Amphetamine-type stimulant use and the risk of injury or death as a result of a road-traffic accident: a systematic review of observational studies

Amphetamine-type substances are frequently detected among drivers injured or killed due to road-trauma. However, the role of this substance in crash causation remains equivocal. We performed a systematic review to evaluate existing evidence regarding the association between amphetamine use and the risk of injury or death due to road traffic accidents. A bibliographical search of PubMed, SafetyLit, Scopus, and Science Direct literature databases from 01 January 1980 until May 2015 was performed. The quality of included studies was assessed using the Newcastle-Ottowa Scale (NOS) (cut-off of ≥7 indicated high quality). Inter-rater reliability between three independent reviewers for the NOS was calculated using Cohens kappa (κ) statistic, and best-evidence synthesis was performed. A total of 182 articles were found. Nine studies met eligibility criteria for inclusion for review, and seven studies were included for best-evidence synthesis. Best-evidence synthesis demonstrated a conflicting level of evidence for associations between the use of-amphetamine-type substances and the risk of sustaining an injury, and a moderate level of evidence between amphetamine use and the risk of death due to road trauma. This is the first review to synthesise evidence regarding the association between amphetamine-type substance use and the risk of injury or death due to a road traffic accident. More conclusive evidence of death due to road trauma among amphetamine users may reflect significant and global deficits in functioning associated with effective vehicular control under the influence of this substance. Additional high quality, sufficiently powered studies are required to elucidate the magnitude of these associations.