Frequently Asked Questions

Interventional clinical trials (also called Treatment studies) study the effects of new investigational treatments (like drugs or procedures), new combinations of treatments, or new ways to do surgery or radiation therapy.

Prevention clinical trials look for better ways to prevent diseases in people who have never had them or prevent a disease from coming back. They might use medicines, vaccines, or lifestyle changes, as well as other methods.

Diagnostic clinical trials look for better tests or procedures for diagnosing a specific disease or condition.

Screening clinical trials study the best way to detect certain diseases or health conditions.

Quality of Life clinical trials (or Supportive Care clinical trials) explore ways to improve comfort and the quality of life for people with a chronic illness.

Learn more about types of clinical trials.

A ‘protocol’ is a study plan for clinical trials. All clinical trials have a protocol. It is carefully designed to safeguard the health of participants and answer specific research questions. The protocol describes

• Who can join the clinical trial
• How many people will take part
• Whether there will be a control group and other ways to limit research bias
• The schedule of tests, procedures, and medications
• How the investigational treatment is given
• How long the clinical trial will last

While in a clinical trial, participants are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of their treatment.

Clinical trials are sponsored or funded by a variety of organizations or individuals. That includes physicians, medical institutions, foundations, voluntary groups, and pharmaceutical companies. They can also be funded by government agencies such as the National Institutes of Health (NIH) and the Department of Veteran’s Affairs (VA) in the United States, the Canadian Institutes of Health Research (CIHR) in Canada, and others. Clinical trials can take place in many places, such as hospitals, universities, doctors’ offices, or community clinics.

Many professionals work together at clinical trial sites to keep participants safe and ensure the research is done properly. The principal investigator (or PI) leads the clinical trial and directs the team of doctors, nurses, and other healthcare workers. A study coordinator manages day-to-day activities. The study coordinator is often the main contact for participants.

Clinical trials often take place in:

• Doctors’ offices
• Hospitals and medical centers
• Universities
• Community clinics

Some clinical trials have more than one location for performing different parts of the research. Some clinical trials can also take place in the participant’s home. Many clinical trials now use a mix of methods. This means participants can have remote visits unless they need or prefer to go in person.

Informed consent is a process that helps you understand a clinical trial before you decide to take part. The clinical trial staff will explain the clinical trial’s purpose, how long it will last, and any risks or benefits. They will also explain what will happen during the trial and how they will keep your information private. You can ask any questions you have. Before you can join, you must sign a consent form with these details. Even after you have signed the form, you can leave the clinical trial at any time, for any reason.

Randomization is how patients are put into different treatment groups in a trial. A computer usually picks randomly (by chance) which clinical trial treatment each participant gets, or the order they get treatments. The computer program makes sure that the groups are balanced, meaning they are similar in terms of sex, average age, disease severity, and or other factors that could affect the results. People are put into groups by chance alone, which helps prevent bias. Bias happens when a clinical trial's results are affected by human choices or other factors not related to the treatment being tested. For example, if clinical trial doctors could choose which patients go into which groups, some might, without meaning to, put sicker patients in the treatment group and healthier patients in the control group. This might affect the clinical trial results. Randomization helps ensure that bias does not happen.

Learn more about the benefits and risks of randomization.

A placebo looks like a drug or treatment but does not have any active ingredients. You may have heard of the “placebo effect.” This refers to when people think they are getting a treatment and feel better, even if the “treatment” is just a placebo. This happens because they believe that they are being treated. Usually when a placebo is used, the participants do not know who is getting the placebo. This type of clinical trial is called a “single-masked study.” Sometimes, neither the participants nor the clinical trial staff know who is getting the placebo. This type of clinical trial is called a “double-masked study.” Sponsors use a placebo to make sure that any effects they find in the clinical trial are actually caused by the treatment being studied. However, comparing an investigational treatment to a placebo alone may not be right in some conditions or diseases that already have approved treatments.

In cancer clinical trials, a placebo is only used if there is no other treatment for that type of cancer. This helps compare an investigational treatment to the placebo. Placebos are rarely used in cancer trials because the best available treatment, called the “standard of care”, is usually given instead.

A side effect is an unwanted result from taking a drug or using a medical treatment. An adverse event is an unwanted result that a participant has during a clinical trial. These adverse events may include any unintended signs or symptoms such as unwanted health changes, abnormal laboratory findings, and other medical problems. An adverse event may or may not be caused by the drug or treatment being studied in the clinical trial. Clinical trial staff keep track of all the adverse events that happen in clinical trials, even if they might not be related to the clinical trial treatment. It is important to let the clinical trial staff know about any changes in your health or new events during the trial.

Before clinical trials can start in people, the investigational treatment is first tested for safety in the lab on cells or animals. These are called pre-clinical studies. Once the sponsors have enough information, they ask for permission from the government regulatory agencies and independent ethics committees to begin clinical trials.

A “healthy volunteer” or “clinical research volunteer” is someone with no known significant health problems who takes part in research to study a new drug, device, or intervention. Healthy volunteers provide sponsors with crucial data about how an investigational treatment affects the body.

In some studies, sponsors need to compare healthy volunteers with people who have a specific disease or condition. Research with healthy volunteers is designed to develop new knowledge, not to help the people in the clinical trial directly.