Episodic alcohol use and risk of nonfatal injury.

Usual and acute alcohol consumption are important risk factors for injury. Although alcohol-dependent people are thought to be at increased risk of injury, there are few reports suggesting that their risk is greater than that of nondependent alcohol users in a given episode of alcohol use. The authors conducted a case-crossover analysis of data on 705 injury patients from a hospital emergency department in Mexico City, Mexico, collected in 2002. The majority of the sample was male (60%) and over 30 years old (51%). With use of a multiple matching approach that took into account three control time periods (the day prior to the injury, the same day in the previous week, and the same day in the previous month), the estimated relative risk of injury for patients who reported having consumed alcohol within 6 hours prior to injury (17% of the sample) was 3.97 (95% confidence interval: 2.88, 5.48). This increase in the relative risk was concentrated within the first 2 hours after drinking; there was a positive association of increasing risk with increasing number of drinks consumed. These data suggested that relative risk estimates were the same for patients with and without alcohol use disorders.