Examining the Effect of Gender On Item Endorsement of Drug Attitudes: An IRT-Differential Item Functioning Study of Chilean Adolescents

Background and Purpose: Considerable research exists that suggests that efforts at preventing and treating drug use need to incorporate ways to change adolescent perceptions and attitudes towards the perceived benefits of using substances. In fact, a cornerstone of numerous drug prevention programs is to have children and adolescents develop negative perceptions about drugs. Despite these efforts, less is known about the way gender may influence how U.S. youth answer questions that measure attitudes and perceptions of drug dangerousness. To our knowledge such research does not exist with non-U.S. populations. To address this gap, we designed a study to examine how Chilean male and female adolescents may differentially answer survey questions about attitudes they hold towards cigarettes and marijuana use. Methods: Data are from the first wave of the Santiago Longitudinal Study (SLS), a NIDA-funded study of community-dwelling adolescents in Santiago, Chile (R01 DA021181). The sample consisted of 777 participants (Mean age=14, 49% females) of low SES. Youth completed a two-hour interviewer-administered questionnaire with standardized measures that were pilot tested and validated prior to the study. Interviews were conducted in Spanish in private offices at the University of Chile by Chilean staff trained in the administration of standardized instruments. This research examines how gender influences the attitudes that low-income adolescents from Chile have about cigarettes and marijuana. Results: Differential item functioning was carried out to examine the presence of differential endorsement of each item of the Cigarette and Marijuana Drug Attitude Scales. Differential item functioning examines whether gender, or other individual characteristics unrelated to the latent construct being studied, influences how participants endorse items of a scale. Potential differential responses of boys and girls on the 19 items of the Cigarette and Marijuana Drug Attitudes Scale (modified from the U.S. Monitoring the Future study and the Chilean national school-based surveys of drug use) were analyzed with Differential Item Functioning (DIF) using Mplus. Using a IRT DIF model, we found that adolescent boys with the same level of attitudes towards cigarettes as females were more likely to endorse the item ‘The harmful effects of cigarettes have been exaggerated'. Controlling for attitudes towards marijuana, boys were more likely to endorse the item ‘My boyfriend/girlfriend would disapprove'. On the other hand, adolescent girls with the same level of attitude toward marijuana as boys were more likely to endorse the items ‘Concerned about possible loss of control of myself'. Conclusions and Implications: The study findings indicate that gender influences how adolescents construct attitudes and perceptions towards drugs, suggesting that social work prevention and promotion messages can perhaps more selectively tailor these specific perceptions as jumping off points. In the presentation we will discuss how these findings, from an international sample, provide support for the development of interventions in areas outside the U.S. and how they may serve to inform interventions in the U.S. as well.