Active vs. Control Group
The control group receives the “standard” treatment, which serves as a comparison to the active group that receives the investigational treatment under study. The purpose of having both groups is to evaluate the efficacy of the investigational treatment against the existing or prevailing treatments, if they already exist.

Adverse Event
An undesirable medical event that occurs during a clinical trial or within a specific period after its conclusion. An adverse event may not necessarily be linked to the treatment being tested in the study.

Blinding
A clinical trial design in which either the research team or the participants are unaware of which treatment(s) have been assigned to which participants.

Single-blind
In a single-blind study, the clinical staff are aware of which participants are receiving which treatment, but the participants do not know.

Double-blind
In a double-blind study, neither the participants nor the clinical staff (including doctors) know which treatment the participants are receiving. Only the study pharmacist knows this information and administers the study medications according to a strict protocol.

Contract Research Organization (CRO)
Entities that assist pharmaceutical, biotechnology, and medical device companies with outsourced clinical research efforts.

Clinical Studies & Clinical Trials
Experiments or observational studies conducted on human volunteers to answer specific health-related questions.

Interventional Study
Also known as a clinical trial, this type of study allows researchers to evaluate the effects and efficacy of interventions on health conditions by providing participants with one or more treatments in a controlled environment. The interventions vary according to the study’s protocol and the participant’s assigned group.

Observational Study
Also referred to as a clinical study, this type of study monitors health outcomes among participants receiving care from their regular healthcare providers, without any investigational treatments being provided. Participants are tracked via in-person visits, journals, or remote devices like wearables.

Efficacy
In pharmacology, efficacy refers to the maximum therapeutic effect achievable from a drug or treatment in a clinical or research setting—essentially, whether the treatment works and how well it works.

Eligibility Criteria
The specific requirements that potential participants must meet to enroll in a clinical trial, as defined by the study protocol.

Inclusion Criteria
The characteristics or conditions that a prospective participant must meet to be included in a trial or study.

Exclusion Criteria
The conditions or factors that disqualify a potential participant from participating in a trial or study.

Enrollment
The point at which a participant is officially included in a clinical trial, following the process of obtaining informed consent.

Food & Drug Administration (FDA)
A U.S. government agency within the Department of Health and Human Services that ensures the safety, effectiveness, and security of drugs, vaccines, medical devices, food, cosmetics, and dietary supplements.

Indication
The specific reason for conducting a test, administering medication, or performing a procedure, based on a particular disease, symptom, or condition. This is different from a diagnosis, which is the identification of a disease or condition.

Informed Consent
The process by which a prospective participant learns key information about a clinical trial before agreeing to participate. This process involves explaining the trial’s purpose, procedures, risks, and potential benefits. Participants must fully understand the information before they sign consent forms to enroll. It is a continuous process, with updates provided throughout the study. Informed consent is not a contract, and participants can withdraw from the trial at any time.

Institutional Review Board (IRB)
An independent group that reviews clinical trial protocols to protect the rights and welfare of human research participants. The IRB is made up of doctors, scientists, advocates, and other experts, and it may also be called an ethical review board (ERB) or research ethics board (REB).

Intervention
A procedure, medication, therapy, device, or treatment used to alter the outcome of a condition, typically with the goal of improving or curing the condition.

Investigators

• Principal Investigator (PI): The lead physician responsible for the scientific and technical management of a clinical trial at a specific site.
• Sub Investigator (Sub-I): A researcher, often a physician or mid-level provider (e.g., Nurse Practitioner or Physician Assistant), involved in the execution and management of the clinical trial.

Investigational Drug
A drug or biological substance that has been approved by the FDA for human testing, also referred to as an Investigational New Drug (IND) or investigational medicinal product.

Outcome Measure
A tool or method used to assess a participant’s progress or response to treatment during the course of a clinical trial.

Phase
Clinical trials are conducted in distinct phases, each serving a different purpose:

• Phase I: Tests a new drug, vaccine, or device in a small group (20-80 people) to evaluate safety, determine dosage, and identify side effects.
• Phase II: Expands to a larger group (100-300 people) to further assess safety and efficacy.
• Phase III: Involves large groups (1,000-3,000 people) to compare the investigational treatment to a placebo or standard treatment, confirming effectiveness and monitoring side effects.
• Phase IV: Post-market studies that provide additional information about the drug’s long-term use.

Placebo
An inactive substance used in clinical trials to compare the effectiveness of a new treatment against a group that receives no active treatment.

Protocol
A written plan that outlines the details of a clinical trial, including study design, methodology, treatment schedules, medication dosages, outcome measures, and statistical analysis methods.

Randomization
The process of assigning participants to treatment groups in a clinical trial in a random manner, typically used in blinded studies.

Serious Adverse Event
Any event during a clinical trial that is life-threatening, fatal, or causes a birth defect. This can include incidents not related to the treatment being studied.

Sponsor
The organization, institution, or individual responsible for overseeing the clinical trial, including funding, data collection, and analysis.

Study Completion Date
The date when the last participant completes their final visit or when the final tests are performed in the clinical trial.

Subject (Volunteer / Patient / Participant)
A volunteer who participates in a clinical trial, with their responses or reactions to the study interventions being monitored and evaluated. Also referred to as a participant.