Published on July 13, 2021

Informed consent is one of the most important aspects of research ethics. Since the 1960s, the moral right of individuals to self-determine whether or not they wish to participate in clinical research has been recognized by regulatory bodies, and it remains one of the most important ethical developments in human biomedical research.

There are strict guidelines and regulations governing how informed consent in clinical research is obtained, which all researchers are bound to follow. Prior to the start of any clinical research, an institutional review board (IRB) or independent ethics committee (IEC) confirms that adequate consent will be obtained in a way that does not jeopardize the rights, safety, or well-being of research participants. However, consent is recorded—whether on paper or electronically—IRB approval hinges on how the criteria of valid informed consent are met, which we’ll explore next.

What is the criteria of valid informed consent?

In order to meet informed consent criteria, clinical researchers must fully explain the study goals and investigational actions to participants. Only once they fully understand the risks and benefits can they voluntarily decide whether or not they wish to consent. In order for consent to be ethically valid, a few critical elements are required. Participants must:

  • Know exactly what and how much they are agreeing to.
  • Express their intent to participate.
  • Decide freely and voluntarily to participate.
  • Understand that they can withdraw consent at any time.

Disclosure of information

Participants have a right to autonomy—the right to make decisions about their own health and medical conditions. To do so, participants must be provided with all the information that a reasonable person in their place would want about possible treatment.
Such information could include what the investigation involves, the possible benefits and risks, and the likelihood of complications. Even rare risks must be disclosed—especially if the harm could be severe. Researchers should encourage participants to ask questions and allow plenty of time for participants to read the informed consent document and provide a copy for them to review. Once all of the required information has been disclosed, participants must also be given an appropriate amount of time to ask questions and discuss their decision with family and friends.
To meet informed consent criteria, a researcher is also obligated to tell a participant about any conflicts of interest. For example, if the researcher is also the patient’s physician, then he or she would need to reveal any ties to the pharmaceutical company sponsoring the trial, or if he or she has a financial interest in the trial’s outcome.
This is an area where remote eConsent shines, allowing all of the information mentioned above to be provided to the participant clearly and efficiently. From the comfort of their own homes, participants are able to access information and review it at their own pace and even involve family members. Multimedia components such as video, audio, and images can break down complex information. Best of all, participants can come back to the information again and again until they feel comfortable in their choice.


Once adequate information has been provided, researchers have an obligation to ensure that the information is understood by participants. In order to meet informed consent criteria, they must be able to understand the information presented and appreciate the potential consequences of participation. This principle refers to a participant’s decision-making capacity. The participant must have the ability to make and be held accountable for their own decisions. It is important for site staff to ask potential participants questions to ensure they have grasped the information provided. In remote eConsent, videoconferencing with site staff can be used for this purpose.


Consent for clinical research must be obtained without manipulation, undue influence, or coercion. Due to the vulnerability of participants, sensitivity is required to ensure there is no undue influence and the decision to participate is truly voluntary. For example, if the researcher also works as a physician, then his or her patients must understand that they are free to consent to or refuse participation in the study without repercussions to their patient/provider relationship. Voluntariness extends throughout the entire duration of the trial—participants can withdraw consent at any time.

What are the types of informed consent in clinical trials?

Traditional Consent

Traditional consent occurs when a participant agrees to participate in the study, after meeting the criteria listed above. It is a limited form of consent, as participants are agreeing to have their data used only in the manner laid out during the consent process.
In the past, participants provided traditional consent for a research study by traveling to a study site, meeting with site staff, and signing paper informed consent forms (ICFs). More recently, eConsent has made this process far less burdensome for both participants and site staff by removing the requirement for site visits and offering digital consent and education options. It also prevents the possibility of consent being invalidated due to inadequate information or hard-to-understand language on ICFs. eConsent solutions can use audio, video, and translation options to communicate information in a way that’s easy to understand. Lastly, eConsent allows impartial witnesses to be present via video—and even recorded—ensuring the consent meets regulatory requirements even in a remote use case.

Broad consent

Broad consent is a specific type of consent related to the storage, maintenance, and secondary research uses of both private information and identifiable biospecimens. In a nutshell, broad consent provides the legal basis for institutions to collect, store, and use subjects’ data and identified biospecimens for unspecified future research.  

In the past, for example, if American researchers had not secured adequate consent for a specific research use outside of the preliminary study, they had to either obtain an IRB waiver of consent or remove personal identifiers to use anything they gathered during that study. Now, under a revised Common Rule—as long as regulatory broad consent is obtained—then any subsequent storage, maintenance, and secondary research uses of an individual’s identifiable biospecimens and data would not require additional consent.

Tracking broad consent is now much easier due to eConsent. It provides a traceable electronic trail, leaving no ambiguity as to when and what a participant agreed to. It can also be easily transferred between platforms.

Continued consent

Continued consent refers to obtaining consent repeatedly from its participants throughout the course of the study—even if the initial consent was obtained at their entry into the study. Depending on the research and its goals, informed consent may not be a one-time event but rather an ongoing and dynamic process. Furthermore, providing initial consent does not mean that a participant will agree to continue in the study through its completion. Study participants always have the right to withdraw consent at any point.
Obtaining re-consent is an important ethical aspect in clinical research as new information becomes available. For example, the researcher is responsible to update participants if they discover new information that could affect:

  • the subject’s willingness to continue participation in the trial
  • the rights, safety, and well-being of study subjects
  • the study conduct, methodology, procedures, or outcomes
  • the IRB’s approval for the study conduct

eConsent can save a huge amount of work associated with continued consent. In the past, serious errors sometimes occurred when an obsolete or unapproved version of ICF was used—which is a completely avoidable error when an eConsent solution with version control is used.
In summary, informed consent in clinical research addresses participants’ knowledge, competence, and willingness to participate in research. Castor eConsent is a powerful platform to address each of these critical components. It enables a participant-centric education and consent process while reducing the workload for site staff. Learn more about Castor eConsent

Electronic Informed Consent (eConsent) Software for Clinical Trials

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