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What is a Clinical Trial?

A clinical study involves research using human volunteers that is intended to expand medical knowledge related to a specific condition. There are two main types of clinical studies:  clinical trials (also called interventional studies) and observational studies.

Clinical Trials

In a clinical trial, participants receive specific interventions according to the research plan created by the investigators. Interventions may include:

  • New treatment, perhaps a medical device or medication
  • New process related to treatment
  • Changes to the participants' daily activities, such as their eating habits

Clinical trials may compare a new medical approach to a standard one that is in use every day in healthcare settings. or compare interventions that are already available to each other. When a new product or approach is being studied, it is not usually known whether it will be helpful, harmful, or no different than available care options. The investigators try to determine the safety and efficacy of the intervention by measuring certain outcomes in participants.

Types of Clinical Trials

Observational Studies

In an observational study, investigators assess health outcomes in groups of participants according to a research plan or protocol. Participants may receive interventions (which can include a medical device or medications or medical procedures. Unlike a clinical trial, the specific intervention is chosen by the participants rather than by the investigator.

Phase I trials

Phase I trials are designed to determine the safety of a new cancer therapy. They evaluate how a new medication should be given (orally, intravenously, or by injection), how often, and at what dosage, but are not designed to test if a new therapy is effective. Phase I trials generally enroll only a small number of patients.

Phase II trials

Phase II trials provide information about how well a new medication works and generate more information about patient safety. Phase II studies usually focus on a specific type of cancer.

Phase III trials

Phase III trials compare new treatments with standard ones to determine which is safer and more effective. Phase III trials generally involve a large number of participants and often take place at several health centers at the same time. Patients are randomly assigned to receive either the new cancer therapy or a standard one.

Who Can Participate in a Clinical Study?

Clinical studies have standards outlining who can participate, called eligibility criteria. Some research studies seek participants who have the illnesses or conditions that will be studied, while other studies are looking for healthy participants. A third category in some studies contains a predetermined group of people who are asked by researchers to enroll.

Considerations for Participation

Participating in a clinical study contributes to our medical knowledge. The results of these studies can make a difference in the care of future patients by furthering our understanding of the benefits and risks of therapeutic, preventive, or diagnostic, or interventions.

Anyone interested in participating in a clinical study should know as much as possible about the study and feel comfortable asking the research team general questions about the study, the related procedures and any related expenses they may be expected to cover.

If you or someone you know is interested in participating in cancer research, contact a member of our team. For more information, call (260) 266-9100 and ask to speak to a clinical research coordinator. You may also e-mail

Clinical research coordination team

Abby Reed, RN

(260) 425-6811

Christine Spillson, BSN, CCRC

(260) 425-6848

Source: U.S. National Library of Medicine

Parkview Comprehensive Cancer Center

Parkview Regional Medical Center

Entrance 4

11141 Parkview Plaza Drive

Fort Wayne, Indiana 46845