title: Bullying of preterm children and emotional problems at school age: cross-culturally invariant effects.
abstract: OBJECTIVE
  To investigate whether adolescents who were born extremely preterm (<26 weeks gestation), very preterm (<32 weeks gestation), or with very low birth weight (<1500 g) are more often bullied, and whether this contributes to higher emotional problem scores.
  
  
  METHODS
  We used 2 whole population samples: the German Bavarian Longitudinal Study (BLS) (287 very preterm/very low birth weight and 293 term comparison children) and the UK EPICure Study (183 extremely preterm and 102 term comparison children). Peer bullying was assessed by parent report in both cohorts at school years 2 and 6/7. The primary outcome was emotional problems in year 6/7. The effects of prematurity and bullying on emotional problems were investigated with regression analysis and controlled for sex, socioeconomic status, disability, and preexisting emotional problems.
  
  
  RESULTS
  Preterm-born children were more often bullied in both cohorts than term comparisons (BLS: relative risk, 1.27; 95% CI, 1.07-1.50; EPICure: relative risk, 1.69; 95% CI, 1.19-2.41). Both preterm birth and being bullied predicted emotional problems, but after controlling for confounders, only being bullied at both ages remained a significant predictor of emotional problem scores in both cohorts (BLS: B, 0.78; 95% CI, 0.28-1.27; P < .01; EPICure: B, 1.55; 95% CI, 0.79-2.30; P < .001). In the EPICure sample, being born preterm and being bullied at just a single time point also predicted emotional problems.
  
  
  CONCLUSIONS
  Preterm-born children are more vulnerable to being bullied by peers. Those children who experience bullying over years are more likely to develop emotional problems. Health professionals should routinely ask about peer relationships.
authors: Department of Psychology, University of Warwick, Coventry, United Kingdom; Division of Mental Health and Wellbeing, Warwick Medical School, Coventry, United Kingdom. Electronic address: D.Wolke@warwick.ac.uk.
authors: Dieter
authors: D
authors: Wolke
authors: Department of Psychology, University of Warwick, Coventry, United Kingdom.
authors: Nicole
authors: N
authors: Baumann
authors: Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
authors: Victoria
authors: V
authors: Strauss
authors: Department of Health Sciences, University of Leicester, Leicester, United Kingdom.
authors: Samantha
authors: S
authors: Johnson
authors: University College London Institute of Women's Health, University College London, London, United Kingdom.
authors: Neil
authors: N
authors: Marlow
mesh_terms: D000293:Adolescent; D058445:Bullying; D002648:Child; D002653:Child Behavior Disorders / Q000453:epidemiology* / Q000209:etiology*; D003431:Cross-Cultural Comparison; D004644:Emotions; D005260:Female; D005858:Germany; D005865:Gestational Age; D006801:Humans; D007234:Infant, Premature / Q000523:psychology*; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D006113:United Kingdom