title: Some controversies in planning and analysing multi-centre trials.
abstract: It is shown that a rational approach to planning multi-centre trials will lead to an unequal distribution of patients across centres. Consequently different approaches to estimation will yield different estimates. However, some such approaches are not reasonable and it is concluded that multi-centre trials are less problematic than is commonly supposed.
authors.affiliation: Department of Statistical Science, University College London, U.K.
authors.forename: S
authors.initials: S
authors.lastname: Senn
mesh_terms: D015982:Bias; D003627:Data Interpretation, Statistical; D015987:Effect Modifier, Epidemiologic; D006801:Humans; D015337:Multicenter Studies as Topic / Q000592:standards*; D018579:Patient Selection; D010934:Planning Techniques; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards*