Arm
A group of patients receiving a particular treatment (or placebo) in a clinical trial. A study may have several arms which patients are randomly assigned to.
Baseline characteristics
Data collected at the beginning of a clinical study for all participants and for each arm or comparison group. These data include demographics, such as age and gender, and study-specific measures like results from certain blood tests.
‘Blind’
This term applies to trials where a new treatment is compared against another treatment or a placebo (usually phase III trials). A trial is either ‘single-blind’ if either the participants or the researchers do not know which option the participants are receiving, or ‘double-blind’ if both the participants and the researchers do not know which option the participants are receiving. This makes the results of the trial more objective and therefore more reliable.
Clinical trial
A clinical trial is a particular type of clinical research that compares one treatment with another. It may involve patients or healthy people, or both, and a treatment if often tested on large numbers of people before the results are considered reliable.
Clinical Trial of an Investigational Medicinal Product (CTIMP)
A clinical trial involving one or more medicines.
Cohort
A group of individuals with some characteristics in common.
Contract Research Organisation
An organisation providing contracted services to the pharmaceutical industry to provide support for research studies involving drugs and/or medical devices.
Control/control group
An alternative to a new treatment (e.g. an existing treatment – usually current standard care, a placebo or no treatment) that is used as a comparison to the new treatment. The group that is allocated to the control arm or treatment is called the ‘control group’.
Eligibility criteria
Eligibility criteria set out the details of who can and cannot be included in a research study. This is in order to define a distinct study population to make a study robust, and also for safety reasons. Inclusion criteria describe those people who can take part in a study; exclusion criteria describe those people who cannot take part.
Informed consent
The process of learning what is involved in participating in a clinical research study and then agreeing (consenting) to take part.
Multi-centre trial
A trial being carried out at more than one location.
National Institute for Health Research (NIHR)
Established in 2006 under the Government’s ‘Best Research for Best Health’ strategy to “create a health research system in which the NHS supports outstanding individuals, working in world-class facilities, conducting leading-edge research focused on the needs of patients and the public”.
NIHR Clinical Research Network (CRN)
A network of 15 local and 30 specialty units across England who support patients, the public and health organisations to participate in high quality research.
Phase I
Phase I clinical trials test a new drug or treatment for the first time in a small group of ‘healthy’ volunteers.
Phase II
Phase II clinical trials test the study drug or treatment with a larger group of people, including patients with the particular disease.
Phase III
Phase III clinical trials, test the study drug or treatment with large groups of people, including patients, to confirm its effectiveness, monitor side effects, and compare it to other commonly used treatments.
Phase IV
Phase IV clinical trials are done after the drug or treatment has been approved for public use. These studies continue testing the drug or treatment to collect information about its effect in various populations.
Protocol
The written description of a clinical study. It includes the study’s objectives, design, and methods. It may also include relevant scientific background and statistical information. It will always state the eligibility criteria and define the inclusion and exclusion criteria for recruiting participants.
Randomised trial
In a randomised trial participants are allocated to receive one type of treatment or another by a random process, usually using a computer. This helps ensure the results are objective and unbiased.
Sponsor
The organisation or partnership which takes overall responsibility for robust arrangements to initiate, manage, run, monitor and finance a research study.