title: Factors often not considered before a multicenter trial is started.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medical Sciences, Universidade Estadual de Campinas, Säo Paulo, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Hardy
mesh_terms: D006801:Humans; D007258:Informed Consent; D015337:Multicenter Studies as Topic / Q000592:standards*; D012107:Research Design; D018401:Sample Size; D014956:Writing