Keep up to date with the latest news and articles from BMC Medical Research Methodology and BioMed Central.
Karla Hemming*, Alan J Girling, Alice J Sitch, Jennifer Marsh and Richard J Lilford
Corresponding author: Karla Hemming firstname.lastname@example.org
BMC Medical Research Methodology 2011, 11:102 doi:10.1186/1471-2288-11-102
(2011-09-12 16:34) University of Sheffield
Hemming et al (2011) give a useful review of sample size calculations with a fixed
number of clusters. As they acknowledge their equations (17) to (19) are derived from
Donner and Klar (200). I would like to point out the issue of fixed number of clusters
was also discussed by Campbell (2000) that the authors’ equation (13) was
first given as equation (2) in that paper and as equation (9.7) in Machin and Campbell
(2005). Mike Campbell References Campbell MJ Cluster randomized trials in general (family) practice research. Statistical
Methods in Medical Research 2000, 9; 81-94 Donner A and Klar N. Design and analysis of cluster randomized trials. London, Arnold
2000 Machin D and Campbell MJ Design of Studies for Medical Research. Chichester, John
Wiley and Sons Ltd, 2005
BioMed Central Ltd unless otherwise stated. Part of Springer Science+Business Media.