Associations between the practice of bullying and individual and contextual variables from the aggressors' perspective.

Objectives: To estimate the prevalence of bullying among Brazilian students from the aggressor's perspective and to analyze its association with individual and contextual variables.

Methods: This was a cross-sectional population-based study carried out with data from the National Survey on Student Health. A total of 109,104 students attending eight grade in public and private schools were included. Data were collected through a self-applied questionnaire. A model of association between bullying and variables in the following domains was tested: sociodemographics, risk behaviors, mental health, and family context. Univariate and multivariate analyses were also performed.

Results: The prevalence of aggressors in bullying situations was 20.8%. The following variables remained associated in the final multivariate model: male gender (OR: 1.87; 95% CI: 1.79-1.94), lower participation of 16-year-old students (OR: 0.66; 95% CI: 0.53-0.82), and students from private schools (OR: 1.33; 95% CI: 1.27-1.39). Most aggressors reported feeling lonely (OR: 1.22; 95% CI: 1.16-1.28), insomnia episodes (OR: 1.21; 95% CI: 1.14-1.29), and a high prevalence of physical violence in the family (OR: 1.97 95% CI: 1.87-2.08). Aggressors missed classes more frequently (OR: 1.45; 95% CI: 1.40-1.51), and they regularly consumed more tobacco (OR: 1.21; 95% CI: 1.12-1.31), alcohol (OR: 1.85; 95% CI: 1.77-1.92), and illegal drugs (OR: 1.91; 95% CI: 1.79-2.04); they also demonstrated increased sexual intercourse (OR: 1.49 95% CI: 1.43-1.55) and regular exercise (OR: 1.20; 95% CI: 1.16-1.25).

Conclusions: The data indicate that bullying is an important aspect that affects the learning-teaching process and the students' health.