The risk of intentional injury with acute and chronic alcohol exposures: a case-control and case-crossover study

Alcohol is associated with intentional injury, but most studies have operationalized it as alcoholism and have not examined acute exposure. The study aimed to clarify the relative contributions of drinking over a few hours and of alcohol use disorders to the risk of intentional injury inflicted by another person.

The study used a case-control design with two control groups: (1) Community controls matched to cases, and (2) the cases themselves, comparing consumption on the day of injury with consumption on previous days, in a case-crossover comparison. Cases were patients with an acute injury presenting to any of the three emergency departments in one county; 102 had an intentional injury. Community controls (N = 1,856) were recruited by random-digit dialing. Recent alcohol consumption was recorded in self-reported standard drinks. Current alcohol use disorders were defined using DMS-IV criteria.

In the case-control analysis, drinking in a 6-hour window was associated with risk of intentional injury (odds ratio [OR] = 10, 95% confidence interval [CI]: 4.7-22). In case-cross-over comparison of the cases' own drinking in the 6 hours prior to injury with their own drinking the day before, the OR was 34 (95% CI: 4.7-250). In case-control analyses, alcohol dependence was associated with intentional injury (OR = 6.0, 95% CI: 3.5-10), but alcohol abuse was not (OR = 0.7, 95% CI: 0.4-1.3).

Drinking over a few hours is strongly associated with intentional injury. Current alcohol dependence is also, but with a lower OR. The findings may have implications for efforts to prevent intentional injury.