The prevalence of alcohol, cannabinoids, benzodiazepines and stimulants amongst injured drivers and their role in driver culpability

Epidemiology and Causal Factors in Fitness to Drive

“…The low prevalence of THC in drivers who had crashes is the reason that only a few studies have calculated concentration-dependent ORs. In culpability studies increased risks were verified with higher concentrations: Longo et al (2000b) revealed for concentrations of THC ≤1.0 ng/mL an OR of 0.4, for concentrations of 1.0-2.0 ng/mL an OR of 0.5, and for higher concentrations an OR of 1.8. Drummer et al (2004) put the risk increase of causing a crash at 2.7 over all concentrations of THC, and for concentrations of >5 ng/mL THC as 6.6.…”

“…The results of culpability studies in samples of injured drivers demonstrated, depending on the individual design of the study, increased risks for alcohol, THC, benzodiazepines, stimulants and opioids with considerably increased ORs for combinations of psychoactive drugs (e.g. Soderstrom et al 1990Soderstrom et al , 2005Terhune et al 1992; Benzodiazepine/Driving Collaborative Group 1993; Longo et al 2000b;Lowenstein and Koziol-McLain 2001;Drummer et al 2004; for more citations see Drummer 2009). In these studies the ORs are generally 'means' because the prevalence of almost all the agents was so small that concentration-dependent calculations of ORs could not be carried out.…”

“…From 2500 injured drivers in Australia, about one-quarter had at least one psychoactive agent in blood. Alcohol (8.6%) was the most frequently detected, followed by THC (2.8%) and benzodiazepines (1.8%) and stimulating agents (0.8%) (Longo et al 2000a).…”

“…One of the few studies that differentiated according to the level of concentration of the medicament (Longo et al 2000b), showed for benzodiazepines an OR of 1.3 for sub-therapeutic levels, of 3.3 for therapeutic concentrations and of 3.6 for overtherapeutic/toxic levels. Hence, even for medicaments there is a positive correlation between risk and concentration.…”

Beeinflussung der Fahrtüchtigkeit durch Arzneimittel

“…Fahrer, in deren Blut nach einem Unfall Benzodiazepine nachgewiesen wurden, waren einer australischen Studie zufolge zu einem signifikant höhe-ren Anteil (69,6%) schuldhaft an dem Unfall beteiligt als arzneimittelfreie Fahrer (52,8%; [37]). Fast alle Fahrer (15 von 16), bei denen neben Benzodiazepinen auch Alkohol nachgewiesen wurde, waren schuldhaft am Unfall beteiligt.…”