Obtaining informed consent for research is a structured process that begins well before a participant signs any document and continues throughout the entire study. It requires disclosing what the study involves, confirming the participant understands the risks and benefits, giving them time to ask questions, and documenting their voluntary agreement. Each of these steps has specific regulatory requirements, and skipping any one of them can invalidate the consent.
The Consent Process, Step by Step
The FDA considers the consent process to begin as early as recruitment. Advertising used to find potential participants is treated as the starting point of the ongoing consent process, which means even your recruitment materials need to be accurate and non-coercive.
Once you identify a prospective participant, and before any research activities begin, someone knowledgeable about the study must conduct a consent discussion. This is not simply handing over a form. It’s a conversation led by a person who can explain the study’s purpose, procedures, risks, benefits, and alternatives, and who can answer questions on the spot. The consent form itself serves as a written record and a take-home reference, but the real work happens in the discussion.
During this conversation, you need to cover all the elements required under federal regulations (21 CFR 50.25), including:
- What the study involves: its purpose, expected duration, and the procedures the participant will undergo
- Risks and discomforts: reasonably foreseeable ones, described in plain terms
- Potential benefits: to the participant or to others
- Alternatives: other treatments or options available outside the study
- Confidentiality: how records will be protected
- Compensation and treatment for injury: what happens if something goes wrong
- Contact information: who to reach with questions about the study, their rights, or in case of injury
- Voluntary participation: an explicit statement that they can withdraw at any time without penalty
After the discussion, give the participant adequate time to consider their decision. Pressuring someone for an immediate answer undermines the voluntary nature of consent. Once they agree, the participant (or their legally authorized representative) signs and dates the consent form. That date matters: it confirms consent was given before any research activity began. The form must have been previously approved by an Institutional Review Board (IRB).
Consent doesn’t end at the signature. You’re required to continue providing information as the study progresses. If new risks emerge, if the study protocol changes, or if anything arises that could affect the participant’s willingness to continue, you need to inform them and, in many cases, re-consent them.
Writing a Consent Form People Can Understand
Most consent forms are written at a reading level far above what participants can comfortably process. Federal guidelines recommend writing at a sixth to eighth grade reading level or lower. In practice, many forms land well above that, filled with legal and scientific terminology that obscures rather than informs.
Plain language editing makes a real difference here. Use short sentences, common words, and active voice. Replace “randomization” with an explanation of how participants are assigned to groups. Instead of listing drug class names, describe what the treatment does. Avoid compound sentences that stack multiple ideas together. The goal is a document that someone without a science background can read once and understand what they’re agreeing to.
One practical test: if you can’t read a sentence aloud and have a non-researcher follow it, rewrite it. Many IRBs now have readability requirements and will flag forms that exceed grade-level thresholds during review.
Verifying the Participant Actually Understands
A signature confirms agreement, but it doesn’t prove comprehension. One of the most effective ways to check understanding is the teach-back method: after explaining a concept, you ask the participant to explain it back to you in their own words. This isn’t a test or quiz. It’s a conversational technique where you say something like, “I want to make sure I explained that clearly. Can you tell me what you understand about the risks?”
Research supports this approach. In a study comparing standard consent discussions to those incorporating teach-back, participants in the teach-back group scored higher on knowledge assessments about risks and benefits and reported feeling more engaged in the process. If a participant can’t accurately describe what the study involves or what the risks are, that’s a signal to go back and re-explain before moving forward.
Additional Protections for Vulnerable Populations
Certain groups require extra safeguards beyond the standard consent process.
For children and minors, federal regulations require both parental permission (which functions as consent) and assent from the child. Assent means the child agrees to participate in an age-appropriate way. For younger children, this might be a simplified verbal explanation. For adolescents, it could involve a written assent form separate from the parental consent.
Research involving prisoners faces additional restrictions and requires extra review time from the IRB. The concern is that the conditions of incarceration can inherently compromise voluntariness, so studies must meet a higher bar to demonstrate that participation is genuinely free from coercion.
For individuals with cognitive impairments, you need to assess whether the person has the capacity to consent for themselves. If they don’t, consent must come from a legally authorized representative, sometimes called surrogate consent. Even when a surrogate provides consent, you should still explain the study to the participant to whatever extent they can understand.
Consent for Non-English Speaking Participants
When you encounter a participant who doesn’t speak English, federal regulations allow the use of a short form consent process with prior IRB approval. This approach requires an interpreter who is fluent in both English and the participant’s language, plus an independent witness.
The witness must be an adult (18 or older), fluent in both languages, and impartial, meaning they can’t be a member of the study staff involved in the research. Their role is to confirm that the information was accurately conveyed, that the participant’s questions were answered, and that consent was voluntary. Importantly, the person acting as interpreter and the person serving as witness must be two different people. A single staff member cannot fill both roles.
Electronic Consent
Electronic informed consent (eConsent) is permitted under federal regulations, but it must meet the same requirements as paper-based consent. The information presented, the process used, and the documentation must all comply with FDA rules on electronic records and signatures (21 CFR Part 11), informed consent (21 CFR Part 50), and IRB oversight (21 CFR Part 56).
In practice, this means your eConsent platform needs to support identity verification, maintain an audit trail showing when documents were viewed and signed, and store records securely. Many eConsent systems incorporate multimedia elements like videos or interactive graphics to improve comprehension, which can be especially useful for complex study designs. The key requirement is that the electronic process doesn’t reduce the quality of the consent experience. Participants must still be able to ask questions and receive answers, whether through live chat, phone, or video call.
When Consent Can Be Waived
In limited circumstances, an IRB can approve a study without standard informed consent or with certain elements altered. This applies only to minimal risk clinical investigations, and the IRB must find and document that five specific criteria are met. Waivers are most common in research involving de-identified data, certain public health surveillance activities, or situations where requiring consent would make the research impractical and the risk to participants is negligible.
A waiver doesn’t mean ethical oversight disappears. The IRB still reviews the study, and the decision to waive consent must be formally justified and documented.
Storing Consent Records
Signed consent forms are legal documents and must be retained for a defined period. Under FDA regulations (21 CFR 312.62), investigators must keep records for two years after a marketing application is approved for the drug or indication being studied. If no application is filed, or if the application isn’t approved, records must be kept for two years after the investigation is discontinued and the FDA is notified. Many institutions impose longer retention periods, so check your local IRB and institutional policies as well.
Store originals securely, whether in locked filing cabinets for paper forms or in validated electronic systems for eConsent records. Participants should always receive a copy of the signed form for their own records.