This article deals with the feasibility of a case-control design for determining the relative injury risk of motorists who have used alcohol, and/or illicit drugs, and/or medicines. Methods of data collection are presented, as well as analytical and statistical methods. Preliminary study results indicate that the use of illicit drugs by Dutch motorists is rapidly growing. Increased risk of road trauma (p <0.05) was assessed for single use of benzodiazepines or of alcohol, when resulting in a BAC between 0.5 and 1.3 g/L. High relative risk factors were assessed for combinations of several drugs and for BACs over 1.3 g/L. An extremely high risk factor was assessed for combined use of drugs and alcohol (generally resulting in high BACs). No enhanced risk was (yet) assessed for single use of alcohol resulting in a BAC between 0.2 and 0.5 g/L, and for single use of cannabis, amphetamines, cocaine, tricyclic antidepressants or opiates. Only for single opiate use, an odds ratio of more than 1 was found; this result, however, was not statistically significant. (Author/publisher) For the covering abstract of the conference see ITRD Abstract No. E201067.
Abstract