title: Confoundng factors in research populations.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Rosenfeld
mesh_terms: D015986:Confounding Factors, Epidemiologic; D006801:Humans; D011613:Psychotherapy; D015203:Reproducibility of Results; D012107:Research Design; D018401:Sample Size; D016896:Treatment Outcome