Core clinical research terminology

A

• Adverse drug reaction: An unintended and harmful response to a medicinal product occurring at therapeutic doses. The term refers to medical occurrences for which a causal relationship with the medicinal product is at least reasonably suspected.
• Adverse event: Any unfavorable or unintended medical occurrence in a patient or clinical trial participant, regardless of its relationship to a medicinal product or study procedure. The term is distinguished from an adverse drug reaction (ADR) by the absence of an implied causal relationship.
• ALCOA: A set of principles defining the essential characteristics of reliable and trustworthy records in clinical research and the pharmaceutical industry. The acronym refers to records that are attributable, legible, contemporaneous, original, and accurate.
• Amendment: A general term referring to a change or modification made to a clinical trial document or regulatory record. Depending on the context, it may refer to a protocol amendment, an informed consent amendment, or revisions to other essential documents
• Applicable regulatory requirement(s): The laws, regulations, guidelines, and other legally enforceable requirements governing the planning, conduct, recording, and reporting of clinical research. The term includes requirements established by regulatory authorities and other applicable governing bodies within a particular jurisdiction or regulatory framework.
• Approval: A general term referring to formal authorization or permission granted by a regulatory, ethical, institutional, or other competent authority. Depending on the context, it may refer to regulatory approval, institutional review board (IRB) or independent ethics committee (IEC) approval or favourable opinion, or another form of authorization used in clinical research.
• Artificial intelligence: Computer systems designed to perform tasks that typically require human intelligence, such as learning, reasoning, language processing, and decision-making. The term includes a broad range of technologies that are increasingly applied in clinical research, healthcare, and pharmaceutical development.
• Audit: A systematic and independent examination of clinical trial activities, records, documents, and related processes to determine compliance with applicable requirements. The term refers to an independent assessment and is distinguished from routine monitoring performed as part of trial oversight.
• Audit trail: A chronological record of the creation, modification, or deletion of data and associated metadata that documents the history of a record throughout its lifecycle. The term refers to information identifying what was changed, when the change occurred, and by whom.

B

• Bias: A systematic error that causes study results or inferences to differ from the truth.
• Bioavailability: The rate and extent to which an active substance or active moiety is absorbed and becomes available at the site of action or in the systemic circulation. The term describes the exposure achieved following administration of a medicinal product.
• Bioequivalence: The absence of a significant difference in the rate and extent of absorption between two pharmaceutical products when administered under comparable conditions. The term is used to determine whether two products provide equivalent systemic exposure within predefined acceptance criteria.
• Blinding (masking): A study design technique in which knowledge of treatment assignment is withheld from trial participants, investigators, outcome assessors, or other designated individuals to minimize the influence of such knowledge on study conduct and assessment.

C

• Case report form: A structured document or electronic interface used to record protocol-required data for each clinical trial participant. The term refers to the standardized collection of clinical and study data in accordance with the study protocol and applicable regulatory requirements.
• Certified copy: A copy of an original record that has been verified as an accurate and complete reproduction of the original. The term distinguishes a certified copy from an ordinary duplicate through documented verification.
• Clinical research: Scientific research involving human participants that aims to generate knowledge about health, disease, medical interventions, or healthcare. The term includes interventional and observational studies conducted to answer clinically relevant research questions.
• Clinical study: A scientific investigation involving human participants that evaluates the safety, efficacy, or other effects of a medical intervention. Depending on the regulatory or scientific context, the term may be used interchangeably with clinical trial.
• Clinical study report (CSR): An integrated report describing the design, conduct, analysis, and results of a clinical study or trial. The term refers to the comprehensive document prepared to present the complete findings of a study for regulatory review and scientific documentation.
• Clinical trial: A clinical study in which one or more interventions are prospectively assigned to human participants to evaluate their effects on health-related biomedical or behavioral outcomes. The term generally refers to interventional studies and is distinguished from observational research.
• Clinical trial registry: A publicly accessible database that contains structured information about clinical trials. The term refers to registries maintained by regulatory authorities, governmental organizations, or other recognized entities.
• Comparator: A treatment, intervention, control, or reference against which the effects of an investigational intervention are evaluated in a clinical study. The term includes active comparators, placebo, standard of care, and other control interventions, depending on the study design.
• Compassionate use: The use of an investigational medicinal product outside a clinical trial to treat a patient with a serious or life-threatening condition when no satisfactory authorized treatment is available. The term refers to regulatory mechanisms that allow such access under specified conditions and may vary between jurisdictions.
• Compliance (regulatory): Adherence to trial-related requirements, good clinical practice (GCP), and applicable regulatory requirements. The term distinguishes regulatory compliance from participant compliance with the prescribed treatment regimen.
• Compliance (treatment): A participant's adherence to the prescribed treatment regimen or other study-related instructions. The term distinguishes treatment compliance from regulatory compliance with trial-related requirements.
• Confidentiality (business Information): The obligation to protect proprietary, commercial, or other confidential information exchanged between organizations involved in clinical research. The term refers to information protected by contractual, legal, or regulatory obligations rather than participant privacy.
• Confidentiality (participant data): The obligation to protect the identity and personal information of research participants from unauthorized access, use, or disclosure. The term refers to the safeguarding of identifiable participant information in accordance with ethical, legal, and regulatory requirements.
• Contract: A legally binding agreement that establishes the rights, obligations, and responsibilities of two or more parties. In clinical research, the term commonly refers to agreements between sponsors, research sites, service providers, including contract research organizations (CROs), and other stakeholders involved in clinical research.
• Contract research organization (CRO): A person or organization contracted by a sponsor to perform one or more trial-related duties and functions. The term includes service providers offering clinical, scientific, regulatory, data management, statistical, quality, or other services in support of clinical research.
• Corrective and preventive action (CAPA): A quality management process for identifying, investigating, and addressing actual or potential nonconformities. The term combines corrective actions, which address existing issues, and preventive actions, which aim to prevent their occurrence.

D

• Direct access: Permission to examine, analyze, verify, and reproduce records and reports that are important to the evaluation of a clinical trial. The term commonly refers to access granted to regulatory authorities, sponsors, monitors, auditors, and other authorized persons.
• Documentation: Records and documents created or maintained to support the planning, conduct, oversight, and evaluation of a clinical trial. The term includes both trial-specific records and documentation required to demonstrate compliance with applicable standards and regulatory requirements.

E

• Essential documents: The historical term for the documents maintained throughout a clinical trial to support its conduct and evaluation. The concept refers specifically to documentary evidence and has been superseded by the broader concept of essential records.
• Essential records: Documents, data, and associated metadata, in any format, that collectively document the planning, conduct, and management of a clinical trial. The term extends the traditional concept of essential documents beyond documentary records alone.
• Ethics committee: An independent body responsible for reviewing biomedical research involving human participants to protect their rights, safety, and well-being. The term is used generically and includes bodies such as independent ethics committees (IECs) and institutional review boards (IRBs).

F

• FDA Form 1572: An official U.S. Food and Drug Administration form completed by investigators conducting clinical investigations under an investigational new drug (IND) application. By signing the form, the investigator identifies the trial site, key personnel, and facilities and agrees to conduct the study in accordance with applicable regulatory requirements.
• Functional service provision (FSP): An outsourcing model in which a sponsor contracts a service provider to perform one or more defined functional activities, such as monitoring, data management, or biostatistics. Unlike full-service outsourcing, responsibility is assigned by function rather than by an entire clinical trial or development program.

G

• Good clinical practice (GCP): A system of ethical, scientific, and quality principles governing the conduct and oversight of clinical research involving human participants. The term refers to the underlying concept rather than any single guideline, and is reflected in multiple international and national GCP frameworks.

I

• Impartial witness: A person who is independent of the clinical trial and cannot be unfairly influenced by those involved in the trial. The term commonly refers to an individual who attends the informed consent process when a participant or the participant's legally acceptable representative is unable to read.
• Independent data monitoring committee (IDMC): An independent committee of experts that periodically reviews accumulating clinical trial data during the course of a study. The committee evaluates predefined safety and other relevant trial data and may recommend continuation, modification, or termination of the trial.
• Independent ethics committee (IEC): Independent ethics committee: An ethics committee that is independent of the investigator, sponsor, and undue influence, and is responsible for the ethical review of biomedical research involving human participants. The term is commonly used in international good clinical practice guidelines and is broadly equivalent to an institutional review board (IRB) in the United States.
• Informed consent (IC): A participant's voluntary agreement to take part in a clinical trial after receiving and understanding adequate information about the study. The term refers to an ongoing process of communication between the investigator and the participant rather than to the informed consent form (ICF) itself.
• Institution: A public or private entity, agency, medical or dental facility, or other organization in which clinical research is conducted. An institution may include one or more investigator sites participating in a clinical trial.
• Institutional review board: An independent committee responsible for the ethical review of biomedical research involving human participants. The term is used primarily in the United States and is broadly equivalent to an independent ethics committee under international good clinical practice guidelines.
• Interim clinical trial (study) report: A report describing the progress and interim results of a clinical trial based on data available at a specified time before trial completion. It is prepared before the final clinical trial report and does not represent the definitive analysis of the study.
• Investigational product: A pharmaceutical form of an active substance or placebo being tested or used as a reference in a clinical trial. The term also includes authorized medicinal products when used or assembled, formulated, packaged, or administered in a manner different from the approved conditions of use.
• Investigator: A person responsible for the conduct of a clinical trial at an investigator site. Related roles include the principal investigator, sub-investigator (co-investigator) and coordinating investigator.
• Investigator (coordinating): An investigator responsible for coordinating the work of investigators participating in a multicentre clinical trial. The coordinating investigator has responsibilities spanning multiple participating investigator sites.
• Investigator (principal): An investigator responsible for the conduct of a clinical trial at an individual investigator site. In multicentre clinical trials, each participating investigator site is led by its own principal investigator.
• Investigator (sub-investigator): A member of the investigator site team designated by the investigator to perform delegated trial-related activities under the investigator's supervision. The role is commonly referred to as co-investigator in some organizations.
• Investigator’s Brochure (IB): A compilation of the clinical and nonclinical data on an investigational product that are relevant to its study in human participants. The brochure provides investigators with the information needed to understand the rationale, administration, safety, and monitoring of the investigational product.
• IRB approval: Institutional Review Board (IRB) Approval is the formal consent and endorsement obtained from an IRB, also known as an ethics committee or research ethics board. This approval signifies that the research protocol, methods, and informed consent procedures meet ethical and regulatory standards. It ensures the protection of participants’ rights, safety, and well-being, allowing the study […]

L

• Legally acceptable representative (LAR): An individual, juridical, or other body authorized under applicable law to consent on behalf of a prospective participant to participation in a clinical trial. The authority of a legally acceptable representative is determined by applicable law.

M

• Monitoring: The process of overseeing a clinical trial to verify that it is conducted, documented, and reported in accordance with the protocol, applicable requirements, and accepted quality standards. The term includes both on-site and centralized monitoring activities.
• Multicentre trial: A clinical trial conducted at two or more investigator sites under a common protocol. The participating sites follow the same study design and procedures while enrolling participants independently.

N

• Nonclinical study: A study conducted without human participants to evaluate the pharmacological, toxicological, or other biological properties of a medical intervention. The term distinguishes investigations performed outside human subjects from clinical studies.

O

• Opinion (ethics committee): The formal conclusion of an ethics committee regarding a clinical trial or related submission following ethical review. Depending on the applicable regulatory framework, the opinion may be favorable, unfavorable, or subject to specified conditions.

P

• Placebo: An inactive substance or intervention designed to resemble the investigational product without containing its active therapeutic component. In clinical trials, a placebo may be used as a comparator to assess the effects of the investigational intervention.
• Plain language summary of study results: A summary of the results of a clinical study written in language intended to be understandable to a general audience. It presents the study findings without relying on technical or scientific terminology.
• Protocol: A document that describes the objectives, design, methodology, statistical considerations, and organization of a clinical trial. It defines how the trial is intended to be conducted and evaluated.
• Protocol amendment: A documented description of one or more changes to a clinical trial protocol. The term refers to revisions made after the protocol has been issued and distinguishes them from the original protocol.
• Protocol deviation: A departure from the procedures or requirements specified in an approved clinical trial protocol. The term refers to any instance in which trial conduct differs from the protocol, regardless of its cause or significance.
• Protocol violation: A term used by some organizations to describe a significant protocol deviation or instance of noncompliance. The term is not consistently defined across regulatory frameworks, and many organizations classify protocol deviations by significance instead of distinguishing deviations from violations.

Q

• Quality: The degree to which the characteristics of a process, activity, data, or output satisfy predefined requirements. In clinical research, the term refers to the overall standard achieved rather than the activities of quality assurance (QA) or quality control (QC).
• Quality assurance: Planned and systematic activities that provide confidence that a clinical trial is conducted and documented in accordance with applicable quality requirements. It is distinct from quality control (QC), which focuses on operational checks and verification.
• Quality control: Operational techniques and activities undertaken to verify that the requirements for quality have been fulfilled. Quality control is a component of quality assurance (QA) and focuses on the quality of specific trial processes and outputs.

R

• Randomization: The process of assigning participants to treatment groups using a random method to reduce systematic differences between comparison groups. The term refers to the allocation procedure rather than the treatment groups themselves.
• Regulatory authority: A governmental body with legal responsibility for regulating clinical research and medicinal products within its jurisdiction. The term refers to the competent authority (CA) established under the applicable regulatory framework.
• Regulatory inspection: An official examination by a regulatory authority (RA) of a sponsor, investigator site, service provider, or other trial-related party to assess compliance with applicable regulatory requirements. Unlike an audit, a regulatory inspection is conducted by a governmental authority.

S

• Safety: The absence or acceptable control of risks to the rights, well-being, or health of clinical trial participants associated with trial participation. The term refers to the protection of participants rather than the evaluation of trial efficacy.
• Serious adverse event (SAE): An adverse event (AE) that meets one or more predefined criteria for regulatory seriousness. Seriousness is a regulatory classification, whereas severity describes the intensity of the event.
• Serious adverse reaction: An adverse reaction that meets one or more predefined criteria for regulatory seriousness. The term refers to a serious event for which a causal relationship with a medicinal product is at least reasonably suspected.
• Service provider: A person or organization that provides services to a sponsor or investigator to support trial-related activities. The term includes commercial, academic, and other organizations performing delegated functions in clinical research.
• Source data: Information contained in source records that serves as the original record of clinical observations and other trial-related findings. The term refers to the data itself rather than the records in which the data are documented.
• Source documents: The historical term for the original documents or other media in which source data are recorded. Current terminology generally uses the broader concept of source records, although source documents remains widely used within organizations.
• Sponsor: An individual, company, institution, or organization that assumes responsibility for the initiation, management, and financing of a clinical trial. The term refers to the party responsible for the trial and is distinct from service providers performing delegated activities.
• Sponsor-investigator: An individual who simultaneously acts as both the sponsor and the investigator of a clinical trial. The role combines the regulatory responsibilities assigned to each function.
• Standard operating procedures (SOPs): A written documents that provides standardized instructions for performing a specific process or activity. Organizations typically maintain a set of standard operating procedures (SOPs) governing different aspects of their operations.
• Sub-investigator: See Investigator (sub-investigator).
• Subject: An individual who participates in a clinical trial, either by receiving the investigational intervention or serving as a control. The term includes both patients and healthy volunteers, although trial participant is increasingly preferred in many contexts.
• Subject identification code: A unique identifier assigned to a trial participant for use within a clinical trial. It replaces direct personal identifiers in trial records to protect participant confidentiality.

T

• Trial site: A location at which clinical trial activities are conducted under the responsibility of an investigator. A single institution may include one or more trial sites participating in the same or different clinical trials.

U

• Unexpected adverse drug reaction: An adverse drug reaction (ADR) whose nature, severity, or outcome is not consistent with the available reference safety information for the medicinal product. Unexpected refers to inconsistency with the known safety profile rather than the frequency or seriousness of the reaction.

V

• Vulnerable participants: Individuals who may be at increased risk of coercion or undue influence in making decisions about participation in a clinical trial or protecting their own interests. The historical term vulnerable subjects remains widely used.

W

• Well-being: The physical and mental integrity of a clinical trial participant. The term refers to the participant's overall welfare in the context of clinical research.