title: [Is a control group necessary?].
authors.forename: X
authors.initials: X
authors.lastname: Bonfill
authors.forename: M
authors.initials: M
authors.lastname: Porta Serra
mesh_terms: D002986:Clinical Trials as Topic / Q000592:standards*; D006801:Humans; D011897:Random Allocation; D012107:Research Design / Q000592:standards*
vernacular_title: Es necesario un grupo de control?