What is a clinical trial?
A clinical trial is a research study that involves testing or studying a drug or medical device to see if it is a safe and effective treatment for people. There are strict rules that control how clinical trials are conducted, to ensure the safety of those who participate.
Experimental drug trials are categorised into one of four phases:
- Phase I clinical trials test a new drug or treatment for the first time in a small group of ‘healthy’ volunteers.
- Phase II clinical trials test the study drug or treatment with a larger group of people, including patients with the particular disease.
- 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 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.
What is a protocol?
All clinical studies are based on a set of rules or directions called a protocol. A protocol describes what types of people are eligible to participate in the study; establishes the schedule of tests, procedures, medications, and dosages; and sets the length of the study.
How is research regulated?
Clinical research studies go through several robust checks and approvals before they can begin. These reviews are conducted by a Research Ethics Committee, the Health Research Authority and other regulatory authorities, as well as by clinical and managerial teams within the hospital.
Are there risks involved in participating in clinical research?
There are risks involved in clinical research, as there are in standard medical care and in day-to-day life. All research studies are designed to minimise the risks involved.
Trials are being undertaken every day within the NHS and are often managed by doctors and health professionals that may be responsible for your care anyway.
The specific risks associated with any research study are described in detail in the consent document, which you are asked to sign before taking part in research. In addition, the major risks of participating in a study will be explained to you by a member of the research team, who will answer your questions about the study.
What about confidentiality?
If you take part in a study, staff other than your doctors will need access to your medical records. Everyone who sees your records has to be trained in Good Clinical Practice (GCP) and follow the hospital’s confidentiality guidelines.
If a study takes place across several sites and information needs to be shared with other researchers, your personal details will not be included to protect your confidentiality.
The Health Research Authority (HRA) website explains when we can and cannot use information about you for research and your choices and rights. If you would like to find out more about why and how patient data is used in research please read the HRA leaflet on patient data and research or visit the Understanding Patient Data website.
Do I have to take part?
No. Taking part in research is entirely voluntary. If you are invited to participate in a study, you will have time to consider whether you would like to do, and if you decide not to take part your NHS treatment will not be affected and you will continue to be looked after like any other patient.
Can I withdraw from a trial or research study?
Participating in research is always voluntary, and you can change your mind and leave a clinical trial or research study at any time. If you decide to withdraw from a study, this will not affect your access to standard healthcare.
Will I be paid?
Whether you receive any payment depends on the study. The research team for the study you are involved in will be able to provide you with details.
- Arm– A group of patients receiving a particular treatment (or placebo) in a clinical trial.
- 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.
- 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.
- Cohort – A group of individuals with some characteristics in common.
- Control/control group– An alternative to a new treatment (e.g. an existing treatment, a placebo or no treatment) that is used as a comparison to the new treatment.
- Eligibility criteria– 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 a clinical research study and then agreeing to take part.
- Multi-centre trial– A trial being carried out at more than one location.
- 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.
- 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.