Associations between substance use among car and van drivers in Norway and fatal injury in road traffic accidents: A case-control study

► 508 killed drivers were compared with 9261 random drivers. ► Samples were analysed for alcohol and 17 illegal and medicinal drugs. ► Very strong association was found between alcohol use and fatal traffic accident. ► Strong association was found for use of two or more substances or use of amphetamines. ► High odds ratios were probably related to substance use combined with risk-taking behaviour.