When Can Researchers Waive Informed Consent?

When is research allowed to proceed without ordinary informed consent?

Some research would be extremely difficult, scientifically compromised, or occasionally impossible if every participant had to provide conventional prospective informed consent.

Consider a minimal-risk study using existing identifiable records from thousands of people. Or research in which revealing the full purpose beforehand would invalidate the behavior being studied. Emergency research raises an even more difficult problem when eligible patients cannot consent and an intervention must be administered quickly.

These situations do not create a general permission to bypass consent.

Instead, some ethical and regulatory frameworks allow informed consent to be waived or altered when specified conditions are satisfied and the appropriate reviewing authority approves the exception.

Consent may be waived only when the applicable criteria are satisfied

A consent waiver is an exception, not a shortcut

The ordinary starting point in human-participant research is prospective informed consent.

Under the revised U.S. Common Rule, an investigator ordinarily must obtain the legally effective informed consent of the participant or legally authorized representative before involving that person in covered research. CIOMS similarly states that researchers should not initiate human research without individual informed consent or consent from a legally authorized representative unless explicit approval for an exception has been obtained from a research ethics committee.

A waiver therefore needs a justification grounded in the framework governing the research.

Waiver and alteration are different

Researchers do not always face a binary choice between complete conventional consent and no consent whatsoever.

An alteration can sometimes preserve substantially more participant choice than a complete waiver.

CIOMS explicitly recommends first considering whether consent could be modified in a way that preserves participants' ability to understand the general nature of the research and decide whether to participate before resorting to a full waiver.

Waiving informed consent is not the same as waiving the signature

This distinction is fundamental.

A study may still obtain informed consent while being permitted to proceed without collecting participants' signatures. That is a waiver of documentation, not necessarily a waiver of consent.

Conversely, a true consent waiver allows research to proceed without obtaining the ordinary prospective informed-consent decision itself.

This is why consent without a participant signature should not be confused with research conducted without informed consent.

Under the revised Common Rule, several criteria must be satisfied for a general waiver

For research governed by the revised U.S. Common Rule, 45 CFR 46.116(f)(3) permits an IRB to approve a general waiver or alteration only after finding and documenting all applicable criteria.

The research must involve no more than minimal risk. It must not be practicable to carry out the research without the requested waiver or alteration. If the research involves identifiable private information or identifiable biospecimens, it also must not be practicable to conduct the research without using that information or those specimens in an identifiable format. The waiver or alteration must not adversely affect participants' rights and welfare, and participants or legally authorized representatives must receive additional pertinent information afterward whenever appropriate.

These criteria operate together. Meeting one does not make the others disappear.

Minimal risk is necessary in some waiver pathways, but it is not sufficient

"It's minimal risk" is one of the most common incomplete arguments for waiving consent.

Under the Common Rule's general waiver provision, minimal risk is only one criterion. A study that is minimal risk but perfectly practicable to conduct with ordinary consent would not qualify under that provision merely because obtaining consent would require additional work.

FDA's current rules similarly permit an IRB to waive or alter informed consent for certain minimal-risk clinical investigations only when all of the specified criteria are satisfied. FDA's 2023 final rule was intended to harmonize this pathway more closely with the Common Rule.

So "minimal risk" opens a question. It does not answer it.

"Impracticable" does not simply mean inconvenient

A waiver criterion often asks whether the research could practicably be conducted without the waiver or alteration.

Researchers should not automatically translate this into "obtaining consent would take too much time" or "our response rate would be lower."

Practicability depends on the circumstances. A very large retrospective dataset may include people who cannot reasonably be contacted. Requiring consent might also introduce substantial selection that defeats the research question in some designs.

The research team should explain concretely why the study cannot practicably accomplish its objectives with ordinary consent rather than relying on generic claims about cost or inconvenience.

Rights and welfare still matter when consent is waived

A waiver does not suspend the researcher's obligations to participants.

Under the Common Rule, the waiver or alteration must not adversely affect participants' rights and welfare. CIOMS similarly limits waivers to research meeting its ethical criteria, including no more than minimal risk, and places the decision within research ethics review.

Privacy protections, confidentiality, minimization of risk, appropriate data governance, fair selection, scientific validity, and other participant protections therefore remain relevant.

Consent is one safeguard among several. Removing it can make the adequacy of the remaining safeguards more important, not less.

Sometimes participants should receive information afterward

Some studies cannot disclose particular information prospectively without compromising the research.

A behavioral experiment, for example, might need to withhold the exact hypothesis temporarily because knowing it would change participants' behavior.

Under the revised Common Rule's general waiver provision, participants must be provided with additional pertinent information after participation whenever appropriate. This can support debriefing in research involving incomplete disclosure or deception.

Whether debriefing is appropriate, what it should contain, and whether participants should have additional choices afterward depend on the research and applicable requirements.

Alteration can sometimes be preferable to complete waiver

Suppose participants can be told that they are joining behavioral research, what procedures they will complete, the risks, the time commitment, and their right to withdraw, but revealing one narrow aspect of the hypothesis beforehand would invalidate the study.

An approved alteration may permit the researcher to withhold that particular information temporarily while preserving the rest of the consent process.

That is ethically different from eliminating consent altogether.

When a narrower exception can accomplish the research objective, researchers and ethics committees should consider whether it preserves more participant autonomy.

Research using existing records or data may qualify, but not automatically

Retrospective record review is frequently associated with consent waivers because obtaining consent from every person represented in a large existing dataset may sometimes be impracticable.

But "retrospective" is not itself a waiver criterion.

The study may be exempt under one regulatory pathway, qualify for a waiver under another, or require consent depending on the nature of the information, identifiability, research activities, applicable law, and governing framework.

Researchers should determine the study's regulatory status rather than treating "chart review" as a magic phrase that removes consent.

Emergency research has separate and much stricter pathways

Research in emergency settings presents a different problem from ordinary minimal-risk waiver research.

FDA regulations at 21 CFR 50.24 provide an exception from informed-consent requirements for specified emergency research involving life-threatening situations when consent is not feasible and numerous additional protections are satisfied. These include IRB findings, independent physician concurrence, community consultation, public disclosure, and other safeguards.

This should not be generalized to ordinary research merely because obtaining consent would be difficult.

Special populations and subparts can change the analysis

Additional protections may apply to research involving children, pregnant women, prisoners, neonates, or other populations governed by specific regulations.

For example, parental permission requirements in research involving children have their own waiver provisions under HHS regulations. Some categories of research impose restrictions on using the general waiver provisions at all.

A general statement that "consent can be waived for minimal-risk research" therefore becomes particularly unreliable once special regulatory protections apply.

Broad-consent refusal creates a specific limitation under the Common Rule

The revised Common Rule contains a notable limitation involving broad consent.

If an individual was asked to provide broad consent for storage, maintenance, and secondary research use of identifiable private information or identifiable biospecimens and refused, an IRB cannot subsequently waive consent under the general waiver provision for those uses.

This prevents a participant's explicit refusal of broad consent from simply being bypassed through the general waiver pathway.

A waiver should be no broader than necessary

If only one part of the research creates the impracticability, researchers should consider whether the waiver or alteration can be limited to that part.

For example, consent might be waived for screening existing records to identify potentially eligible participants while ordinary consent is still obtained before those individuals undergo a research intervention.

The ethical objective is not to maximize the scope of the exception. It is to solve the specific problem that makes ordinary consent impracticable while preserving participant choice where reasonably possible.

When a large record review may support a waiver request

Whether this hypothetical study actually qualifies would depend on the governing framework and the review body's findings. The example shows the structure of a waiver argument rather than a guaranteed outcome.

Common misconceptions about waiving informed consent

Build the waiver request around the actual criteria

If you believe ordinary informed consent would make your research impossible or scientifically unworkable, do not begin by writing, "We request a waiver because the study is minimal risk."

Work through each criterion that actually applies.

Most importantly, identify who actually has authority to approve the waiver. A well-argued exception remains only a proposal until the required authorization has been obtained.

Before requesting a waiver of informed consent

Questions about waiving informed consent

Waive consent only when the exception is justified, not merely convenient

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