title: Derivation versus validation.
authors.affiliation: Department of Epidemiology and Public Health Institute of Child Health, 30 Guilford Street London WC1N 1EH, UK. Awade@ich.ucl.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Wade
mesh_terms: D000465:Algorithms; D002648:Child; D006305:Health Status Indicators; D006801:Humans; D011379:Prognosis; D015203:Reproducibility of Results