Once researchers test new therapies or procedures in the laboratory and promising results are obtained, planning commences to design the trial project. Subjects tend to be randomly allocated to study and control groups. Phase IV studies are conducted after the treatment has been marketed. No clinical trial is an entity unto itself. Each trial should be considered as part of an evolving research program.
Confirmatory studies are essential for all clinical trials.
There are several reasons why clinical trials, in and of themselves, are important. The first is that the trials' findings contribute to the knowledge base in understanding the etiology, development, progression, and possible remediation of a disease or condition. Such recognition of the development of a disease or condition leads to the second reason why clinical trials are performed. Advancement is made in the area of remediation as a result of new ideas and approaches developed through research. In relation to communication disorders, these reasons are reflected in the overall importance of experimental-clinical research.