Glossary of Research Terms


Basic scientist: a research scientist who works in a laboratory; sometimes referred to as a “bench researcher.”

Blind, randomized clinical trial: a clinical trial in which the participants do not know whether they are receiving the study drug or therapy or whether they are receiving a sugar pill (placebo).

Clinical researcher: a physician or nurse who conducts or oversees clinical trials, which involve patients.

Clinical trial: a study in humans that tests a new approach to medical treatments, such as medication, surgery, radiation therapy, and different combinations of existing treatments or new methods. Clinical trials also allow researchers to find better ways to prevent, diagnose, understand and cope with disease.

Control group or control arm: the part of a clinical trial that includes participants who are receiving a placebo and/or the normal standard of care for their disease and are not receiving the study drug or therapy.

Cross-over option: enables study participants in one arm of a clinical trial to cross over into the other arm if the other arm proves to be clinically superior during the course of the study.

Double-blinded, randomized clinical trial: a clinical trial in which neither the participants nor the clinicians overseeing the trial know which therapy the participants will receive.

Efficacy: the maximum benefit produced by a drug or treatment, regardless of dosage.

FDA: U.S. Food and Drug Administration, the federal agency that approves new drugs and devices for use in the United States.

Inclusion/exclusion criteria: these are criteria or requirements that determine whether an individual can or cannot participate in a clinical trial. Inclusion criteria can include age, disease type and previous treatment. Exclusion criteria are conditions that prohibit enrollment.

Institutional Review Board (IRB): a committee of scientists, doctors and consumers at a health care facility where a clinical trial takes place. The IRB reviews protocols for all clinical trials and must grant approval for them to move forward. The IRB ensures that a study is well designed, does not involve undue risks and includes safeguards for patients.

Investigator-initiated clinical trial: a “home-grown” clinical trial that has been designed by an institution’s own faculty member. It is typically an early-phase trial that is studying a compound or modality that the research investigator has designed or that the institution’s basic scientists have developed. Investigator-initiated trials are prestigious because they are a sign of intellectual momentum within an institution.

Multi-center clinical trial: a trial that is conducted at many treatment centers at the same time. A multi-center trial may enroll dozens, hundreds or even thousands of participants.

Observational study: a study in which people volunteer their information or biological samples for the sake of research. No drugs or other therapies are tested.

NIH-funded clinical trials: a clinical trial that is funded by the National Institutes of Health (NIH). The NIH funds thousands of clinical trials each year.

Placebo: a sugar pill, liquid, powder or other apparent treatment or therapy that has no treatment value.

Placebo effect: the documented positive clinical improvement that study participants often experience, even if they are receiving a placebo and not the study drug. Scientists believe the placebo effect derives from the peace of mind that comes with the extra attention typically provided to study participants.

Pharmaceutical-based clinical trial: a clinical trial designed and requested by a pharmaceutical company that has developed a new treatment or therapy.

Phase I clinical trial:  a clinical trial that seeks to determine the safety (lack of toxicity) and the best dose level of a new therapy. Prior to the study, medical scientists do not know whether the therapy or medication is safe or effective. Phase I trials usually test a drug in a small number of healthy people.

Phase II clinical trial: a clinical trial or study that involves a larger population than a Phase I study but that continues to explore the basics of a therapy or drug, including its safety (lack of toxicity) and the most effective dose level. Study participants in Phase II clinical trials are patients; they have the disease or condition being studied.

Phase I/II clinical trial: a clinical trial, often performed by researchers today, that combines Phase I and Phase II studies into one continuous project.

Phase III clinical trial: a trial that begins after scientists have confirmed that the drug or therapy is safe, and they know the most effective dose. During the Phase III study, researchers put the medicine to the test by comparing it directly to a previously approved treatment. The goal is to find out whether the new therapy provides an improved outcome or length of survival when compared to the old therapy or the current best available treatment. This head-to-head comparison helps determine whether the new treatment should be approved by the U.S. Food and Drug Administration and brought to market.

Principal Investigator (PI): the individual who serves as director of a clinical trial. If a trial has multiple sites, each site may also have a site principal investigator who oversees work at that location. All other individuals assisting with the trial are co-investigators.

Prospective clinical trial: a clinical trial in which the participants are identified and then followed forward in time.

Randomization: a method used to prevent bias in research. In a study that compares a new drug or therapy to standard treatment, study participants are assigned by chance – or randomized — to a group, also known as an “arm.” A study may or may not be designed to have participants split evenly into one or more groups. If the study includes two groups, with participants assigned to each group in equal numbers, a participant will have a 50 percent chance of assignment into either group. A computer program will make the assignment.

Retrospective study: a study that looks back in time; data is gathered from medical records and interviews with patients who are known to have or have had a disease.

Single-arm clinical trial: a trial in which all study participants receive the study drug or therapy. The study compares these participants to a historical control, rather than a placebo. Brain tumor studies are often designed as single-arm trials because the number of available study participants tends to be low.

Single-center clinical trial: a trials initiated by one researcher that is available at only one center.

Translational research: the act of translating laboratory findings into new treatments for patients. The development of Phase I studies involves translational research.

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