title: Erratum to: Sample size calculations for cluster randomised controlled trials with a fixed number of clusters.
authors.affiliation: Department of Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK. k.hemming@bham.ac.uk.
authors.forename: Karla
authors.initials: K
authors.lastname: Hemming
authors.affiliation: Department of Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Girling
authors.affiliation: Department of Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK.
authors.forename: Alice J
authors.initials: AJ
authors.lastname: Sitch
authors.affiliation: Department of Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Marsh
authors.affiliation: Department of Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lilford