hello to you, too, calstang. I too would like to find an equation for p-value and power. i looked but no luck.

i have asked this board before, and i did find the wolframalpha two binomial distribution test when i asked before. but i dont know how to get the underlying equations for that formula.

i think when i asked about this before, a couple of our posters provided some references that probably have equations in them.

but i don't know how to search for stuff on this message board.

i do agree that the new info posted here today about p<.001 needed for efficacy stop, and that could completely explain why 50% mortality reduction may have been achieved at the interim and yet they didn't shut it down.

i want to look at the equations for p-value and power to see how the n=390 affects the power compared to the n=195 interim.