CNRC logo
CNRC Banner
Home Logo About Logo Research Logo Studies Logo News Logo
Home About Research Mind Matters News and Events









Clinical research trials are used to test and evaluate investigational drugs and treatments.

Monitoring and ethical procedures

Everyone in a clinical trial is carefully monitored. Frequent study-related medical exams and tests are performed to ensure safety. Researchers follow strict ethical and scientific principles to make sure that patients are protected and valid results are produced.


A plan of how the study will be run, which is called a protocol, is written to ensure that every researcher involved in the study follows the same ethical and scientific principles. The protocol is written by the study's sponsor. All researchers taking part in the study will use the same protocol. It describes how the study will be conducted in great detail including the number of participants to be enrolled, the amount of drug to be used and the types of medical tests to be provided, etc.

Patient Safety

To ensure patient safety, the protocol is reviewed and approved by the organization that sponsors the study as well as by an Institutional Review Board. In the review of the protocol, the board seeks to ensure that participants in the study will not be exposed to unreasonable or unethical risks.
The process of evaluating new treatments does involve some risk. Investigational drugs are first tested for safety in Phase I trials. These studies use a small group of volunteers to determine the best dose of the study drug. If the drug is shown to be safe and well tolerated, it moves to Phase II and III trials, where larger numbers of patients with a specific disease receive the treatment. Side effects can vary from patient to patient. It is important to remember that clinical trials can result in unexpected, sometimes dangerous, complications as well as potential therapeutic benefits. However, the progress of patients in clinical trials is carefully monitored.

Before the trial

Before enrolling anyone in a clinical trial, study site staff will explain the possible risks and benefits to potential study participants, as well as the procedures to be used in the study and a participant's right to leave a study at any time. These issues are summarized in a document called an informed consent form. All clinical trial participants are asked to read, understand, and sign the consent form before beginning study treatment. It is important to ask the study site staff to explain any part of the form that is unclear.


Participants in a study must meet the eligibility criteria (inclusion and exclusion criteria) that are outlined in the protocol. These criteria, which differ from trial to trial, include such characteristics as gender, age, health problems, and previous or current treatments. These criteria help exclude those who might be harmed by the study drugs (such as pregnant women) or other treatments involved in the research. These criteria also help to produce scientifically reliable results by making sure that the study only enrols certain types of patients. (For example, patients with certain disease characteristics.) Thus researchers can determine the benefits and disadvantages of the study drug more accurately. For example, the study treatment may be effective for one type of a disease but not another, or may be more effective in women than men.

Leaving a trial

Trial participants may leave the trial at any time for any reason. If you choose to leave the study, you will have the chance to discuss other treatments with your own doctor or a doctor from the study.


Not all clinical trials involve the use of a placebo (a substance that looks like the study drug, but contains no active drug). Some Phase III trials may compare investigational therapies to the standard therapy used to treat the disease of question. However, in some cases, there is no standard treatment. When this is the case, the investigational treatment may be compared to a placebo. When a placebo is used, study participants are informed before they agree to take part in the study that there is a chance that they will not receive the study medication but may instead receive placebo

Treatment Group

Most clinical trials have a "treatment group" (which receives the study drug) and a "control group" (which may receive standard treatment or placebo). In a blinded or masked study, participants are not told which group they are in. The reason for a blinded or masked study is to avoid study bias. If people expect to do better on a study drug, they may report hopeful signs to researchers simply because they want to believe they are doing better. Similarly, physicians may also be blinded to the treatment a patient is receiving because, if they believe an experimental treatment may work better, it may influence their report of how the patient is doing. In either case, the study drug may appear to work better than it really does. To prevent this from happening, a study may be blinded or masked.


In trials where there is both a treatment and a control group, participants are assigned to either group by chance. This process is called "randomisation." Patients are randomised to avoid study bias. Randomisation is used to help ensure that study results are influenced only by the treatment being tested.

Discussing your participation with your GP

You do not need a referral from your GP to participate in a trial. It is up to you to decide if you wish to participate or not. However, patients are usually encouraged to discuss participation in the study with their own GP and their family. You can continue to see your regular physician. Clinical trials do not replace normal health care. In fact, trial coordinators should provide regular updates about the study to your regular physician.