In Phase III studies, the study drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely. Phase IV studies are done after the drug or treatment has been marketed. These studies continue testing the study drug or treatment to collect information about their effect in various populations and any side effects associated with long-term use. All clinical trials are based on a set of rules called a protocol. While in a clinical trial, participants are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of their treatment.
All clinical trials have guidelines about who can get into the program.
Guidelines are based on such factors as age, type of disease, medical history, and current medical condition. Before you join a clinical trial, you must qualify for the study. Some research studies seek volunteers with illnesses or conditions to be studied in the clinical trial, while others need healthy volunteers. The factors that allow someone to participate in a clinical trial are called inclusion criteria and the factors that keep them from participating are called exclusion criteria. It is important to note that inclusion and exclusion criteria are not used to reject people personally.