Small clinical trials might be warranted for the study of rare diseases, unique study populations (e.g., astronauts), individually tailored therapies, in environments that are isolated, in emergency situations, and in instances of public health urgency. However, when the clinical context does not provide a sufficient number of research participants for a trial with adequate statistical power but the research question has great clinical significance, research can still proceed under certain conditions. Whenever feasible, clinical trials should be designed and performed so that they have adequate statistical power. A study design that is considered appropriate includes sufficient sample size (n) and statistical power and proper control of bias to allow a meaningful interpretation of the results.
Scientific research has a long history of using well-established, well documented, and validated methods for the design, conduct, and analysis of clinical trials.
