Potvin C or B? [Two-Stage / GS Designs]
One regulator (I leave it to your imagination which one of EMA’s working parties he belongs to) told me that
Our [i.e., his agency’s] statisticians don’t believe* that in Potvin’s Method C the patient’s risk is preserved at ~5%. They suggest to use only Method B because application of Pocock’s α 0.0294 is well known.I suggested to tell them to have a closer look at the empiric alphas (the endless tables in the paper). BTW, specifically Method C (not B!) is recommended by the FDA and in the recent Canadian GL.
- Quoting my late father: “If you don’t want to know, but to believe – go to church.” Was in the 1960s; so for the sake of political correctness add temple, mosque, synagogue, stupa, pagoda, shrine, Lenin’s mausoleum, …
The quality of responses received is directly proportional to the quality of the question asked. ☼