title: Difficulties in evaluating non-randomized studies.
authors.affiliation: Department of Radiotherapy, Institut Gustave-Roussy, Villejuif, France.
authors.forename: R
authors.initials: R
authors.lastname: Arriagada
authors.forename: A
authors.initials: A
authors.lastname: Auquier
mesh_terms: D002986:Clinical Trials as Topic; D011897:Random Allocation; D012107:Research Design