Thank you for your support. This discussion is exciting for me. But hold on..... seems like i misunderstood something. Once again, let's use a two scenarios (S1 and S2). S1: I would like to conduct samplesize estimation in a noninferiority study. The drug 2 is not worse than drug 1, where the success rate of drug 1 is 97% and the success rate for drug 2 is 95%. So difference in the endpoints is 2%, i suggested margin (probably nullpdiff) 1% or 3% or 4%. I was sure that in this case the assumption for margin = 1 is that drug 2 will have success rate between 94 and 96%. S2: let's assume that drug 2 to will be superior to drug 1. Still the succes rates are the same for both drugs, but then i have to expect margin at least 3? Other questions: if i have set the nullpdiff option as positive value then swaping the order in the groupps option changes the calculation from superior to noninferiority samplesize calculation. And if i won't swap order in groupps option and i will change the value of nullpdiff for negative then i will as well change from superiority to noninferiority study? What should i do to decrease the samplesize? the drugs do not differ between each other, i either believe that this one with 95% success rate(SR) is superior to drug with 97% SR. Please, suggest a solution for that case. The study will take too much time if i will have 1500 participants per arm. In my time zone it after midnight, 00:22. Have a nice night! Thanks again, and i hope to talk to you tomorrow.
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