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Glossary of Terms

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If you prefer you can download the glossary as a PDF documentClick on the terms below to go to a description of that term. To return to the top of this page click the >> back to the top link which appears at the end of every description.

Advance Decision (see also advance directive)

Advance decisions to refuse treatment may be made by people before they become ill, in case they lose capacity in the future. It is made clear in the Mental Capacity Act 2005 that advance decisions will not apply to any treatment that a doctor considers necessary to sustain life, unless they are in writing, signed and witnessed and contain an express statement that the decision stands “even if life is at risk”.  >> back to the top

Advance Directive (see also advance decision)

An Advance Directive is a written statement made when a person is well about what they want to happen to them if they experience a relapse.  >> back to the top

Advocate

An advocate is someone who has been trained to speak up for others or to help them speak up for themselves. They can help people make decisions about joining a clinical trial or support them during a trial. >> back to the top

Adverse reactions

Adverse reactions, are unwanted side effects, caused by a drug or other treatment. For example, if you are given a drug to treat a mental illness and it makes you sick, the sickness would be described as an adverse reaction.  >> back to the top

Arms

An arm is one of the treatment groups in a trial. If a trial is testing 2 treatments, there will be 2 ‘arms’.  One arm might be the usual treatment.  >> back to the top

Baseline measures

At the beginning of a trial you may have to answer questions about your medical history, or how you are feeling now, or have some tests before being given the treatment. These are called baseline measures. These measures will allow the researchers to know where you started, so they can tell at the end of the trial whether there has been any change.  >> back to the top

Bias

When people’s individual opinions lead to incorrect conclusions about the effects of treatment, this is bias. It’s really important to avoid bias in health research, as it can distort the results and could lead to unsafe or inefficient treatments being licensed for use, or useful treatments being overlooked. Researchers try to avoid bias by using randomisation and by ‘blinding’ those assessing the results of treatments.  >> back to the top

Blinding and double-blinding

Blinding means that whoever is assessing the effects of treatment will not know which treatment the person has received. This helps to prevent bias. Sometimes service users will assess the effects of treatment, sometimes the researcher will, and sometimes a researcher who is independent of the trial will carry out this assessment. Blinding means that some or all of these people may be kept unaware of which treatment the person has received.

In a double blind trial, neither you nor the researchers running the trial will know which treatment you are receiving. The aim is to avoid your hopes and expectations about the treatment, as well as the hopes and expectations of the researchers, influencing the way the improvements and side effects are assessed.

It is not always possible to avoid researchers and service users knowing which treatment they are having. For example, the trial may be comparing an injection with a tablet. If the researcher knows which treatment you are receiving, it may be necessary for another researcher, who has not been involved in conducting the trial, to assess the impact of the different treatments. >> back to the top

Chief investigator

The chief investigator (also called a principal investigator) is the researcher in overall charge of a trial. If you take part in a trial you may never meet the chief investigator, especially if the trial is very large and taking place in several countries. But this person is responsible for the design of the trial and how it is run, as well as for analysing the results. He or she is helped by a trial steering committee and a data monitoring committee. >> back to the top

Clinical trial

Clinical trials are research studies involving patients, which compare a new or different type of treatment with the best treatment currently available. No matter how promising a new drug or treatment may appear during tests in a laboratory, it must go through clinical trials before its benefits and risks can really be known, and before it is approved for use. >> back to the top

Confidentiality

If you agree to join a trial, some people will need to be told that you are taking part. These people are:

If there is someone who provides you with substantial care and support (for example a carer) it would be good for them to know too, so that they have the information they need to support you.

The fact that you are taking part in a trial will be written in your medical notes. Researchers cannot tell anyone else that you are taking part in a trial unless you give your permission.

During the trial, all of the information collected about you will be kept confidential, as with any other medical records. When researchers publish the results of a trial, they are not allowed to include any information that would identify people - your name will not be used in any reports or publications. >> back to the top

Control group

Most clinical trials include a control group. If you are part of the control group, you will not receive the treatment being trialled.  Instead, you’ll receive the usual treatment, or, if there is no usual treatment, a placebo.   >> back to the top

Court of Protection

The Mental Capacity Act 2005 has created a new Court of Protection which has jurisdiction relating to the whole Act and is the final arbiter for capacity matters. It has its own procedures and nominated judges. The old Court of Protection could only deal with decisions about money, but the new Court will be able to make decisions about medical treatment which used to have to go to the High Court. >> back to the top

Cross-over trials

If you take part in a crossover trial, your treatment will change partway through the trial. So, for example, if a trial is comparing the effectiveness of 2 different sorts of exercise to help combat depression, you might take part in exercise A for the first part of the trial and then exercise B for the second, then perhaps back to A again - and so on. You cross over from one treatment group to the other, and comparisons are then made between how well you felt during the different periods. Often there will be several cross-overs in a cross-over trial.  >> back to the top

Data monitoring committee (Often called the Independent Data Monitoring and Ethics Committee - IDMEC).

Most trials have a data monitoring committee that follows the progress of the trial and makes sure it is being run properly. The people on the data monitoring committee are independent of the researchers running the trial. If they think that participants are experiencing serious or unexpected side effects, or if evidence has emerged that one of the treatments being compared is clearly better than the others, they can advise that a trial is stopped.  >> back to the top

Data Protection Act

The Data Protection Act 1998 seeks to strike a balance between the rights of individuals and the sometimes competing interests of those with legitimate reasons for using personal information. The DPA gives individuals certain rights regarding information held about them. It places obligations on those who process information (data controllers) while giving rights to those who are the subject of that data (data subjects). Personal information covers both facts and opinions about the individual.
For more information click here. >> back to the top

Double-blind trials

See blinding >> back to the top

Drug interaction

If you take two different medicines at the same time, they may have a different effect than if they are taken on their own. One may cancel the effects of the other or the two may cause more serious side-effects when taken in combination. This is called drug interaction.   >> back to the top

Eligibility criteria

All trials have guidelines about who can take part. These are called 'eligibility criteria', consisting of inclusion criteria and exclusion criteria. For example, the eligibility criteria for a trial looking at bi-polar disorder might say that the only people who can take part are people who are over 18 but under 80, and who have no other health problems.   >> back to the top

Enduring Power of Attorney

An Enduring Power of Attorney (EPA), is a legal document that enables someone (the donor) to appoint one or more persons (attorney(s)) to manage their financial affairs and property, either now or in the future. >> back to the top

Exclusion criteria

Exclusion criteria determine who won’t be able to join a trial – for example, many trials exclude women who are pregnant, or who may become pregnant. This avoids any possible danger to a baby. Trials may also exclude people who are taking a drug that interacts with the treatment being studied.  >> back to the top

Guardian

Under Scottish law, a guardian is someone who is legally recognised as the person acting for another adult who lacks mental capacity. >> back to the top

Health Technology Assessment (HTA) programme

The purpose of the HTA programme is to ensure that high quality research information on the costs, effectiveness and broader impact of health technologies is produced in the most effective way for those who use, manage and provide care in the NHS.

Health technology is a term that covers any method used by those working in the health services to promote health or prevent, diagnose and treat disease and improve rehabilitation and long-term care. 'Technologies' in this context are not confined to new drugs or pieces of sophisticated equipment, but include procedures, settings of care and screening programmes. >> back to the top

Inclusion criteria

Inclusion criteria help researchers decide who can join a trial. For example, some trials only include people of a certain age, or at a particular stage in their illness. You may have to have a medical examination before a trial (e.g. a blood test) to assess whether you are suitable to take part.  (See also eligibility criteria)

Independent scientific review (also known as peer review)
This is the process which involves independent researchers (people are not connected with the clinical trial) looking at the trial protocol to check its scientific quality before the trial begins. They check that the research question is important and that the protocol reaches required scientific standards e.g. that the question has not been answered before, enough people are involved to make the results meaningful, and the methods are appropriate. >> back to the top

Informed consent

You cannot be entered into a trial without signing a form saying that you have given your informed consent, except in extreme circumstances (for example, if you're admitted to hospital in an emergency and you're unconscious). If you sign this form, you are saying that you believe you have been given all the important facts about a trial, you understand them and that you have decided to take part in the trial of your own free will. Even after giving your informed consent, you are free to withdraw from the trial at any time without giving a reason and without it having an impact on your healthcare. >> back to the top

The Mental Capacity Act 2005 has strict rules about entering people into a trial without informed consent – researchers must consult a carer or nominated person, and if these cannot be found, and it is urgent to enter the person into a trial, they must have the agreement of a registered practitioner who is not involved in the research project.  >> back to the top

Intervention

Within the context of healthcare, an intervention is something that is given to a service user as a treatment. For example, giving a drug is an intervention. Counselling is also an intervention. Within the context of a clinical trial, the ‘intervention arm’ is the name given to the group of people receiving the new treatment.  >> back to the top

Lasting Power of Attorney

The Mental Capacity Act 2005 allows a person to appoint an attorney to act on their behalf if they should lose capacity in the future. This is like the current Enduring Power of Attorney (EPA), but allows the attorney to make health and welfare decisions as well as financial ones. It is called Lasting Power of Attorney (LPA). >> back to the top

Medical Research Council

The UK Medical Research Council (MRC) is a national organisation funded by the UK taxpayer. It funds and supports research in many areas with the aim of improving the health and quality of life of the UK public and contributing to the wealth of the nation.  >> back to the top

Mental capacity

Under the Mental Capacity Act 2005, you can be deemed to lack mental capacity if you are unable to make a decision for yourself  “because of an impairment of, or a disturbance in the functioning of, the mind or brain.” >> back to the top

Mental Health Research Network (MHRN)

The UK MHRN aims to provide the infrastructure to support large scale, high quality research in mental health and social care in the UK.  It also aims to act as a central point of information and reference, connecting service users and carers to researchers and mental health professionals. For more information click here.  >> back to the top

Meta-analysis

Small beneficial effects of treatments, rather than miracle cures, are often the best that can be hoped of new medical treatments. These small improvements can be very important, but many trials do not manage to recruit sufficient numbers of participants to detect these small improvements. This means that researchers cannot give an accurate answer about how safe or effective a new treatment is. In this case, researchers can bring together the results of a number of similar trials to give a fuller answer about the value of a particular treatment. This method of combining results of more than one trial is called a meta-analysis. >> back to the top

MHRA
The Medicines and Healthcare products Regulatory Agency (MHRA) is a part of the Department of Health. Its job is to protect and promote public health and patient safety by ensuring that medicines, healthcare products and medical equipment meet appropriate standards of safety, quality, performance and effectiveness, and are used safely.  >> back to the top

Open trial

An open trial has different meanings: >> back to the top

Open label trials
In an open label trial, both you and your doctor will know which treatment you are receiving. This is the opposite of a double-blind trial. >> back to the top

Outcome measures

During the trial you are likely to be asked questions and have examinations and tests to assess the effects of treatment. These are known as outcome measures. This may involve more visits to the clinic than normal, or more tests than normal - for example, extra blood might be taken when you give a blood sample. Sometimes the tests are carried out as part of your routine care.  >> back to the top

Placebo

A placebo is a fake or dummy treatment. It allows researchers to test for the 'placebo effect'. This is a psychological response where people feel better even though the treatment they are receiving is not working. By comparing people’s responses to the placebo and to the treatment being tested, researchers can tell whether the treatment is having any real benefit. Placebos are designed to be harmless to have no effect, but they may make people feel better.  >> back to the top

Protocol

A protocol is the plan for the trial, and it must include information on: 

The protocol is often long and technical as it describes in great detail what the researchers must do during the trial. This is the document they continually work from. It cannot be changed without going back to a research ethics committee for approval.  >> back to the top

Quality of life studies

As well as measuring the physical effects of a treatment (for example changes to your blood pressure), many trials now try to assess the impact of treatments on people’s quality of life. For example, a ‘quality of life’ study might ask you about:

Randomised controlled trial

Most clinical trials are randomised controlled trials. If you take part in a randomised trial, a computer, not a doctor, will decide which treatment to give you. This decision will be random. It will be due to chance alone, and not based on your doctor’s decision.  >> back to the top

Randomisation is the best way of ensuring that people in the different parts of a trial are broadly similar. By comparing similar groups of people, researchers can be sure that their trial is checking the difference between the treatments being studied, and not the differences between the people taking part.

Randomisation is important because researchers need to ensure that the results of a clinical trial are not biased. It is quite easy for people to be biased without realising it.  For example, suppose a new treatment is being tested that has quite bad side effects. Without randomisation, researchers, doctors and the sickest patients might avoid the new treatment. As the trial continued, more and more of the sickest patients would join the comparison group getting the old treatment, so this group would then have more and more of the sickest patients in it. The people in the new treatment group might do better simply because they are not as ill when they started the treatment. These results could be interpreted wrongly – people might believe that the new treatment works better than the old one. Randomising patients to different treatment groups avoids biasing the results in this way.

A randomised controlled trial has a control group. This is a group of people who are offered the usual (or standard) treatment.  If there is no usual treatment, they will be offered a placebo.  The control group provides a comparison to help researchers to see whether the treatment they are testing is any more or less effective.

You should only be asked to take part in a randomised controlled trial if both you and your doctor are uncertain which treatment would be best for you.  >> back to the top

Researcher

This site uses the term researcher to refer to health or social care professionals who provide treatment to participants in a clinical trial.  >> back to the top

Research ethics committee

The job of a research ethics committee is to make sure that research carried out in the NHS respects the dignity, rights, safety and well-being of the people who take part in medical research. A trial that takes place within the NHS cannot go ahead if a research ethics committee has not approved it, and the protocol for a trial cannot be changed without the approval of the research ethics committee. Research ethics committee members include researchers and health care professionals as well as members of the public.

Research Governance Framework for health and social care
The Research Governance Framework was developed by the Department of Health to improve research quality and to safeguard the public. It aims to do this by

For more information click here. >> back to the top

Side effects

Side effects, or adverse reactions, are undesired effects of a treatment. For example, if you are given a drug to treat a mental illness and it makes you sick, the sickness would be described as a side effect. Clinical trials will often look at the short-term and long-term side effects of a treatment.  >> back to the top

Sponsor

Under the Research Governance Framework for health and social care, the sponsor is the individual, group or organisation which takes responsibility for checking that there are proper arrangements to initiate, manage, monitor and finance a piece of research.  Any research that takes place in the NHS or social care in England must have a sponsor.  Normally, the sponsor will be one of the organisations taking the lead for part or all of the research.   >> back to the top

Trial Steering Committee

Most trials have a trial steering group or committee. This is to ensure the trial is running well. In the UK, this committee often includes service user or carer representatives, as well as the researchers, doctors and nurses who are leading the trial. >> back to the top

Welfare attorney

Under Scottish law, a welfare attorney is someone who is legally contracted or appointed to make decisions about the personal welfare of an adult who lacks mental capacity. >> back to the top


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