title: We are family--parents, siblings, and eating disorders in a prospective total-population study of 250,000 Swedish males and females.
abstract: OBJECTIVE
  We examined how parental characteristics and other aspects of family background were associated with the development of eating disorders (ED) in males and females.
  
  
  METHODS
  We used register data and record linkage to create the prospective, total-population study the Stockholm Youth Cohort. This cohort comprises all children and adolescents who were ever residents in Stockholm County between 2001 and 2007, plus their parents and siblings. Individuals born between 1984 and 1995 (N = 249, 884) were followed up for ED from age 12 to end of 2007. We used Cox regression modeling to investigate how ED incidence was associated with family socioeconomic position, parental age, and family composition.
  
  
  RESULTS
  In total, 3,251 cases of ED (2,971 females; 280 males) were recorded. Higher parental education independently predicted a higher rate of ED in females [e.g., adjusted hazard ratio (HR) 1.69 (95% CI: 1.42, 2.02) for degree-level vs. elementary-level maternal education], but not in males [HR 0.73 (95% CI: 0.42, 1.28), p < 0.001 for gender interaction]. In females, an increasing number of full-siblings was associated with lower rate of ED [e.g., fully adjusted HR 0.92 (95% CI: 0.88, 0.97) per sibling], whereas an increasing number of half-siblings was associated with a higher rate [HR 1.05 (95% CI: 1.01, 1.09) per sibling].
  
  
  CONCLUSIONS
  The effect of parental education on ED rate varies between males and females, whereas the effect of number of siblings varies according to whether they are full or half-siblings. A deeper understanding of these associations and their underlying mechanisms may provide etiological insights and inform the design of preventive interventions.
authors.affiliation: CHESS (Centre for Health Equity Studies), Karolinska Institutet/Stockholm University, Stockholm, Sweden.
authors.forename: Jennie C
authors.initials: JC
authors.lastname: Ahrén
authors.forename: Flaminia
authors.initials: F
authors.lastname: Chiesa
authors.forename: Ilona
authors.initials: I
authors.lastname: Koupil
authors.forename: Cecilia
authors.initials: C
authors.lastname: Magnusson
authors.forename: Christina
authors.initials: C
authors.lastname: Dalman
authors.forename: Anna
authors.initials: A
authors.lastname: Goodman
mesh_terms: D000293:Adolescent; D002648:Child; D004522:Educational Status; D001068:Feeding and Eating Disorders / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008423:Maternal Age; D010290:Parents; D010331:Paternal Age; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D035781:Siblings; D055815:Young Adult
keywords: adolescents; eating disorders; family characteristics; females; males; socioeconomic position