SOME OPTIMAL AND NON-OPTIMAL TWO-STAGE DESIGNS USING AN α-SPENDING FUNCTION
✍ Scribed by H. I. PATEL
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 465 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0277-6715
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✦ Synopsis
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 a-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.