Clinical Trial Safety

Learn why you should consider enrolling in a research study and understand your rights and protections as a research participant.

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Clinical trial safety for participants

Participation in research sometimes carries risk. Some studies carry very small risks, while others—particularly those involving new medications—may carry significant risks.

Many regulations and processes are in place in the United States to minimize the risk to patients in clinical trials. Patients enrolled in clinical trials are followed very closely to assure their health and safety. Below are some of the protections for patients enrolled in research.

Informed consent

Researchers must provide patients with an informed consent form; a document that includes essential information about the research study, including the benefits and risks of the study and an overview of the rights of patients participating in research. You can read more about the informed consent form here.

Institutional Review Board (IRBIRB)

In the United States, an Institutional Review Board (IRB) must approve any study that is supported by federal research funds or is used to apply for drug approval to the FDA before any patients are enrolled. Most hospitals, cancer centers and academic institutions have an IRB that reviews all research conducted at that institution. The IRB includes physicians, researchers and consumers who assure that:

  • the study is ethical
  • participant risks are minimized
  • participant rights and welfare are protected
  • the informed consent form is understandable and appropriate for the study

Upon review, IRBs have the authority to approve, disapprove or require modifications of the study design, consent form and recruitment materials.

All approved clinical research studies have plans for protecting the privacy of participants’ medical records and any information they provide, including their responses to study questionnaires.

Data Safety Monitoring Board (DSMBDSMB)

Usually the results of a clinical trial are not made publicly available until after the study is completed and all the data has been analyzed. However, while the study is being conducted, a committee known as the Data Safety Monitoring Board (DSMB) looks at data while the study is in progress to further monitor safety and ensure no harm is done. The DSMB members may include physicians, scientists, ethicists, statistical experts, and patient advocates. All DSMB members are independent of the research team. The DSMB has the authority to pause or even stop a clinical trial if there is any concern about the safety of the participants.

Stopping rules

When researchers design a clinical trial, they include safety measures known as stopping rules. These rules outline the conditions under which a clinical trial may be stopped early to assure the safety of participants. If one or more patients experiences a serious side effect, or if one group of patients in the study does much better or much worse than expected, they may stop the study early and share the new information with the research team and study participants.

Adverse events

Adverse events are negative changes in health that occur in patients who are enrolled in research. Researchers keep records of any adverse events (for example nausea, anemia, high blood pressure, or low blood counts) that occur to patients during a trial. If one or more patients in a study experiences a serious adverse event, the DSMB may pause or stop the study to reevaluate safety.

Participants in clinical trials are encouraged to report any side effects or changes in their health. The consent form includes the contact information to report any of these changes.

PaceboControlled studies

Participants in clinical trials involving drugs are often concerned about the possibility that they will receive a placebo. A placebo is an intervention whose appearance, administration and delivery schedule is the same as the medication, but lacks the drug’s active ingredient.

Clinical trials are only allowed to include placebos under certain circumstances where the use of a placebo does not cause the patient increased risk or harm.

  • For diseases with a well-established treatment, patients are often randomly assigned to one of two groups:
    1. a group that receives the established therapy (also known as "usual care") and the new drug
    2. a group that receives the established therapy and a placebo
  • In studies involving diseases or conditions for which there is no known effective therapy, participants may be randomly assigned to the group that receives the drug being tested or to the group that receives the placebo.

Before a clinical trial begins, participants are told when a placebo is involved, but they are not told whether they are included in the placebo group.

Withdrawal from a study

You may withdraw from a study at any time, for any reason. Additionally, there may be reasons why your doctor or the research team decide to remove you from the study. These reasons may include:

  • a serious side effect
  • progression of your cancer
  • noncompliance with the study protocol

The research team may ask if you would be willing to continue contributing your information to the study even if you are no longer actively participating or taking a study medication. Continued access to your information can help researchers understand long-term safety of the intervention or agent. It is your decision whether or not you would like to continue to provide updates to the research team.