Clinical Research Key Terms

Blinded Study  

• A type of research where the participants do not know which treatment they receive. There are two types of blinded studies, single and double.  
• In a single-blind study, only the participants are unaware of the treatment they receive, while the researchers know.
• In a double-blind study, neither the participants nor the researchers know who is getting the real treatment and who is getting a placebo. This helps ensure that the results are more reliable. See: randomization.  

Clinical Study  

• A clinical study (also known as a clinical trial) is the scientific investigation of new treatments, medications, or procedures in people to determine their safety and effectiveness.

Eligibility Criteria  

• The specific rules or requirements that must be met for someone to participate in a clinical study, such as age and medical history.  Before you enroll in a study, the research team will review your medical records and may run tests to ensure you meet the study’s eligibility criteria.

Informed Consent  

• A process where you are given detailed information about the study, including its purpose, procedures, risks, and benefits, and you agree to participate by signing a document known as an informed consent form (ICF).

Informed Consent Form (ICF)  

• A written document that provides detailed information about the study and confirms that you understand and agree to participate. It is part of the informed consent process.

Open-Label Treatment Period  

• A period of time in a clinical study where both the participants and researchers know what treatment the participants receive. Typically, no placebo is given to participants during this period, so everyone has access to the study treatment.
• An open-label treatment period usually follows a single- or double-blind treatment period.

Phases  

• Clinical studies have four phases, during which researchers must follow strict rules to keep participants safe. For more information about how drugs are developed and tested, read The Four Phases of Clinical Studies.

Placebo  

• An inactive treatment, such as a sugar pill, which is given to patients to help researchers compare the real study treatment’s effectiveness.  

Principal Investigator  

• The lead physician at the research site who is responsible for monitoring participants’ health while ensuring safe and effective clinical study practices.

Protocol  

• A detailed plan that outlines how a clinical study will be conducted, including what procedures will be followed, which treatments will be tested, and how data will be collected.

Randomization  

• The process of assigning participants to different treatment groups by chance, similar to flipping a coin. This helps ensure that the results are not biased and that the treatment effects can be accurately measured. This process is used for a double-blind treatment period.  

Research Site  

• A facility where patient enrollment and study procedures take place under the supervision of qualified medical professionals (Principal Investigator and Study Coordinator). Research sites may include a hospital, university, or clinic.

Screening Period  

• The screening period is when the study team evaluates whether people are eligible to take part in the clinical trial. Various medical tests may occur, and the person will be asked about their personal and family medical history. If a patient passes the screening criteria, they can enroll in the clinical study. 

Screening Visit

• If a research site believes a patient is a good candidate for a clinical study, they will schedule a screening visit. During the screening visit the patient will sign the ICF and enter the screening period.

Side Effect  

• An unwanted effect or reaction to a treatment or medication that is usually known and documented. Research sites prioritize patient safety by providing care for study participants experiencing side effects. Side effects are a key part of evaluating the safety of a new treatment.

Sponsor  

• The organization or individual that initiates, funds, and oversees the clinical study. Sponsors ensure that the study is conducted properly and that all regulatory requirements are met.

Study Coordinator  

• A research professional working with and under the direction of the Principal Investigator (PI). The study coordinator supports, facilitates, and coordinates daily clinical trial activities.

Study Drug  

• The experimental treatment which is tested in the clinical study. Also known as study medication, investigational treatment, or investigational product.