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Re: st: Reverse null hypothesis?

From   Richard Goldstein <>
Subject   Re: st: Reverse null hypothesis?
Date   Wed, 16 Jun 2004 08:30:49 -0400

this is known as a non-inferiority trial -- a recent article in
Statistics in Medicine talked about sample size estimation for
these studies and discussed how to use nQuery Advisor and PASS
software for this purpose: Julious, S.A. (2004), "Sample sizes
for clinical trials with normal data," 23: 1921-1986

Rich Goldstein

Steve Harvey wrote:
Dear Statalisters:

I'm having trouble with what may be a fairly basic statistics question.

I have a new intervention and want to know if the intervention is at least as good as the standard treatment. I want to be certain that the intervention is not poorer than the standard treatment. So...

Ho: M1 < M2
Ha: M1>= M2

If I want to be 95% certain that I can reject Ho, do I need to do anything different in terms of calculating sample size and means testing than under the normal Ho: M1 = M2? Do the probability distributions under these conditions differ from those when I assume Ho: M1 = M2?



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