title: Beyond randomised versus observational studies.
authors.affiliation: Clinical Epidemiology Research Center, West Haven Veterans Affairs Medical Center, West Haven, Connecticut, USA.
authors.forename: John
authors.initials: J
authors.lastname: Concato
authors.forename: Ralph I
authors.initials: RI
authors.lastname: Horwitz
mesh_terms: D015986:Confounding Factors, Epidemiologic; D006801:Humans; D019370:Observation; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012107:Research Design