Bolland, Kim and Whitehead, John and Cobo, Erik and Secades, Julio J. (2009) Evaluation of a sequential global test of improved recovery following stroke as applied to the ICTUS trial of citicoline. Pharmaceutical Statistics, 8 (2). pp. 136-149. ISSN 1539-1604
Full text not available from this repository.Abstract
Two-stage designs offer substantial advantages for early phase II studies. The interim analysis following the first stage allows the study to be stopped for futility, or more positively, it might lead to early progression to the trials needed for late phase II and phase III. If the study is to continue to its second stage, then there is an opportunity for a revision of the total sample size. Two-stage designs have been implemented widely in oncology studies in which there is a single treatment arm and patient responses are binary. In this paper the case of two-arm comparative studies in which responses are quantitative is considered. This setting is common in therapeutic areas other than oncology. It will be assumed that observations are normally distributed, but that there is some doubt concerning their standard deviation, motivating the need for sample size review. The work reported has been motivated by a study in diabetic neuropathic pain, and the development of the design for that trial is described in detail.