Interim Analysis and Power [Two-Stage / GS Designs]

posted by Emrah Soner Özdeş – Turkey, 2014-12-26 09:55 (4192 d 14:24 ago) – Posting: # 14178
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Herr Schütz;

❝ Please help me understand the details. I get on basis of Cmax:

❝ PE=88.31% and CV=27.5% with N1=24, and assuming balance you'll have a power of about 65% (alpha 5%, GMR 95% as per Potvin and not 88.31%). Where did I go wrong here?


It seems that I need to check my calculations for power value since point estimator and CV values are same with the one you calculated. Could you advice a reliable formula to check my calculations ?

❝ I assume you wrote in your protocol that your way through the decision tree would be dictated by Cmax and not AUCt? You'll be going into stage 2 before declaring success or failure.


No it will be dictated by both Cmax and AUCt. Assuming that both endpoints are outside the 90% CI and power is below 80% for only one endpoint ? What would be the next step ?

Thanks in advance

Emrah

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