[In a clinical trial, method is not sufficient, the purpose must be relevant]

The aim of a trial is relevant if it is well formulated, has a strong scientific basis and if anticipated results are useful for patients' management. The aim must be simple and specific, clearly expressing the treatments to be compared, the study population and the primary endpoint. Moreover, the formulation must include the working hypothesis: superiority or equivalence/non inferiority. Endpoints must be valid and have either a pathogenic relevance (explanatory attitude in early phases of development) or a clinical relevance (pragmatic attitude in later development). A synthesis of available knowledge is crucial to avoid useless trials. The aim of a trial must be the result of a consensual and multidisciplinary reflection prior to the beginning of the study.