Active vs. Control 

The control is the group that receives “standard” treatment in comparison to the active group that receives the investigational treatment “being studied”.  The purpose of the two or more groups is to show that the efficacy of the investigational treatment in comparison to prevailing or existing treatments if already in existence.

Adverse Event

A change or medical event that is undesirable that occurs during a clinical trial or within a certain time period after the trial has ended. An adverse event may not necessarily be related to the treatment being administered in the study.


A clinical trial design in which the research team or participant does not know which treatment/s have been assigned to which participants.


In a single-blinded study, the clinical staff providing the trial is aware of which participants are receiving which treatment.


In a double-blind trial the participants, doctors, and other clinical trial staff are not aware of which study treatment a participant is receiving. Only the study pharmacist knows this and releases study medications to participants after extensive review and according to strict protocol.

Contract Research Organization (CRO)

Are entities that support the outsourced clinical research efforts of pharmaceutical, biotechnology, and medical device companies.

Clinical Studies & Clinical Trials

Are experiments or observations conducted on human volunteers to answer specific health questions.

Interventional study 

Also known as a clinical trial, is a means for researchers to evaluate the effects and efficacy of an intervention on certain health conditions by providing participants one or more intervention in controlled environments. Such interventions vary based on the protocol and the groups each participant is assigned to.

Observational study

Also known as a clinical study, examines health outcomes amongst participants who receive care from their regular physician/s without an investigational treatment being provided. Participants are monitored through in-person visits, journals, and remote devices like wearables.


In pharmacology, efficacy refers to the maximum response achievable from an applied or dosed therapeutic agent in a research or clinical setting. In other words, whether it works and how well it works.

Eligibility Criteria

The requirements that patients interested in a certain clinical trial are required to meet before being enrolled in a study, as defined by the protocol.

Inclusion Criteria

Requirements a prospective participant must meet before being included in a trial or study.

Exclusion criteria

Characteristics that disqualify a prospective participant from being included in a trial or study.


The point in which a prospective participant officially becomes included in a trial or study. This occurs after informed consent has been obtained.

Food & Drug Administration (FDA)

Food and Drug Administration is a federal agency within the U.S. Department of Health and Human Services. The FDA oversees the safety, effectiveness, and security of human and veterinary drugs, vaccines, biological products, medical devices, cosmetics, dietary supplements, food supplies.


Is a reason to complete a specific test, medication, procedure, or surgery based on a certain disease, symptom, or other, varying circumstances. This should not to be confused with a diagnosis, which is the identification of certain disease rather than reason for a treatment or intervention.

Informed consent

Informed consent is the process of learning key facts about a clinical trial before deciding to participate or not. The physicians and/or nurses involved in the trial explain all facets and risks associated with the trial. It is paramount the prospective patient fully understands what is being discussed, and prospective participants must communicate back a strong understanding of what was discussed. Through the life of a study, information is regularly provided to the participant, making this process continuous. Written documentation will be provided detailing the purpose, duration, required procedures, risks, potential benefits, and key contacts for the trial. At this point the prospective patient decides to sign and enroll in the trial. Informed consent is not a contract, and the participant may withdraw from the trial at any time.

Institutional Review Board (IRB)

An IRB is an administrative body that reviews all components of a human clinical trial in order to protect the rights and wellbeing of human research participants. An IRB is usually composed of doctors, scientists, advocates, researchers, and specialized community members. An IRB is also known as an ethical review board (ERB), research ethics board (REB), or independent ethics committee (IEC).


In medical terms, an intervention refers to the use of a procedure, medicine, therapy, device or other means to modify an outcome and is usually undertaken to help treat or cure a condition.


Principal Investigator (PI)

A PI is usually a leading physician specializing in the disease or condition being studied and is responsible for leading the scientific and technical handling of a clinical trial at a specific clinical site.

Sub Investigator (Sub-I)

A Sub-I refers to a clinical trial research member involved in the management and execution of a clinical trial or study. This person is commonly a physician or mid-level provider like a Nurse Practitioner or Physician Assistant.

Investigational drug 

A chemical or biological substance approved by the FDA for human testing. Also referred as an Investigational New Drug (IND) or investigational medicinal product.

Outcome measure

Is a tool used to assess a participant’s current status or endpoints related to the intervention or treatment provided through the course of a clinical trial.


Clinical trials are conducted in phases as defined by the FDA. The trials at each phase have a different purpose and help scientists answer different questions:

  • Phase I trials test an experimental drug, vaccine or device in a small group of people (20-80) to evaluate safety, determine safe dosage ranges, and identify side effects.
  • Phase II trials involve larger groups of people (100-300) and further gauge safety and efficacy.
  • Phase III trials are usually large studies (1,000-3,000) comparing the experimental drug or vaccine to a placebo or standard treatment. This is done in order to confirm effectiveness, the benefits and further monitor side effects.
  • Phase IV trials, also known as Post Market Studies (PMS), are done to provide additional information about the best use of the drug.


Placebos are inactive substances with no therapeutic effect that are used to compare the effectiveness of investigational treatments to the control group, which essentially receive no treatment at all.


A written document that describes the study plan of the clinical trial. A protocol includes but is not limited to the design, methodology, test schedules, procedures, medications, administration dosages, outcome measures, study length, and statistical considerations for the analysis of the study.


A method in which enrolled participants are assigned treatment groups in blinded studies or trials.

Serious adverse event

Any life-threatening, fatal, or birth defect causing occurrence that happens at any point during the monitoring phases of a clinical trial. This includes incidents not related to the trial or interventions being provided through the study.


A company, institution, organization, or person who oversees or pays for the administration, data collection, and analysis of a clinical trial.

Study completed date

The date the last trial participant makes their final visit to the study location and/or the last tests are collected or performed.


A volunteer who participates in a clinical trial and whose reactions or responses to the interventions being studied are evaluated through the course of the clinical trial. Also referred to as a participant.