Prevalence of alcohol and other psychoactive substances in motor vehicle drivers in Spain, 2018: Cross-sectional dataset analysis with studies from 2008 and 2013.

Driving under the influence of substances is particularly common in developed countries. In Spain, in 2010, roadside oral fluid drug screening became mandatory, and in 2014, the zero tolerance legal system was established. The aim of the current study is to analyze the prevalence of alcohol (in breath) and drugs (in oral fluids) in a representative sample of motor vehicle drivers in Spain in 2018. This study focuses specifically on multiple substance use (i.e., polysubstance use), and seeks to analyze the factors associated with driving after consumption of substances, as well as the evolution of the presence of drugs in drivers from 2008, 2013 and 2018 studies. A total of 2881 drivers were included in this study. In 2018, alcohol was detected in 3.9 % of the cases, alcohol plus another substance(s) was found in 0.8 % of the cases, only one drug (excluding alcohol) made up 5.1 % of the cases and drivers testing positives to more than one drug at a time (apart from alcohol) constituted 1.1 %. There were less cases of positives for any drugs or alcohol in 2018 and 2013 (2018: 10.9 %, z=3.6, p=0.0003; 2013: 9.3 %, z=5.7, p<0.0001) than in 2008 (14.0 %), yet the frequency observed in 2018 is more than that of 2013 (z=2, p=0.05). Multiple drug use (without alcohol), increased from 0.5 % in 2008 to 1.1 % in 2018 (z=2.2, p=0.03). Alcohol/drug driving continues to be frequent in Spain, leading to the need for intervention in this field, particularly on polydrug use and driving.