title: Confounding and effect modification: their significance in medical research.
authors.forename: B A
authors.initials: BA
authors.lastname: Olayinka
mesh_terms: D015982:Bias; D015986:Confounding Factors, Epidemiologic; D015987:Effect Modifier, Epidemiologic; D006801:Humans; D012107:Research Design / Q000592:standards*