A clinical trial is a research study in human volunteers to answer specific health questions. Clinical trials are the fastest and safest way to find treatments that work in people and ways to improve health. Interventional trials determine whether experimental treatments or new ways of using known therapies are safe and effective under controlled environments. Observational trials address health issues in large groups of people or populations in natural settings.

Participants in clinical trials can play a more active role in their own health care, gain access to new research treatments before they are widely available, and help others by contributing to medical research.

All clinical trials have guidelines about who can participate. Using inclusion/exclusion criteria is an important principle of medical research to produce reliable results. Factors that allow participation in a clinical trial are called “inclusion criteria” and those that disallow are called “exclusion criteria”. These criteria are based on factors such as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions. Before joining a clinical trial, a participant must qualify for the study. Some studies seek participants with certain illnesses or existing conditions, while others need healthy participants. It is important to note that inclusion and exclusion criteria are not used to reject people personally. The criteria are used to identify appropriate participants and keep them safe. This helps to ensure that researchers will be able to answer the questions they plan to study.

The clinical trial process depends on the kind of trial being conducted. The clinical trial team includes doctors, nurses, social workers and other health care professionals. They check the health of the participant at the beginning of the trial, give specific instructions during the trial, monitor the participant carefully and stay in touch after the trial is completed. Some trials involve more tests and visits than the participant would normally have for an illness. In all types of trials, the participant works with a research team. CT participation is successful when the protocol is followed and there is frequent contact with the research staff.

This is the process of learning the key facts about a clinical trial before deciding on participation, and a continuing process throughout the study to provide information for participants. This helps to decide whether to participate or not. The doctors and nurses involved in the trial explain the details of the study. Then the research team provides an informed consent document that includes details about the study, its purpose, duration, required procedures, and key contacts. Risks and potential benefits are explained in the informed consent document. The participant then decides whether or not to sign the document. Informed consent is not a contract, and participants may withdraw from the trial at any time.

Clinical trials that are well-designed and well-executed are the best approach for eligible participants to:

• Take an active role in their own healthcare.
• Gain access to new treatments before they are widely available.
• Help others by contributing to medical research.

The risks in clinical trials are:

• There may be unpleasant and serious side effects to a treatment.
• The treatment may not be effective.
• The protocol may require much of the participant’s time and attention, including trips to the site, numerous treatments and hospital stays.

Side effects are undesired effects of a drug or a treatment. Negative effects may include headache, nausea, hair loss, skin irritation or other problems. Experimental treatments must be evaluated for immediate and long-term side effects.

The ethical and legal codes that govern medical practice also apply to clinical trials. In addition, most clinical research is regulated by the European Union Clinical Trials Directive (2001/20/EC), providing a framework for member states defining how clinical trials must be conducted. It contains various safeguards to protect the participants. Trials follow a carefully controlled protocol, a study plan which details what researchers will do in the study. As a clinical trial progresses, researchers report the results of the trial at scientific meetings, to medical journals, and to various government agencies.

Yes. A participant can leave a clinical trial, at any time.

Clinical trials are sponsored by various organisations, medical institutions, foundations, voluntary groups, pharmaceutical companies and national health institutions.

A protocol is a study plan on which the clinical trial is based. The plan is designed to safeguard the health of the participants and to answer specific research questions. A protocol describes who may participate in the trial; the schedule of tests, procedures, medications, and dosages and the length of the study.

A placebo is an inactive pill, liquid, or powder that has no treatment value. Experimental treatments are often compared with placebos to assess the treatment’s effectiveness. In some studies, the participants in the control group can receive a placebo instead of an active treatment.

• Treatment trials test new treatments, new combinations of drugs or new approaches to surgery or radiation therapy.
• Prevention trials look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include medicines, vitamins, vaccines, minerals or lifestyle changes.
• Diagnostic trials are conducted to find better tests or procedures for diagnosing a particular disease or condition.
• Screening trials test the best way to detect certain diseases or health conditions.
• Supportive trials explore ways to improve comfort and the quality of life for individuals with a chronic illness.

Clinical trials are conducted in phases. The trials at each phase have a different purpose and help scientists answer different questions:

• Phase I – Researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range and identify side effects.
• Phase II – The studied drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
• Phase III - The studied drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments and collect information that will allow the drug or treatment to be used safely.
• In Phase IV trials, post marketing studies delineate additional information including the drug’s risks, benefits and optimal use.