title: Differential outcome of the IDEFICS intervention in overweight versus non-overweight children: did we achieve 'primary' or 'secondary' prevention?
abstract: BACKGROUND
  The aim of this study was to explore whether the IDEFICS intervention had a differential effect on 11,041 children's weight trajectories depending on their baseline body mass index status.
  
  
  METHODS
  Two subgroups of children are considered in the present analysis: those who were overweight or obese prior to the intervention and those who were neither overweight nor obese.
  
  
  RESULTS
  Among children in all eight countries who did not have prevalent overweight or obesity (OWOB) at baseline, 2 years later, there was no significant difference between intervention and control groups in risk of having developed OWOB. However, we observed a strong regional heterogeneity, which could be attributed to the presence of one distinctly outlying country, Belgium, where the intervention group had increased risk for becoming overweight. In contrast, among the sample of children with prevalent OWOB at baseline, we observed a significantly greater probability of normalized weight status after 2 years. In other words, a protective effect against persistent OWOB was observed in children in intervention regions compared with controls, which corresponded to an adjusted odds ratio of 0.76 (95% confidence interval: 0.58, 0.98).
  
  
  CONCLUSIONS
  This analysis thus provided evidence of a differential effect of the IDEFICS intervention, in which children with overweight may have benefited without having been specifically targeted. However, no overall primary preventive effect could be observed in children without initial overweight or obesity.
authors.affiliation: Section for Epidemiology and Social Medicine (EPSO), Department of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Lissner
authors.affiliation: Department of Public Health, University of Ghent, Ghent, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: De Bourdeaudhuij
authors.affiliation: Research Centre, National Institute for Health Development, Tallinn, Estonia.
authors.forename: K
authors.initials: K
authors.lastname: Konstabel
authors.affiliation: Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Mårild
authors.affiliation: Section for Epidemiology and Social Medicine (EPSO), Department of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Mehlig
authors.affiliation: Department of Paediatrics, University of Pécs, Pécs, Hungary.
authors.forename: D
authors.initials: D
authors.lastname: Molnár
authors.affiliation: GENUD (Growth, Exercise, Nutrition, and Development) Research Group, University of Zaragoza, Zaragoza, Spain.
authors.forename: L A
authors.initials: LA
authors.lastname: Moreno
authors.affiliation: Leibniz Institute for Prevention Research and Epidemiology - BIPS, Bremen, Germany.|Faculty of Mathematics and Computer Science, University of Bremen, Bremen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Pigeot
authors.affiliation: Epidemiology & Population Genetics, Institute of Food Sciences, CNR, Avellino, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Siani
authors.affiliation: Research and Education Institute of Child Health, Strovolos, Cyprus.
authors.forename: M
authors.initials: M
authors.lastname: Tornaritis
authors.affiliation: Department of Politics, Philosophy & Religion, Lancaster University, Lancaster, UK.
authors.forename: G
authors.initials: G
authors.lastname: Williams
mesh_terms: D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D010290:Parents / Q000193:education; D063766:Pediatric Obesity / Q000517:prevention & control*; D011322:Primary Prevention / Q000379:methods*; D015397:Program Evaluation; D055502:Secondary Prevention / Q000379:methods; D012959:Socioeconomic Factors; D044465:White People
keywords: Childhood obesity; intervention; primary prevention; secondary prevention