title: Uses of ecologic studies in the assessment of intended treatment effects.
authors.forename: P A
authors.initials: PA
authors.lastname: Groome
authors.forename: W J
authors.initials: WJ
authors.lastname: Mackillop
mesh_terms: D015982:Bias; D002277:Carcinoma / Q000453:epidemiology / Q000628:therapy*; D003131:Combined Modality Therapy; D005931:Glottis; D006801:Humans; D007822:Laryngeal Neoplasms / Q000453:epidemiology / Q000628:therapy*; D009864:Ontario / Q000453:epidemiology; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States