The association between family affluence and smoking among 15-year-old adolescents in 33 European countries, Israel and Canada: the role of national wealth

To examine the role of national wealth in the association between family affluence and adolescent weekly smoking, early smoking behaviour and weekly smoking among former experimenters. Data were used from the Health Behaviour in School-aged Children (HBSC) study conducted in 2005/2006 in 35 countries from Europe and North America that comprises 60 490 students aged 15 years. Multi-level logistic regression was conducted using Markov chain Monte Carlo methods (MCMC) to explore whether associations between family affluence and smoking outcomes were dependent upon national wealth. Family Affluence Scale (FAS) as an indicator for the socio-economic position of students. Current weekly smoking behaviour is defined as at least weekly smoking (dichotomous). Early smoking behaviour is measured by smoking more than a first puff before age 13 years (dichotomous). Weekly smoking among former experimenters is restricted to those who had tried a first puff in the past. The logistic multi-level models indicated an association of family affluence with current weekly smoking [odds ratio (OR) = 1.088; 95% credible interval (CrI) = 1.055-1.121, P  < 0.001], early smoking behaviour (OR = 1.066; CrI = 1.028-1.104, P  < 0.001) and smoking among former experimenters (OR = 1.100; CrI = 1.071-1.130; P  < 0.001). Gross domestic product (GDP) per capita was associated positively and significantly with the relationship between family affluence and current weekly smoking (OR = 1.005; CrI = 1.003-1.007; P  < 0.001), early smoking behaviour (OR = 1.003; CrI = 1.000-1.005; P = 0.012) and smoking among former experimenters (OR = 1.004; CrI = 1.002-1.006; P  < 0.001). The association of family affluence and smoking outcomes was significantly stronger for girls. The difference in smoking prevalence between rich and poor is greater in more affluent countries