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

The aim of this study was to determine the association between alcohol or drug use with fatal injury in road traffic accidents by calculating odds ratios (ORs) using a case-control design. The 'cases' were 508 drivers killed in road traffic accidents in the period 2003-2010 from whom blood samples were sent to the Norwegian Institute of Public Health for alcohol and drug testing, and the 'controls' were 9261 random drivers in normal traffic. Blood samples from 'cases' and oral fluid samples from 'controls' were analysed for alcohol, 15 drugs which have legislational concentration limits in Norway, in addition to two other commonly detected psychoactive drugs. The ORs for being killed in a traffic crash with blood alcohol concentration above the legal limit of 0.02 g/dL was 199.5 (95% CI 112.6-353.2). For the use of amphetamines without other substances the OR was 41.6 (95% CI 12.6-137.1), and for use of two or more substances 85.0 (95% CI 46.3-156.1). The OR for general use of only one medicinal drug was 6.0, and no significant ORs were found for the specific use of only zopiclone or THC. The ORs were generally higher for involvement in single-vehicle accidents. It is likely that the observed ORs, particularly for alcohol, are not only related to the risk posed by the substance alone, but a combination with behavioural factors, such as sensation seeking or risk taking behaviour. (c) 2012 Elsevier Ltd. All rights reserved.