Binge drinking among Brazilian students: A gradient of association with socioeconomic status in five geo-economic regions

Background: Socioeconomic status (SES) may be directly associated with binge drinking (BD) and country inequality. The aims of this study were to describe the characteristics of BD among high school students in Brazil and the association of BD with students' socioeconomic status in the five different Brazilian macro-regions. Methods: A national cross sectional survey was carried out using a multistage probabilistic sample of 17,297 high school students aged 14-18 years drawn from 789 public and private schools in each of the 27 Brazilian state capitals. Self-report data about BD behaviors and SES were analyzed via weighted logistic regressions and a funnel plot. Results: Almost 32% of the students engaged in BD in the past-year. Being in the highest SES stratum doubled the risk of BD among students in all five Brazilian macro-regions. There was a gradient in the association between past-year BD and socioeconomic status: as SES increased; the chance of having recently engaged in BD also increased. In Brazilian capitals as a whole, being a boy versus being a girl (adjusted odds ratio - aOR = 1.40 [95%CI 1.26; 1.58]), being older (aOR = 1.47 [95%CI 1.40; 1.55]) and attending private versus public schools (aOR = 1.39 [95%CI 1.18; 1.62]) were associated with greater risk for BD. Conclusions: Contrary to what is observed in developed countries, students living in Brazilian capitals may be at an increased risk of BD when they belong to the highest socioeconomic status. There might be similar associations between high SES and BD among adolescents growing up in other emerging economies.