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A clinical trial with an interim analysis.

P Y Chi·D R Bristol·J V Castellana
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Abstract

We consider a fixed-sample parallel-group clinical trial with an interim analysis that tests H0:mu x = mu y against H1:mu x less than mu y. If we do not reject at the interim analysis, then the probability of making a type I error by rejecting H0 in favour of H2:mu x greater than mu y and the power at the final analysis are not appreciably affected by performing the interim analysis for certain relevant critical regions.

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P Y Chi, D R Bristol, J V Castellana. A clinical trial with an interim analysis.. https://doi.org/10.1002/sim.4780050411

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