If you were to participate in a clinical trial, you might receive your treatment at a large cancer center, a university hospital, or your local medical center or physician's office. Clinical trials are also conducted at the National Cancer Institute on the campus of the National Institutes of Health in Bethesda, Maryland. Depending on the type of trial and on the approach being studied in it, the trial may be treating participants at one or two highly specialized centers or at hundreds of locations at the same time. You would follow the trial's protocol under the guidance of a team including your physician, an oncology nurse, or other health professionals, who would report your experience with the treatment back to the center responsible for the trial's overall coordination. Experts could then use the information from all the participants to evaluate the new treatment, screening method, or preventive measure under investigation.
Clinical trials enroll people who are alike in certain ways depending on the study's purpose.
Every protocol identifies some specific characteristics that the people should have in order to participate in the study. These characteristics are called eligibility criteria. They may include the type of disease and its stage, age and general health. Eligibility criteria are a key part of medical research. They help assure that the study results answer the research question.