English for Clinical Research

"randomised controlled trial (RCT)"

A study in which participants are randomly assigned to intervention or control groups to reduce bias.

""The efficacy of the new drug was established through a large randomised controlled trial.""

"double-blind"

A trial design in which neither participants nor investigators know who receives the active treatment.

""The double-blind design prevented observer bias from influencing the outcome assessments.""

"placebo-controlled"

A trial that compares an active treatment against an inactive placebo to isolate the treatment effect.

""Participants in the placebo-controlled arm received identical capsules containing no active compound.""

"crossover design"

A study in which each participant receives each treatment sequentially, acting as their own control.

""The crossover design reduced variability by allowing each patient to serve as their own control.""

"adaptive trial"

A trial that uses pre-specified rules to modify its design or conduct based on accumulating data.

""The adaptive trial allowed investigators to drop the lower dose arm after the interim analysis.""

"open-label extension"

A phase of a trial in which all participants receive the active treatment and know what they are receiving.

""Patients who completed the blinded phase were invited to join the open-label extension for 12 months.""

"stratified randomisation"

A method that ensures important prognostic variables are evenly distributed across treatment groups.

""Stratified randomisation by age and disease severity balanced the two arms at baseline.""

"allocation concealment"

A method of hiding the assignment sequence so that investigators cannot predict the next assignment.

""Allocation concealment was achieved using a centralised telephone randomisation service.""

"first-in-human (FIH)"

The initial administration of an investigational compound to human subjects, typically a Phase I trial.

""The first-in-human trial assessed safety at escalating doses in six healthy volunteers per cohort.""

"dose-escalation"

A sequential increase of the dose given to cohorts of participants to determine tolerability.

""Dose-escalation continued until the maximum tolerated dose was reached at 400 mg.""

"maximum tolerated dose (MTD)"

The highest dose that does not cause unacceptable toxicity in a defined proportion of participants.

""The maximum tolerated dose was declared at 300 mg after two dose-limiting toxicities appeared at 400 mg.""

"proof of concept (PoC)"

An early trial that demonstrates whether the mechanism of action works as hypothesised in patients.

""The Phase IIa proof-of-concept study confirmed target engagement in the intended patient population.""

"pivotal trial"

A late-phase trial whose results are used to support regulatory approval of a new treatment.

""The pivotal trial enrolled 1,200 patients across 80 sites in 15 countries.""

"end-of-Phase-II meeting"

A formal meeting with regulators to agree on Phase III trial design before large investment is made.

""At the end-of-Phase-II meeting, the FDA agreed that a single pivotal trial would be sufficient.""

"interim analysis"

A pre-planned statistical examination of accumulating data before the trial formally concludes.

""The independent data monitoring committee performed an interim analysis at 50% enrolment.""

"futility stopping"

Early termination of a trial when accruing data suggest the primary endpoint will not be achieved.

""The trial was stopped for futility after the interim analysis showed a conditional power below 10%.""

"primary endpoint"

The main outcome measure used to determine whether the trial hypothesis is supported.

""The primary endpoint was overall survival at 24 months in the intention-to-treat population.""

"secondary endpoint"

Additional outcomes assessed to provide supplementary evidence about efficacy or safety.

""Progression-free survival was a key secondary endpoint specified in the statistical analysis plan.""

"surrogate endpoint"

A laboratory or clinical marker intended to predict clinical benefit without directly measuring it.

""HbA1c was used as a surrogate endpoint to reflect long-term glycaemic control.""

"composite endpoint"

A combined measure that includes two or more individual outcomes counted as a single event.

""The composite endpoint of myocardial infarction, stroke, or cardiovascular death was reached by 8% of patients.""

"patient-reported outcome (PRO)"

Any report of a patient's health status that comes directly from the patient without clinician interpretation.

""The patient-reported outcome instrument was completed electronically at each clinic visit.""

"clinically meaningful difference"

The smallest change in an outcome that patients or clinicians perceive as important or beneficial.

""A three-point reduction on the pain scale was considered the clinically meaningful difference for sample size calculations.""

"time-to-event analysis"

A statistical method examining the time until a specific event such as death or relapse occurs.

""A Kaplan-Meier time-to-event analysis illustrated the survival advantage in the treatment arm.""

"biomarker-stratified analysis"

An analysis that examines outcomes separately in subgroups defined by a biological characteristic.

""The biomarker-stratified analysis showed a stronger treatment effect in patients with high PD-L1 expression.""

"adverse event (AE)"

Any untoward medical occurrence in a participant that does not necessarily have a causal relationship with the treatment.

""All adverse events regardless of causality were recorded in the electronic case report form.""

"serious adverse event (SAE)"

An adverse event that results in death, hospitalisation, disability, or another clinically important outcome.

""The investigator reported the SAE within 24 hours via the expedited safety reporting pathway.""

"dose-limiting toxicity (DLT)"

A side effect that is severe enough to prevent increasing the dose to the next level in an escalation study.

""Grade 3 neutropenia occurring in two of six patients constituted a dose-limiting toxicity.""

"causality assessment"

An evaluation of the likelihood that a treatment caused an adverse event, typically rated on a scale.

""The investigator rated the causality as probable based on the temporal relationship and absence of other explanations.""

"suspected unexpected serious adverse reaction (SUSAR)"

A serious adverse reaction that is both unexpected and suspected to be related to the investigational product.

""The sponsor submitted the SUSAR report to all competent authorities within seven days of becoming aware.""

"signal detection"

The process of identifying new or changing safety information from accumulated data that may require action.

""Signal detection algorithms are applied to spontaneous reports to flag disproportionate reporting patterns.""

"risk management plan (RMP)"

A document outlining the known and potential risks of a medicine and how they will be prevented or minimised.

""The risk management plan required educational material for prescribers before the product was authorised.""

"benefit-risk assessment"

A systematic evaluation weighing the positive therapeutic effects of a medicine against its potential harms.

""The regulatory committee conducted a formal benefit-risk assessment before granting conditional approval.""

"Good Clinical Practice (GCP)"

An international ethical and scientific quality standard for designing, conducting, and reporting clinical trials.

""All investigators completed GCP training certification before the first patient was screened.""

"informed consent"

A process by which a participant voluntarily confirms willingness to participate after being fully informed of the trial.

""Informed consent was obtained in the participant's native language using an approved consent form.""

"investigational new drug (IND)"

An application allowing a sponsor to transport and test an unapproved drug in clinical trials within the US.

""The sponsor filed an IND with the FDA before initiating Phase I studies at American clinical sites.""

"clinical study report (CSR)"

A comprehensive document integrating the pre-clinical and clinical data from a completed clinical trial.

""The clinical study report was submitted to the regulatory agency within 12 months of database lock.""

"protocol deviation"

Any departure from the approved trial protocol, whether planned or accidental, that affects the conduct of the study.

""The protocol deviation was classified as major because the patient received the wrong dose on two occasions.""

"source data verification (SDV)"

The process of confirming that data in the case report form accurately reflect the original source documents.

""The clinical research associate performed 100% source data verification for the first five enrolled patients.""

"data monitoring committee (DMC)"

An independent group that periodically reviews safety and efficacy data to protect participant welfare.

""The data monitoring committee met quarterly to review unblinded safety data during the trial.""

"new drug application (NDA)"

A regulatory submission requesting approval to market a new drug in the United States.

""After two successful pivotal trials, the sponsor submitted the NDA with full clinical data package.""

"intention-to-treat (ITT)"

An analysis that includes all randomised participants regardless of whether they completed or complied with treatment.

""The intention-to-treat analysis preserved the advantages of randomisation by including all 1,200 enrolled patients.""

"per-protocol analysis"

An analysis restricted to participants who fully adhered to the protocol without major deviations.

""The per-protocol analysis confirmed the results of the primary ITT analysis, supporting the robustness of findings.""

"statistical analysis plan (SAP)"

A pre-specified document describing the statistical methods that will be applied to the trial data.

""The statistical analysis plan was finalised and version-controlled before the database was locked.""

"multiplicity adjustment"

A statistical correction applied when testing multiple hypotheses to control the risk of false-positive findings.

""A Bonferroni multiplicity adjustment was applied to the three co-primary endpoints.""

"power calculation"

A calculation determining the sample size needed to detect a clinically meaningful effect with sufficient probability.

""The power calculation assumed 80% power to detect a 20% reduction in the primary endpoint with alpha 0.05.""

"imputation"

A statistical method used to handle missing data by replacing missing values with plausible estimates.

""Multiple imputation was used to handle missing data under the assumption of missing at random.""

"database lock"

The point at which data are frozen and no further changes are permitted before unblinding and analysis.

""Database lock occurred six weeks after the last patient completed their final study visit.""

"hazard ratio (HR)"

A measure of the relative rate of an event occurring in one group compared with another over time.

""A hazard ratio of 0.72 indicated a 28% reduction in the risk of disease progression in the treatment arm.""