Background: 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 driving under the influence of drugs (DUID) suspects in Finland and compare them with the general Finnish population during 1993–2006.
Methods: We used register data consisting of 5,832 DUID suspects apprehended by the police. A reference group (n=74,809) was drawn from the general Finnish population. Deaths were traced from National Death Register. Survival and differences in mortality hazard were estimated by using Kaplan-Meier plots and Cox regression models.
Results: The hazard of death was higher among both male (HR 9.6, CI 8.7–10.6) and female (HR 9.1, CI 6.4–12.8) DUID suspects compared to reference population. Among male DUID suspects cause-specific hazards were highest for poisoning/overdose, violence and suicide. 24% of DUID suspects and 8% of references were under the influence of drugs/alcohol during 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 8.4–11.9) or benzodiazepines with alcohol (HR 9.6, CI 8.2–11.2) than with findings for amphetamines (HR 4.6, CI 2.7–7.6).
Conclusion: 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.