title: Psychosocial factors associated with bulimia nervosa during pregnancy: An internal validation study.
abstract: OBJECTIVE
  The aim of this paper was to internally validate previously reported relations (Knoph Berg et al., Aust N Z J Psychiatry, 42, 396-404, 2008) between psychosocial factors and bulimia nervosa (BN) outcomes during pregnancy.
  
  
  METHODS
  This study is based on the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. Participants were women enrolled during pregnancy (N = 69,030). Internal validity was evaluated by way of bootstrapped parameter estimates using the overall sample and a split sample calibration approach.
  
  
  RESULTS
  Bootstrap bias estimates were below the problematic threshold, and extend earlier findings (Knoph Berg et al., Aust N Z J Psychiatry, 42, 396-404, 2008) by providing support for the validity of the models at the population level of all pregnant women in Norway. Bootstrap risk ratios indicated that prevalence, incidence, and remission of BN during pregnancy were significantly associated with psychosocial factors. The split sample procedure showed that the models developed on the training sample did not predict risks in the validation sample.
  
  
  CONCLUSIONS
  This study characterizes associations between psychosocial exposures and BN outcomes among pregnant women in Norway. Women with lifetime and current self-reported psychosocial adversities were at a much higher risk for BN during pregnancy. Psychosocial factors were associated with BN remission during pregnancy, inviting the prospect of enhancing therapeutic interventions. We consider the findings in the context of reproducibility in science.
authors.affiliation: Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Eating Disorders Program, Specialised Child and Adolescent Health Service, Department of Health in Western Australia, Perth, Australia.|Centre for Clinical Interventions, Department of Health in Western Australia, Perth, Australia.|School of Paediatrics and Child Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, Australia.|School of Psychology and Speech Pathology, Faculty of Health Sciences, Curtin University, Perth, Australia.
authors.forename: Hunna J
authors.initials: HJ
authors.lastname: Watson
authors.affiliation: Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Ann
authors.initials: A
authors.lastname: Von Holle
authors.affiliation: Division of Mental Health Services, Akershus University Hospital, Lørenskog, Norway.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Knoph
authors.affiliation: Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Department of Biostatistics, UNC Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hamer
authors.affiliation: Division of Mental Health Services, Akershus University Hospital, Lørenskog, Norway.
authors.forename: Leila
authors.initials: L
authors.lastname: Torgersen
authors.affiliation: Division of Mental Health Services, Akershus University Hospital, Lørenskog, Norway.|Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Ted
authors.initials: T
authors.lastname: Reichborn-Kjennerud
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.|Department of Global Public Health and Primary Care, Faculty of Medicine and Dentistry, University of Bergen, Oslo, Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Stoltenberg
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
authors.affiliation: Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Department of Nutrition, UNC Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Bulik
mesh_terms: D000328:Adult; D052018:Bulimia Nervosa / Q000523:psychology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D011247:Pregnancy; D011248:Pregnancy Complications / Q000523:psychology*; D055815:Young Adult
keywords: MoBa; The Norwegian Mother and Child Cohort Study; bulimia nervosa; course; eating disorders; incidence; internal validation; pregnancy