A clinical trial (or research study) is a scientific study showing the effectiveness of new treatments. Through these studies, doctors find new and better ways to diagnose and treat illnesses. Many new treatments are found to be safe and effective. However, before a new treatment is determined to be effective it must be tested. Participating in a research study is voluntary and requires that participants understand the risks, benefits, and procedures involved with the study. Participants may leave a study at any time.