Research fundamentals: III. elements of a research protocol for clinical trials.

A clinical trial is a powerful technique for evaluating the effectiveness of an experimental intervention. The initial stages of planning a clinical trial involve choosing and refining a research question, selecting a study design, and deciding on appropriate statistical tests and sample sizes. The success of the study depends upon how well these issues are thought out in advance, and how they can be put into practice. The protocol is the written document that allows the investigator to communicate details of how the research question will be answered. In the following article, the basic components of the research protocol are described. Issues related to quality control, data entry, and pilot testing are discussed. This is the third in a series of research fundamental concept papers, written by members of the SAEM Research Committee.