The prevalence and characteristics of illicit drug related driver fatalities in Western Australia, 2000-2012

Background_x000D_
Illicit drugs are widely regarded as a significant and increasing cause of driver impairment and crash risk. The aim of this study was to update the evidence regarding illicit drugs as a risk factor in Western Australian crashes by documenting the prevalence of illicit drugs among fatally injured drivers and the characteristics of these drivers._x000D_
_x000D_Method_x000D_
WA Police crash records of drivers fatally injured 2000-2012 were linked with ChemCentre toxicology records to identify the presence and nature of illicit drugs, alcohol and other drugs among drivers. Univariate analyses were undertaken of all crash, driver, and drug variables, while multivariate binary logistic regression was undertaken to model the risk factors for drivers who tested positive for an illicit drug._x000D_
Results_x000D_
Approximately 23% of drivers fatally injured during the period tested positive for one or more illicit drugs. The annual illicit drug related fatality rate per 100,000 licensed drivers did not significantly vary over the period. The odds of a fatally injured driver testing positive was significantly higher for males; those aged under 40 years; those driving without a valid licence; those testing positive to alcohol in the range 0.05gm%-0.149gm%, and those using benzodiazepines with and without opioids._x000D_
Discussion_x000D_
The findings highlight the potential for impairment among Western Australian drivers from illicit drugs – alone and in combination with alcohol and other impairing drugs – and the need for countermeasures to target ‘at risk drivers’. A number of recommendations for the policing and enforcement of illicit drug driving are presented.