What to Know About Informed Consent in Clinical Trials

Medically Reviewed by Poonam Sachdev on December 10, 2021
4 min read

Human clinical trials are the final stage of research for any new medical treatment. Medical breakthroughs rely on willing participation from people who agree to be part of the studies. Joining a clinical trial has rewards, but there are also possible drawbacks for participants. 

Everyone who joins a clinical trial goes through a process of giving informed consent. Informed consent in healthcare is required legally and ethically, particularly when you're agreeing to an experimental treatment. What is informed consent? Simply put, it means that the research team will make sure you understand as much as possible about the trial, the risks, and the benefits of participating in the trial. 

Any new medication, medical device, or medical procedure goes through multiple stages of medical research. The earliest research happens in a laboratory and uses computer modeling, research on individual cells, and other methods that don’t require experiments on living creatures. After that, the researchers move on to animal trials to see how the new treatments work on complex organisms.

Clinical trials with human participants are the last stage of research for medical treatments. Human trials have significant oversight from government regulators and industry review boards. These oversight bodies make sure that the trials are safe for participants.

Most medical treatments have three phases of human trials. 

  • Phase 1 is a test on a small group of participants to determine if the treatment is safe. This phase lasts several months.
  • Phase 2 requires a larger group of participants. The trial helps researchers study the effectiveness of the treatment and possible side effects. It may last from several months to two years.
  • Phase 3 is a much larger group of participants, and researchers see how the treatment works over a long period of time. This phase may last up to four years.

Some studies incorporate a fourth phase with a very large group of participants. Other treatments get approval after Phase 3, though researchers continue to study the treatment to see how people respond to it in real-world conditions.

Eligibility for clinical trials depends on the study. Researchers set guidelines for the types of people they want as study subjects and choose volunteers to meet those criteria. Once they recruit people who meet the criteria they need, the potential participants undergo additional screening to ensure they are appropriate subjects. Volunteers may need to get blood tests, answer questionnaires, and disclose facts about their health history before being invited to participate.

Some people join clinical trials because they have a particular health condition. When people aren’t responding to existing treatments, they can seek out clinical trials of emerging therapies for their condition. Trials offer access to new treatments before they are approved.

The purpose of informed consent is to make sure you make an educated choice about your clinical trial participation. There is more to the process than simply asking you if you agree to participate. Doctors need to share detailed information about the study and what it will mean for you. 

The elements of informed consent include:

  • An explanation of the trial’s purpose, clinical procedures to be followed, how long you will participate, and the investigational treatments or procedures
  • An explanation of foreseeable risks and side effects you may experience
  • A description of benefits you may get from the treatments you receive
  • Information about existing treatments or procedures that might help you
  • Confidentiality procedures
  • Information about any compensation you’ll be entitled to and whether the research team will be responsible for medical treatments if injury occurs
  • A list of contacts to answer any questions you have during the trial
  • A statement confirming that your participation is voluntary and that you can discontinue your participation at any time without penalty

The research team should also discuss other possible issues, including:

  • Circumstances that would lead the researchers to ask you to leave the study
  • What happens if you leave the study early
  • What happens if you become pregnant during the trial
  • A guarantee that significant findings will be shared on an ongoing basis, particularly if they might affect your decision to keep participating
  • Any costs you will be responsible for, such as travel expenses

Once you understand all those factors, you have enough information to give informed consent in clinical trials. You can ask as many questions as you need to, though, in order to feel comfortable with the information. 

If you are joining a trial to get access to a new treatment, you should ask about the study design and the chance that you will be part of a control group. Many studies have a treatment group and a control group that doesn’t receive treatment. That allows researchers to compare outcomes for people who receive the new treatment against outcomes for a similar group of people who didn’t receive it.

If there is a chance that you may not be receiving the new treatment, you should take time to think about that possibility. Participating in the trial may mean discontinuing other treatments you have been on up until this point. If that would have a negative effect on your health, you may choose not to move forward with the trial.

In some cases, researchers find that the treatment is so effective that they cannot ethically withhold it from any of the trial participants. When that happens, members of the control group are offered the new treatment. Meanwhile, if another treatment that could help you is approved before the end of your trial, you can withdraw from the trial to pursue the new treatment option.

If you are considering volunteering for a clinical trial, take the time to understand what it will mean for you. Informed consent is important for ensuring that both researchers and trial participants are getting the most out of the clinical trial.