Life Sciences Terms That Are Easily Misread

double-blind

In clinical use

Neither the participants nor the researchers know which treatment each participant is receiving until the trial is over.

Appears in:

Protocol title, ICF

Source:

NCI

blinding / masking; unblinding

In clinical use

Blinding or masking: a procedure that keeps one or more parties to the trial unaware of the treatment assignment. Unblinding: revealing the assignment.

Eye studies often say "masked" in place of "blinded".

Appears in:

Protocol, ICF

Source:

ICH E6(R3); CDISC

open-label

In clinical use

A study in which both the investigators and the participants know which treatment is being given.

Appears in:

Protocol title, ICF

Source:

NCI; CDISC

double-dummy

In clinical use

A technique for keeping a trial blind when two treatments cannot be made to look identical. Each participant takes one active treatment and a placebo that matches the other.

Appears in:

Protocol, ICF

Source:

ICH E9

placebo

In clinical use

An inactive substance or intervention that looks the same as, and is given the same way as, the treatment being tested.

Appears in:

ICF, protocol title

Source:

NCI

sham (procedure)

In clinical use

An inactive procedure designed to mimic, as closely as possible, the active procedure being studied.

Appears in:

Protocol, ICF, device studies

Source:

NCI (sham-controlled)

randomised (randomized)

In clinical use

Assigned to a treatment group by chance, so that neither the researcher nor the participant chooses the group.

Appears in:

Protocol title, ICF

Source:

NCI; ICH E6(R3)

arm

In clinical use

A planned pathway through the study to which participants are assigned, describing the treatments, controls or observations they receive.

Appears in:

Protocol title, ICF

Source:

CDISC (study arm)

parallel-group

In clinical use

A design in which participants are randomised to one of two or more arms, and each arm receives a different treatment.

Appears in:

Protocol title

Source:

ICH E9

crossover

In clinical use

A design in which all participants receive the same two or more treatments, in an order that depends on the group they are randomly assigned to.

Appears in:

Protocol, ICF

Source:

NCI

control; control group

In clinical use

The comparison against which the study treatment is judged. The control group receives a placebo, another treatment or no treatment.

Appears in:

Protocol title, ICF

Source:

CDISC; NCI

comparator; active comparator

In clinical use

The product used as a reference in a trial: an investigational or authorised medicine (an active control), a placebo or standard of care.

Appears in:

Protocol title

Source:

ICH E6(R3)

baseline

In clinical use

An initial measurement taken at an early time point and used for comparison over time to look for changes.

Appears in:

Protocol, ICF, questionnaire

Source:

NCI

screening

In clinical use

In a trial: evaluating a person for possible participation, including whether the inclusion and exclusion criteria are met. In public health: checking for disease when there are no symptoms.

Two technical senses. The document type decides which applies.

Appears in:

Protocol, ICF, patient information

Source:

CDISC; NCI

screen failure

In clinical use

A potential participant who does not meet the study's eligibility criteria at screening.

It is not a verdict on the person.

Appears in:

Protocol, site documents

Source:

CDISC

run-in period

In clinical use

A period at the start of a trial used to establish a baseline, for example to assess compliance or to identify participants who cannot perform study activities.

Appears in:

Protocol, ICF

Source:

CDISC

washout period

In clinical use

The interval during which a participant must not receive a specified treatment before starting a study treatment.

Appears in:

Protocol, ICF

Source:

CDISC

endpoint

In clinical use

An event or outcome that can be measured objectively to determine whether the treatment being studied is beneficial.

Appears in:

Protocol, study report

Source:

NCI

event

In clinical use

An occurrence recorded in a trial. In outcome studies it means the complications that the treatment is intended to prevent or delay.

Appears in:

Protocol title

Source:

CDISC; NCI (event-free survival)

extension (study or period)

In clinical use

A design in which participants enrolled in one study continue into a related study for longer-term monitoring of safety, tolerability or effectiveness.

Appears in:

Protocol title, ICF

Source:

NCIt C207613

single-arm

In clinical use

A study with only one treatment arm, available to all participants.

Appears in:

Protocol title

Source:

NCIt C82640

registry (patient registry)

In clinical use

An organised system that uses observational methods to collect uniform data on people with a particular disease, condition or exposure.

Different from a clinical trial registry, which is a public database of trials (CDISC).

Appears in:

ICF

Source:

NCIt C129000

protocol

In clinical use

The document that describes the objectives, design, methodology, statistical considerations and organisation of a trial.

Appears in:

All trial documents

Source:

ICH E6(R3)

site (investigator site)

In clinical use

The location where trial-related activities are conducted or coordinated under the investigator's oversight.

Appears in:

Protocol, ICF, site questionnaires

Source:

ICH E6(R3)

follow-up; lost to follow-up

In clinical use

Follow-up: monitoring a person's health over time after treatment. Lost to follow-up: a participant who was not available for follow-up procedures.

Appears in:

Protocol, ICF, study report

Source:

NCI; NCIt C70740

intention-to-treat

In clinical use

The principle of assessing a treatment on the basis of the treatment each participant was assigned, not the treatment actually given.

Appears in:

Protocol, study report

Source:

ICH E9 (via CDISC)

trial

In clinical use

An interventional investigation in human participants, intended to discover or verify the effects of an investigational product.

Appears in:

All trial documents

Source:

ICH E6(R3)

subject; participant

In clinical use

An individual who takes part in a clinical trial, either receiving the investigational product or as a control.

E6(R3) says "trial participant" where earlier versions said "subject".

Appears in:

Protocol, ICF, CRF

Source:

ICH E6(R3)

investigator

In clinical use

The person responsible for the conduct of the trial. The responsible leader of a team may be called the principal investigator.

ICFs often say "study doctor".

Appears in:

ICF, protocol

Source:

ICH E6(R3)

sponsor

In clinical use

The individual, company, institution or organisation that takes responsibility for initiating, managing and arranging the financing of a trial.

Appears in:

ICF, protocol

Source:

ICH E6(R3)

monitoring; monitor

In clinical use

Overseeing the progress of a trial and ensuring it is conducted, recorded and reported in line with the protocol, SOPs, GCP and regulations.

The monitor is a person, not a device.

Appears in:

ICF (who may see records), site documents

Source:

ICH E6(R3)

source records

In clinical use

The original documents or data of the trial, such as participants' medical records, or certified copies of them.

A trap specific to translators, for whom "source" usually means the text being translated.

Appears in:

Protocol, monitoring documents

Source:

ICH E6(R3)

informed consent

In clinical use

A process by which a person voluntarily confirms willingness to take part, after being informed of all aspects of the trial relevant to that decision. It is documented by a signed and dated form.

Appears in:

ICF

Source:

ICH E6(R3)

assent

In clinical use

The affirmative agreement of a minor to take part. Silence is not assent, and formal consent still comes from the parent or guardian.

Appears in:

Paediatric assent form

Source:

ICH E6(R3); NCI (assent process)

authorization (HIPAA)

In clinical use

In US studies, the written permission needed before a person's protected health information can be used or disclosed. It may be combined with consent to take part in research.

Appears in:

US ICFs

Source:

45 CFR 164.508

impartial witness

In clinical use

A person independent of the trial who attends the consent process when the participant or their representative cannot read, and who reads the consent form and other information supplied.

Appears in:

ICF signature page

Source:

ICH E6(R3)

legally acceptable representative

In clinical use

A person or body authorised under law to consent on behalf of a prospective participant.

Appears in:

ICF signature page

Source:

ICH E6(R3)

compliance; adherence

In clinical use

For a participant: following a medical regimen or schedule correctly and consistently. For a trial: adherence to trial, GCP and regulatory requirements.

Appears in:

ICF, protocol, questionnaire

Source:

NCI; ICH E6(R3)

withdrawal

In clinical use

The participant's own act of ending participation in a study. The same word also means the symptoms that follow stopping an addictive substance.

Appears in:

ICF, protocol

Source:

CDISC; NCI

discontinuation; dropout

In clinical use

Discontinuation: ending an enrolled participant's involvement before all protocol-required elements are complete. Dropout: a participant who, for any reason, does not continue to the last required visit.

Appears in:

Protocol, study report

Source:

CDISC; ICH E9

adverse event

In clinical use

Any unfavourable medical occurrence in a participant given the investigational product. It need not have a causal relationship with the treatment.

Appears in:

ICF, protocol, CRF

Source:

ICH E6(R3)

adverse drug reaction; side effect

In clinical use

Adverse drug reaction: an unfavourable, unintended response where a causal relationship with the medicine is a reasonable possibility. Side effect: an effect of a treatment beyond its desired effect.

Appears in:

ICF, label

Source:

ICH E6(R3); NCI

serious vs severe

In clinical use

Severe describes intensity (mild, moderate, severe). Serious is based on outcome: death, a life-threatening event, hospitalisation, lasting disability or a birth defect. A severe headache can be of minor medical significance.

Appears in:

ICF, protocol, safety reports

Source:

ICH E2A; ICH E6(R3)

tolerability vs tolerance

In clinical use

Tolerability: the degree to which a treatment's overt adverse effects can be tolerated by the participant. Drug tolerance: the body getting used to a medicine, so that more or a different medicine is needed.

Appears in:

Protocol title, label

Source:

ICH E9 (via CDISC); NCI

challenge; rechallenge

In clinical use

Rechallenge: reintroducing a treatment that was withdrawn or paused to the same participant. Challenge agent: a product given to produce a response needed before the study medicine's action can be assessed.

Appears in:

Protocol, safety reports

Source:

CDISC

rescue medication

In clinical use

A medicine named in the protocol that may be given when the study treatment is not working well enough, is having too great an effect, or to manage an emergency.

Appears in:

Protocol, ICF

Source:

CDISC

drug

In clinical use

Any substance, other than food, used to prevent, diagnose, treat or relieve the symptoms of a disease.

Appears in:

All documents

Source:

NCI

investigational (experimental) drug; investigational product

In clinical use

A drug that has passed laboratory testing and been approved for testing in people. It may be approved for one condition and still be investigational for another. The investigational product is the active substance or placebo tested or used as a reference in the trial.

Appears in:

ICF, protocol

Source:

NCI; ICH E6(R3)

dose vs dosage

In clinical use

Dose: the amount of medicine taken at one time. Dosage: the amount given over a period, for example one 100 mg tablet four times a day.

Appears in:

Label, protocol, ICF

Source:

NCI; CDISC

regimen

In clinical use

A treatment plan that specifies the dosage, the schedule and the duration of treatment.

Appears in:

Protocol title, ICF

Source:

NCI

indication; contraindication

In clinical use

Indication: the disease or condition for which a treatment is studied or approved. Contraindication: anything that is a reason not to give a treatment because it may be harmful.

Appears in:

Label, protocol

Source:

CDISC; NCI

label; labelling

In clinical use

The approved description of a medicine or device: its indication, who should use it, adverse events, instructions for use and safety information.

Appears in:

Regulatory documents, IFU

Source:

CDISC

off-label

In clinical use

The legal use of an approved medicine for a condition, or in a way, for which it has not been approved.

Appears in:

Protocol, patient information

Source:

NCI; CDISC

orphan drug

In clinical use

A drug used to treat, prevent or diagnose a rare disease.

Appears in:

Regulatory documents

Source:

NCI

compassionate use (expanded access)

In clinical use

A way to provide an investigational therapy to a seriously ill patient who is not eligible for a clinical trial and has no other treatment available.

Appears in:

ICF, regulatory documents

Source:

NCI

half-life

In clinical use

The time needed for a substance to lose half of its activity.

Appears in:

Investigator's brochure, label

Source:

NCIt C70916

vehicle

In clinical use

A carrier or inert medium in which an active medicine is formulated or administered.

Appears in:

Protocol, dermatology studies

Source:

NCIt C927

therapeutic index (narrow)

In clinical use

The ratio of the dose that produces toxicity to the dose that produces the desired effect. A narrow index means the two doses are close together.

Appears in:

Exclusion criteria, label

Source:

CDISC; NCIt C120270

inducer; inhibitor

In clinical use

Inducer: a substance that increases the activity of a drug-metabolising enzyme, such as a cytochrome P450 enzyme. Inhibitor: a substance that reduces an enzyme's activity.

Appears in:

Exclusion criteria, label

Source:

NCIt C111374, C471; NCI

blood thinner (anticoagulant)

In clinical use

A substance used to prevent and treat blood clots in blood vessels and the heart.

Appears in:

Patient guide

Source:

NCI

positive; negative (test result)

In clinical use

Positive: the test shows that the person has the disease, condition or marker tested for. Negative: it is not present.

Appears in:

ICF, patient information, laboratory reports

Source:

NCI

unremarkable

In clinical use

No noteworthy findings; of normal appearance.

Appears in:

Medical records, CRF

Source:

NCIt C96301

benign

In clinical use

Not cancer.

Appears in:

Patient information, medical records

Source:

NCI

culture

In clinical use

Growing micro-organisms or cells in the laboratory.

Appears in:

Laboratory reports, protocol

Source:

NCI

discharge

In clinical use

Either a fluid that comes out of the body, or the release of a patient from care.

Appears in:

Patient information, medical records

Source:

NCI

mass

In clinical use

A lump in the body.

Appears in:

Medical records, patient information

Source:

NCI

tender; tenderness

In clinical use

Discomfort elicited through touch or pressure.

Appears in:

Medical records, CRF

Source:

NCIt C75540

complaint (chief complaint)

In clinical use

The primary reason for a patient's visit.

Appears in:

Medical records, CRF

Source:

NCIt C85497

history (medical history)

In clinical use

A record of information about a person's health, such as illnesses, surgeries, allergies, medicines taken and test results.

Appears in:

CRF, ICF, questionnaire

Source:

NCI

acute vs chronic

In clinical use

Acute: symptoms that begin and worsen quickly. Chronic: a disease that usually lasts three months or longer.

Both words describe time course.

Appears in:

Study titles, patient information

Source:

NCI

progression; progressed

In clinical use

The course of a disease as it becomes worse or spreads.

Appears in:

ICF, protocol

Source:

NCI

advanced (cancer)

In clinical use

Cancer that is unlikely to be cured, or that has spread from where it started.

Appears in:

ICF, protocol title

Source:

NCI

locally (advanced, recurrent)

In clinical use

At or near the place in the body where the cancer started, or spread only to nearby tissue or lymph nodes.

Appears in:

Protocol title

Source:

NCI

failed; failing (a therapy)

In clinical use

A lack of response to therapy: the treatment did not work, or stopped working.

The failure is the treatment's, not the patient's.

Appears in:

Protocol title, ICF

Source:

NCIt C200647; NCI (second-line therapy)

first-line; second-line therapy

In clinical use

First-line: the first treatment given for a disease. Second-line: treatment given when the first does not work or stops working.

Appears in:

Protocol title

Source:

NCI

response; complete response

In clinical use

Response: an improvement related to treatment. Complete response: the disappearance of all signs of cancer, which does not always mean a cure.

Appears in:

Protocol, ICF, study report

Source:

NCI

stable disease

In clinical use

Cancer that is neither decreasing nor increasing in extent or severity.

Appears in:

Protocol, study report

Source:

NCI

supportive care; best supportive care

In clinical use

Care that improves quality of life by preventing or treating the symptoms of a disease and the side effects of its treatment.

Appears in:

Protocol title, ICF

Source:

NCI

morbidity vs mortality

In clinical use

Morbidity: having a disease or symptom, or the amount of disease in a population. Mortality: the death rate.

Appears in:

Protocol title

Source:

NCI

efficacy vs effectiveness

In clinical use

Efficacy: the intended effect as shown in adequate, well-controlled clinical trials. Effectiveness: the intended effect as determined from efficacy and other evidence, including real-world observation.

Appears in:

Protocol title, study report

Source:

CDISC

significant (statistically)

In clinical use

A difference between groups that is greater than would be expected by chance alone.

Appears in:

Study report, plain-language summary

Source:

NCI