Definitions for "Clinical significance"
Results are clinically significant when they make enough difference to you and your patient to justify changing your way of doing things. For example, a drug which is found in a megatrial of 50,000 adults with acute asthma to increase FEV1 by only 0.5% ( P value.0001) has failed this test of significance.
The extent to which the results of a study will be important, useful, and applicable in the treatment of patients.
Change in a subject's clinical condition regarded as important whether or not due to the test article. Some statistically significant changes (in blood tests, for example) have no clinical significance. The criterion or criteria for clinical significance should be stated in the protocol.