Random alcohol testing reduced alcohol-involved fatal crashes of drivers of large trucks.

OBJECTIVE

This study examined the impact of random alcohol testing, implemented on August 1, 1994, on the likelihood that the driver of a large truck involved in a fatal motor vehicle crash was alcohol-involved.

METHOD

Among fatal crashes, the proportion of alcohol-positive large truck drivers (intervention group) was compared with the proportion of alcohol-positive light passenger vehicle drivers (control group). Annual Fatality Analysis Reporting System (FARS) data (1988-2003) were compiled for each of the 50 states and Washington, D.C., for the control and intervention groups. Using these pooled cross-sectional data, logistic regression modeled the likelihood that a driver was alcohol-positive (blood alcohol concentration > 0) before compared with after random alcohol testing. We attributed the difference-in-difference (the difference in likelihoods of being alcohol positive pretesting versus post-testing in large truck versus passenger vehicle drivers) to the impact of random testing.

RESULTS

Drivers of large trucks were 18.6% less likely to be alcohol-involved after random testing was implemented than before random testing (odds ratio [OR] = 0.814, 95% confidence interval [CI]: 0.713-0.930). The control group of passenger car drivers was 4.7% less likely to be alcohol-involved after random testing was implemented (OR = 0.953, 95% CI: 0.924-0.983). The net reduction in the odds of alcohol involvement for drivers of large trucks was 14.5% (OR = 0.855, 95% CI: 0.748-0.976).

CONCLUSIONS

Controlling for the general declining trend in alcohol-involved drivers in fatal crashes, random alcohol testing was correlated with a 14.5% reduction in alcohol involvement among large truck drivers.