title: Ecological studies are a poor means of testing aetiological hypotheses.
authors.forename: S
authors.initials: S
authors.lastname: Ebrahim
authors.forename: G D
authors.initials: GD
authors.lastname: Smith
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology