Common Terms

Clinical Research
Medical research involving people to test new treatments and therapies.

Clinical Trial
A research study where one or more human subjects are prospectively assigned to one or more interventions (which may include placebo or other controls) to evaluate the effects on health-related biomedical or behavioral outcomes.

Healthy Volunteer
A person with no known significant health problems who participates in clinical research to test a new drug, device, or intervention.

Inclusion/Exclusion Criteria
Inclusion criteria are factors that allow someone to participate in a clinical trial. Exclusion criteria are factors that prevent participation.

Informed Consent
The process of explaining the risks and potential benefits of a clinical trial to help someone decide whether to participate.

Patient Volunteer
A person with a known health problem who participates in research to better understand, diagnose, treat, or cure their disease or condition.

Phases of Clinical Trials
 Clinical trials progress through phases, each answering different questions:
•    Phase I: Tests safety and side effects in a small group (20–80 people).
•    Phase II: Evaluates effectiveness and safety in a larger group (100–300 people).
•    Phase III: Confirms effectiveness, monitors side effects, compares to standard treatments in large groups (1,000–3,000 people).
•    Phase IV: Conducted after FDA approval to monitor long-term safety and optimal use.

Placebo
A pill or liquid that looks like the treatment but contains no active ingredients.

Protocol
A carefully designed plan to protect participants and answer specific research questions.

Principal Investigator
A doctor who leads the clinical research team and monitors participants’ health throughout the study.

Randomization
The process of assigning participants to different treatment groups by chance to avoid bias.
Single- or Double-Blind Studies
•    Single-blind: Participants do not know which treatment they receive, but the research team does.
•    Double-blind: Neither participants nor the research team know who receives which treatment; only the pharmacist knows.

Types of Clinical Trials
•    Diagnostic trials: Test better ways to diagnose diseases.
•    Natural history studies: Observe how diseases or health progress over time.
•    Prevention trials: Seek ways to prevent diseases or their return.
•    Quality of life trials: Explore methods to improve comfort and well-being for those with chronic illness.
•    Screening trials: Test the best methods to detect diseases early.
•    Treatment trials: Test new treatments, drug combinations, or new surgical/radiation approaches.