Clinical research is designed to answer a specific scientific question. In clinical research the lead researcher – also called the principal investigator or PI – creates a study plan or protocol that specifies who may be eligible to participate in the research (based on specific criteria), what and how often data are gathered from the study participants, the number and makeup of the study population (based on age, gender, race, and ethnicity), and how the data will be analyzed to answer the research question. The National Institutes of Health (NIH) breaks down clinical research into three categories (reference):
- Patient-oriented research involves human subjects or uses materials from humans;
- Epidemiological and behavioral studies investigate disease in large populations and attempt to link human health and disease to a specified cause; and
- Outcomes and health services research studies the link between the care people receive and the outcome they experience with the aim of improving the quality of clinical care.
A research study that is designed to test the efficacy (effectiveness) and safety of a drug or treatment, or a medical device is called a clinical trial. Depending on the type and stage of development of the medical product being tested, a clinical trial may enroll a small number of healthy volunteers, a small number of people with the disease or condition for which the product is designed, or many patients in a large scale study that is conducted in a single site or multiple sites in one or many countries. For more details, see a graphical representation of clinical trial phases.
A study sponsor refers to the source or entity that funds the study. A study may have more than one sponsor. A sponsor, for example, can be a governmental agency, a pharmaceutical company, a philanthropic organization, or an individual. Often however, the sponsor is a federal agency such as the NIH or a pharmaceutical company. In the United States, sponsors spend approximately $100 billion annually on health care-related research (reference). In addition to supporting the study, a sponsor may be involved in its design and conduct. In investigator-initiated studies, the PI designs the study and then seeks a sponsor. Once a study is approved for funding by the sponsor, the PI must apply and obtain permission (approval) from the Institutional Review Board (IRB) to conduct the study.
The IRB is a committee that is comprised of doctors, scientists, and clergy and other non-medical persons and is charged with performing key functions related to the conduct of the research study. IRBs review, approve, and monitor clinical studies. When IRB members review a study, they make sure that the study is scientifically sound, ethical, and in compliance with all federal, state and local regulations related to the protection of human subjects. In the United States, the Food and Drug Administration (FDA) and the Office for Human Research Protections (OHRP) have empowered IRBs to ensure the ethical conduct of clinical research.
The most important person of all in every clinical trial is the study volunteer, often called a study participant. Without these volunteers no clinical research can be done.