Choosing to participate in a clinical trial is an important personal decision. The following frequently asked questions will provide you with detailed information about clinical trials. In addition, it is often helpful to talk to your health care provider, family members, or friends about deciding to join a trial. After you have identified some trial options, the next step is to contact the study research staff and ask questions about specific trials.
- What is a clinical trial?
- What is a protocol?
- What are clinical trial phases?
- What protections are there for people who participate in clinical trials?
- What is informed consent?
- Who can participate in a clinical trial?
- Who sponsors clinical trials?
- What happens during a clinical trial?
- What is a placebo?
- What is a control or control group?
- What is a blinded or masked study?
- What is a double-blind or double-masked study?
- What are side effects and adverse reactions?
- What are the benefits and risks associated with clinical trials?
- What should I know before I join a clinical trial?
- How should I prepare for the meeting with the research coordinator or doctor?
- What questions should I ask?
- Should I continue working with my primary health care provider if I participate in a trial?
- Can I leave a clinical trial after it has begun?
- Will I be paid for participating in a clinical trial?
A clinical trial is a research study to answer specific questions about vaccines or new therapies or new ways of using known treatments. Clinical trials (also called medical research and research studies) are used to determine whether new drugs or treatments are both safe and effective. Carefully conducted clinical trials are the fastest and safest way to find treatments that work.
Ideas for clinical trials usually come from researchers. Once researchers test new therapies or procedures in the laboratory and get promising results, they begin planning Phase I clinical trials. New therapies are tested on people only after laboratory and animal studies show promising results.
All clinical trials are based on a set of rules called a protocol. A protocol describes what types of people may participate in the trial; the schedule of tests, procedures, medications, and dosages; and the length of the study. 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 of experimental drugs proceed through four phases:
- In Phase I clinical trials, 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.
- In Phase II clinical trials, the study 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.
- In Phase III studies, the study 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.
- Phase IV studies are done after the drug or treatment has been marketed. These studies continue testing the study drug or treatment to collect information about their effect in various populations and any side effects associated with long-term use.
The government has strict guidelines and safeguards to protect people who choose to participate in clinical trials. Every clinical trial in the U.S. must be approved and monitored by an Institutional Review Board (IRB) to make sure the risks are as low as possible and are worth any potential benefits.
An IRB is an independent committee of physicians, statisticians, community advocates, and others that ensures that a clinical trial is ethical and the rights of study participants are protected. All institutions that conduct or support biomedical research involving people must, by federal regulation, have an IRB that initially approves and periodically reviews the research.
Informed consent is the process of learning the key facts about a clinical trial before you decide whether or not to participate. These facts include:
- Why the research is being done.
- What the researchers want to accomplish.
- What will be done during the trial and for how long.
- What risks are involved in the trial.
- What benefits can be expected from the trial.
- What other treatments are available.
- The fact that you have the right to leave the trial at any time.
If you are considering joining a clinical trial, the research staff will give you informed consent documents that include the details about the study. If English is not your native language, you can ask for the consent documents in languages other than English. Since joining a clinical trial is an important decision, you should ask the research team any questions you may have about the study and the consent forms before you make a decision.
It is also a good idea to take the consent documents home and discuss them with family members or friends. Talking about your options can help you to feel comfortable with your decision. If you decide to join the clinical trial, be sure to ask for a copy of the informed consent documents so you can review them at any time.
Remember informed consent is more than signing a form. It is a process that continues through the study. You should feel free to ask the research team questions before, during, and after the study. Informed consent continues as long as you are in the study.
All clinical trials have guidelines about who can get into the program. Guidelines are based on such factors as age, type of disease, medical history, and current medical condition. Before you join a clinical trial, you must qualify for the study. Some research studies seek volunteers with illnesses or conditions to be studied in the clinical trial, while others need healthy volunteers. Healthy volunteers participate in Phase I trials, vaccine studies, and trials on research on preventive care for children or adults.
The factors that allow you to participate in a clinical trial are called inclusion criteria and the factors that keep you from participating are called exclusion criteria.
It is important to note that inclusion and exclusion criteria are not used to reject people personally. Instead, the criteria are used to identify appropriate participants and keep them safe. The criteria help ensure that researchers will be able to answer the questions they plan to study.
Clinical trials are sponsored by government agencies: such as the National Institutes of Health (NIH); pharmaceutical companies; individual physician- investigators; health care institutions such as health maintenance organizations (HMOs); and organizations that develop medical devices or equipment. Trials can take place in a variety of locations, such as hospitals, universities, doctors’ offices, or community clinics.
The clinical trial process depends on the kind of trial you participate in. The team will include doctors and nurses as well as social workers and other health care professionals. They will check your health at the beginning of the trial, give you specific instructions for participating in the trial, monitor you carefully during the trial, and stay in touch with you after the study.
Some clinical trials involve more tests and doctor visits than you would normally have for your illness or condition. For all types of trials, you will work with a research team. Your participation will be most successful if you follow the protocol carefully and stay in contact with the research staff. Some terms that will help you understand what happens in a trial are defined below.
A placebo is an inactive pill, liquid, or powder that has no treatment value. In clinical trials, experimental treatments are often compared with placebos to assess the treatment’s effectiveness. In some studies, the participants in the control group will receive a placebo instead of an active drug or treatment.
A control is the standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment, while the control group is given either a standard treatment for the illness or a placebo.
A blinded or masked study is one in which participants do not know whether they are in the experimental or control group in a research study. Those in the experimental group get the medications or treatments being tested, while those in the control group get a standard treatment or no treatment.
A double-blind or double-masked study is one in which neither the participants nor the study staff know which participants are receiving the experimental treatment and which ones are getting either a standard treatment or a placebo. These studies are performed so neither the patients’ nor the doctors’ expectations about the experimental drug can influence the outcome.
Side effects are any undesired actions or effects of drug or treatment. Negative or adverse effects may include headache, nausea, hair loss, skin irritation, or other physical problems. Experimental treatments must be evaluated for both immediate and long-term side effects.
There are both benefits and risks associated with clinical trials. By participating in a clinical trial, you can:
- Take an active role in your own health care.
- Gain access to new treatments that are not available to the general public.
- Obtain expert medical care at leading health care facilities during the trial.
- Help others by contributing to medical research.
Clinical trials have risks:
- There may be side effects or adverse reactions to medications or treatments.
- The treatment may not be effective for you.
- The protocol may require a lot of your time for trips to the study site, treatments, hospital stays, or complex dosage requirements.
You should know as much as possible about the research study. It is important for you to feel very comfortable asking questions and the staff should answer them in a way you can understand. A list of sample questions appears below.
- Plan ahead and write down the questions you want to ask.
- Ask a friend or relative to come with you for support and to hear the responses to your questions.
- Bring a tape recorder so you can replay the discussion after you get home.
Some questions you might ask about the research include:
- Why is this research being done?
- What is the purpose of the study?
- Who is sponsoring the study?
- Who has reviewed and approved this study?
- Why does the research team think the treatment, drug, or medical device will work?
Some questions about your participation in the study include:
- Where is the study site?
- What kinds of therapies, procedures, and/or tests will I have during the trial?
- Will they hurt? If so, for how long?
- How will the tests in the study compare to tests I would have outside the study?
- How long will the study last?
- How often will I have to go to the study site?
- Who will provide my medical care after the study ends?
- Will I be able to take my regular medications during the trial?
- What medications, procedures, or treatments must I avoid while in the study?
- What are my responsibilities during the study?
- Will I have to be in the hospital during the study?
- Will the study researchers work with my doctor while I am in the study?
- Can anyone find out that I am participating in a study?
- Can I talk to other people in the study?
- Will I be able to find out the results of the trial?
Questions about risks and benefits include:
- How do the possible risks and benefits of the study compare with approved treatments for me?
- What are the possible immediate and long-term side effects?
Other questions include:
- What other treatment options do I have?
- Will I have to pay anything to participate in the study?
- What are the charges likely to be?
- Is my insurance likely to cover those expenses?
Yes. Most clinical trials provide short-term treatments related to a designated illness or condition, but not extended or complete primary health care. In addition, by having your health care provider work with the research team, you can ensure that your other medications or treatments will not conflict with the clinical trial protocol.
Yes. You can leave a clinical trial at any time. If you plan to stop participating, let the research team know why you are leaving the study.
Some clinical trials will pay you for joining the trial, while others will not. In some programs, researchers will reimburse you for expenses associated with participating in the research. Such expenses may include transportation costs, child care, meals, and accommodations.
This information is provided by the National Library of Medicine (NLM).