|Date added||June 17, 2014|
|Category||2014 CMRSC XXIV Vancouver|
|Tags||Research and Evaluation, Session 2B|
|Author/Auteur||Sacha Dubois, Justin Gates, Paula Reguly, Bruce Weaver, Michel Bédard|
|Stream/Volet||Research and Evaluation|
Slidedeck Presentation Only (no paper submitted)
Background and Aims: Drug and medication use while driving may be a crash risk factor for commercial motor vehicle (CMV) truck drivers. For example, given the extended driving periods inherent in transport truck driving, drivers might rely on stimulants to sustain attention and mitigate the effects of fatigue. Further, work-related exposures, such as vibration, manual handling and poor ergonomics contribute to an increased risk for injuries and chronic conditions and are common reasons for opioid analgesic (OA) use by CMV truck drivers. Given the potential impact of stimulants and OAs, the objectives of this study were to: (a) generate prevalence estimates of stimulant and OA use in CMV truck drivers involved in fatal crashes; (b) document the relationship between drug use (stimulant, OAs) and responsibility for fatal crashes.
Methods: Crash data were drawn from the Fatality Analysis Reporting System (FARS) database (1993 thru 2008). Prevalence estimates of positive stimulant and OA drug tests were calculated based on the overall annual percentage of truck drivers that tested positive for a stimulant or OA. Two separate logistic regression models (one for stimulants and one for OA) were used to assess whether drug-positive drivers were more likely than drug-negative drivers to be responsible for the crash while controlling for age, other drug use, and driving history. Presence of one or more crash-related unsafe driver actions (UDAs) was used as a proxy measure of responsibility.
Results: Between 1993 and 2008 65,361 CMV truck drivers were involved in fatal crashes. Annual detection rates typically ranged between 0.4% to 0.7% for stimulants and 0.1 and 0.2% for OAs (N=119) and did not exceed 0.98% and 0.46% respectively for any year in the study period. Approximately 90% of stimulants detected (N=404) were: methamphetamine (33.9%), amphetamine (24.5%), cocaine (17.3%), or benzoylecgonine (15.3%). The majority of pain medications detected in drivers positive for one OA were: morphine (18.6%), hydrocodone (17.6%), methadone (12.7%), codeine (11.8%), or propoxyphene (10.8%). The responsibility analysis included 8,325 truck drivers who were male, aged 20 and over, blood-tested for drugs, with a confirmed BAC of zero, and either driving trucks with a gross vehicle weight rating greater than 26,000lbs (21%) or truck-tractors (79%). Approximately 22% of stimulant and OA positive drivers were polydrug users compared to 7% (χ2=90.87, p < .001) and 3% (χ2=93.56, p < .001) of stimulant and OA negative truck drivers respectively. Truck drivers using stimulants (OR:1.78; 95% CI: 1.41;2.26) or OAs (OR: 2.80; 95% CI: 1.64; 4.81) had greater adjusted odds of committing an UDA. Middle-aged users of OAs (but not stimulants) had greater odds of committing an UDA than younger or older users.
Conclusion: The limited detection prevalence of both drugs is encouraging. However, these results indicate that the presence of either stimulants or OAs is associated with greater odds of committing an UDA, suggesting implications for the commercial transport industry.
Sacha Dubois, Justin Gates, Paula Reguly, Bruce Weaver, Michel Bédard