Alternative hypotheses for the effects of drugs in small-scale clinical studies

New drugs that will be investigated in the future are expected to deal with chronic diseases, where the number of patients available for controlled clinical trials will be small and where the long-term sequelae that it is hoped will be ameliorated take a long time to occur. Thus, it would be useful to construct powerful tests of hypotheses that can be used to compare subtle intermediate measures of change in condition. This paper examines the probabilistic characteristics of these measures and the changes in them that might be expected from drug therapy.