Being bullied: associated factors in children and adolescents 8 to 18 years old in 11 European countries.

Objectives: To analyze the prevalence of bullying victims among children and adolescents aged 8 to 18 years in 11 European countries and to investigate the associated sociodemographic, physical, and psychosocial factors.

Methods: Being a bullying victim was measured by using the social acceptance (bullying) scale from the Kidscreen-52, a health-related quality-of-life questionnaire administered to 16 210 children and adolescents aged 8 to 18 and their parents in postal or school-based surveys in 11 European countries. Standardized mean differences (effect size) were computed to measure the percentage of children/adolescents scoring 1 SD below the mean on the Kidscreen bullying scale.