title: Attrition in Long-Term Nutrition Research Studies: A Commentary by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition Early Nutrition Research Working Group.
abstract: Long-term follow-up of randomised trials and observational studies provide the best evidence presently available to assess long-term effects of nutrition, and such studies are an important component in determining optimal infant feeding practices. Attrition is, however, an almost inevitable occurrence with increasing age at follow-up. There is a common assumption that studies with <80% follow-up rates are invalid or flawed, and this criticism seems to be more frequently applied to follow-up studies involving randomised trials than observational studies. In this article, we explore the basis and evidence for this "80% rule" and discuss the need for greater consensus and clear guidelines for analysing and reporting results in this specific situation.
authors.affiliation: *Childhood Nutrition Research Centre, UCL Institute of Child Health, London, UK†Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden‡University Children's Hospital, Zagreb, Croatia§Erasmus MC, Sophia Children's Hospital, Rotterdam, The Netherlands||Division of Metabolic and Nutritional Medicine, Ludwig-Maximilans-Universität München, Dr von Hauner Children's Hospital, University of Munich Medical Center¶Munich Municipal Hospitals, Harlaching Hospital Department of Paediatrics, Munich, Germany#Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Mary S
authors.initials: MS
authors.lastname: Fewtrell
authors.forename: Magnus
authors.initials: M
authors.lastname: Domellöf
authors.forename: Iva
authors.initials: I
authors.lastname: Hojsak
authors.forename: Jessie M
authors.initials: JM
authors.lastname: Hulst
authors.forename: Kathy
authors.initials: K
authors.lastname: Kennedy
authors.forename: Berthold
authors.initials: B
authors.lastname: Koletzko
authors.forename: Walter
authors.initials: W
authors.lastname: Mihatsh
authors.forename: Theo
authors.initials: T
authors.lastname: Stijnen
mesh_terms: D000367:Age Factors; D035843:Biomedical Research / Q000379:methods / Q000592:standards*; D002648:Child; D053198:Child Nutrition Sciences / Q000379:methods / Q000592:standards*; D005060:Europe; D005500:Follow-Up Studies; D005762:Gastroenterology / Q000379:methods / Q000592:standards*; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D064887:Observational Studies as Topic / Q000592:standards; D010352:Patient Dropouts; D010372:Pediatrics / Q000379:methods / Q000592:standards*; D016032:Randomized Controlled Trials as Topic / Q000592:standards; D012955:Societies, Medical