The incidence and role of drugs in fatally injured drivers

Blood specimens were collected from a sample of 1882 drivers from 7 States, during 14 months in the years 1990 and 1991. The sample comprised operators of passenger cars, trucks and motorcycles who died within 4 hours of their crash. Alcohol and 43 other drugs were studied, to determine their prevalence rates, their casual role in the crashes, and associated driver, vehicle, and crash factors. Coroner or medical examiner reports were obtained on all cases to ascertain cause of death, time of death and other details. Police accident reports and reports from the Fatal Accident Reporting System (FARS) were also obtained. Alcohol was found in 51.5% of the specimens, and other drugs were found in 17.8%. Other than alcohol, the most prevalent drugs were cannabis (6.7%), cocaine (5.3%), benzodiazepine tranquilisers (2.9%), and amphetamines (1.9%). Responsibility analysis was used to suggest impairment effects which were found for alcohol alone and for alcohol-drug combinations. Further research was recommended to follow up indications of alcohol-drug additive effects.