HIV instruction, HIV knowledge, and drug injection among high school students in the United States

Background. The prevalence of HIV-related behaviors and determinants of these behaviors among adolescents in the United States have not been well studied. Methods. To determine the prevalence of HIV-related drug behaviors and to assess the effects of HIV-related school-based instruction and HIV knowledge on these behaviors, data were analyzed from a 39-item, self-administered questionnaire completed by a probability sample of all students in grades 9 through 12 in the United States. Results. Usable responses were obtained from 8098 students. Of these, 2.7% (95% confidence interval [CI] = 2.3-3.2) and 1.7% (95% CI = 1.3-2.1) reported injecting illicit drugs ever and during the past year, respectively. Corresponding prevalences of needle sharing were 0.8% (95% CI = 0.5-1.1) and 0.5% (95% CI = 0.3-0.7). Regression analysis revealed that students with higher knowledge scores were less likely and males more likely to have ever injected drugs. HIV knowledge was similarly associated with other outcome measures of drug-injection behavior. Although HIV instruction did not directly influence drug-injection behavior independently of demographic characteristics, it was positively associated with HIV knowledge. Conclusions. While these results do not establish a causal relationship, they suggest that HIV knowledge and school-based instruction may play a role in maintaining low levels of drug-injection behavior among high school students.