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SOME OPTIMAL AND NON‐OPTIMAL TWO‐STAGE DESIGNS USING AN α‐SPENDING FUNCTION
Author(s) -
PATEL H. I.
Publication year - 1996
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/(sici)1097-0258(19960830)15:16<1739::aid-sim341>3.0.co;2-t
Subject(s) - interim , sample size determination , interim analysis , context (archaeology) , computer science , sample (material) , function (biology) , mathematical optimization , statistics , mathematics , clinical trial , medicine , paleontology , chemistry , archaeology , chromatography , evolutionary biology , biology , history , pathology
While designing a group sequential clinical trial in the pharmaceutical industry setting, we often face a problem of determining the time for an interim analysis. For a two‐stage trial we compute the sample sizes n and N per treatment group for the interim and final analyses. respectively, that minimize the average trial size for a specified overall power. We consider this optimization when we monitor the trial using a Lan–DeMets α‐spending function. Two additional problems considered in this context are (i) finding the sample sizes that maximize the overall power for a specified average trial size, and (ii) finding the sample sizes that achieve specified powers at the interim and final analyses.