Clinical Research Glossary
100+ clinical research terms with ICH E6(R3) references, definitions, and examples.
Accelerated Approval
RegulatoryAn FDA pathway allowing approval of drugs for serious conditions based on a surrogate endpoint or intermediate clinical endpoint reasonably likely to predict clinical benefit, with post-marketing requirements to confirm the expected benefit.
ADaM (Analysis Data Model)
Data ManagementA CDISC standard that defines the structure and content of analysis-ready datasets derived from SDTM data, supporting efficient generation of statistical analyses and displays for regulatory submissions.
Adverse Drug Reaction (ADR)
SafetyA response to a medicinal product that is noxious and unintended, where a causal relationship between the product and the adverse event is at least a reasonable possibility.
Adverse Event
SafetyAny untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product.
Audit
QualityA systematic and independent examination of trial-related activities and documents to determine whether evaluated activities were conducted in accordance with the protocol, GCP, and applicable regulatory requirements.
Audit Trail
Data ManagementA secure, computer-generated, time-stamped electronic record that automatically captures the creation, modification, or deletion of data, including the identity of the operator and the date and time of the action.
Bioavailability
Study DesignThe fraction of an administered dose of a drug that reaches the systemic circulation unchanged, and the rate at which this occurs.
BLA (Biologics License Application)
RegulatoryA regulatory submission to the FDA requesting approval to market a biological product in the United States, demonstrating that the product meets standards for safety, purity, and potency.
Black Box Warning
SafetyThe strictest warning required by the FDA to appear on prescription drug labeling, alerting prescribers and patients to serious risks that may lead to death or severe injury.
Blinding/Masking
Study ConductA procedure in which one or more parties involved in the trial are kept unaware of the treatment assignment to reduce bias in the assessment of outcomes.
Breakthrough Therapy Designation
RegulatoryAn FDA program for drugs intended to treat serious conditions where preliminary clinical evidence indicates substantial improvement over available therapies on clinically significant endpoints.
CAPA (Corrective and Preventive Action)
Clinical OperationsA systematic approach to identifying, investigating, and addressing the root causes of quality problems or non-conformances, implementing corrections to resolve existing issues, and establishing preventive measures to reduce the likelihood of recurrence.
Case Report Form
DocumentationA printed, optical, or electronic document designed to record all protocol-required information on each trial subject.
Causality Assessment
SafetyThe systematic evaluation of the likelihood that an adverse event was caused by the investigational product or another factor, using established criteria to determine the relationship between exposure and outcome.
CDISC (Clinical Data Interchange Standards Consortium)
Data ManagementAn international nonprofit organization that develops and supports global data standards for clinical research, enabling consistent and efficient exchange of clinical trial information.
Chain of Custody
Clinical OperationsThe documented chronological history of the handling, transfer, and storage of investigational products, biological samples, or other controlled materials, establishing accountability at each step from origin to final disposition.
CIOMS Form
SafetyA standardized one-page format developed by the Council for International Organizations of Medical Sciences for reporting suspected adverse drug reactions from clinical trials to regulatory authorities.
Clinical Research Associate (CRA)
Study ConductA professional employed by the sponsor or contract research organization who monitors clinical trials at investigational sites to ensure protocol compliance, data quality, and participant safety.
Clinical Research Coordinator (CRC)
Study ConductA specialized research professional who works at the investigational site under the supervision of the investigator to coordinate and manage the day-to-day operational aspects of clinical trials.
Confidence Interval
BiostatisticsA range of values calculated from study data that is expected to contain the true treatment effect with a specified probability, typically 95%, providing information about both the estimated effect size and the precision of that estimate.
Contraindication
SafetyA specific situation or condition in which a drug, procedure, or treatment should not be used because it may be harmful to the patient.
Control Group
Study DesignA group of participants in a clinical trial who receive a comparator treatment, placebo, or no treatment to serve as a baseline for evaluating the effects of the investigational intervention.
Crossover Study
Study DesignA clinical trial design in which participants receive multiple treatments in sequence, with each participant serving as their own control by receiving all study treatments during different periods.
Data Cleaning
Data ManagementThe process of detecting, correcting, and resolving inaccurate, incomplete, or inconsistent data in the clinical trial database to ensure data quality and reliability for analysis.
Data Integrity
Data ManagementThe degree to which data are complete, consistent, accurate, trustworthy, and reliable throughout the data lifecycle.
Database Lock
Data ManagementThe formal process of making the clinical trial database unmodifiable once all data have been entered, reviewed, cleaned, and verified, marking the transition from data collection to statistical analysis.
Dechallenge
SafetyThe discontinuation or dose reduction of a suspected drug following an adverse event to observe whether the event resolves or improves, providing evidence about the causal relationship.
Dose Escalation
Study DesignA systematic approach to increasing the dose of an investigational product during a clinical trial, typically employed in early-phase studies to identify safe and potentially effective dose levels.
Double-Blind Study
Study DesignA clinical trial in which both the participants and the investigators are unaware of the treatment assignments, providing maximal protection against bias in the conduct and assessment of the study.
Drug Accountability
Clinical OperationsThe system of documentation and procedures that accounts for all investigational product received at a site, dispensed to participants, returned by participants, and remaining in inventory, ensuring complete traceability throughout the trial.
Drug-Drug Interaction
SafetyA pharmacological phenomenon that occurs when the effect of one drug is altered by the presence of another drug, potentially leading to enhanced or diminished therapeutic effects or increased toxicity.
eCRF (Electronic Case Report Form)
Data ManagementA digital version of the case report form designed within an electronic data capture system for recording protocol-required data for each trial participant.
EDC (Electronic Data Capture)
Data ManagementA computerized system designed for the collection, management, and processing of clinical trial data in electronic format, replacing traditional paper-based data collection methods.
Enrollment
Clinical OperationsThe process of officially registering a qualified participant into a clinical trial after confirming eligibility and obtaining informed consent, marking the point at which the individual becomes a study subject.
Essential Documents
DocumentationDocuments that individually and collectively permit evaluation of the conduct of a study and the quality of the data produced.
Expected vs Unexpected Adverse Event
SafetyA classification distinguishing adverse events whose nature, specificity, severity, or frequency is consistent with the reference safety information from those that are not previously documented or that differ in important characteristics.
Expedited Reporting
SafetyThe regulatory requirement to report certain serious safety findings to health authorities and ethics committees within specified short timeframes, typically within seven to fifteen calendar days of becoming aware of the event.
Fast Track Designation
RegulatoryAn FDA program designed to expedite the development and review of drugs intended to treat serious conditions and fill an unmet medical need, providing increased communication with FDA and eligibility for Rolling Review.
Feasibility Study/Assessment
Clinical OperationsA systematic evaluation conducted before trial initiation to determine whether a clinical trial can be successfully conducted at a particular site or in a specific region, considering factors such as patient population, site capabilities, and regulatory environment.
IDE (Investigational Device Exemption)
RegulatoryAn FDA approval that allows an investigational medical device to be used in a clinical study to collect safety and effectiveness data required to support a premarket approval application or 510(k) submission.
IND (Investigational New Drug)
RegulatoryAn application submitted to the FDA requesting permission to administer an investigational drug or biological product to humans in clinical trials in the United States.
Independent Ethics Committee (IEC)
EthicsAn independent body constituted of medical/scientific professionals and non-medical/non-scientific members whose responsibility is to ensure the protection of the rights, safety, and well-being of human subjects involved in a trial.
Informed Consent
EthicsA process by which a subject voluntarily confirms willingness to participate in a clinical trial after being informed of all aspects relevant to the decision.
Inspection
RegulatoryAn official review of documents, facilities, records, and other resources by regulatory authorities to assess compliance with applicable regulations, standards, and guidelines.
Institutional Review Board (IRB)
EthicsAn independent body constituted of medical, scientific, and non-scientific members whose responsibility is to ensure protection of the rights, safety, and well-being of human subjects involved in research.
Intent-to-Treat (ITT) Analysis
BiostatisticsA statistical analysis strategy that includes all randomized participants in the groups to which they were originally assigned, regardless of whether they completed the study treatment or adhered to the protocol.
Interim Analysis
BiostatisticsA planned statistical analysis conducted before all participants have completed the study, typically to evaluate accumulating data for evidence of efficacy, futility, or safety concerns that might warrant early termination of the trial.
Investigator
PersonnelA person responsible for the conduct of the clinical trial at a trial site.
Investigator's Brochure (IB)
DocumentationA compilation of the clinical and nonclinical data on the investigational product that are relevant to the study of the product in human subjects.
IWRS/IRT (Interactive Web/Voice Response System)
Clinical OperationsA computerized system used in clinical trials to manage randomization, treatment allocation, drug supply, and participant status through interactive web-based or telephone interfaces.
Maximum Tolerated Dose (MTD)
Study DesignThe highest dose of an investigational product that can be administered without causing unacceptable toxicity, typically determined through dose escalation studies.
MedDRA (Medical Dictionary for Regulatory Activities)
SafetyAn internationally standardized medical terminology developed by ICH to facilitate the electronic exchange of regulatory information for medical products throughout their lifecycle.
Medical Coding
Data ManagementThe process of assigning standardized terminology codes to verbatim medical terms reported in clinical trials, using dictionaries such as MedDRA for adverse events and WHO Drug for medications.
Monitor
PersonnelA person employed by the sponsor who is responsible for overseeing the progress of a clinical trial and ensuring it is conducted properly.
Monitoring
Study ConductThe act of overseeing the progress of a clinical trial and ensuring that it is conducted, recorded, and reported in accordance with the protocol, standard operating procedures, GCP, and applicable regulatory requirements.
Open-Label Study
Study DesignA clinical trial in which both the participants and the investigators know which treatment is being administered, without any blinding or masking procedures.
Orphan Drug Designation
RegulatoryA special status granted by the FDA to drugs and biologics intended to treat rare diseases affecting fewer than 200,000 people in the United States, providing incentives for development.
P-Value
BiostatisticsThe probability of obtaining results at least as extreme as those observed in the study, assuming that the null hypothesis of no treatment effect is true.
Parallel Study
Study DesignA clinical trial design in which participants are randomized to receive one treatment throughout the study, with different groups receiving different treatments simultaneously.
Patient Recruitment
Clinical OperationsThe activities and strategies employed to identify, attract, and screen potential participants for enrollment in a clinical trial, encompassing advertising, physician referrals, database searches, and community outreach.
Per-Protocol Analysis
BiostatisticsA statistical analysis that includes only participants who completed the study according to protocol requirements, without major protocol violations, adequate treatment exposure, and complete outcome assessments.
Periodic Safety Update Report (PSUR)
SafetyA comprehensive, periodic assessment of the benefit-risk balance of a medicinal product, submitted to regulatory authorities at defined intervals throughout its lifecycle.
Pharmacodynamics (PD)
Study DesignThe study of how a drug affects the body, including its mechanism of action, biochemical and physiological effects, and the relationship between drug concentration and effect.
Pharmacokinetics (PK)
Study DesignThe study of how the body affects a drug, encompassing the absorption, distribution, metabolism, and excretion of the substance over time.
Pharmacovigilance
SafetyThe science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.
Placebo
Study DesignAn inactive substance or treatment that is designed to appear identical to the investigational product but contains no therapeutic ingredients.
Primary Endpoint vs Secondary Endpoint
BiostatisticsThe primary endpoint is the main outcome measure used to evaluate whether the treatment hypothesis is supported and forms the basis for regulatory approval decisions, while secondary endpoints provide supportive evidence and characterize additional treatment effects.
Priority Review
RegulatoryAn FDA program that shortens the target time for reviewing a marketing application from the standard ten months to six months for drugs that offer significant improvements in safety or effectiveness for serious conditions.
Protocol
DocumentationA document that describes the objectives, design, methodology, statistical considerations, and organization of a clinical trial.
Protocol Amendment
DocumentationA written description of a change or formal clarification to a protocol that must be approved by the sponsor, IRB/IEC, and regulatory authorities before implementation.
Protocol Deviation
Study ConductAny change, divergence, or departure from the study design or procedures defined in the protocol that is not implemented through a formal protocol amendment.
Protocol Violation vs Deviation
Clinical OperationsProtocol deviations are departures from the approved protocol that may or may not impact participant safety or data integrity, while protocol violations are a subset of deviations that significantly impact participant safety, data quality, or scientific validity of the trial.
Quality Assurance (QA)
QualityAll planned and systematic actions established to ensure that the trial is performed and data are generated, documented, and reported in compliance with GCP and applicable regulatory requirements.
Quality Control (QC)
QualityThe operational techniques and activities undertaken within the quality assurance system to verify that the requirements for quality of trial-related activities have been fulfilled.
Quality Management System
QualityA formalized system that documents processes, procedures, and responsibilities for achieving quality policies and objectives.
Query Management
Data ManagementThe systematic process of identifying, tracking, and resolving data discrepancies, inconsistencies, or missing information in clinical trial databases to ensure data quality and completeness.
Randomization
Study ConductThe process of assigning trial subjects to treatment or control groups using an element of chance to reduce bias in allocating interventions.
Rechallenge
SafetyThe intentional re-administration of a suspected drug to a patient who previously experienced an adverse event while taking that drug, performed to help establish whether the drug caused the original event.
Regulatory Authority
RegulatoryA body with the power to regulate clinical trials and approve medicinal products for marketing within its jurisdiction.
Risk-Based Monitoring (RBM)
QualityA monitoring approach that focuses oversight activities on the most critical data and processes, allocating resources based on risk assessment rather than applying uniform monitoring intensity across all aspects of a trial.
Safety Signal
SafetyInformation from one or multiple sources that suggests a new potentially causal association, or a new aspect of a known association, between an intervention and an adverse event or set of related adverse events.
Sample Size Calculation
BiostatisticsThe statistical determination of the number of participants required for a clinical trial to have adequate statistical power to detect a clinically meaningful treatment effect, accounting for expected variability, desired significance level, and anticipated dropout rates.
Screen Failure
Clinical OperationsA potential participant who undergoes screening procedures but is determined to be ineligible for enrollment in the clinical trial based on the protocol-defined inclusion and exclusion criteria.
SDTM (Study Data Tabulation Model)
Data ManagementA CDISC standard that defines the structure, content, and organization of clinical trial data submitted to regulatory authorities, establishing domains for different types of observations and standardized variable names and formats.
Serious Adverse Event
SafetyAny adverse event that results in death, is life-threatening, requires hospitalization, results in disability, or is a congenital anomaly.
Single-Blind Study
Study DesignA clinical trial in which participants are unaware of their treatment assignment, but the investigators and study personnel know which treatment each participant is receiving.
Site Selection
Clinical OperationsThe process of identifying, evaluating, and choosing investigational sites to participate in a clinical trial based on their capability to conduct the study according to the protocol, GCP requirements, and regulatory standards.
Source Document
DocumentationOriginal documents, data, and records from which a subject's clinical trial data are obtained, including hospital records, clinical and office charts, laboratory notes, memoranda, pharmacy records, and patient diaries.
Source Document Verification (SDV)
QualityA process of comparing data collected in the case report form against source documents to confirm that the data were transcribed accurately and completely.
Source Documents
DocumentationOriginal documents, data, and records where clinical trial data are first recorded.
Sponsor
PersonnelAn individual, company, institution, or organization that takes responsibility for the initiation, management, and/or financing of a clinical trial.
Statistical Power
BiostatisticsThe probability that a statistical test will correctly reject a false null hypothesis, representing the likelihood of detecting a true treatment effect when one actually exists.
Study Close-Out
Clinical OperationsThe series of activities conducted at the conclusion of a clinical trial or site participation to ensure all regulatory requirements are met, documentation is complete, investigational products are reconciled and returned, and the trial file is inspection-ready.
Subject/Participant
Study ConductAn individual who participates in a clinical trial, either as a recipient of the investigational product or as a control.
SUSAR (Suspected Unexpected Serious Adverse Reaction)
SafetyA serious adverse reaction to an investigational medicinal product that is both suspected to be related to the product and is unexpected based on the reference safety information.