Mortality and causes of death among drugged drivers

Studying drugged drivers gives complementary information about mortality of drug users, which mainly has been studied among opioid abusers. The aim of this study was to analyse mortality rates and causes of death among drivers under the influence of drugs (DUID) in Finland and compare them with the general Finnish population during 1993-2006.

Register data from 5832 DUID suspects apprehended by the police were studied, with a reference group (n=74 809) drawn from the general Finnish population. Deaths were traced from the National Death Register. Survival and differences in mortality hazards were estimated using Kaplan-Meier plots and Cox regression models.

The hazard of death was higher among male (HR 9.6, CI 8.7 to 10.6) and female (HR 9.1, CI 6.4 to 12.8) DUID suspects compared to the reference population. Among male DUID suspects, cause-specific hazards were highest for poisoning/overdose, violence and suicide. 24% of DUID suspects and 8% of reference subjects were under the influence of drugs/alcohol at the time of death. Poly-drug findings indicated excess in mortality among drugged drivers. Hazard of death was higher among male DUID suspects who had findings for benzodiazepines only (HR 10.0, CI 8.4 to 11.9) or benzodiazepines with alcohol (HR 9.6, CI 8.2 to 11.2), than with findings for amphetamines (HR 4.6, CI 2.7 to 7.6).

DUID suspects had an increased risk of death in all observed causes of death. Findings for benzodiazepines indicated excessive mortality over findings for amphetamines. Preventive actions should be aimed especially at DUID subgroups using benzodiazepines.