title: CONSORT statement: extension to cluster randomised trials.
authors.affiliation: Health Services Research Unit, University of Aberdeen, Aberdeen, AB25 2ZD. m.k.campbell@abdn.ac.uk
authors.forename: Marion K
authors.initials: MK
authors.lastname: Campbell
authors.forename: Diana R
authors.initials: DR
authors.lastname: Elbourne
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Altman
mesh_terms: D016000:Cluster Analysis; D019983:Guideline Adherence; D017408:Guidelines as Topic; D011643:Publishing / Q000592:standards*; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000592:standards; D012107:Research Design