Objective
To describe prevalence, patterns of drug and alcohol use in truck and bus drivers, and look at trends in substance use/abuse across time. To evaluate the risk of work-related injury and motor vehicle accidents in drivers with evidence of moderate and heavy alcohol use, illicit substance abuse, and inappropriate or excessive prescription drug use.

Background
There is widespread concern over substance use in the workplace in general, and commercial drivers and persons in other safety-sensitive positions in particular. Despite this, a paucity of data on the association of alcohol/drugs with accidents in drivers exists.

Methods
Data source: The National Longitudinal Survey of Youth (NLSY) 79, a long-running survey by US Bureau of Labor Statistics involving 12,600. Subjects were aged 14-22 at the start of survey in 1979. Participants are surveyed annually or biannually thereafter. Retention, response rates >60% throughout the 1990s, early 2000's. Data was downloaded through BLS, and followed longitudinally for each participant. Prevalence rates for drug/alcohol use calculated using initial 1992 data, modifying rates based on subsequent survey results. Incidence rates for occupational injury calculated using person-time at risk from 1992, less any periods when subject did not work in trucking.

Limitations
Small number of subjects limits the ability to evaluate outcomes, association with many exposures. Inability to determine whether a driver was actually impaired while driving.

Conclusions
Heavy drinking patterns may be associated with increased injury risk in drivers. Lost work time following injury is higher as well. Alcohol use especially heavy drinking appears higher in drivers than in the overall survey population. Legitimate prescription drug use is associated with injury in drivers, especially use of opiate painkillers.