Drugged driving in the Nordic countries--a comparative study between five countries.

The purpose of this study was to compare whether the high incidence of drugged driving in Norway was different to that in the other Nordic countries. All blood samples received by Nordic forensic institutes during one week in 1996, from drivers suspected by the police of driving under the influence (Denmark: n = 255, Finland: n = 270, Iceland: n = 40, Sweden: n = 86, Norway: n = 149), were analysed for alcohol and drugs (benzodiazepines, cannabinoids, amphetamines, cocaine, opiates and a number of antidepressant drugs) independent of the primary suspicion, and using the same analytical cut-off levels at the different institutes. The primary suspicion was directed towards drugs in more than 40% of the Norwegian cases, drugs were detected in more than 70% of these samples. In only 0-3% of the cases from Denmark, Finland and Iceland, were drugs suspected, while the corresponding frequency for Sweden was 17%. However, evidential breath analyses were used for about three-quarters of the Swedish drivers suspected to be influenced by alcohol. Blood alcohol concentrations (BAC's) below the legal limits were found in 32, 18 and 2% of the Norwegian, Icelandic and Finnish cases, respectively (BAC < 0.05%), in 10% of the Danish cases (BAC < 0.08%) and in 20% of the Swedish cases (BAC < 0.02%). Drugs were most frequently found in the Norwegian and Swedish cases with no alcohol (80-83%). Similar frequencies of drugs in samples with BAC's above the legal limits (19-22%), were obtained for all countries. Benzodiazepines, tetrahydrocannabinol and amphetamine represented the most commonly detected drugs. Our results show that differences between Norway and other Nordic countries with regard to drugs and driving, are connected to the selection criteria made by the police and with more focus on drugged driving in Norway.