title: Debate about the single etiognostic study.
authors.forename: Jan
authors.initials: J
authors.lastname: Van den Broeck
authors.forename: Meera
authors.initials: M
authors.lastname: Chhagan
authors.forename: Shuaib
authors.initials: S
authors.lastname: Kauchali
mesh_terms: D016021:Epidemiologic Studies; D006801:Humans; D012107:Research Design; D018570:Risk Assessment / Q000379:methods*