Objective: To examine alcohol and drug use among truck drivers compared to car or van drivers in Norway by analyzing samples of oral fluid.
Methods: Drivers were selected for a voluntary and anonymous study using a stratified multistage cluster sampling procedure. Drivers of trucks were recruited at two control stations for heavy vehicles in southeastern Norway in collaboration with the Norwegian Roads Administration, and drivers of cars and vans were recruited in a roadside survey in collaboration with the mobile police service. Samples of oral fluid were taken by using the Statsure Saliva Sampler (Statsure Diagnostic Systems, Framingham, MA), and the drivers' gender, age, and nationality were recorded. Samples of oral fluid were analyzed for alcohol or drugs, in total 28 psychoactive substances.
Results: About 97 percent of the truck drivers and 94 percent of the car or van drivers agreed to participate in the study. Of the 882 studied truck drivers studied, 1.4 percent were female and 29.1 percent were Norwegian; of the 5305 car or van drivers, 27.6 percent were female and 90.9 percent were Norwegian. Alcohol or drugs were found in 1.9 and 6.6 percent of the samples from truck drivers and car/van drivers, respectively. The adjusted odds ratio (OR) for the detection of a psychoactive substance in a sample from a truck driver compared to car or van driver was 0.29; the 95 percent confidence interval (95% CI) was 0.17 to 0.53. The adjusted OR for the detection of an illegal drug was 0.42 (95% CI: 0.18-0.82), the adjusted OR for the detection of a psychoactive medicinal drug was 0.29 (95% CI: 0.13-0.68), and the adjusted OR for the detection of alcohol was 0.13 (95% CI: 0.02-1.10).
Conclusions: The proportion of oral fluid samples containing psychoactive substances was lower for truck drivers than for car or van drivers.