Background: There have been no large-scale international comparisons on bullying and health among adolescents. This study examined the association between bullying and physical and psychological symptoms among adolescents in 28 countries. Methods: This international cross-sectional survey included 123,227 students 11, 13 and 15 years of age from a nationally representative sample of schools in 28 countries in Europe and North America in 1997–98.The main outcome measures were physical and psychological symptoms. Results: The proportion of students being bullied varied enormously across countries. The lowest prevalence was observed among girls in Sweden (6.3%, 95% CI: 5.2–7.4), the highest among boys in Lithuania (41.4%, 95% CI 39.4–43.5). The risk of high symptom load increased with increasing exposure to bullying in all countries. In pooled analyses, with sex stratified multilevel logistic models adjusted for age, family affluence and country the odds ratios for symptoms among students who were bullied weekly ranged from 1.83 (95% CI 1.70–1.97) to 2.11 (95% CI 1.95–2.29) for physical symptoms (headache, stomach ache, backache, dizziness) and from 1.67 (95% CI 1.55–1.78) to 7.47 (95% CI 6.87–8.13) for psychological symptoms (bad temper, feeling nervous, feeling low, difficulties in getting to sleep, morning tiredness, feeling left out, loneliness, helplessness). Conclusion: There was a consistent, strong and graded association between bullying and each of 12 physical and psychological symptoms among adolescents in all 28 countries.

This paper discusses the concepts of vulnerability and susceptibility and their relevance for understanding and tackling health inequalities. Tackling socioeconomic inequalities in health is based on an understanding of how an individual’s social position influences disease risk. Conceptually, there are two possible mechanisms (not mutually exclusive): there is either some cause(s) of disease that are unevenly distributed across socioeconomic groups (differential exposure) or the effect of some cause(s) of disease differs across groups (differential effect). Since differential vulnerability and susceptibility are often used to denote the latter, we discuss these concepts and their current use and suggest an epidemiologically relevant distinction. The effect of social position can thus be mediated by causes that are unevenly distributed across social groups and/or interact with social position. Recent improvements in the methodology to estimate mediation and interaction have made it possible to calculate measures of relevance for setting targets and priorities in policy for health equity which include both mechanisms, i.e. equalize exposure or equalize effects. We finally discuss the importance of differential susceptibility and vulnerability for the choice of preventive strategies, including approaches that target high-risk individuals, whole populations and vulnerable groups.

This chapter deals with social concepts and theories. Finn Diderichsen, Tim Evans, and Margaret Whitehead address the fundamental question of how societies generate and maintain social and health inequities. A unifying framework, the Diderichsen model, is then presented as a basis for designing research and policy development on this issue. Key features of this framework are the five different mechanisms that may operate to generate inequities in health and the policy entry points to disrupt these mechanisms. The question of which of these mechanisms is important in a particular society can be tested empirically within this framework. Indeed, many of the empirical analyses presented in the thirteen country chapters in the book are based on this framework. The identification of policy entry points in the pathways to social inequities in health is a unique aspect of the Diderichsen model.