title: Re: Should meta-analyses of interventions include observational studies in addition to randomized controlled trials? A critical examination of underlying principles.
authors.forename: Carlos
authors.initials: C
authors.lastname: Pereira
authors.forename: Euclides
authors.initials: E
authors.lastname: Castilho
mesh_terms: D015982:Bias; D015986:Confounding Factors, Epidemiologic; D036262:Empirical Research; D016021:Epidemiologic Studies; D006801:Humans; D015201:Meta-Analysis as Topic; D017410:Practice Guidelines as Topic; D016032:Randomized Controlled Trials as Topic