title: Violence, bullying and academic achievement: a study of 15-year-old adolescents and their school environment.
abstract: OBJECTIVE
  This study investigated academic achievement among adolescents exposed to violence, sexual abuse and bullying. Moreover, we sought to determine the individual and contextual influence of the adolescents' school environment in terms of bullying, classmate relationships and teacher support on academic achievement. Finally, we wished to assess whether school-level influence is different for the adolescents exposed to violence and sexual abuse versus the adolescents not exposed to these forms of abuse.
  
  
  METHODS
  This is a cross-sectional study of a sample of 7,343 adolescents between the ages of 15 and 16 from 56 schools in Oslo, Norway. We investigated associations between violence, sexual abuse, bullying, classmate relationships, teacher support and academic achievement. Linear regression was used to investigate associations on the individual level. Multilevel analyses were conducted to test for school level differences while controlling for both individual and contextual factors.
  
  
  RESULTS
  On the individual level, all combinations of violence and sexual abuse categories were significantly associated with lower grades. This was also true for bullying, while teacher support resulted in better grades. At the school level, the analysis showed that students in schools with higher levels of bullying performed worse academically. Each unit of increment in bullying in school corresponded to an average 0.98 point decrease in grades (p<.01) when we controlled for sociodemographic characteristics. The association remained significant when the model was tested separately for the nonbullied students, with a small reduction in the coefficient value (-.84, p<.01). No overall significance was found for the interaction between the school environment and adolescent exposure to violence, indicating that the school environment affects all students.
  
  
  CONCLUSIONS
  Factors on both levels can contribute to reduced grades. This stresses the need to investigate individual and contextual factors simultaneously when examining academic achievement. Our results indicated that students attending schools with higher levels of bullying may show poorer school performance. This was true for all students regardless of previous exposure to violence and sexual abuse. This emphasizes the need for preventive efforts that focus not only on vulnerable groups, but on all students and the school context.
authors.affiliation: Norwegian Centre for Violence and Traumatic Stress Studies, Kirkeveien 166, N-0407 Oslo, Norway.
authors.forename: Ida Frugård
authors.initials: IF
authors.lastname: Strøm
authors.forename: Siri
authors.initials: S
authors.lastname: Thoresen
authors.forename: Tore
authors.initials: T
authors.lastname: Wentzel-Larsen
authors.forename: Grete
authors.initials: G
authors.lastname: Dyb
mesh_terms: D000293:Adolescent; D058445:Bullying / Q000523:psychology*; D003430:Cross-Sectional Studies; D004522:Educational Status; D005178:Faculty; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D009664:Norway; D012574:Schools / Q000458:organization & administration; D012742:Sex Offenses; D012944:Social Support; D013334:Students / Q000523:psychology*; D014754:Violence / Q000523:psychology*