Hauschke, D., Schall, R. and Luus, H. G. 'Statistical Significance'. About the Author Dieter Hauschke has extensive experience in theoretical and practical aspects of equivalence trials and its application to pharmaceutical drug development including bioequivalence, therapeutic equivalence and safety assessment. He has worked at Byk Gulden Pharmaceuticals since 1986. Dieter Hauschke is author or co-author of over 50 research articles and book chapters. I think one should be cautious about accepting his advocacy of testing a shifted null hypothesis.
Dieter refers to tests available for testing shifted null hypotheses.
With the more modern approach, emphasising estimation, confidence intervals deliver the necessary information. In my view a significant result is usually only ever a very crude way of deciding, at the end of a trial, whether it is worth carrying on with the drug. In my experience, the term 'clinically relevant difference' is frequently used in clinical trials for sample size planning. Specification of this value requires that the biostatistician and the clinician think about what constitutes a maximum clinically irrelevant difference. In the case of a significant test result for the classical hypothesis of no difference, the clinician often assume that the trial results in a clinically relevant difference.