Methodology of clinical research: An overview

The goal of clinical research is to establish safety efficacy and effectiveness of treatments or intervention. In order to obtain it, different clinical studies are needed, with a quite definite hierarchy of research objectives, in order to gather all information needed for appraising the clinical role of the intervention being tested. Clinical trials are generally considered as the best tool for learning whether a new treatment is safe and effective in patients. They are conducted in all areas of medicine but represent only a small part of the research for developing a new treatment. In particular, even after providing evidence for the approval of treatment, further research is needed on the implementation of results of clinical research into clinical practice and health policy. This is the place of outcome research that investigates the impact of various influences, especially interventions, on final endpoints that matter to decision makers with special emphasis on the use of patient-reported outcomes. This article reviews the methodological characteristics of each research phase, with particular emphasis on comparative trials and effectiveness studies.