A clinical trial is a kind of research that involves treatment and people. Clinical trials help researchers answer questions such as:
Clinical trials are done in steps called phases. At each phase, researchers try to answer a different question. Each phase needs a different set of participants, so a participant joins only one trial at a time.
Phase I: Is it safe?
Phase II: Does it work?
Phase III: Is it better than what we have now?
Phase IV: What else can happen?
There are two main types of clinical studies:
Observational studies are where the researcher takes no study-related medical action. Patients are treated based on normal clinical decisions if needed. People in these studies are monitored over a period of time and the study team collects and looks at data about the participants.
Interventional clinical trials are where the researcher takes action to prevent, understand better or treat a disease. They test the safety and effectiveness of a new drug or other treatment. Interventional clinical trials follow strict rules to protect patients.