Abstract
BACKGROUND: The relationship between driver blood alcohol concentration (BAC) and crash involvement is well understood. However, the role of alcohol use disorders (AUDs) (i.e., dependence or abuse) in crash occurrence, as distinguished from non-clinical heavy alcohol consumption, has not been adequately explored. METHODS: Data from the 2010-2011 Crash Risk Study conducted in Virginia Beach, VA, were used in this study. Drivers involved in crashes were compared with control drivers, and four drinker groups were examined: alcohol dependent, alcohol abusers, heavy drinkers, and all other current (i.e., normative) drinkers. Logistic regression analyses were conducted on two outcomes: having a moderate BAC (≥0.05 g/dl), and crash involvement. RESULTS: Overall, 2411 crash-involved and 5514 control drivers provided useable data, 52.4% of which were men and 70.8% Whites. The prevalence of drivers with AUDs was lower for the crash-involved drivers (8.7%) than for the control drivers (12.7%). Only heavy drinkers, but not abusive or dependent drinkers, were over four times more likely to drive with moderate BACs at nighttime. More important, at nighttime, the odds of crash involvement for dependent drinkers were only one third of those for normative drinkers. Daytime crashes, however, were more likely to involve normative drinkers than any of the other three drinker types. CONCLUSIONS: Drivers with AUDs are not more likely than normative drinkers to drive with moderate BACs at night. After accounting for the influence of BAC, dependent drinkers have a lower risk of being involved in a crash, at any time of the day.