Investigating the role of fatigue, sleep and sleep disorders in commercial vehicle crashes: A systematic review.

Commercial vehicle driving is an occupation in which increasing demands are being placed on drivers as a consequence of economic and trade expansion. Crash rates are high, as is the injury risk to all road users where commercial vehicles are involved. Fatigue and sleep deprivation are of increasing concern, and sleep disorders have been shown in car drivers to increase crash risk. Commercial drivers may have higher crash risk due to exposure and high sleep disorder prevalence; however, reviews thus far have not provided sufficient conclusion. The aim of this systematic review was to investigate the evidence of the role of fatigue, sleep and sleep disorders in commercial motor vehicle crashes. Relevant electronic databases and grey literature were searched and 16 peer-reviewed published studies met the study criteria. Factors found to have an association with crashes were daytime sleepiness (Epworth Sleepiness Scale), and sleep debt. While not employed as a search term, obesity was shown to be a risk factor for sleep disorders, daytime sleepiness and incurring a crash or near miss. Most studies suffered from small sample size as well as specific methodological flaws making generalisation difficult and indicating the need for a large, well-designed study with empirical measures of both risk factors and outcomes.