Clinical Trial Terminology

There are several terms that are commonly used when discussing clinical trials. Here are some that come up often:^1,2

Adverse event

An undesirable experience associated with the use of a medical product in a participant.

Arm

A grouping of study participants who receive a specific intervention, or no intervention, according to the study protocol.

Baseline characteristics

Data collected at the beginning of the study for each participant, including demographics like age, gender, and race. Data for study-specific characteristics like prior treatment, weight, etc., will also be collected.

ClinicalTrials.gov identifier (NCT number)

The unique identification code assigned to each clinical trial that is registered on ClinicalTrials.gov.

Controlled Trial

A type of clinical trial that examines an intervention compared with a standard (called the control).

Double Blind Trial

A clinical trial where at least 2 parties involved, usually the patient and the investigator, do not know what intervention the patient is receiving. This is to avoid potential bias.

Exclusion Criteria

Factors that would prevent a person from participating in a study.

FDA

Food and Drug Administration.

Inclusion Criteria

Factors that allow a person to participate in a study.

Intervention

The focus of the clinical study. This could be a drug, a medical device, a medical procedure, other investigational products, as well as surveys, education, or interviews.

Investigator

A person who is conducting research of a clinical study.

Open Label

A term describing a clinical trial where blinding is not used. All parties involved know which study participants have been assigned to which interventions.

Outcome Measure

A measurement that is outlined in the study protocol that is used to determine the effect of the intervention.

Placebo

A substance that does not contain active ingredients and is designed to appear the same as the intervention being examined.

Primary Outcome Measure

The main outcome measure that is evaluating the effect of the study intervention.