title: Multiple comparisons with two controls for ordered categorical responses.
abstract: In clinical studies, ordered categorical responses are common. To compare the efficacy of several treatments with a control for ordinal responses, the normal latent variable model has recently been proposed. This approach conceptualizes the responses as manifestations of an underlying continuous normal variable. In this article, we extend this idea to develop the multiple comparison method for use when there are two controls in the clinical trial. The proposed method is constructed such that the familywise type I error rate is controlled at a prespecified level. In addition, for a given level of test power, the procedure to evaluate the required sample size is provided. The proposed testing procedure is also illustrated by an example from a clinical study.
authors.affiliation: a Department of Statistics , The Chinese University of Hong Kong , Hong Kong , China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yang
authors.affiliation: a Department of Statistics , The Chinese University of Hong Kong , Hong Kong , China.
authors.forename: Siu
authors.initials: S
authors.lastname: Hung Cheung
authors.affiliation: a Department of Statistics , The Chinese University of Hong Kong , Hong Kong , China.
authors.forename: Wai-Yin
authors.initials: WY
authors.lastname: Poon
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D015233:Models, Statistical; D012107:Research Design; D018401:Sample Size
keywords: Familywise error rate; latent normal model; multiple comparisons; multiple controls; ordinal responses