Marijuana use and prior injury among injured problem drinkers

The purpose of this paper is to better understand marijuana use among injured problem drinkers in the emergency department (ED). The specific objectives are: 1) to assess the prevalence of marijuana use; 2) to identify factors associated with marijuana use; 3) to determine whether prior injury is associated with marijuana use; and 4) to determine whether marijuana-using problem drinkers want to change behaviors.

The authors conducted a post-hoc analysis on data obtained prospectively. Subjects had injury and problem drinking: either measurable alcohol level (blood alcohol concentration, BAC), report of drinking, or an Alcohol Use Disorders Identification Test (AUDIT) score of > or =8. The study was conducted on weekend nights; 3,776 injured ED patients were screened, 383 refused, 578 were enrolled, and 433 had complete data.

Of the 433 subjects, 48.3% reported using marijuana in the three months prior. Marijuana-using problem drinkers had more hazardous drinking, higher AUDIT scores (14.0 vs. 11.4, p < 0.001), and higher risk-taking scores (12.4 vs. 10.1, p < 0.001). More used other drugs (69.7% vs. 30.3%, p < 0.001). In regression analyses, marijuana use remained an independent predictor of prior injury (OR = 2.16, 95% CI = 1.25 to 3.75), particularly prior alcohol-related (OR = 2.26, 95% CI = 1.45 to 3.53) and motor-vehicle-related (OR = 1.69, 95% CI = 1.03 to 2.79) injury. Readiness-to-change scores were similar (4.14 vs. 4.22, p = 0.21) between users and nonusers.

Marijuana use among injured problem drinkers is prevalent. Their risk of prior injury is increased. Counseling for alcohol and injury should address marijuana use.