcohol (2.6%). More than one substance was detected in 4% of the subjects. The proportion of positive results decreased with age, and was more likely among men and on urban roads. The pattern for alcohol use was similar but did not change with age and increased among drivers recruited at night. Cannabis was more likely to be detected at younger ages and cocaine was associated with night driving. Alcohol use before driving has decreased over the last decade; however, the consumption of other illegal drugs seems to have increased. The pattern of illegal psychoactive substance observed is similar to that declared in surveys of the general population of adults.