title: Study design VI - Ecological studies.
abstract: Previously in this series I have given an overview of the main types of study design and the techniques used to minimise biased results. In this article I describe more fully ecological studies, their uses, advantages and limitations.
authors.affiliation: Child and Adolescent Health Research Unit, University of Edinburgh, Edinburgh, Scotland, UK.
authors.forename: Kate Ann
authors.initials: KA
authors.lastname: Levin
mesh_terms: D016021:Epidemiologic Studies; D006801:Humans