title: Observational etiologic research: part 3-case-control studies: it's all about the source population.
authors.affiliation: Center for Clinical Transfusion Research, Sanquin Research, Leiden, The Netherlands; Jon J. van Rood Center for Clinical Transfusion Research, Leiden University Medical Center, Leiden, The Netherlands; Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Rutger A
authors.initials: RA
authors.lastname: Middelburg
authors.forename: Johanna C
authors.initials: JC
authors.lastname: Wiersum-Osselton
authors.forename: Leo M G
authors.initials: LM
authors.lastname: van de Watering
authors.forename: Johanna G
authors.initials: JG
authors.lastname: van der Bom
mesh_terms: D016022:Case-Control Studies; D057189:Checklist; D035061:Control Groups; D004194:Disease / Q000209:etiology*; D015340:Epidemiologic Research Design; D006801:Humans; D018579:Patient Selection; D015203:Reproducibility of Results; D015983:Selection Bias