Socio-economic inequalities in smoking and drinking in adolescence: Assessment of social network dynamics

Aims: We investigated whether (1) adolescents selected friends with a similar socio-economic status (SES), (2) smoking and alcohol consumption spread in networks and (3) the exclusion of non-smokers or non-drinkers differed between SES groups. Design: This was a longitudinal study using stochastic actor-oriented models to analyze complete social network data over three waves. Setting: Eight Hungarian secondary schools with socio-economically diverse classes took part. Participants: This study comprised 232 adolescents aged between 14 and 15 years in the first wave. Measurements: Self-reported smoking behavior, alcohol consumption behavior and friendship ties were measured. SES was measured based upon entitlement to an income-tested regular child protection benefit. Findings: Non-low-SES adolescents were most likely to form friendships with peers from their own SES group [odds ratio (OR) = 1.07, 95% confidence interval (CI) = 1.02-1.11]. Adolescents adjusted their smoking behavior (OR = 24.05, 95% CI = 1.27-454.86) but not their alcohol consumption (OR = 1.65, 95% CI = 0.62-4.39) to follow the behavior of their friends. Smokers did not differ from non-smokers in the likelihood of receiving a friendship nomination (OR = 0.98, 95% CI = 0.87-1.10), regardless of their SES. Alcohol consumers received significantly more friendship nominations than non-consumers (OR = 1.16, 95% CI = 1.01-1.33), but this association was not significantly different according to SES. Conclusions: Hungarian adolescents appear to prefer friendships within their own socio-economic status group, and smoking and alcohol consumption spread within those friendship networks. Socio-economic groups do not differ in the extent to which they encourage smoking or alcohol consumption.